Bibliography

Sources are grouped by confidence tier, following the book's citation-honesty policy (see any chapter's further-reading, or _style-bible.md). Tier 1 are works we are confident exist; Tier 2 are real ideas whose exact publication we have not pinned down; Tier 3 are constructed teaching examples, labeled where they appear.

Tier 1 — Verified canonical sources

• Adams, D. Life, the Universe and Everything (1982). Pan Books. — source of the chapter epigraph ("throw yourself at the ground and miss"); used as an intuition for orbit as perpetual falling.
• Allen, H. J., & Eggers, A. J. (1958). "A Study of the Motion and Aerodynamic Heating of Ballistic Missiles Entering the Earth's Atmosphere at High Supersonic Speeds." NACA Report 1381. — primary source for the blunt-body insight (§7.2) and the peak-deceleration result $a_{\max}=v_E^2\sin\gamma_E/(2eH)$ (§7.6).
• Anderson, J. D. Hypersonic and High-Temperature Gas Dynamics. AIAA. — shock layers, stagnation-point heating, the blunt-body principle, real-gas (dissociation/ionization) effects (§7.2–7.3).
• Anderson, J. D., Jr. Fundamentals of Aerodynamics. McGraw-Hill. — dynamic pressure, drag coefficient, compressible flow, and the stagnation-temperature relation $T_0 = T_\infty(1+\tfrac{\gamma-1}{2}M^2)$.
• Anderson, J. D., Jr. Hypersonic and High-Temperature Gas Dynamics (2nd ed.). AIAA. — aerodynamic heating, stagnation-point heating, compression (not friction) as the source of heat; blunt-body reasoning.
• Anderson, J. D., Jr. Introduction to Flight. McGraw-Hill. — gentler treatment of the same aerodynamic fundamentals; standard atmosphere and lift/drag.
• Appendix B of this book (Physical Constants and Astronomical Data) — all planetary mu, radii, semi-major axes, and periods used in the worked examples (Sun mu = 1.327e11 km^3/s^2; Earth mu = 3.986e5; Mars mu = 4.283e4, R = 3390 km; Jupiter mu = 1.267e8; AU = 1.496e8 km).
• Appendix B of this book (Physical Constants and Astronomical Data) — Mars mu = 4.283e4 km^3/s^2, R = 3390 km, escape 5.03 km/s, surface g = 3.71 m/s^2; Earth/Sun/Mars mu, AU; g0 = 9.80665. All worked-example constants.
• ASM International. Metals Handbook / Aerospace Structural Metals Handbook. — alloy properties for aluminum, titanium, and stainless steel, including cryogenic and elevated-temperature behavior (the data behind §23.3 and §23.6's cryo-strengthening claim).
• Bate, R. R., Mueller, D. D., & White, J. E. Fundamentals of Astrodynamics. Dover. — Ch. 1 introduction to orbits; classic, inexpensive.
• Battin, R. H. An Introduction to the Mathematics and Methods of Astrodynamics. AIAA. — explicit guidance and velocity-to-be-gained targeting, by an architect of the Apollo guidance system.
• Braun, R. D., & Manning, R. M. "Mars Exploration Entry, Descent, and Landing Challenges." — the reference treatment of the Mars EDL problem/mass wall in §34.4 and case-study-01 (thin-atmosphere trap; why heavy landing needs new methods). (IEEE Aerospace / J. Spacecraft & Rockets class of paper.)
• Cal Poly San Luis Obispo. CubeSat Design Specification (open standard). — the primary document defining the unit, the mechanical envelope, and the deployer interface (§33.2). (Primary source.)
• CCSDS — Consultative Committee for Space Data Systems (ccsds.org). — international "Blue Book" standards defining telemetry and telecommand packetization referenced in §31.4.
• Chaikin, A. A Man on the Moon: The Voyages of the Apollo Astronauts. Viking. — the definitive Apollo narrative, including the lunar-orbit-rendezvous decision.
• Chapter 11 of this book (Interplanetary Trajectories) — every trajectory number reused here (v_inf 2.95/2.65 km/s, C3 8.7, TMI 3.59, cruise 259 d, synodic 780 d, entry ~5.6 km/s) is derived there; this chapter applies, not re-derives, them.
• Columbia Accident Investigation Board (2003). CAIB Report, Volume I. — the RCC leading-edge breach and TPS failure of §7.3; primary source, freely available.
• Columbia Accident Investigation Board (CAIB) Report, Volume I, 2003 — the foam strike, the RCC breach, the re-entry-heating failure, and the "echoes of Challenger" organizational findings. A real government report, freely available.
• Culick, F. E. C. Unsteady Motions in Combustion Chambers for Propulsion Systems (AGARD/NATO RTO AG-AVT-039). — rigorous acoustics/heat-release coupling behind the Rayleigh criterion.
• Curtis, H. D. Orbital Mechanics for Engineering Students. Elsevier. — Ch. 1 two-body setting and orbital vocabulary behind "sideways speed."
• Dyson, George. Project Orion: The True Story of the Atomic Spaceship (2002). Henry Holt. — documented history of nuclear pulse propulsion, including the chemical-explosive test flights and the treaty that ended it (§21.3).
• Eckart, P. Spaceflight Life Support and Biospherics. Kluwer/Microcosm. — physics and chemistry of life-support loops (electrolysis, Sabatier, water recovery, bioregenerative), with mass/power figures.
• Fortescue, P., Swinerd, G., & Stark, J. Spacecraft Systems Engineering. Wiley. — solar arrays, batteries, power management and distribution at introductory level.
• Franklin, G. F., Powell, J. D., & Emami-Naeini, A. Feedback Control of Dynamic Systems. Pearson. — the standard undergraduate controls text; PID, root locus, frequency response.
• Gere, J. M., & Goodno, B. J. Mechanics of Materials. Cengage. — stress, strain, Hooke's law, thin-walled pressure vessels (hoop/longitudinal stress), column and shell buckling (§23.4).
• Goebel, D. M., & Katz, I. Fundamentals of Electric Propulsion: Ion and Hall Thrusters (JPL Space Science and Technology Series). Wiley, 2008. — the definitive modern reference; power–thrust–Isp relations, Child–Langmuir space-charge limit, ion and Hall thruster physics. (Circulated freely as a NASA/JPL publication.)
• Goldstein, H. Classical Mechanics. — the central-force / Kepler problem in the calculus form used in §8.2 (angular-momentum conservation, the orbit equation, the Laplace–Runge–Lenz vector).
• GPS.gov, "Space Segment" (U.S. government). — authoritative GPS constellation description (24-slot baseline, six planes, 55 deg inclination, semi-synchronous ~11 h 58 min period); primary source for Case Study 1.
• Halliday, D., Resnick, R., & Walker, J. Fundamentals of Physics. Wiley. — Newton's laws, momentum and its conservation, universal gravitation, gravitational potential energy (calculus-based intro treatment).
• Harrje, D. T., & Reardon, F. H. (eds.). Liquid Propellant Rocket Combustion Instability (NASA SP-194). — primary-source record of combustion instability, including the F-1 program.
• Heppenheimer, T. A. Countdown: A History of Space Flight. Wiley. — readable one-volume sweep from the theorists to the Shuttle.
• Humble, R. W., Henry, G. N., & Larson, W. J. Space Propulsion Analysis and Design. McGraw-Hill. — thrust and Isp as the start of an engine-sizing design process.
• Huzel, D. K., & Huang, D. H. Modern Engineering for Design of Liquid-Propellant Rocket Engines (AIAA Progress in Astronautics and Aeronautics, vol. 147). — injectors, chambers, cooling, and turbopumps (Rocketdyne design practice).
• Inter-Agency Space Debris Coordination Committee (IADC). Space Debris Mitigation Guidelines (2002, rev.). — Primary source for the 25-year rule, passivation, and disposal practice in §35.3; adopted in a UN version (2007).
• Jahn, R. G. Physics of Electric Propulsion. McGraw-Hill, 1968 (Dover reprint). — the classic that organized the field into electrothermal / electrostatic / electromagnetic; physical framing of each accelerator.
• Kalman, R. E. (1960). "A New Approach to Linear Filtering and Prediction Problems." Journal of Basic Engineering, 82(1), 35–45. — the original Kalman filter paper.
• Kanas, N., & Manzey, D. Space Psychology and Psychiatry. Springer. — isolation, confinement, and crew-dynamics material for §28.6.
• Kessler, D. J., & Cour-Palais, B. G. "Collision Frequency of Artificial Satellites: The Creation of a Debris Belt." Journal of Geophysical Research 83(A6), 1978. — The founding paper of the field; the collision-cascade mechanism and the "debris belt" behind §35.1.
• Koon, W. S., Lo, M. W., Marsden, J. E., & Ross, S. D. Dynamical Systems, the Three-Body Problem and Space Mission Design. — invariant manifolds / tube dynamics and the low-energy transfer ("interplanetary superhighway"); made freely available online by the authors.
• Kraft, C. Flight: My Life in Mission Control (2001). Dutton. — by the inventor of the flight-director role (Project Mercury); why mission control is organized as it is.
• Kranz, G. Failure Is Not an Option (2000). Simon & Schuster. — first-hand account of the flight-director role, flight rules, control-room culture ("Tough and Competent"), and Apollo 13.
• Larson, W. J., & Pranke, L. K. (eds.). Human Spaceflight: Mission Analysis and Design. McGraw-Hill. — consumables budgeting, ECLSS architectures, radiation, habitability.
• Larson, W. J., & Wertz, J. R. (eds.). Space Mission Analysis and Design (SMAD). Microcosm/Kluwer. — the classic mission-design process, requirements, and the design loop of §29.1.
• Lovell, J., & Kluger, J. Lost Moon: The Perilous Voyage of Apollo 13 (also published as Apollo 13). Houghton Mifflin. — the commander's account; source for the Case Study 1 operations detail.
• Markley, F. L., & Crassidis, J. L. Fundamentals of Spacecraft Attitude Determination and Control. Springer. — rigorous treatment of attitude representations (quaternions, DCMs, Euler-angle singularities) and estimation.
• McDougall, W. A. …the Heavens and the Earth: A Political History of the Space Age. Basic Books. — Pulitzer-winning political history of the Space Race; the "history is decision-making under constraint" backbone.
• McInnes, C. R. Solar Sailing: Technology, Dynamics and Mission Applications. Springer. — the definitive solar-sail reference; radiation pressure, lightness number, sail trajectories (§21.4).
• Mindell, D. A. Digital Apollo: Human and Machine in Spaceflight. MIT Press. — history of the Apollo Guidance Computer and the automation-vs-pilot design debate; background for Case Study 1 and §27.6.
• NASA Ames Research Center. "State of the Art of Small Spacecraft Technology" (NASA technical report, periodically updated). — survey of small-sat subsystems with real parts and performance numbers (§33.3).
• NASA SP-8000 series design-criteria monographs (e.g., "Liquid Rocket Engine Turbopumps," "...Injectors," "...Combustion Stability"). — professional-depth design criteria; free NASA technical reports.
• NASA SP-8113, Liquid Rocket Engine Combustion Stabilization Devices. — engineering standard for baffles/cavities.
• NASA Space Vehicle Design Criteria monographs (NASA SP-8xxx series, via NTRS) — primary-source guidance on propellant slosh loads, POGO suppression, and propellant management.
• NASA-STD-5001 and NASA-STD-5002 (Structural Design and Test Factors of Safety / Loads Analyses for spaceflight hardware). — the standards behind the ~1.25 yield / 1.4 ultimate factors of safety of §23.4; verify current revision.
• NASA. Human Exploration of Mars Design Reference Architecture 5.0 (NASA-SP-2009-566), 2009. — the canonical government human-Mars study behind §34.6: conjunction-class, pre-deployment/split mission, ISRU, nuclear thermal propulsion, aerocapture. Primary source for the DRA 5.0 architecture.
• NASA. NASA Systems Engineering Handbook (NASA/SP-2016-6105 Rev 2). — the MDR/PDR/CDR review lifecycle, verification & validation, and the "test like you fly" philosophy. Freely available.
• NASA. NASA Systems Engineering Handbook (NASA/SP-2016-6105). — the lifecycle phases (Pre-Phase A–F) and review gates (MDR/PDR/CDR) of §29.6; authoritative vocabulary.
• NASA. Artemis program and Moon-to-Mars Architecture documents (nasa.gov). — primary source for §39.1–39.2 (SLS/Orion, Gateway/NRHO, HLS, lunar-south-pole rationale). Specifics update continually.
• NASA. Commercial LEO Destinations program and the ISS transition/de-orbit plan (nasa.gov). — primary source for §39.3 (ISS retirement ~2030; NASA as "one customer of many").
• NASA/JPL DESCANSO monograph series, Deep Space Communications and Navigation Systems. — authoritative treatment of DSN link design, coding, ranging, Doppler, and delta-DOR (§26.3, §26.5). NASA technical reports.
• NASA/JPL. "Basics of Space Flight." — free primer whose orbit-types section parallels §§9.1–9.5 with real missions.
• Neufeld, M. J. Von Braun: Dreamer of Space, Engineer of War (Knopf) and The Rocket and the Reich (Free Press). — definitive, unflinching scholarship on von Braun, Peenemünde, and the V-2's slave-labor production.
• Newton, I. Philosophiæ Naturalis Principia Mathematica (1687), Book I. — the original derivation that Kepler's laws follow from an inverse-square force (source for the §8.5 history callout).
• Outer Space Treaty (1967), Liability Convention (1972), Registration Convention (1976). — Primary legal texts for §35.5; Articles I, II, IV, VI, VII, VIII of the OST cited directly. Public, maintained by UNOOSA.
• Rechtin, E., & Maier, M. W. The Art of Systems Architecting. CRC Press. — heuristics for architecting coupled, under-specified systems (§29.5).
• Regan, F. J., & Anandakrishnan, S. M. Dynamics of Atmospheric Re-Entry. AIAA Education Series. — entry trajectory dynamics, the corridor, and heating in one dedicated text.
• Report of the Presidential Commission on the Space Shuttle Challenger Accident ("Rogers Commission Report"), 1986 — the O-ring failure, joint rotation, the launch decision, and Feynman's Appendix F (reality vs. public relations; the 1-in-100 vs. 1-in-100,000 disconnect). A real government report, freely available.
• Rogers Commission. Report of the Presidential Commission on the Space Shuttle Challenger Accident (1986). — includes Feynman's Appendix F (the chapter epigraph); the canonical reliability/organizational-failure case. (Sets up Ch. 37.)
• Sarafin, T. P. (ed.). Spacecraft Structures and Mechanisms: From Concept to Launch. Microcosm/Kluwer. — the definitive practitioner reference: loads, load paths, primary vs. secondary structure, factors of safety, materials, testing (whole chapter).
• Sellers, J. J. Understanding Space: An Introduction to Astronautics. McGraw-Hill. — readable chapters on the space mission operations concept, ground stations, telemetry, and commanding.
• Shannon, C. E. "A Mathematical Theory of Communication," Bell System Technical Journal (1948). — founding paper of information theory; source of the chapter epigraph and the Shannon limit.
• Siddiqi, A. A. Challenge to Apollo: The Soviet Union and the Space Race, 1945–1974 (NASA History Series). — authoritative account of Korolev, the R-7, and the Soviet program.
• Sidi, M. J. Spacecraft Dynamics and Control: A Practical Engineering Approach. Cambridge University Press. — spacecraft attitude control loops, actuator sizing, worked designs; the bridge from control theory to real vehicles.
• Sklar, B. Digital Communications: Fundamentals and Applications. Prentice Hall. — link budget, $E_b/N_0$, modulation, channel coding, coding gain, and the Shannon limit (§26.1, §26.4).
• Sutton, G. P. History of Liquid Propellant Rocket Engines. AIAA. — engine-by-engine history; source for the turbopump lineage and the oxidizer-rich staged-combustion story.
• Sutton, G. P., & Biblarz, O. Rocket Propulsion Elements (9th ed.). Wiley. — Ch. 1 survey of why rockets are built as they are; performance numbers (Isp, mass ratio) previewed in §1.2.
• Szebehely, V. Theory of Orbits: The Restricted Problem of Three Bodies. Academic Press. — the classic monograph; zero-velocity curves, collinear/triangular points, and their stability in full.
• Tapley, B. D., Schutz, B. E., & Born, G. H. Statistical Orbit Determination. Academic Press. — the definitive graduate text on batch and sequential (Kalman/EKF) estimation of orbits, including process noise; the full linear-algebra version of §13.5–13.6.
• Turner, M. J. L. Rocket and Spacecraft Propulsion (3rd ed.). Springer. — dedicated chapters on nuclear thermal, electric, solar-sail, and advanced/interstellar propulsion at this book's level; the closest single-text match to the whole chapter.
• U.S. Standard Atmosphere, 1976 (NOAA/NASA/USAF). — the tabulated reference atmosphere that the single-scale-height exponential model approximates.
• Vallado, D. A. Fundamentals of Astrodynamics and Applications. Microcosm Press. — conic classification by energy; the energy relations mission planners use (Ch. 1-2).
• Vaughan, D. The Challenger Launch Decision: Risky Technology, Culture, and Deviance at NASA (1996). University of Chicago Press — the origin of the term "normalization of deviance."
• von Braun, W. The Mars Project (Das Marsprojekt), 1948 (Eng. 1953). — the 1948 engineering study cited in §34.1 (orbital assembly + minimum-energy transfers); source for "the plan is older than the rocket."
• Wertz, J. R. (ed.). Spacecraft Attitude Determination and Control. D. Reidel / Kluwer. — the encyclopedic handbook: sensors, actuators, determination methods (TRIAD, QUEST, Kalman), environmental torques.
• Wertz, J. R., Everett, D. F., & Puschell, J. J. Space Mission Engineering: The New SMAD. Microcosm Press. — mission-design mindset, requirements/constraints, and the delta-v budget as master constraint; anchor for the "Design Your Mission" project.
• Wolfe, T. The Right Stuff. Farrar, Straus and Giroux. — the Mercury program and early-astronaut culture as literature.
• Zubrin, R., with Wagner, R. The Case for Mars: The Plan to Settle the Red Planet and Why We Must. — origin of the "travel light and live off the land" ISRU-and-pre-deployment philosophy (Mars Direct) underlying §34.5 and case-study-02; the case-study-02 epigraph paraphrases Zubrin's thesis.
• Åström, K. J., & Murray, R. M. Feedback Systems: An Introduction for Scientists and Engineers. Princeton University Press (free online). — the control-theory foundation for §27.4: feedback, PID, stability, tuning.

Tier 2 — Attributed (specifics unverified)

• "Atomic Rockets" (Winchell Chung), online — well-regarded reference site collecting the equations and real numbers of nuclear, electric, sail, and exotic propulsion.
• Appendix H (this book), Launch Vehicle and Engine Reference. — the source of every vehicle payload, reuse, and cost figure used here; itself explicitly Tier 2 (widely reported, version-dependent). All §30.1–30.2 vehicle numbers are drawn from it and stay consistent with it.
• The New York Times, editorial on Robert Goddard (13 Jan 1920) and its correction (17 Jul 1969). — the "rocket cannot work in a vacuum" claim and retraction; widely reproduced.
• Aerospace factors of safety (~1.25 yield, 1.4 ultimate for metallic launch structure; higher for composites/crewed). — standard practice; exact values per NASA-STD-5001.
• AIAA mass-properties / mass-growth-allowance practice (e.g., AIAA S-120) — the source of the margin-by-phase percentages in §29.4, quoted as standard industry practice.
• Aldrin, E. E. "Line-of-Sight Guidance Techniques for Manned Orbital Rendezvous" (Sc.D. thesis, MIT, 1963) — the orbital-rendezvous theory behind Gemini/Apollo; source for the §6.6 history callout. (Real thesis; exact title as reported.)
• Appendix H of this book (Launch Vehicle and Engine Reference). — internal one-page number sheet; all Falcon/Starship/Merlin/Raptor figures here are consistent with it, and it carries the governing tier warnings.
• Appendix H of this book — Starship/Super Heavy (methalox, ~100–150 t to LEO target, fully reusable goal, ~1,200 t propellant); Raptor 2 (full-flow staged combustion, Isp ~330 SL / ~350 vac, RVac ~380 s); SLS heavy lift (DRA-class launcher). All Tier 2, version-dependent, aspirational where noted.
• August 1972 solar particle event — a real, exceptionally intense SPE between Apollo 16 and 17; the "unshielded dose could have caused radiation sickness" framing is widely cited, with dose estimates varying by source.
• Augustine, N. R. Augustine's Laws. AIAA. — source of the epigraph; the organizational/economic face of margins and cost/mass growth (§§29.4–29.5). Individual "laws" are widely quoted and paraphrased; exact wording/number not pinned here.
• Belbruno, E. Fly Me to the Moon: An Insider's Guide to the New Science of Space Travel. Princeton Univ. Press. — weak stability boundaries and ballistic capture by their inventor, including the Hiten rescue.
• Blue Origin New Shepard; Virgin Galactic; SpaceX Crew Dragon; Space Adventures/Soyuz tourist flights (Dennis Tito, 2001). — real, flown suborbital and orbital human vehicles used in §39.4 and Case Study 1. Performance figures (apogee, speed, ticket price) are attributed/approximate.
• Braeunig, R. A. "Rocket & Space Technology" (web) — free orbital-mechanics reference for cross-checking circular-velocity/period/vis-viva arithmetic.
• Breakthrough Starshot / Breakthrough Initiatives program material — the beamed light-sail-to-Alpha-Centauri concept (§21.5); power, sail, and pointing challenges.
• Brian Douglas, "Control System Lectures" (YouTube). — the clearest free introduction to PID, stability, and loop shaping.
• CelesTrak (celestrak.org) and Space-Track (space-track.org) — the public two-line element catalogs and SGP4/TLE-format documentation; source of real TLEs for Case Study 1.
• CelesTrak (celestrak.org) — public two-line element sets; used to verify real nodal-regression rates against §12.2.
• CelesTrak (T.S. Kelso) and Space-Track.org — public two-line element sets and TLE-format/SGP4 documentation; source and method for Case Study 1's ISS element reading.
• CERN ALPHA experiment — trapping and holding antihydrogen atoms (§21.6); demonstrates the storage problem is real but only at the few-atom scale.
• Chandrasekhar, S. Newton's Principia for the Common Reader. Oxford. — accessible route into Newton's geometric proofs (further-reading).
• Clark, J. D. Ignition! An Informal History of Liquid Rocket Propellants. Rutgers University Press (1972). — first-hand history of propellants and oxidizers, including hypergolics; widely circulated.
• Clarke, A. C. "Extra-Terrestrial Relays." Wireless World (Oct 1945). — proposed the geostationary communications relay; source of the §9.3 history and the chapter epigraph. NOTE: epigraph wording is as widely reproduced; not verified against the original page, so treat exact wording as Tier 2.
• ClearSpace-1 (ESA), RemoveDEBRIS (Surrey, net + harpoon, 2018–19), Astroscale ELSA-d (2021) / ADRAS-J (2024) — active-removal demonstrations in §35.4.
• Commercial Crew loss-of-crew probability target (order ~1-in-270 for ascent/entry) — widely cited NASA requirement; exact governing value varies by document/date.
• Constellation filings toward >100,000 satellites (Starlink, Kuiper ~3,236, Guowang ~13,000, OneWeb) — §35.6 scale figures.
• Cosmos 954 re-entry over Canada (1978) and the ~C$3M settlement — the sole Liability Convention invocation, §35.5.
• Curiosity RAD detector: deep-space GCR dose ~1.8 mSv/day measured on the cruise to Mars; ~0.3 Sv per 180-day transit; a round-trip human Mars mission often estimated ~0.6–1 Sv total (via Ch. 28).
• Curiosity/MSL (landed 2012): first sky-crane landing; ~900 kg rover, ~2,400 kg under chute; near the ~1-t parachute-based landing ceiling (the "mass wall").
• DRACO (Demonstration Rocket for Agile Cislunar Operations), NASA–DARPA program material — current status of nuclear thermal propulsion; uses low-enriched uranium.
• Earth-rotation surface speed $v = 2\pi R_{eq}/T_{sidereal} = 0.465$ km/s at the equator (from $R_{eq} \approx 6378$ km, $T_{sidereal} \approx 86{,}164$ s); the eastward launch credit $0.465\cos\phi$ is standard.
• Earth–Mars departure C3 ranges ~8–17 km^2/s^2 over the synodic cycle; ~8.7 is a near-minimum window (favorable geometry).
• Ebeling, C. E. An Introduction to Reliability and Maintainability Engineering. — series/parallel systems, the bathtub curve, k-of-n redundancy, exponential model (representative standard text).
• ESA Space Debris Office. ESA's Annual Space Environment Report. — Source for the §35.2 population figures (~36,000 tracked >10 cm; ~1,000,000 at 1–10 cm; ~130,000,000 >1 mm; ~10,000 t total mass). Updated yearly; figures climb.
• ESA/JAXA BepiColombo mission pages — solar-electric propulsion (QinetiQ T6 gridded ion thrusters) plus gravity assists to reach Mercury orbit.
• Everyday Astronaut (YouTube). — "why did SpaceX switch to…" deep dives on steel, methane, and full-flow staged combustion, several built on SpaceX-engineer interviews.
• Explorer 1 (1958) flat-spin episode — the spacecraft was set to spin about its minimum-inertia (long) axis and migrated to a flat spin about the maximum-inertia axis; standard illustration of the major-axis rule (widely reported in astronautics histories).
• Explorer 1 / James Van Allen discovery of the radiation belts (1958) — NASA histories and Van Allen's own accounts (§1.3 From History).
• Eyles, D. Sunburst and Luminary: An Apollo Memoir. — a firsthand account of writing the Apollo lunar-module guidance software, including the 1201/1202 program alarms; a real memoir by an AGC programmer (exact page references not pinned here).
• FAA/AST and U.S. GAO launch-industry reports — third-party discussion of launch-cost trends and reuse economics.
• Falcon 9 max-Q ~30–35 kPa and fairing pair mass ~1,900 kg — widely reported figures; vary by version/mission.
• Falcon 9 nine-engine octaweb, engine-out capability, and the CRS-1 (Oct 2012) in-flight engine shutdown — widely reported vehicle facts; specific per-engine reliability figures are not public.
• Falcon 9 performance (~22.8 t LEO expendable / ~17 t recovered; ~5.5–8.3 t GTO), the reuse payload penalty, and cost/kg figures (~$10–20k expendable → ~$2–3k Falcon 9). — widely reported; consistent with Appendix H.
• Falcon-9-class tank diameter (3.66 m) and design load factors (~6 g axial, ~2 g lateral). — widely reported / representative payload-user's-guide values.
• Fengyun-1C ASAT test (11 Jan 2007, ~865 km, ~3,000 tracked fragments) — §35.1.
• Forward, R. L. — published work on beamed-sail and antimatter interstellar propulsion; the serious end of the far frontier.
• Free-molecular heating jettison threshold ~1,135 W/m² — a commonly cited payload-fairing jettison criterion; representative industry value, exact source varies by launch provider/mission.
• Gemini 4 rendezvous attempt (1965) failing due to the counterintuitive orbital-mechanics of station-keeping — widely reported NASA history; supports the §6.6 "orbital paradox" narrative.
• Geostationary transfer: a Cape-Canaveral GTO inclined ~27 degrees, combined apogee/plane-change burn ~1.8 km/s — widely reported operational figures.
• GMAT (NASA General Mission Analysis Tool); poliastro (Python) — free numerical propagators implementing Cowell's method (§12.6).
• Goddard, R. H. "A Method of Reaching Extreme Altitudes" (Smithsonian Miscellaneous Collections, 1919). — the monograph behind the 1920 NYT ridicule; a real primary source.
• Hassler, D. M., et al. "Mars' Surface Radiation Environment Measured with the Curiosity Rover's RAD" (Science, 2014), and the associated cruise-phase RAD results. — origin of the ~1.8 mSv/day deep-space cruise rate and Mars-mission dose estimates. Verify exact figures against the paper.
• Heppenheimer, T. A. The Space Shuttle Decision (NASA SP-4221) — the budget and political origins of the design (§37.1).
• Historical: Euler (collinear points, 1760s); Lagrange, Essai sur le problème des trois corps (1772, triangular points); Poincaré, Science and Method (1908, the sensitive-dependence quote and the King Oscar II prize episode).
• Iridium 33 / Cosmos 2251 collision (10 Feb 2009): masses (~560 kg / ~900 kg), altitude (~789 km), closing speed (~11.7 km/s), ~2,000+ cataloged fragments — widely reported values used in CS-01; exact figures vary by source.
• ISS orbital parameters used in Case Study 1 (i = 51.64°, altitude ~420 km, period ~93 min, ~16 orbits/day) — widely reported; the specific TLE values are representative, not a single real epoch.
• ISS regenerative ECLSS performance — water recovery ~90%+ (upgrades toward ~98%), oxygen recovery ~50% via Sabatier. Widely reported NASA operational values; exact numbers depend on configuration and epoch.
• JAXA Hayabusa/Hayabusa2 (Itokawa 2010, Ryugu 2020) and NASA OSIRIS-REx (Bennu 2023); NEAR-Shoemaker (Eros 2001). — flown proof that we can rendezvous with, sample, and return material from small bodies (§39.5).
• JAXA IKAROS and The Planetary Society LightSail-2 mission pages — the flown solar-sail demonstrations and their measured performance (IKAROS photon thrust ~1.1 mN).
• Jenkins, D. R. Space Shuttle: The History of the National Space Transportation System — comprehensive technical history (orbiter, SSME, TPS, SRBs); the reference for the chapter's vehicle specifications.
• JPL, "Curiosity's Seven Minutes of Terror" (video). — the canonical popular explanation of autonomous Mars EDL; a real, widely available NASA/JPL production (find by title).
• JPL, Basics of Space Flight (online), telecommunications and tracking sections. — DSN, ranging, Doppler, and VLBI/delta-DOR at an introductory level.
• JPL, DSN Telecommunications Link Design Handbook (810-005). — antenna gains, system noise temperatures, and link parameters for the Deep Space Network; module numbers/revisions vary.
• Kepler, J. Astronomia Nova (1609) and Harmonices Mundi (1619) — the primary sources for the first/second laws and the third law respectively; the epigraph is Kepler's own words on the third law (from Harmonices Mundi, a widely reproduced translation).
• Kerbal Space Program (with re-entry heating enabled, or the "Deadly Reentry" mod) — makes the corridor and ballistic-coefficient effects tactile.
• Kerbal Space Program life-support mods (USI-LS, Kerbalism) — model open-loop consumable mass and recycling; Kerbalism also models radiation. Community software.
• Kerbal Space Program with the FAR (Ferram Aerospace Research) mod — commercial game + community mod; a hands-on dynamic-pressure/aeroelastic model for feeling max-Q.
• Kerbal Space Program with the MechJeb mod. — an inspectable GN&C stack (ascent guidance, attitude control, landing autopilot); a commercial game plus a free mod.
• Kerbal Space Program — commercial game; the best hands-on "lab" for feeling that orbit is sideways speed and that rockets are ~90% fuel.
• Kerbal Space Program — commercial game; used as a hands-on way to feel gravity/drag losses via its delta-v readout.
• Kerbal Space Program — commercial game; used illustratively for feeling the mission-design spiral.
• Kerbal Space Program — electric-charge model, fading solar panels, night-side brownouts, RTGs.
• Kerbal Space Program — engine propellant/type effects on delta-v and thrust made tangible; a commercial game.
• Kerbal Space Program — reaction-wheel ("SAS") torque, saturation feel, and RCS-based slews/dumping as hands-on illustrations.
• Kerbal Space Program — the map/orbit readout is the six elements and the "time to apoapsis" is Kepler's equation live (further-reading; commercial game).
• Kerbal Space Program. — a commercial game that makes the first and third laws and orbital decay tangible.
• Launch-vehicle payload user's guides (SpaceX Falcon 9/Heavy; ULA Atlas V / Vulcan; Arianespace Ariane 6; Rocket Lab Electron; ISRO). — authoritative, freely published performance curves (payload vs orbit and $C_3$), fairing dimensions, environments; the current version of Appendix H's ballpark tables.
• Leibniz's vis viva (mv^2) and the 17th-18th c. "vis viva controversy" — standard history-of-physics episode giving the equation its name (see e.g. Stanford Encyclopedia of Philosophy, "Leibniz's Physics").
• Lions, J. L., et al. ARIANE 5 Flight 501 Failure — Report by the Inquiry Board (1996). — the definitive software-reliability case study; the 64-bit-to-16-bit overflow and the identical-backup common-cause failure.
• Liou, J.-C., & Johnson, N. L. "Risks in Space from Orbiting Debris." Science 311, 2006 (and follow-on NASA LEGEND modeling). — Basis for "LEO already supercritical" and "remove ~5–10 large objects/year" in §35.4.
• Mars ascent to low Mars orbit ~4.0–4.3 km/s including gravity/drag losses; trans-Earth injection from low Mars orbit ~2.1 km/s (Hohmann symmetry with the 2.65 km/s arrival excess).
• Mars atmosphere: ~96% CO2, surface pressure ~600 Pa (~0.6% of Earth), surface density ~0.020 kg/m^3, surface temperatures to below -80 C, global dust storms. Standard planetary-science values.
• Mars orbit-insertion practice: real orbiters (Mars Reconnaissance Orbiter, MAVEN, Mars Odyssey) capture into a high ellipse (~1–1.5 km/s MOI) and then aerobrake to the science orbit; the case-study-02 architecture follows this pattern.
• McDonald, A. J., & Hansen, J. R. Truth, Lies, and O-Rings (2009) — the launch-eve teleconference from inside the room (verify specifics against the Rogers Report).
• McDowell, J. "Jonathan's Space Report" / planet4589 catalogs. — meticulous public tracking of launched satellites and live mega-constellation counts.
• Merlin 1D performance figures (thrust ~845 kN SL / ~914 kN vac; Isp ~282 s SL / ~311 s vac; nozzle exit ~0.9 m) — widely reported, version-dependent; consolidated in Appendix H.
• Michael Minovitch's 1960s gravity-assist analysis at JPL — the origin of chained-flyby "Grand Tour" trajectories. Real history; exact attributions vary by account.
• MIL-STD-1629A, "Procedures for Performing a Failure Mode, Effects and Criticality Analysis." — the classic codification of FMEA/FMECA and its severity/criticality scales.
• Mission specifications used in worked examples/case studies (New Horizons: ~12 W X-band, 2.1 m HGA, ~1–2 kbit/s at Pluto ~32 AU; Voyager 2: ~21 W, 3.7 m HGA, ~21.6 kbit/s at Neptune ~30 AU; Mars Reconnaissance Orbiter: 100 W, 3 m HGA, ~0.5–6 Mbit/s) — widely reported approximate values.
• Modern GPS flies ~31 operational satellites (above the 24-slot baseline) for robustness/geometry — widely reported (CS-01).
• Molniya orbit operational parameters: ~12-hour (half-sidereal-day) period, e ≈ 0.74, apogee ~39,900 km, critical inclination 63.4°, argument of perigee 270°, three-satellite constellation for continuous high-latitude coverage — widely reported/standard figures used in Case Study 2.
• Molniya program: first Molniya-1 launch 1965, USSR high-latitude comms via 63.4 deg HEO — widely documented history (§9.4).
• Morgan Stanley / Citi and other investment-bank space-economy outlooks. — origin of the ">$1 trillion by 2040" projection (§39.6). Projections, NOT measurements; the trillion is driven mostly by growing existing satellite businesses.
• MOXIE (Perseverance ISRU demo, 2021–): produced O2 from Martian CO2 via solid-oxide electrolysis (2CO2 -> 2CO + O2) at a few g/hr (~6–12 g/hr), >12 successful runs across a Martian year. First ISRU on another planet. (Peer-reviewed: Hoffman et al., Science Advances, 2022 — confirm exact citation.)
• NASA "DSN Now" (live status web tool). — real-time antenna-to-spacecraft links, bands, and data rates.
• NASA / AEC technical reports on Project Rover and NERVA (Kiwi, Phoebus, NRX, XE-Prime) — primary source for the demonstrated ~825 s specific impulse, thrust, and reactor power used in Case Study 1. Exact report numbers vary; search NASA's technical report server.
• NASA / DOE Kilopower and KRUSTY (2018 test) — compact space fission reactor, U-235 core, Stirling convertors (~30%), 1–10 kW class.
• NASA / ESA mission pages for JWST (Sun–Earth L2), SOHO and ACE (Sun–Earth L1), Gaia (L2), and Genesis (L1) — official explanations of why each mission chose its libration point and how its halo orbit works.
• NASA / JPL Deep Space Network documentation on radiometric tracking (sequential ranging, Doppler, and delta-DOR) — the real precisions and geometry behind Case Study 2. Long-standing NASA/JPL resources; find current documents by title.
• NASA / Marshall Space Flight Center write-ups on the Space Shuttle Super Lightweight Tank (Al-Li 2195). — ~3,400 kg tank mass saved vs the Lightweight Tank and its near-one-to-one conversion into ISS payload (Case Study 1). Figures vary by source.
• NASA / WMAP "Lagrange Points" education primer — the five points, their stability, and their uses.
• NASA and manufacturer fact sheets for the RS-25 (SSME), F-1, and RL10. — thrust, Isp, and throttle ranges at stated power levels; authoritative but version/power-level-dependent.
• NASA Apollo/ALSEP history — SNAP-27 RTG (~70 W) powered the Apollo 12–17 surface science stations through the lunar night.
• NASA career radiation limit ~0.6 Sv (order-of; risk-based, evolving) — the benchmark §34.3 compares the cruise dose against.
• NASA career radiation limit ~0.6 Sv (recent single-limit standard), historically age/sex-dependent limits set by a 3% REID criterion. Attributed to NASA spaceflight radiation standards.
• NASA CEA (Chemical Equilibrium with Applications), Glenn Research Center. — standard free code for adiabatic flame temperature, equilibrium exhaust composition, molecular weight, and theoretical Isp (the rigorous version of §18.2–18.3).
• NASA Deep Space 1 / NSTAR technology reports — first use of an ion engine as a deep-space mission's main propulsion (1998).
• NASA Glenn Research Center. "Beginner's Guide to Rockets" — free educational pages on thrust, specific impulse, and the rocket equation.
• NASA Glenn Research Center. "Newton's Laws of Motion" and "Weightlessness in Orbit." — free educational pages; free fall vs. absent gravity.
• NASA history and educational resources on the SSME, the TPS, the SRBs, and the STS program.
• NASA History Office, history.nasa.gov. — mission histories, oral histories, technical reports; the primary-source backbone of much of this chapter.
• NASA history-office accounts of Apollo 6 and Apollo 13 pogo events — the phenomenon and its accumulator fix in context.
• NASA history/education resources on the Apollo command module heat shield (AVCOAT), the entry corridor, and the guided lifting entry — used to sanity-check Case Study 1's Apollo numbers.
• NASA Human Research Program — "The Human Body in Space" and the HRP risk reports. — microgravity and radiation effects (bone loss ~1–1.5%/month, fluid shift, SANS) and countermeasures (ARED, ~2 h/day exercise). Real, long-running NASA resource; find current pages by title.
• NASA JPL. Deep Space Network / "DSN Now" live tracking display. — a real, long-running resource illustrating the DSN as a scarce, scheduled resource (§31.5). Current URL by search.
• NASA Launch Services Program (LSP) and the NASA Launch Vehicle Performance website. — $C_3$ performance data used to match science payloads to vehicles (Case Study 2).
• NASA mission pages — Juno (~14 kW at 1 AU, ~486 W at Jupiter, 18,698 cells, ~60 m² arrays, 2 rpm spin); Voyager (RTGs still running ~47 yr on); Curiosity/Perseverance (MMRTG); Dragonfly (MMRTG, Titan).
• NASA Orbital Debris Program Office. Orbital Debris Quarterly News; ORDEM environment model; NASA Standard Breakup Model. — Debris flux (the Phi in §35.2), the ~40 J/g catastrophic-fragmentation EMR threshold (CS-01), and event analyses (Iridium–Cosmos, Fengyun-1C).
• NASA Radioisotope Power Systems program (online) — RTG operation, MMRTG (~110 W, ~45 kg, ~4.8 kg PuO2), GPHS-RTG (~300 W, ~10.9 kg Pu-238, ~57 kg), Pu-238 supply (~1.5 kg/yr, restarted ~2015). Pu-238 half-life 87.7 yr, ~0.54 W/g.
• NASA — Kepler / K2 mission material and the "Second Light" (K2) concept literature. Reaction-wheel failures (wheel 2, 2012; wheel 4, 2013) and the solar-radiation-pressure balancing that resurrected the mission; K2 ran ~2014–2018, ending when hydrazine was exhausted.
• NASA — public "space environment," human-spaceflight, and space-radiation resources: vacuum, Van Allen belts, radiation dose, and microgravity physiology behind §1.3–1.4. (Long-running NASA pages; exact URLs vary.)
• NASA. "Report of the Apollo 13 Review Board" (the Cortright Report, 1970). — primary failure investigation; root cause of the oxygen-tank explosion and the operational response. Exact scan/URL varies.
• NASA. Life Support Baseline Values and Assumptions Document (BVAD). — source class for the per-crew-day consumables figures (O2 ~0.84, potable water ~2.5, food ~1.8 kg; CO2 out ~1.0 kg). A real, periodically revised NASA document; exact values vary by revision.
• NASA. Mars Climate Orbiter Mishap Investigation Board Report (1999). — the units-mismatch interface failure discussed in §29.6 (a real, publicly released report).
• NASA. MOXIE (Mars Oxygen ISRU Experiment) results, Perseverance rover (2021–). — first demonstrated production of a consumable (oxygen) on another planet; the proof-of-concept behind §39.2. Real, documented; gram-per-hour scale.
• NASA/JPL Dawn mission; Marc Rayman's "Dawn Journal" (JPL) — ion propulsion in practice; NSTAR performance (~2.3 kW, ~92 mN, Isp ~3,100 s), 425 kg xenon, ~11.5 km/s total delta-v, the "weight of a sheet of paper" thrust description.
• NASA/JPL Mars 2020 / Perseverance mission (landed 18 Feb 2021, Jezero Crater): entry mass ~3,650 kg, rover ~1,025 kg, entry speed ~5.4 km/s, peak decel ~10–12 g, 21.5 m supersonic parachute deploy ~Mach 1.7 at ~11 km, sky-crane touchdown ~0.75 m/s, EDL ~7 min. Widely reported EDL figures; used in case-study-01. One-way light time that day ~11.4 min (Mars ~2.05e8 km).
• NASA/JPL. "Basics of Space Flight" (online) — patched conics, C3, launch windows, gravity assists at this book's level; long-running NASA educational resource.
• NASA/JPL. "Basics of Space Flight" — free online primer on orbital energy, escape, and interplanetary injection.
• NASA/NOAA space-weather resources; US Standard Atmosphere (1976) and the NRLMSISE-00 / JB2008 thermospheric density models — basis for the ~10× solar-cycle density variation flagged in §12.3.
• Newton, I. A Treatise of the System of the World (1728). — the cannonball thought experiment (chapter epigraph); translations/editions vary.
• Patel, M. R. Spacecraft Power Systems. CRC Press. — dedicated treatment of arrays, batteries, RTGs, and distribution.
• Public regulatory filings (FCC / ITU) for Starlink and OneWeb. — orbital shells, altitudes, inclinations, and satellite counts of §33.5; the primary basis for the approximate constellation figures. (Details change as constellations are revised.)
• RAD750 processor characteristics (~200 MHz, ~hundreds of krad TID tolerance, PowerPC 750 heritage, ~$200k) — widely reported approximate values.
• Representative material property values used in §23.3 and the case studies — Al 2xxx/2195, Ti-6Al-4V, 301/304L stainless, CFRP laminate (density, UTS, E). Handbook ballpark; alloy- and temper-dependent.
• RPA (Rocket Propulsion Analysis) / the Python rocketcea wrapper. — friendlier equilibrium-chemistry front-ends for sweeping mixture ratio.
• Scott Carpenter, "Godspeed, John Glenn," spoken at the launch of Friendship 7 (Mercury-Atlas 6), 20 February 1962. — the chapter epigraph; a real, widely documented launch transmission (exact recording archived by NASA; venue pinned, wording standard).
• Scott Manley (YouTube) — "how hard is it to get to orbit," delta-v map, and "why rockets are so big" explainers pairing with §1.1–1.2.
• Scott Manley (YouTube) — explainer videos on gravity turns, gravity losses, and launch trajectories.
• Scott Manley (YouTube) — explainer videos on interplanetary transfers, launch windows, porkchop plots, and gravity assists (the frame-change picture).
• Scott Manley (YouTube) — explainer videos on ion and Hall thrusters.
• Scott Manley (YouTube) — explainer videos on Lagrange points, halo orbits, why JWST is at L2, and low-energy transfers.
• Scott Manley (YouTube) — explainer videos on life support, radiation, and artificial gravity.
• Scott Manley (YouTube) — explainer videos on max-Q, dynamic pressure, and why rockets throttle down.
• Scott Manley (YouTube) — explainer videos on nuclear rockets, solar sails, and Orion, numerically honest about demonstrated-vs-theoretical.
• Scott Manley (YouTube) — explainer videos on orbital elements and the anomalies (further-reading).
• Scott Manley (YouTube) — explainer videos on orbital energy, vis-viva, and the "orbital paradox" (higher = slower).
• Scott Manley (YouTube) — explainer videos on orbital perturbations, sun-synchronous orbits, and station-keeping.
• Scott Manley (YouTube) — explainer videos on re-entry heating, heat shields, and why capsules are blunt.
• Scott Manley (YouTube) — explainer videos on reaction wheels, gyroscopes, momentum dumping, and spacecraft attitude control.
• Scott Manley (YouTube) — explainer videos on RTGs and spacecraft power.
• Scott Manley (YouTube) — explainer videos on satellite tracking, TLEs, and how orbits are determined.
• Scott Manley (YouTube) — explainer videos on the rocket equation, specific impulse, and the delta-v map.
• Scott Manley (YouTube) — explainer videos on the Space Shuttle, the SSME/RS-25, and the Challenger and Columbia accidents.
• Scott Manley (YouTube) — explainer videos on thrust, specific impulse, and engine performance.
• Scott Manley (YouTube) — intuitive explainers on GEO, sun-synchronous, and Molniya orbits.
• Scott Manley (YouTube) — mission-design and delta-v-budget explainer videos.
• Scott Manley (YouTube) — reconstructions of launch failures (N-1 and modern anomalies).
• Scott Manley (YouTube). — expert explainer videos on the history of rocketry, the V-2, and the Space Race.
• Scott Manley (YouTube). — explainer videos on Apollo 13, the Deep Space Network, and deep-space operations, pairing with §31.5 and Case Study 2.
• Scott Manley (YouTube). — explainer videos on constellations, Starlink, and rideshare deployment.
• Scott Manley (YouTube). — explainer videos on rocket ascent guidance, propulsive landing, and autopilots.
• Scott Manley (YouTube). — explainer videos on the Deep Space Network and deep-space communications.
• Scott Manley (YouTube). — explainer videos on why things orbit, escape velocity, and orbital decay.
• Scott Manley (YouTube). — numerate explainers on Falcon 9 landings, the full-flow cycle, and Starship.
• Scott Manley (YouTube); LeoLabs; CelesTrak — accessible tracking/conjunction resources (further reading).
• Scott Manley and Everyday Astronaut (YouTube) — explainer videos on Starship's steel and on rocket structures/loads.
• Scott Manley and Everyday Astronaut (YouTube) — visual explainers of gas-generator, staged-combustion, and full-flow engine cycles, and of Raptor.
• Scott Manley and Everyday Astronaut (YouTube). — launch-vehicle and launch-operations explainers at this chapter's level, with real launch footage (§30.1, §30.5).
• Scott Manley and other expert explainers (YouTube). — technically honest breakdowns of Artemis, Starship, and Mars architectures.
• Scott Manley; Everyday Astronaut (YouTube) — explainers on staging, propulsive landing, and reusability.
• Scott Manley; Everyday Astronaut (YouTube). — accessible explainers on rocket fuels, methalox, cryogenics, and full-flow staged combustion, with real vehicles.
• Site latitudes used: Kourou $5.2^\circ$N, Cape Canaveral/Kennedy $28.5^\circ$N, Baikonur $45.9^\circ$N, Vandenberg $34.7^\circ$N, Wenchang $19.6^\circ$N, Sriharikota $13.7^\circ$N. — widely published geographic values.
• Solà, J. "Quaternion kinematics for the error-state Kalman filter." — widely circulated tutorial on Hamilton vs. JPL quaternion conventions and attitude kinematics.
• Space Foundation. The Space Report (annual). — source of the "few hundred billion dollars, mostly satellite services" size estimate in §39.6; note its boundary definition.
• Space Shuttle external tank generation masses (SWT ~35,000 kg, LWT ~30,000 kg, SLWT ~26,600 kg). — widely reported, rounded.
• Space Shuttle main-engine throttle-down to ~65–72% ("the bucket") through max-Q, and the "Go at throttle up" call — widely documented from Shuttle flight operations.
• SpaceX / Elon Musk interviews and statements (2018–2019) on the Starship carbon-fiber-to-stainless-steel switch. — cryogenic strength gain, high-temperature tolerance and heat-shield mass savings, and the roughly 50:1 raw-material cost ratio (§23.6). Real, publicly explained decision with approximate quoted numbers.
• SpaceX / NASA launch webcasts — the "vehicle is supersonic / passing through max-Q" and throttle-down callouts; freely available recordings.
• SpaceX / operator press kits and payload user's guides — primary-ish source for Merlin thrust and Isp and Falcon 9 mass/burn-time figures (version-dependent).
• SpaceX launch and test-flight webcasts. — primary footage of propulsive landings and Starship test flights (the iterate-fast method in action).
• SpaceX mission press kits and launch webcasts — the propulsive-landing sequence (boostback/entry/landing burns, grid fins), droneship vs. RTLS profiles, and the October 2024 Super Heavy tower catch. Primary public source but marketing-adjacent; cross-check figures.
• SpaceX, Falcon User's Guide. — operator's payload document; authoritative Falcon 9 LEO/GTO payload, recovered vs expended. Use to replace this chapter's rounded tonnages.
• SPT-100 Hall thruster performance (~1.35 kW, ~83 mN, Isp ~1,600 s) and NSTAR performance — widely reported flight/vendor figures (version- and throttle-dependent).
• Starlink electric propulsion — widely reported use of krypton (early) then argon (later) Hall thrusters for orbit-raising, station-keeping, and disposal.
• Sutton, K., & Graves, R. A. (NASA technical report, early 1970s). Stagnation-point convective-heating correlation — source of the $\dot q \propto \sqrt{\rho/R_n}\,v^3$ scaling used in §7.3. NOTE: I used only the SCALING, not the absolute constant, to avoid the well-known unit ambiguity in the constant; verify the exact report and constant before quoting an absolute heat flux.
• Sutton, K., & Graves, R. A., Jr. "A General Stagnation-Point Convective-Heating Equation for Arbitrary Gas Mixtures." NASA TR R-376 (1971). — origin of the stagnation-point heating scaling $\dot q \propto \sqrt{\rho/R_n}\,v^3$ used qualitatively in §5.5; verify exact report ID by title search.
• Sweeting, M. N. "Modern Small Satellites — Changing the Economics of Space" (review article, Proceedings of the IEEE). — democratization and economics of small satellites (§33.1, §33.6); exact citation not pinned here.
• Syncom 3 (1964), first geostationary communications satellite, relayed the Tokyo Olympics — widely reported spaceflight history (§9.3 history callout).
• The Aerospace Corporation / CSIS launch-economics analyses. — independent cost-per-kilogram and reuse break-even studies (the sober counterweight to marketing figures).
• The Apollo 11 descent 1201/1202 program-alarm episode and Steve Bales/Jack Garman GO calls — a well-documented historical event; specific processor-loading percentages here are illustrative.
• The recovery of Ceres (1801): Piazzi's discovery and loss, and Gauss's orbit prediction leading to its re-observation — a well-documented historical episode; specific arc lengths and dates vary slightly by source.
• Theodore von Kármán — source of the chapter epigraph ("The scientist describes what is; the engineer creates what never was"); widely attributed, exact origin not pinned.
• Tsiolkovsky, K. E. "Exploration of Outer Space by Means of Rocket Devices" (1903) — the original derivation; English translations vary.
• Tundra orbit (24 h geosynchronous HEO, 63.4 deg) used by satellite-radio broadcasters (e.g. Sirius) for northern service — widely reported (§9.4, CS-02).
• United States Holocaust Memorial Museum / Mittelbau-Dora Memorial (online resources). — on the prisoners who built the V-2. Real institutions; verify current URLs.
• UNOOSA treaty database and UN Register of space objects; US 18th/19th Space Defense Squadron conjunction data messages; US Office of Space Commerce (civil STM). — §§35.3, 35.5, 35.6.
• US FCC "5-year rule" order (2022) on post-mission disposal for LEO satellites; NASA/US Government Orbital Debris Mitigation Standard Practices. — The tightened disposal timeline in §35.3.
• Vehicle performance figures used in worked examples (Tier 2, widely reported, version-dependent): Falcon 9 masses (from Ch. 3) and ~549 t lift-off; Merlin 1D ~845 kN sea-level thrust and ~40% minimum throttle; CRS-1 (2012) engine-1 failure with successful primary delivery and stranded secondary payload; AMOS-6 (2016) pad loss traced to a helium COPV; N1 30-engine first stage, four failed flights (1969–72); Saturn V stage masses and F-1/J-2 specific impulses (S-IC avg Isp ~290 s is a teaching average of ~263 s sea level / ~304 s vacuum; J-2 ~421 s vacuum).
• Vehicle/mission specifics cited in-text and labeled Tier 2: MarCO (two 6U interplanetary CubeSats, InSight relay, 2018); Transporter-1 (143 satellites on one Falcon 9, Jan 2021); Iridium (66 satellites, ~780 km); Planet Dove/Flock (~150 3U imagers, ~475–520 km SSO, ~3–4 m resolution); Starlink (~550 km, 53°); OneWeb (~1,200 km, ~648 satellites, near-polar). Standard, widely reported figures; exact values vary by source and revision.
• Vehicle/program figures used in worked examples — SSME thrust (~1.8 MN SL / ~2.1 MN vac), Isp (~452 s vac / ~366 s SL), chamber pressure (~200 bar), throttle 67–109%; SRB thrust (~12.5 MN each), propellant (~500 t), burn ~124 s, ~80–82% of liftoff thrust; stack liftoff mass ~2,030 t; payload ~27,500 kg; program cost ~$209B; ~135 flights; launch temperature ~2 °C vs previous coldest ~12 °C; Columbia foam ~0.76 kg at ~230 m/s (~20 kJ) — all widely reported but rounded and version-dependent.
• Voyager mission (NASA/JPL): launch 20 Aug 1977; Jupiter 9 Jul 1979 (closest approach ~570,000 km from Jupiter's center for Voyager 2), Saturn 25 Aug 1981, Uranus 24 Jan 1986, Neptune 25 Aug 1989; the ~176-year outer-planet alignment; both probes now in interstellar space. Widely documented mission history; specific encounter velocities vary by source.
• Zubrin, R. The Case for Mars. — the intellectual origin of the "make propellant on Mars" (Sabatier/ISRU) architecture in §39.2; read for the reasoning, keep Tier discipline for its timelines.

Tier 3 — Illustrative / constructed (labeled in text)

• "First object in space" (a 1944 vertical V-2 test crossing ~100 km) is attributed as "widely reported."
• Al-Li 2195 vs. 2219 property deltas (−5% density, +26% UTS, +32% specific strength, +7% modulus) are representative (Tier 2 handbook ballpark) presented as Tier 3 rounded comparisons.
• All code outputs hand-traced, never executed (hard rule). Arithmetic spot-checks: 1500·5·9.81=73,575 N; p(140 dB)=2e-5·1e7=200 Pa; 8000/20e-6=4e8 Pa; 72e9·6e-4=4.32e7; 3.4e5·1.83/0.004=1.556e8 (156 MPa); 3.5e5·1.83/0.004=1.601e8 (160 MPa); 570/(1.4·360)−1=0.131; 500/(1.25·360)−1=0.111; e^(6000/3412.71)=5.80; (4.5−1)·3=10.5; E/ρ: 70e9/2700=2.59e7, 193e9/7900=2.44e7, 114e9/4430=2.57e7; hoop(1.2,0.0025,3e5)=1.44e8; t=5e5·2.25/3e8=3.75e-3; 2700·2π·2.25·0.00375=143 kg/m; Ti tank 4430·4π·0.1225·7e-4=4.8 kg; wet=600·e^(1500/3138)=968. Re-verify if ever run.
• All code outputs were hand-traced, never executed (per the hard rules): example-01 (32.8 kPa at 14 km), example-02 (176 kN; 65116 kg/m²; 0.50 m/s²), example-03 (374 K; 2214 K; 59×), project-checkpoint (32.8 kPa/14 km; 506 m/s), exercise-solutions (32148; 537; 65116 0.507), CS-01 (32.8/45.5 kPa), CS-02 (v_cap 447/506/573/650). Re-verify if the build ever runs them.
• All cost figures in §22.6 and Case Study 2 (build cost M, refurbishment R, fixed cost F, break-even flight counts, cost-per-tonne) are illustrative round numbers chosen to expose the structure of the amortization argument; real launch costs are proprietary. Labeled in-text.
• All flame temperatures (~3,300–3,650 K), operating mixture ratios (O/F), and mean exhaust molecular weights (~13–24 g/mol) in the tables and worked examples are rounded, approximate, teaching values; real values require equilibrium-chemistry software (CEA) and vary with chamber pressure and expansion. Labeled Tier 2/3 in text.
• All link-budget inputs are rounded/illustrative teaching values: aperture efficiencies ($\eta = 0.6$ spacecraft, $0.7$ ground), system noise temperatures ($T_s = 20$–$30\ \text{K}$), other losses ($L_{\text{other}} = 2$–$3\ \text{dB}$), and required $E_b/N_0$ ($\approx 2.3$–$2.5\ \text{dB}$ coded). Distances are rounded (Pluto encounter taken as $4.83\times10^{12}\ \text{m}\approx$ 3 billion miles).
• All per-component reliabilities, subsystem single-string reliabilities (comsat 0.90-0.99), the 1,000,000-hr MTBF box, and the per-engine r = 0.99 are illustrative round numbers chosen for clarity and clearly labeled as such in-text. Real values are program-specific and often proprietary.
• All per-crew-day consumables and dose rates are rounded; the hydrogen-stoichiometry argument for ~50% O2 recovery assumes a respiratory quotient ≈ 1 and full electrolysis of the Sabatier water product.
• All PID gains, disturbances, and traces (Kp=0.5, Ki=0.5, disturbance +1 deg/step and 0.2 m/s^2, the droop-to-2-degrees and descent-to-2.4-m/s numbers) are pedagogical, not from any flight.
• All specific delta-v-budget legs (comsat GTO→GEO 1,800 m/s incl. plane change; 15-yr station-keeping 750 m/s; disposal 11 m/s; lunar TLI 3,100 / LOI 700 / descent 1,700 m/s) are the standard delta-v-map values of Ch. 3 / Appendix G, rounded for teaching; exact values vary by orbit, launch site, and date.
• All Starship performance and cost figures (dry mass ~120 t, propellant ~1,200 t, payload ~100–150 t to LEO, ~8–16 tanker flights, aspirational $/kg) are design goals for a vehicle still in development, NOT demonstrated capability.
• All tank/strut/mass-budget numbers in the worked examples and case studies are constructed, plausible teaching values, not telemetry from any specific vehicle: the §23.4 tank (r=1.83 m, t=4 mm, p=3.4 bar → 156 MPa), the 7075-T6 strut (limit 360 MPa), the §23.5 upper stage (Δv 6 km/s, Isp 348 s → R=5.80), the 500 kg satellite bus and its thrust tube (0.6 m, 2 mm) and propellant tank (r=0.35 m, p=20 bar).
• All vehicle figures used in worked examples are rounded, approximate values assembled for teaching: V-2 masses (m0 ≈ 12,500 kg, mf ≈ 3,900 kg, propellant ≈ 8,600 kg) and Isp (≈ 203 s → ve ≈ 2.0 km/s); black-powder Isp (≈ 80 s → ve ≈ 785 m/s); R-7 effective ve (≈ 3.0 km/s); the 1950s structural coefficient ε = 0.10 in Case Study 2. Exact values vary by source and vehicle version.
• Antimatter production rate (~nanograms/year) and cost (tens of trillions of USD per gram) are widely cited order-of-magnitude estimates.
• Apollo 13 consumables figures (LM battery capacity ~2000 Ah, ~50 A normal / ~12 A survival load, ~90-hour return) used in Case Study 1 are rounded, illustrative values chosen to show the ratio (power-down endurance vs. need); exact values vary by source.
• Atmospheric densities used with tau ~ Hbeta/(rho0a*v): rho0 ~ 2e-13 (600 km), ~1e-14 (800 km), ~4e-14 (700 km) kg/m^3, H ~ 70–80 km — representative moderate-solar-activity values; density swings ~10x over the solar cycle, so all lifetimes are central estimates with wide error bars (flagged throughout).
• Body constants used in worked examples and code (mu, mean radius, surface gravity, escape velocity for Earth, Moon, Mars, Sun) are standard, rounded values; surface g computed with mean radius gives 9.82 m/s^2 vs. the conventional 9.81.
• Boiloff worked example (100 W heat leak; LH2 h_fg 446 kJ/kg; LOX 213 kJ/kg) — round illustrative numbers; actual heat leaks are design-specific.
• Bulk densities (~360/830/1020/1180 kg/m³ for hydrolox/methalox/kerolox/hypergolic) and the turbopump-power reconstruction (~44 MW hydraulic, ~59 MW shaft, sanity-checked against the widely cited "~70,000 hp" SSME fuel-pump figure) are rounded illustrative estimates; efficiency and discharge-pressure assumptions are stated in text and flagged Tier 2/3.
• Bulk propellant densities (LOX/LH2 ~0.36, LOX/CH4 ~0.83, LOX/RP-1 ~1.02, N2O4/UDMH ~1.16 g/cm³) computed from component densities at the stated mixture ratio.
• Case Study 1 Apollo descent specifics — ~12,000 m radar acquisition, ~1,700 m/s braking start, ~45 kN DPS, ~15,000->7,000 kg descent-stage mass, the 85%/15% AGC loading split, the 300 m / 100 m sigmas — are Tier 2/Tier 3 illustrative round figures; the Moon light-time (1.28 s one-way) is essentially exact.
• Case Study 1 ISS element set (RAAN 247.4°, argument of perigee 130.5°, mean anomaly 325.0°, mean motion 15.50 rev/day, e = 0.0007) — representative/illustrative values (a real TLE changes every few hours); a is recovered as 6,795 km (alt ~424 km).
• Case Study 2 masses (5 t upper body, 20 t spent stage) and the 0.5 m/s separation velocity are illustrative but realistic for a spring-driven stage separation.
• Case Study 2 Molniya design targets (perigee altitude 500 km; the 30,000-km radius "loiter" threshold used for the dwell-time calculation) — chosen round values for a clean worked design; dwell result ~8.1 h of 12 h.
• Case-study-02 vehicle numbers (1200 kg dry orbiter, Isp 320 s, MOI into a 400 km x 30,000 km capture ellipse = 0.94 km/s, TCM 0.10 km/s, 6% margin -> 505 kg propellant, 1705 kg wet) are a constructed but realistic Track-C design; the illustrative launch-vehicle payload-vs-C3 point (~2000-2500 kg to C3~10) is a round teaching figure.
• Chapter epigraph: Tsiolkovsky's "cradle" line — a genuine, widely documented Tsiolkovsky statement (attributed to a 1911 letter). Case Study 1's epigraph is presented as "a common summary," not a specific attributed quotation.
• Chemical exhaust velocities (kerosene ~3.4 km/s, hydrogen ~4.5 km/s) and structural coefficient (ε ≈ 0.08) are standard rounded teaching values; the ~9.4 km/s delta-v to LEO and its ~1.6 km/s of losses are conventional approximate figures (detailed in Ch. 4).
• Conjunction-class ~500-day surface stay / ~900-day total, ~44 deg departure phase (via Ch. 11), and opposition-class Venus-swingby framing are standard mission-design values; exact figures are date- and design-dependent.
• Cost model (fixed annual ~$4B, marginal ~$0.45B; high-flight-rate case ~$0.05B marginal / ~$1B fixed) — illustrative round numbers chosen to expose the structure of reuse economics, not authoritative program figures.
• Coverage-geometry margin factor (~2× the no-overlap floor for a real design fleet): a teaching rule of thumb; a real design uses a Walker/streets-of-coverage optimizer.
• Cryogenic strength figures — stainless up to ~1600–2000 MPa, aluminum ~550 MPa at LOX temperature (§23.6) — are approximate and alloy/temper/temperature-dependent. The direction and rough magnitude of austenitic-stainless cryo-strengthening are well established; the exact values are not pinned and are flagged in the text.
• CS-01 Dove telescope aperture (~9 cm) and diffraction-limited GSD (~3.5 m at 475 km): an illustrative optics estimate that matches the reported ~3–4 m resolution.
• CS-01 Phase 5: "LEO→GPS deploy delta-v ~3.5–4 km/s" is an order-of-magnitude Hohmann-plus-plane-change estimate (coplanar Hohmann ≈ 3.4 km/s by hand); the exact figure is transfer- and inclination-dependent and uses Ch. 10 methods.
• CS-02 "usable arc ~8 h" and "3-satellite Molniya constellation" are representative operational design figures.
• CS-02 IoT constellation (altitudes, ~20 kg satellites, fleet ~260, 6 launches, ~$430M capex): a constructed design example; numbers are illustrative to demonstrate the method.
• Dawn's inferred "~384 kg xenon used, ~40 kg reserve" is a rocket-equation back-calculation from the widely reported ~11.5 km/s realized delta-v (Tier-3 arithmetic on Tier-2 inputs); the mission is widely reported to have ended on hydrazine depletion with xenon remaining.
• Debris flux Phi ~ 1e-5 (m^2 yr)^-1 for >1 cm at congested altitudes (§35.2 collision-probability example and CS-02) — order-of-magnitude value chosen for clarity; real fluxes come from ORDEM/MASTER and vary with altitude/size.
• DoD values (0.25 LEO, 0.70 GEO), RTG efficiency ~6–7%, specific-power ranges (solar ~10–50, RTG ~3–5, fission ~2–6 W/kg), Kilopower ~1,500 kg for 10 kWe — all order-of-magnitude teaching figures.
• DSN precision figures used illustratively (Doppler ~0.1 mm/s, delta-DOR ~ few nrad, ranging ~ metres) and the Case Study 2 fusion numbers (200 nrad Doppler-only plane-of-sky, 2.5 nrad delta-DOR, D ~ 2e8 km) are representative order-of-magnitude values chosen for clarity, not a specific mission's reconstructed budget.
• Energy-density figures (chemical 1.3×10⁷, fission 8.2×10¹³, fusion 3.4×10¹⁴ J/kg) are standard order-of-magnitude values; antimatter (~9×10¹⁶ J/kg of fuel) follows exactly from E = mc².
• Engine specifications used in the chapter, tables, and case studies (Merlin ~845 kN SL / Isp 282–311 s / pc ~97 bar; Raptor 2 ~2,260 kN SL / Isp 327–350 s / pc ~300 bar; RS-25 ~1,860/2,090 kN / Isp 366/452 s / pc ~206 bar; Shuttle SRB ~12,000–14,700 kN / Isp 242/268 s) are approximate, widely reported, version-dependent teaching values assembled to be consistent with Appendix H; not for design use.
• Environmental figures are order-of-magnitude teaching values: sea-level background ~3 mSv/yr; ISS crew ~0.5–0.7 mSv/day (~100× ground); Mars round trip ~0.6–1 Sv; deep-space CMB 2.7 K (−270 °C); sunlit black-plate equilibrium ~+120 °C (higher, toward +260 °C, for high absorptance/low emittance surfaces — surface-property dependent); ISS thermal swing roughly −150 to +120 °C; debris/micrometeoroid closing speeds 10–15 km/s; Voyager 1 >24 billion km, one-way light time ~22.5 h.
• Environmental values (atmospheric density ~5e-13 kg/m^3 at 500 km, Earth field ~3e-5 T in LEO, solar pressure ~4.5e-6 N/m^2 near 1 AU) are representative order-of-magnitude figures.
• Epigraphs: Sagan "mythic arena" (from Cosmos, real/widely quoted; exact page not pinned — Tier 2); Zubrin "travel light and live off the land" (paraphrase of the Mars Direct thesis, The Case for Mars — Tier 2); Perseverance "Touchdown confirmed..." (NASA/JPL EDL broadcast, 18 Feb 2021, real line — Tier 2).
• Epigraphs: Saint-Exupéry, Terre des hommes/Wind, Sand and Stars (chapter epigraph — real, Tier 1 attribution); "weight is the mortal enemy of any flying machine" (CS-01, an aircraft-structures maxim, folk attribution — Tier 3); the Arthur Wellington "an engineer can do for a dollar…" adaptation (CS-02 — real saying, loosely adapted — Tier 3).
• Falcon 9 and Saturn V mass/Isp figures used in worked examples are rounded, approximate values assembled for teaching; exact values vary by vehicle version and mission.
• Falcon 9 ascent figures (liftoff mass ~549 t, liftoff thrust ~7.6 MN, T/W ~1.4, MECO ~T+155 s at ~65 km and ~2.3 km/s, SECO ~200 km at ~7.7 km/s, max-Q ~30 kPa) are rounded, representative teaching values assembled for illustration; they vary by mission, payload, and vehicle block. The stage delta-vs (3.86 / 6.02 km/s) are carried over from Chapter 3's approximate mass set.
• Falcon 9 stage masses/Isp are rounded illustrative values consistent with Chapter 3 (real vehicle is somewhat higher-performing; our absolute tonnages run low while the percentages track reality).
• GEO elevation-angle table (CS-02) assumes a ground station on the satellite's meridian (best case); off-meridian stations see lower elevations.
• GPS taken at r ≈ 26,560 km / altitude ≈ 20,200 km; the operational orbit's exact radius varies slightly (the ideal half-sidereal-day radius is 26,562 km). Used consistently as ~26,560 km.
• Graveyard re-orbit taken as +300 km above GEO, delta-v ≈ 11 m/s — representative of IADC-style disposal guidance, rounded.
• GTO perigee altitudes (300 km in Case Study 1; 400 km in the Checkpoint) and the round LEO/GEO radii (6,771 km / 42,164 km) are representative teaching values.
• GTO teaching orbit: perigee 6,771 km (400 km altitude) to apogee 42,164 km (GEO), giving a = 24,468 km, e = 0.723, T = 38,089 s — a constructed illustrative transfer used across §8.3, §8.6, and Case Study framing.
• Heats of combustion (H2 ~120, CH4 ~50, RP-1 ~43 MJ/kg of fuel) and enthalpy of formation of gaseous water (−241.8 kJ/mol) are standard textbook values (Tier 2).
• Hoverslam worked example (landing mass ~25.6–30 t, single-engine decel) — illustrative; the real profile varies with mission and reserve propellant.
• Illustrative cost figures: Rocket Lab Electron (~$7.5M / ~300 kg), SpaceX Transporter rideshare (~$1M / 200 kg), Falcon 9 (~$67M / ~22,800 kg to LEO); per-satellite constellation cost (<$1M). Round numbers chosen to show ratios, not to quote a current price list.
• Illustrative spacecraft: 150 kg smallsat with Cd*A = 1.5 m^2 (beta = 100 kg/m^2); 15 m^2 drag sail at Cd = 2.2; 3,000 kg GEO comsat; Isp 220 s (monoprop) and 300 s. Round numbers for teaching; real values vary by vehicle.
• Ion exit velocities from accelerating voltage ($v_e = \sqrt{2qV/m}$: ~38 km/s at 1,000 V) are IDEAL upper bounds; real engines reach lower Isp (propellant-utilization and beam losses) — stated as such in §20.2.
• Ion-thruster figures (Dawn/NSTAR-class: ~90 mN thrust, Isp ~3100 s) are round, representative values for teaching the thrust-efficiency tradeoff; exact values vary by operating point.
• ISRU landed-mass-to-Earth-launch-mass multiplier (~5–10, used ~7) and Mars surface-to-orbit delta-v (~4.0 km/s) in Case Study 2 are round, illustrative figures.
• ISS drag inputs in Case Study 1 (air density ~4e-12 kg/m^3, effective area ~2000 m^2, Cd ~2.2 -> ~0.5 N of drag) are representative/illustrative; upper-atmosphere density swings by ~10x over the solar cycle. The reboost thrust (~3 kN) and exhaust velocity (~2900 m/s, Isp ~300 s) are approximate Progress-class figures. The resulting ~5000-7000 kg/yr reboost propellant matches reality in order of magnitude.
• Kepler's-equation worked case: "2 hours after perigee" on the GTO, giving M = 1.1877 rad, E = 1.8771 rad, ν = 147.3° — constructed round-number timing for illustration.
• Latency "control regime" thresholds (<1 s real-time, <10 s supervised, else autonomous) in astrotools/operations.py are a teaching rule of thumb, not a formal standard.
• Launch cost figures ($/kg to LEO): Shuttle era ~$54,000; Falcon 9 ~$2,700; Starship ~$150 (a stated TARGET, not achieved). Rounded, attributed; used for the sensitivity in the checkpoint and §39.6.
• Launch-escape sizing (Apollo LES ~15 g, ~810 kN for a ~5,500 kg capsule) — order-of-magnitude figures for the Case Study 2 feasibility check.
• Loss figures (gravity loss ~1.5 km/s, drag loss ~0.1 km/s, average sin(gamma) ~0.6) are order-of-magnitude representatives; exact values depend on the pitch program and vehicle.
• Lunar night = 354 h (14.77 Earth days); 100 W and 10 kW station loads chosen for the case study.
• Lunar-base oxygen energy cost (~10 kWh/kg) in Exercise 39.20 — illustrative.
• Mars arrival distance (2.5e8 km -> ~14 min one-way light-time) is a representative landing-season value; Mars distance actually ranges ~5.5e7 to ~4e8 km.
• Mars ascent delta-v (~4–4.3 km/s), MAV dry mass (5 t), and the "gear ratios" (Mars-landing ~2, LEO-to-Mars ~2.5, pad-to-LEO ~35) in §39.2 and Case Study 2 — illustrative round numbers; the direction and order of magnitude are robust, the exact values are not.
• Mars departure hyperbolic excess velocity taken as a round v_inf = 3.0 km/s (C3 = 9.0 km^2/s^2) for illustration; the true value is date-dependent (~2.6-3.4 km/s over the synodic cycle) and is computed with launch windows in Ch. 11.
• Mars distances at "opposition" (~0.52 AU) and "conjunction" (~2.52 AU) use a circular-orbit approximation (Earth 1.000 AU, Mars 1.524 AU). Real values swing more widely because Mars's orbit is eccentric (e ~ 0.093): perihelic oppositions reach ~0.37 AU (~3 light-min one-way) and aphelic conjunctions can exceed ~2.6 AU (~22-24 light-min). Values are labeled as representative.
• MAV sizing (5 t capsule, Isp 360 s, 4.1 km/s -> ~11–12 t propellant; direct surface->Earth 6.2 km/s -> ~27 t) is a constructed Track-C design. ISRU plant throughput (~920 g/hr O2, ~115x MOXIE over 420 d) and power (~20 kWe, driving to fission) are order-of-magnitude planning estimates; the ~10 kWh/kg-O2 electrolysis figure folds in real inefficiency.
• Molniya designed with perigee 500/600/1000 km and apogee ~39,400–39,900 km, e ≈ 0.72–0.74; representative, not a specific spacecraft's elements.
• Naive flame-temperature calc (~4,700 K) uses a representative steam cp (55 J/mol·K); illustrative only.
• Numerical specifics used illustratively and labeled in-text: the Sun–Earth L1/L2 instability e-folding (~23 days); libration-point station-keeping budgets (~few m/s/yr Sun–Earth; ~20 m/s/yr Earth–Moon); the Sundman-series term count (~$10^{8{,}000{,}000}$); passive-cooling equilibrium temperatures (JWST sunward ~394 K, cold side ~40 K); Queqiao halo amplitude/period; Jupiter Trojan population estimates. Round numbers chosen for clarity; exact values need mission ephemerides / design data.
• Orion performance ranges (Isp ~2,000–6,000 s, thrust in MN, ~4,000-tonne reference ship) are study estimates from the 1958–65 program, not measured values.
• Parachute terminal-velocity example (3,000 kg capsule, 20 m chute A=314 m^2, Cd=0.5): Earth ~17 m/s, Mars ~84 m/s at surface density 0.020 kg/m^3. Cd and the ~0.008 kg/m^3 chute-deploy density (case-study-01) are illustrative; the conclusion (parachutes alone can't land on Mars) is standard and robust.
• Path efficiencies applied as clean 0.85 / 0.65 (DET-class); Li-ion specific energy 150 W·h/kg; cell efficiency 30%; array ~300 W/m² at the panel.
• Per-leg margins (5% / 10% / 15%) and the margin-by-phase table (25–30% → 0–3%) are illustrative round numbers chosen to teach the principle; real programs set them by standard and by risk.
• Recycler hardware masses (1,500 kg small system; 2,500 kg Mars-class) are illustrative round numbers chosen for the worked examples, not specific flight-hardware masses.
• Reliability model (2,000 vs. 500 Criticality-1 items; per-item reliability 0.99999 / failure 1e-5) — illustrative; the Shuttle is widely described as having thousands of Criticality-1 items, but the exact count and per-item reliability here are chosen for teaching (they reproduce a ~1–2% system loss probability consistent with the observed rate).
• Representative masses (F9-class ~350 t near max-Q; medium launcher ~200 t), $C_d \approx 0.4$–$0.5$, and the normal-force slope $C_{N\alpha} \approx 2$/rad are round order-of-magnitude values for illustration.
• Representative single-value physical inputs chosen for illustration: scale height $H=7.2\ \text{km}$ (also $7.0\ \text{km}$ in some exercises), peak-heating altitude ~60 km, speed of sound ~315 m/s there, shock-layer electron density $n_e\sim10^{17}$–$10^{18}\ \text{m}^{-3}$, air $c_p=1{,}005\ \text{J/(kg·K)}$, TNT specific energy 4.2 MJ/kg.
• Reuse cost-model figures (M, R, F for Falcon 9- and Starship-class vehicles) are round illustrative numbers chosen to reproduce the widely reported ~$2,700/kg and ~20x-vs-Shuttle results; internal costs are not public.
• Space-economy growth projection (compounding $500 B at 4/6/8%/yr) — a constructed illustration of how a projection's answer depends on its assumption.
• Spacecraft masses in worked examples (comsat dry 1,500 kg; lander dry 1,200 kg + 1,000 kg cargo; Isp 320 s chemical / 1,800 s electric) are illustrative sizing inputs, not any specific vehicle's figures.
• Spacecraft parameters used in the worked examples and case studies (moments of inertia, sunlit/frontal areas, center-of-pressure offsets, residual magnetic dipole, reaction-wheel torque/momentum ratings, and the individual pointing-budget error terms) are round, illustrative values chosen for clarity; real values vary by vehicle.
• Starship full-reuse cost aspirations (under $1,000/kg, quoted as low as ~$100/kg) are aspirational and unproven — quoted as ambition, never demonstrated performance (per Appendix H).
• Starship TMI sizing (120 t dry + 100 t payload = 220 t post-burn, Isp 380 s -> ~358 t propellant, mass ratio 2.63) uses aspirational vehicle masses; the conclusion (orbital refueling required) is robust to the exact figures. "3–5 tanker flights" is illustrative.
• Suborbital hop speed (~1.4 km/s to 100 km) uses constant-g $\sqrt{2gh}$, an idealization ignoring gravity/drag losses of the powered climb and the decrease of g with altitude.
• Suborbital peak speed ~1 km/s and delta-v ~1.5 km/s; orbital ~7.8 km/s / ~9.4 km/s — round figures for the energy/mass-ratio comparison in §39.4 and Case Study 1.
• Sun-synchronous inclination ~98 deg quoted for ~800 km altitude; the exact value follows from the J2 formula (Ch. 12). Stated as a quoted design value, not derived here.
• The "Merlin-like" engine used in the thrust-equation worked example and project checkpoint (mdot 300 kg/s, ve 2750 m/s, pe 100 kPa, Ae 0.7 m^2) is an illustrative construction chosen to reproduce Merlin's approximate SL/vac thrust; not an official spec.
• The $q\alpha$ side-force and delta-v-penalty estimates are order-of-magnitude; the exact throttle-down delta-v cost requires a trajectory integration (stated in the text).
• The 100 m × 100 m / 100 kg solar sail (index.md §21.4) is an illustrative design with round numbers chosen for clarity; the 10 g/m² areal density is an optimistic stated goal, not an achieved value.
• The Aldrin epigraph in case-study-02 (Mars "flown by, orbited, smacked into...") is a real, widely-quoted Buzz Aldrin line; exact original venue not pinned down.
• The all-electric-comsat case study (702SP class, ABS-3A / Eutelsat 115 West B, Falcon 9, March 2015, ~6–8-month spiral, two per launch, ~5,000 kg GTO capacity) is a real mission; the specific per-satellite masses and the chemical-equivalent comparison are illustrative reconstructions consistent with the chapter's sizing, not the vehicles' published figures.
• The chapter epigraph is a faithful paraphrase of Gauss's framing of the orbit-determination problem in the preface to Theoria Motus (1809), not a verified verbatim translation; attributed as a paraphrase.
• The closed-loop resupply rate (2.47 kg/crew-day), the ~140-day recycling break-even, and the storm-shelter sizing (20 g/cm² over 8–10 m² → ~1,600–2,000 kg) are constructed teaching scenarios.
• The conjunction-class Mars timeline (180 d out / 500 d surface / 180 d back ≈ 900 d) uses round numbers for legible arithmetic.
• The crewed-mission delta-v budget (TMI 3.6, TCM 0.1, Mars landing 0.6; MAV ascent 4.1, TEI 2.1 km/s) is a constructed but realistic conjunction-class budget; margins (5–20%) are illustrative per Ch. 29 practice. Rolled-up totals (~4.6 km/s Earth-launched, ~6.5 km/s Mars-made) follow from these choices.
• The Earth->Mars Hohmann numbers (v_inf 2.95/2.65 km/s, C3 ~8.7, cruise 259 days, synodic 780 days, lead angle 44 deg) are computed for idealized circular, coplanar planetary orbits at 1.000 and 1.524 AU. Real values are date-dependent and require an ephemeris (planets on elliptical, mutually inclined orbits); labeled illustrative in-text. Round r_Mars = 1.524 AU and R_Earth(mean) = 6371 km are teaching values.
• The Falcon-9-class ascent altitude–speed profiles used to locate max-Q (both the flown/throttled and the full-thrust counterfactual, and the medium-launcher profile in Case Study 2) are constructed, plausible teaching values, not telemetry from any specific flight. They were chosen to land max-Q in the realistic 30–35 kPa band near 12–16 km.
• The gimbal control-authority example (F 750 kN, delta 5 deg, L 12 m -> ~784 kN*m; 1% misalignment disturbance) is illustrative.
• The GTO apogee/GEO circular speeds ($v_a \approx 1.60$, $v_{\text{GEO}} \approx 3.07\ \text{km/s}$) are rounded from a representative 200 km × 35,786 km transfer; the resulting plane-change delta-vs (1.48/1.83/2.27 km/s) are good to ~0.01 km/s and are teaching values, not flight values.
• The guidance-cutoff example (v_go 600 m/s, F 600 kN, m 30,000 kg, ve 3,400 m/s -> 27.5 s) uses representative upper-stage figures.
• The ISS-like TLE elements in the chapter and Case Study 1 (i = 51.64 deg, e = 0.0006, n = 15.50 rev/day, M = 45 deg) are realistic illustrative values, not a specific catalog entry; exact numbers change with every element set.
• The Jupiter gravity-assist worked example (v_inf = 10 km/s, 90-deg turn, 16.4 -> 23 km/s, ~6.6 km/s boost; r_p = 350,000 km giving delta ~103 deg) uses round illustrative numbers of the right magnitude for a Jovian flyby, not a specific Voyager solution. Case-study-01's ~10 km/s actual Voyager-2 Jupiter boost is a widely-reported figure (Tier 2); the 2-D model reproduces the mechanism, not the exact value.
• The launch-impossibility estimate (~128,000 ion engines, ~294 MW, ~3,000 t of array to lift 1,200 kg) uses a round ~100 W/kg space-array specific power (Tier 3).
• The lunar-lander sizing (2 t landed mass, 1.9 km/s descent, Isp 311 s) is a constructed Track-B design example, not a specific vehicle.
• The New Horizons HGA gain (~43 dBi) and half-power beamwidth (~1.2°) are computed from $D = 2.1\ \text{m}$ at 8.4 GHz with $\eta = 0.6$, chosen to be internally consistent and diffraction-limit-consistent.
• The nuclear-electric cargo tug (Case Study 2) — power, α = 20 kg/kW, radiator temperature, and 20 km/s delta-v — is a constructed first-order design; α values in the 20–30 kg/kW range are optimistic future goals.
• The running 1 kW comsat load and its 500 km LEO orbit split (60 min sun / 35 min eclipse, rounded from the computed 58.8 / 35.8 min of a 94.6-min orbit).
• The Sagan epigraph in case-study-01 is attributed to Carl Sagan's writing on the Voyager Golden Record; exact source not pinned down.
• The scalar Kalman navigation numbers (predict 1000 m, process noise 500 m^2, radar 1090 m sigma 10 m -> K=0.9) are illustrative; the mechanism and magnitudes are faithful.
• The severity (1-4) x likelihood (1-5) scoring scale and the FMEA-lite rows are constructed for teaching; real programs use organization-specific scales (e.g., MIL-STD-882).
• The single-scale-height exponential atmosphere ($\rho_0 = 1.225$ kg/m³, $H = 8$ km) is a teaching idealization; it over-estimates density above ~20 km (notably at the ~100–140 km fairing-jettison altitudes), so those jettison altitudes err high/conservative. Flagged in the text and in Case Study 2's Engineering Reality callout.
• The tau ~ Hbeta/(rho0a*v) lifetime formula: a King-Hele-style approximation assuming a and v roughly constant over the decay and an exponential atmosphere; an order-of-magnitude "which side of the rule?" estimate, not a precision propagation.
• The thin-shell buckling relation $\sigma_{\text{cr}} \approx 0.6\,E(t/r)$ with a ~0.25 knockdown factor (Case Study 2) is an illustrative classical value; real shell-buckling analysis is subtle and configuration-specific. Flagged.
• The Tsiolkovsky epigraph ("The Earth is the cradle of humanity...") is a real, widely-attributed quotation (commonly dated to a 1911 letter); exact wording/date of the source not pinned down here.
• The Voyager-Neptune and Mars-orbiter reconstructions match historical data rates only to order of magnitude / within a factor of ~2, being sensitive to assumed noise temperature and operational margin.
• The ~$2,700/kg (Falcon 9) and ~$54,500/kg (Shuttle) headline figures are widely cited but soft; presented as Tier 2 order-of-magnitude, with the price-vs-cost and full-vs-typical-payload caveats stated in-text.
• Thermocouple degradation ~0.8%/yr (illustrative rate, design- and temperature-dependent); GPHS 300 W BOL used as a round teaching value.
• V-2 casualty figures (~9,000 killed as a weapon; ~20,000 prisoners died in production) are widely-cited estimates; sources vary. Framed as "an estimated…"/"on the order of…" throughout.
• Vacuum Isp figures (RS-25 ~452, Raptor ~360, Merlin ~348 s; methalox MAV ~355, hypergolic MAV ~320 s) are widely reported approximate values; engine reconstructions in Case Study 1 match published values to ~1–2%.
• Vehicle figures in worked examples and case studies are rounded, approximate teaching values that vary by vehicle/version/mission: Apollo CM entry mass ~5,500 kg, entry velocity ~11 km/s, nominal $\gamma_E\approx -6.5^\circ$, corridor ~1–2°, $L/D\approx0.3$, peak ~6–7 g; Shuttle tile surface ~1,260 °C, RCC ~1,650 °C, orbiter landing mass ~100 t; designed capsule mass 8,000 kg, $\beta\approx455\ \text{kg/m}^2$, TPS ~10–20% of entry mass; representative LEO peak flux ~0.5 MW/m²; blackout ~3 min.
• Vehicle/mission figures used for illustration are approximate, rounded, and vary by source and version: Falcon 9 lift-off mass ~549 t, ~490 t propellant, ~15 t to LEO (payload fraction ~2.7%); ISS ~420 t at ~420 km altitude, speed ~7.66 km/s, period ~93 min; Rocket Lab Electron ~13 t lift-off, ~300 kg to LEO (~2.3%).
• Vehicle/mission numbers used illustratively and rounded for teaching: ISS mass/area/CD and the 400 km density (hence the ~128 m/day decay); Landsat 705 km / 98.2° / 16-day-233-orbit figures (widely reported operational values); GEO comsat 3,500 kg wet mass, Isp values, and the 48/3 m/s/yr north–south/east–west split. Real values vary by vehicle, epoch, and solar activity; the 400 km air density (~3e-12 kg/m^3) is a representative moderate-activity value that can vary by ~10×.
• Worked-example numbers are illustrative/rounded: the 5 km/s chemical-vs-electric comparison (3,920 vs 185 kg), the LEO→GEO spiral (4.59 km/s) vs Hohmann (3.85 km/s), and the all-electric comsat sizing (708 kg xenon / 2,708 kg launch vs 6,693 kg / 8,693 kg) are self-consistent teaching designs, not any specific flown satellite.
• Worked-example satellite masses (2,000 kg and 3,500 kg on station), the apogee-engine $I_{sp} = 320\ \text{s}$, and the candidate vehicle $C_3$ capacities (2,300–4,000 kg to $C_3 = 8.7$) are illustrative round numbers chosen for teaching; real values vary by vehicle version, configuration, target orbit, and launch window.