Lesson 2 of 4 · Build a test that can answer the question
Build a test that can answer the question
6 minute lesson · 3 checks along the way
Your goal for this lessonConnect test articles, environments, requirements and recorded results without confusing design qualification with flight-unit acceptance.
In this lesson 3 sections · 3 checks
Read & understand
Start with the requirement and the article
General spacecraft engineering distinguishes evidence about a design from checks on a particular manufactured flight unit. Qualification addresses the design’s ability to meet specified conditions; acceptance examines the unit that will be delivered. Projects choose their own model and test strategies. The terms alone do not disclose MisrSat’s test levels or procedures.
A useful test record identifies the article, hardware and software versions, required function, environment and pass criterion. If an interface harness changes after a test, the earlier result belongs to the earlier configuration. Engineers must assess the change and determine what evidence needs to be repeated or supplemented.
Check 1 of 3
10 pointsUse the reading above. You can try again without losing points.
Read & understand
Different environments ask different questions
Thermal-vacuum testing examines behavior under controlled temperature and low-pressure conditions. Mechanical testing addresses loads such as vibration; electrical checks examine commands, power or data interfaces. A single test cannot stand in for every environment. NASA’s PACE photograph is a separate mission example of a chamber setup, not evidence of MisrSat’s facility or test conditions.
Consider a fictional sensor requirement: during each specified chamber plateau, error must remain within ±2 units. Readings of −1, +1 and +3 units fail that criterion because the last exceeds the upper limit. Averaging them into a smaller number would answer a different question and conceal a required condition that did not pass.
Check each condition against the limit
Original teaching diagram. Invented values and criteria; not actual MisrSat test levels or results.
Open full-size diagram in a new tab: Check each condition against the limitNASA’s PACE observatory and technicians inside a thermal-vacuum chamber at Goddard Space Flight Center, shown in NASA’s 6 September 2023 test report. This is general environmental-test context, not MisrSat hardware or Egypt’s AIT centre. People are present during setup, not during vacuum operation. The report date is not asserted as the photograph’s capture date.
Look closely
What can this chamber photograph show, and what requires a test report?
See what to notice
It shows PACE hardware, technicians and a chamber setup at NASA. The photograph alone does not establish temperatures, pressure, pass criteria or completed test results, and it is not an image of MisrSat or Egypt’s test centre.
Check 2 of 3
10 pointsUse the reading above. You can try again without losing points.
Read & understand
Keep the failure and its resolution in the record
In an invented campaign, 18 of 20 required checks pass and two remain unresolved. That is 90 percent passed, not permission to call the entire requirement set complete. A count also cannot show whether the two failures concern essential power control or a minor convenience. Review the requirements and consequences, not only the percentage.
The team should record the anomaly, investigate its cause, assess the correction and perform the appropriate retest. A later pass belongs alongside the earlier failure and the change that resolved it. Keeping that sequence lets another engineer understand why the accepted configuration is supported by evidence.
Check 3 of 3
10 pointsUse the reading above. You can try again without losing points.
Put it together
Your lesson progress
Each check connects to a part of the story. Complete all 3 to earn your 25-point lesson bonus.
Explore further · Optional
Go to the source
Explore the evidence behind this lesson. These optional readings and videos open in a new tab.