¶ Introduction
¶ Purpose, Objective and Scope
This document aims to give a detailed and complete overview of the testing procedure used to qualify the separation mechanism of the Firehorn I vehicle.
The document should provide the reader with an accurate depiction of the tests undergone by each part of the separation mechanism, allowing for easy repeatability.
The document will cover the following parts of the separation mechanism: rings, clamp band (bands and clamp), M3 screws, and pyrocutters.
The M2.5 screws along the band will not be covered as they are non-structural components (their purpose is to allow appropriate alignment of the clamp-ring interface during assembly).
Environment-related testing will be overviewed in a separate environment-specific TSP, linked here and below.
The document will therefore inform the reader of the multiple steps followed, as well as the criteria of Success and Failure.
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¶ Test Documentation
This document is a qualification TSP
The main objective of the qualification stage is to demonstrate that the design meets all the specified requirements.
This stage starts after the Preliminary Design Review (PDR) and ends with the Qualification Review (QR).
The question we are trying to answer in the QR is: Should we redesign this part?
¶ TSP
-
Test specification section explains:
- What part/assembly is being tested during each test.
- What characteristic is being tested.
- Brief description as to how the test is goind to be conducted.
- Explains the Pass/Fail criteria for each step.
- Explains when the test is due to happen and who will be involved in the test.
-
Document should be prepared after the baseline AI&T and ~1 month before the actual test.
-
Test procedure serves as a detailed plan for each individual test, it contains (among other things):
- A list of tools and instrument needed for the test.
- A description of the test location and condition.
- A step by step procedure of what needs to be done before, during and after the test.
-
Document should be prepared after the test specification and at least ~1 week before the actual test.
¶ Applicable and Reference Documents
- 2024_C_ST_SEPARATION_MECHANISM_DDF
- 2024_C_ST_SEPARATION_MECHANISM_DJF
- 2025_C_ST_SEPARATION_MECHANISM_ENVIRONMENT_TSP
- General Requirements List
¶ Requirements to be verified
The Type 1 Requirements are the most important. The Type 2 are validated if the Type 1 are verified.
- 2024_C_SE_ST_SEPARATION-MECHANISM_REQ_02 Interference with RE
The Separation Mechanism shall not interfere in any way with the deployment of the RE systems. - 2024_C_SE_ST_SEPARATION-MECHANISM_REQ_03 Diameter reduction
The Separation Mechanism shall result in a free internal diameter larger than [200]mm. - 2024_C_SE_ST_SEPARATION-MECHANISM_REQ_04 Deployment time
The Separation Mechanism shall deploy in less than [3]s. - 2024_C_SE_ST_SEPARATION-MECHANISM_REQ_05 Assembly time
The assembly of the Separation Mechanism shall take less than [15]min. - 2024_C_SE_ST_SEPARATION-MECHANISM_REQ_06Repair costs
After it has been used, it shall cost less than [20]CHF to repair the Separation Mechanism - 2024_C_SE_ST_SEPARATION-MECHANISM_REQ_07 Load case
The Separation Mechanism shall withstand a bending moment of [3000]Nm around an axis perpendicular to the main LV axis.
- 2024_C_SE_ST_SEPARATION-MECHANISM_REQ_01Separation mechanism declaration of purpose
The Separation Mechanism shall allow the LV to separate and deploy a drogue parachute or a reefed parachute at apogee.
¶ Test Specification
¶ Open issue, Assumption and Constraint
- Issue with time and location availability.
- Have all hardware components available and assembled per latest designs.
- M2.5 screws along the band excluded from testing (non-structural).
- Environmental testing handled separately; this test focuses on mechanical and functional qualification of rings, clamp band, M3 screws, pyrocutters.
¶ Test Description
- Verify mechanical strength, deployment time, assembly constraints of separation mechanism components.
- Perform mechanical load application tests on rings and clamp band.
- Functional tests for pyrocutters firing and activation.
- Verify screw integrity under load.
- Use instrumented setups to measure forces and timing.
- Test in sepcific explosion-proof lab with full separation mechanism assembly.
- Tools: torque wrenches, camera, safety gear for pyrotechnics.
¶ Test Requirements
- Verify compliance with Type 1 requirements:
- Repair cost under CHF20.
- Deployment time under 3 seconds.
- Set-up time under 15 minutes.
- Calibrate test setups and instruments for accuracy.
- Tests must be repeatable and fully documented.
¶ Test Sequence
- No constraints on test activity order.
- Components can be tested independently.
- Pyrocutters tested after mechanical integrity verification.
¶ Pass/Fail Criteria
- Record assembly times and repair costs.
- Any deviation requires redesign.
| Criteria | Importance | Description |
|---|---|---|
| Rings and clamp band integrity | Mandatory | No permanent deformation or failure under bending loads |
| Effective M3 screw component destruction | Mandatory | M3 screw must be separated to allow sepmech functionnality |
| Sepmech activation delay | Mandatory | The mechanism must activate in less than 3s |
| Sepmech setup time | Important | The mechanism should be assembled in less than 15 min in order to maximise efficiency on launch day |
| Sepmech repair cost | Important | The mechanism should be repairable for less than 20 CHF |
¶ Test Organisation
- Team includes structure engineers (mechanical tests), systems engineers (pyrocutters), safety officers (pyrotechnics). If qualified correctly, one person can take up multiple roles.
- Testing scheduled ~1 month in advance, and always should be validated by TL/SE.
- Safety and correct procedure are not to be underestimated. Full and thorough preparation must be realised to ensure smooth unfolding of test events.
¶ Test Procedure
¶ Item Under Test
- Primarily flight hardware versions.
- Prototype hardware (3D printed) can be used for intermediate design validation if needed, or if flight hardware version cannot be used. It must be noted that validation of this test with 3D-printed parts does not validate it with flight hardware. A flight hardware test must be conducted.
¶ Test Set-up
- Mechanical fixtures for holding sepmech in place.
- Torque measurement tools for screws.
- Dedicated firing bunker for pyrocutters.
- Slow-motion cameras for data capture.
¶ Test Equipment Checklist
| Packed ? | Equipment | Packed in | Found in |
|---|---|---|---|
| Torque wrench | Structure Case | Stock 3 / Maker Space | |
| Slow-mo camera / phone | - | Your pocket... | |
| Pyro firing setup | Safe Box in Structure case | Stock 3 / Maker Space | |
| Safety gear | Multiple entities | Multiple entities |
¶ Test Instrumentation Description
- Torque wrenches with ±1% accuracy for screw torque.
- Slo-mo timer (smartphone or camera) for pyrocutters ignition and sepmech timing.
- Secure mounting on test fixtures for reliable data acquisition.
¶ Test Location and Conditions
- Structural test lab (eg. MakerSpace Renens BUNKER facility).
- Ambient lab temperature (~20–25°C), no environmental controls.
¶ Participants
| Responsible for: | Name |
|---|---|
| Equipment Checklist | Emma |
| Data Gathering | Jules |
| Safety | Jules |
| Documenting/Reporting | Emma |
| Preparing the test on-site | Emma / Jules |
¶ Test Safety
¶ Main Risks
| Safety Concern | Probability | Impact | Severity | Mitigation | Post-Mitigation Probability | Post-Mitigation Impact | Post-Mitigation Severity |
|---|---|---|---|---|---|---|---|
| Equipment damage during high load | Medium | High | High | Use calibrated instruments; conduct tests within specs | Low | Medium | Medium |
| Data loss or corruption | Low | Low - Medium | Low - Medium | Regular backups and redundant instrumentation | Very Low | Low | Low |
| Mis-timed pyro firing | Low | Low | Low | Strict pyrotechnic safety protocols and training | Very Low | Low | Low |
¶ Main Hazards
| Safety Concern | Probability | Impact | Severity | Mitigation | Post-Mitigation Probability | Post-Mitigation Impact | Post-Mitigation Severity |
|---|---|---|---|---|---|---|---|
| Pyrotechnic ignition hazards | Low | Critical | Critical | Pyrotechnic safety training, remote firing setup | Very Low | High | High |
| Mechanical injury during test setup | Very Low | Low | Low | Use PPE, clear communication, secure fixtures | Low | Low | Low |
| Electrical hazards from instrumentation | Low | Medium | Medium | Proper grounding, inspection of electrical connections | Very Low | Low | Low |
¶ Tasks and Step-by-Step Procedure
¶ Before Test
¶ Tasks
| Done ? | Task | Time | Operator |
|---|---|---|---|
| Sepmech components verification and instruments setup | 2m | Jules | |
| Setup sepmech assembly (with SepMech ASP document) | 10m | Jules, Emma |
¶ Step-by-step procedure
| Done ? | Step | Tool |
|---|---|---|
| Confirm individual component numbers | Documentation | |
| Calibrate torque wrench and camera | Calibration Kit | |
| Assemble SepMech according to ASP details (assemble both clamp bands, then fasten Upper and Lower rings). Ensure M3 screws are torqued up to specifications (1.75 N.m). | Assembly tools, torque wrench | |
| Assemble mechanism on a test rig capable of handling pyrocutter recoil | Assembly tools | |
| Set up pyrotechnic firing system with remote control or battery (intermediate test), or with the Avionics triggering system | Firing system | |
| Conduct safety briefing and hazard review | Safety docs |
¶ During Test
¶ Tasks
| Done ? | Task | Time | Operator |
|---|---|---|---|
| Vacate the area of testing | Variable | Emma and Jules | |
| Fire pyrocutters and record deployment timing | Variable | Emma/Jules | |
| Monitor data acquisition and safety | Entire test | Emma/Jules |
¶ Step-by-step procedure
| Done ? | Step | Tool |
|---|---|---|
| Trigger pyrocutters via remote firing system | Pyro firing setup | |
| Record deployment time and confirm diameter clearance | High-speed timer | |
| Repeat tests as required according to test matrix | All |
¶ After Test
¶ Tasks
| Done ? | Task | Time | Operator |
|---|---|---|---|
| Safely disassemble test setup | 10m | Emma/Jules | |
| Archive test data and instrumentation logs | 5m | Emma/Jules | |
| Inspect hardware for damage or wear | 15m | Emma/Jules |
¶ Step-by-step procedure
| Done ? | Step | Tool |
|---|---|---|
| Power down and secure all pyrotechnic equipment | Firing system | |
| Remove hardware components carefully from test rigs | Assembly tools | |
| Upload and backup measurement data to central repository | Computer | |
| Perform visual inspection and document any anomalies | Documentation | |
| Store hardware according to handling protocols | Storage boxes |