Space is not just far away — it is hostile in specific ways
A part that works flawlessly on a lab bench can fail in orbit for reasons that have nothing to do with its electrical design:
- Vacuum. Plastics outgas; volatile compounds condense on cold optics. Lubricants evaporate. Anything with trapped air can burst.
- Thermal cycling. A LEO satellite swings between roughly −150 °C and +120 °C every 90 minutes, tens of thousands of times. Solder joints crack; mismatched materials pull apart.
- Radiation. Total ionising dose degrades transistors slowly; single-event effects — a single heavy ion flipping a bit or latching up a chip — happen instantly and randomly. GEO and polar orbits are much worse than the ISS's sheltered inclination.
- Launch. Ten minutes of violent vibration and acoustic load, then the shock of stage separation.
- No repair. Whatever fails, stays failed.
"Space-qualified" means a part has been shown — by test, by analysis, or by flight heritage — to survive the specific version of that environment your mission will see.
The vocabulary
| Term | Meaning |
|---|---|
| Rad-hard | Designed and processed to tolerate radiation (typically ≥100 krad TID, latch-up immune). Expensive, slow, often a generation behind commercially. |
| Rad-tolerant | Commercial design, characterised and screened to a lower dose (say 20–50 krad). The NewSpace middle ground. |
| COTS | Commercial off-the-shelf. Not qualified by the vendor; qualified — if at all — by you, through your own testing. |
| Screening | Testing every part of a lot (burn-in, thermal cycling, X-ray) to weed out infant failures. |
| Lot traceability | Knowing which wafer, which date code, which factory. Without it, a qualification test on one batch proves nothing about the next. |
| TRL | Technology Readiness Level 1–9. TRL 9 = flown and proven in the actual environment. Investors and NASA both ask for it. |
| Flight heritage | "This exact part flew on these missions and worked." The most persuasive qualification there is — and unavailable to anything new. |
The NewSpace bet
Traditional programmes buy rad-hard everything and take five years. Constellation builders do something different: use rad-tolerant or screened COTS parts, design so a single-event upset reboots a board rather than killing a satellite, and accept some attrition across hundreds of spacecraft. A 3-year design life at a tenth of the part cost, replenished by continuous launches, beats a 15-year design life for many businesses. The trade only works if you actually fly enough units to average the risk — a one-off deep-space probe cannot make it.
What this means for procurement
Every part on a flight BOM needs a qualification story: vendor qualification data, your own test campaign, or heritage. Writing that story is often longer than the lead time — and the lead times, as the next lesson shows, are long.