This document defines the test plan and procedure for verifying the thermal insulation performance of the boattail and engine bay internals when exposed to conditions representative of engine exhaust during launch.
The goal of this test is to verify compliance with the following thermal protection and isolation requirements:
To validate that the boattail and internal components of the engine bay remain structurally and functionally unaffected by heat exposure representative of engine exhaust conditions.
To conduct a thermal exposure test (static or dynamic, e.g., with a torch or heated air jet) and evaluate whether the tested components maintain their material integrity and insulation function.
This test only covers the thermal resistance of the boattail and insulation layer under expected engine exhaust conditions (radiative and convective).
It does not include full-scale hot-fire testing, pressure testing, or mechanical load validation.
There are 3 main types of types of documents which relate to testing activities.
The purpose of this test is to verify that the boattail insulation and engine bay internals resist the thermal environment generated by the rocket engine during a hot-fire test.
This test will be performed opportunistically during a propulsion test campaign in the Testing Facility (TF). The objective is to validate thermal protection without interrupting propulsion testing.
Tested Part/Assembly:
Tested Characteristic:
Test Method:
Pass/Fail Criteria:
Test Date & Responsibilities:
This specification must be finalized and approved before the propulsion test readiness review (TRR).
The boattail test will run concurrently with a full-scale hot-fire test.
Required Tools and Instruments:
Test Location and Conditions:
Step-by-Step Process:
This procedure should be reviewed in the TF test readiness meeting, and dry-run sensor integration must be performed at least 1 week before test day.
| Term | Definition |
|---|---|
| TF | Testing Facility – EPFL Rocket Team infrastructure used for hot-fire engine testing |
| TSP | Test Specification and Procedure – Document defining the test setup, method, and criteria |
| IR Camera | Infrared Camera – Thermal imaging device to measure surface temperature distributions |
2024_C_SE_ST_ENGINE-BAY_REQ_13
Exhaust Isolation
"The engine bay internals shall be insulated from the engine's exhausts."
2024_C_SE_ST_ENGINE-BAY_REQ_14
Boattail Thermal Protection
"The boattail design shall avoid thermal damage from the engine exhaust and radiation."
The primary objective of this test is to confirm that the boattail structure and internal thermal insulation are effective in preventing thermal damage from the rocket engine's hot exhaust gases and radiant heat.
The test is considered passed if the following criteria are met:
The test is considered failed if:
| Sub-System | Part Name/ID | Type of Part | Version ID |
|---|---|---|---|
| Structure | Boattail | Flight hardware | TBD |
Note: Specific part/version IDs will be updated once manufacturing and integration are complete.
| Packed ? | Equipment | Packed in | Packed by |
|---|---|---|---|
| ☐ | Boattail assembly (integrated insulation) | Protective crate | TBA |
| ☐ | Thermocouples (Type K or T, high-temp) | Equipment case | TBA |
| ☐ | Data logger (DAQ) | Equipment case | TBA |
| ☐ | IR camera (optional) | Equipment case | TBA |
| ☐ | Fireproof cable sleeves and ties | Equipment case | TBA |
| ☐ | Fire extinguisher | TF (on-site) | TF staff |
| ☐ | Safety goggles, gloves, PPE | Personal bag | TBA |
| ☐ | Laptop for data logging and monitoring | Laptop case | TBA |
| ☐ | Flashlight and inspection camera | Equipment case | TBA |
| ☐ | Test documentation/checklist | Document folder | TBA |
The test instrumentation is designed to measure the thermal response of the boattail and engine bay insulation during exposure to engine exhaust gases.
Thermocouples (Type K, fiberglass-insulated):
Data Acquisition System:
IR Camera (optional):
All sensors will be secured using high-temperature adhesive tape or mechanical fasteners, with wiring protected by fireproof sleeves. Instrumentation setup will be validated before the engine hot-fire begins.
The test will be conducted in the EPFL Rocket Team Testing Facility (TF).
Environment:
Test Bench:
| Responsible for: | Name |
|---|---|
| Equipment Checklist, Data Gathering | TBA |
| Safety | TBA |
| Documenting/Reporting | TBA |
| Preparing the test on-site | TBA |
| Safety Concern | Probability | Impact | Severity | Mitigation | Post-Mitigation Probability | Post-Mitigation Impact | Post-Mitigation Severity |
|---|---|---|---|---|---|---|---|
| Thermocouple detachment during test | Medium | Data loss | Medium | Use high-temp adhesive and secure routing with heat sleeves | Low | Low | Low |
| Instrumentation not synchronized | Medium | Incomplete data logging | Medium | Perform full checklist + dry-run 30 min before firing | Low | Low | Low |
| Boattail not representative of flight | Low | Invalid qualification | High | Use production-equivalent layup + documented build traceability | Very Low | Low | Low |
| Safety Concern | Probability | Impact | Severity | Mitigation | Post-Mitigation Probability | Post-Mitigation Impact | Post-Mitigation Severity |
|---|---|---|---|---|---|---|---|
| Operator exposure to engine exhaust | Low | Severe burn/injury | High | Clear test zone before ignition; remote monitoring only | Very Low | Low | Low |
| Debris ejection due to boattail failure | Low | Eye/facial injury | High | IR camera at distance + physical barriers between personnel and engine | Very Low | Low | Low |
| High-temperature equipment contact post-test | Medium | Minor burn | Medium | Wait minimum 30 min before handling + use gloves and infrared check | Low | Low | Low |
| Done ? | Task | Time | Operator |
|---|---|---|---|
| ☐ | Transport boattail to TF and mount it | 30m | TBA |
| ☐ | Install thermocouples and route cabling | 30m | TBA |
| ☐ | Connect DAQ system and verify logging | 20m | TBA |
| ☐ | Review safety procedures with TF staff | 10m | TBA |
| ☐ | Verify engine firing timeline and location | 10m | TBA |
| Done ? | Step | Tool |
|---|---|---|
| ☐ | Secure boattail in mounting frame or test stand | Mounting hardware |
| ☐ | Apply thermocouples at designated zones with high-temp adhesive or tape | Thermocouples, tape |
| ☐ | Connect thermocouple cables to DAQ system and route away from hot zones | DAQ, cable sleeves |
| ☐ | Confirm sensor readouts are stable and baseline temperatures are correct | Laptop |
| ☐ | Install plexiglass shield and mark safety perimeter | Plexiglass, tape |
| ☐ | Final go/no-go check with propulsion team and safety lead | — |
| Done ? | Task | Time | Operator |
|---|---|---|---|
| ☐ | Monitor temperature readings live | 5m | TBA |
| ☐ | Record DAQ data throughout engine firing | — | TBA |
| ☐ | Visually monitor boattail integrity | — | TBA |
| ☐ | Take pictures or IR footage | — | TBA |
| Done ? | Step | Tool |
|---|---|---|
| ☐ | Start data logging on DAQ software | Laptop |
| ☐ | Observe thermocouple signals for anomalies during firing | DAQ |
| ☐ | Record visual and/or IR video of external surfaces | Camera / IR cam |
| ☐ | Log timestamp for ignition and shutoff | Logbook |
| ☐ | Wait for safe temperature drop before proceeding | Thermometer |
| Done ? | Task | Time | Operator |
|---|---|---|---|
| ☐ | Disconnect and remove thermocouples | 10m | TBA |
| ☐ | Visually inspect boattail for damage | 10m | TBA |
| ☐ | Download and backup DAQ data | 10m | TBA |
| ☐ | Clean site and remove debris | 10m | TBA |
| ☐ | Upload photos, data, and write report | 20m | TBA |
| Done ? | Step | Tool |
|---|---|---|
| ☐ | Allow structure to cool to safe handling temperature | Thermometer |
| ☐ | Detach sensors, taking care not to damage cabling | Gloves, cutters |
| ☐ | Inspect and photograph internal and external surfaces of boattail | Camera, light |
| ☐ | Fill in TR sheet and attach all visual documentation | ERT Google Drive |