Self-Assessment Quiz: Capstone — Your Complete Space Mission

Twenty questions spanning the whole book, framed through the four worked tracks and the Mission Design Review. This is your final self-check: aim for 17 or more, and treat any miss as a pointer back to the chapter it came from. Use $g_0 = 9.81\ \text{m/s}^2$.

Question 1

A Mission Design Review (MDR) primarily confirms that:

A) the spacecraft is built and tested B) the design closes — its budgets are consistent, sized, and margined C) the launch vehicle is fueled D) the science is publishable

Question 2

The "spine" of an MDR — the load-bearing chain — runs:

A) cost → orbit → mass → objective B) objective → orbit → delta-v budget → propulsion → mass → launch vehicle → cost C) launch vehicle → spacecraft → orbit → objective D) power → thermal → comms → GN&C

Question 3

The comsat (Track A) and lunar lander (Track B) use the same $I_{sp}=320\ \text{s}$ engine but have mass ratios 2.38 and 6.72. The difference is entirely due to:

A) different dry masses B) different delta-v budgets, which sit in the exponent C) different launch vehicles D) different orbits' gravity

Question 4

The comsat's plane change is folded into the apogee (GEO) burn because a plane change costs $\Delta v = 2v\sin(\Delta i/2)$, which is:

A) independent of speed B) proportional to orbital speed, so cheaper where the satellite is slow (GEO) C) cheaper in LEO where the satellite is fast D) always 2 km/s

Question 5

Why is electric propulsion mandatory (not just attractive) for the asteroid probe (Track D)?

A) ion engines are cheaper B) the ~5,300 m/s budget at chemical $I_{sp}$ needs ~20× more propellant, busting the mass budget C) the asteroid has no atmosphere D) xenon is lighter than kerosene

Question 6

For the Mars orbiter (Track C), aerobraking replaced ~1.2 km/s of propulsive orbit-lowering with aerodynamics. The mission paid for that saving in:

A) nothing — it is free B) time (months of atmospheric passes) and risk C) extra launch mass D) a bigger launch vehicle

Question 7

The Mars launch window opens only every ~26 months because that is the:

A) transfer time B) synodic period of Earth and Mars C) Martian year D) time to aerobrake

Question 8

A round-trip (sample-return) mission cannot be sized with a single rocket-equation call because:

A) the rocket equation does not apply to returns B) each stage's wet mass is the next stage's payload, so you must size the stages in sequence (onion) C) Earth re-entry needs delta-v D) the Moon has no atmosphere

Question 9

Bringing home a 200 kg capsule from the lunar surface required ~9,300 kg in LEO — a 46:1 ratio — because:

A) the capsule is heavy B) return propellant is payload that must be carried, landed, and only then burned, compounding the tyranny C) the launch vehicle is inefficient D) lunar gravity is stronger than Earth's

Question 10

Earth re-entry contributed 0 m/s to the sample-return budget because:

A) it was forgotten B) the descent is aerodynamic, paid with a heat shield, not propellant C) Earth has no atmosphere D) the capsule uses electric propulsion

Question 11

A Mars orbit-insertion burn is computed from the arrival hyperbola as:

A) $v_\infty$ alone B) $v_{\text{hyp}} = \sqrt{v_\infty^2 + 2\mu/r}$, minus the target orbit's speed C) the circular speed alone D) escape velocity plus $v_\infty$

Question 12

In defending a design, a review board most wants to hear, first:

A) the spacecraft's paint scheme B) the driving requirement C) the software architecture D) the launch date

Question 13

The single most dangerous sentence in mission design, per the chapter, is closest to:

A) "let's add margin" B) "cut the margin to the computed budget to save mass" C) "run a trade study" D) "check the units"

Question 14

Two all-electric comsats fit on one Falcon 9 (and two chemical ones do not) because the electric version's wet mass is:

A) the same B) about half, since higher $I_{sp}$ collapses the mass ratio toward 1 C) larger D) irrelevant to launch

Question 15 (True/False, justify)

"Because the returned sample is only ~1 kg, a lunar sample-return vehicle can be small." True or false? Justify in one sentence.

Question 16 (True/False, justify)

"The delta-v budget is the master constraint because it is the largest number in the design." True or false? Explain.

Question 17 (True/False, justify)

"A flaw found at the MDR is a failure of the design team." True or false? Say why the chapter calls it the best possible outcome.

Question 18 (Short answer)

Name the "survival strategy" the rocket equation forced on each of the four tracks (A, B, C, D).

Question 19 (Short answer)

A spacecraft must provide 2,726 m/s with $I_{sp}=320\ \text{s}$ to a 1,500 kg dry mass. Compute its exhaust velocity, mass ratio, and wet mass (show the steps).

Question 20 (Short answer)

In two or three sentences, explain how a mission's "route across the delta-v map" becomes the single number that sizes its vehicle, and why an error in that number is amplified into the mass and cost.

Answer Key

Topics to review by question