Lander Requirement Traceability¶
The lander specification as a tree, what satisfies and verifies each requirement, where coverage is missing, and which checks fail.
Requirement hierarchy¶
L-1 — The lander dry mass shall not exceed 1800 kg.
L-2 — The lander shall descend under powered control to touchdown.
L-2.1 — The descent engine shall deliver at least 3000 N.
L-2.2 — The landing radar shall range the surface from 5000 m.
L-3 — The lander shall survive touchdown at 2 m/s.
L-3.1 — Each landing leg shall absorb 0.3 m of stroke.
L-3.2 — The lander shall not tip over on a 15 degree slope.
L-4 — The lander shall transmit a recovery beacon after landing.
Traceability matrix¶
Every requirement with its satisfiers and verifiers
| shortName | name | satisfiedBy | verifiedBy |
|---|---|---|---|
| L-1 | mass | lander | weighLander |
| L-2 | descent | ||
| L-2.1 | thrust | engine | hotFire |
| L-2.2 | altimetry | radar | radarRangeTest |
| L-3 | touchdown | ||
| L-3.1 | legStroke | leg | dropTest |
| L-3.2 | tipOver | ||
| L-4 | beacon | transponder |
Coverage gaps¶
Requirements no part satisfies
| shortName | name |
|---|---|
| L-2 | descent |
| L-3 | touchdown |
| L-3.2 | tipOver |
Requirements no case verifies
| shortName | name |
|---|---|
| L-2 | descent |
| L-3 | touchdown |
| L-3.2 | tipOver |
| L-4 | beacon |
Requirements with a gap of either kind
| shortName | name |
|---|---|
| L-2 | descent |
| L-3 | touchdown |
| L-3.2 | tipOver |
| L-4 | beacon |
Requirements satisfied but never verified
| shortName | name |
|---|---|
| L-4 | beacon |
Verdicts¶
Every check of the lander against its requirements
| kind | name | path | verdict |
|---|---|---|---|
| satisfaction | LanderHierarchy::lander | holds | |
| verification | weighLander | LanderHierarchy::lander | holds |
| satisfaction | LanderHierarchy::lander.propulsion.engine | violated | |
| verification | hotFire | LanderHierarchy::lander.propulsion.engine | violated |
| satisfaction | LanderHierarchy::lander.gear.leg | holds | |
| verification | dropTest | LanderHierarchy::lander.gear.leg | holds |
| satisfaction | LanderHierarchy::lander.avionics.radar | holds | |
| verification | radarRangeTest | LanderHierarchy::lander.avionics.radar | holds |
| satisfaction | LanderHierarchy::lander.avionics.transponder | undecided |
Checks that came out false
| kind | name | path | condition |
|---|---|---|---|
| satisfaction | LanderHierarchy::lander.propulsion.engine | engine.thrust >= 3000.0 | |
| verification | hotFire | LanderHierarchy::lander.propulsion.engine |