Which launch option delivers first science on time?
You plan the first science report for the fictional Kestrel Survey mission.
The question
The stakeholder needs a validated report by the end of day 10 and prefers earlier. Readiness takes 3 elapsed days after launch. A spacecraft ready on an observation day can use that window. Validation takes 1 elapsed day after observation.
| Launch day | Observation days | |
|---|---|---|
| Option A | 1 | 5 and 10 |
| Option B | 4 | 8 |
The two options have different observation calendars. All days are relative to this fictional project.
“Recommend the option that can deliver first science and explain the timeline to the mission lead.”
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A strong answer, step by step
Open each step in turn. This is one strong answer, not the only one.
Step 1: Which milestone matters?
What would you do here? Open the move you’d make.
Compare the launch days alone
Tempting, but it misses something. Earlier launch does not by itself establish when a report is ready.
Compare the first listed observation days alone
Tempting, but it misses something. The spacecraft has to be ready by its observation day.
Compare dates for the validated report
The strong move. The report is the stated stakeholder deliverable.
See how a strong candidate says it
“The deadline is for the validated report. I would calculate readiness, find the first observation it can use, and add the validation day.”
Why it works: Launch, first observation and report delivery are different milestones.
Step 2: Which option would you choose?
What would you do here? Open the move you’d make.
Choose A because the report is ready on day 6
The strong move. A reports three days earlier and meets the deadline.
Choose B because its launch day is closer to the deadline
Tempting, but it misses something. The stakeholder prefers an earlier validated report.
Treat A and B as equivalent
Tempting, but it misses something. Both meet the deadline, but A delivers earlier.
See how a strong candidate says it
“A is ready on day 4, observes on day 5 and reports on day 6. B is ready on day 7, observes on day 8 and reports on day 9. Both meet the deadline and A reports first.”
Why it works: With both original schedules feasible, earlier report delivery decides the choice.
Step 3: Which option still meets the deadline?
Option A’s launch moves to day 4. Its observation days stay at 5 and 10. Option B’s schedule is unchanged.
What would you do here? Open the move you’d make.
Keep A and report on its day 10 observation
Tempting, but it misses something. The report needs another day for validation.
Recommend B because it still reports on day 9
The strong move. B meets the day 10 deadline and A now misses it.
Keep A because both options now launch on the same day
Tempting, but it misses something. The options still have different observation days.
See how a strong candidate says it
“A now becomes ready on day 7. It misses day 5 and uses day 10, so the report arrives on day 11. B still reports on day 9. I would recommend B.”
Why it works: The slip changes which observation A can use. Equal launch days do not make the observation calendars equal.
Step 4: How do you hand off the change?
What would you do here? Open the move you’d make.
Send the revised launch date and let the science lead infer the rest
Tempting, but it misses something. The lead still needs the observation and report dates.
State the new sequence, owner and fallback
The strong move. This makes the chosen plan and the missed-deadline fallback explicit.
Call the fallback on time because observation occurs on day 10
Tempting, but it misses something. Observation is a day earlier than the validated report.
See how a strong candidate says it
“Ask the mission lead to confirm B and give the science lead the day 7 readiness, day 8 observation and day 9 report. If B becomes unavailable, flag A’s day 11 as a missed deadline.”
Why it works: The people who approve the plan and need the report can see which dates support it.
The answer, in short
- Decision
- Confirm option B with the mission lead and give the science lead a day 9 report plan.
- Because
- The revised A schedule misses the earlier observation and yields a day 11 report.
- What would change it
- An approved earlier observation for A after readiness could restore its ability to meet the deadline.
Common traps
- Confuse a launch date with delivery.
- Use a window before the spacecraft is ready.
- Forget the validation day.
Check your answer
- Did I calculate to the date the stakeholder needs?
- Did I compare both original schedules?
- Did I recompute the next feasible observation after the slip?
- Did I identify who confirms the plan and what the fallback delivers?
Last reviewed Nov 11, 2026