Student rocket group shatters amateur space record
A USC student rocketry team has reportedly set a new amateur altitude record, sending a solid-fuel, carbon-fiber rocket to about 143 km, well above the Kármán line that informally marks the edge of space. Commenters contrast this “amateur” achievement with professional and government-backed launch capabilities, examining factors like funding, university infrastructure, knowledge transfer, and regulatory limits from the FAA and ITAR. The thread also dives into unit systems and engineering details—such as the use of metric vs U.S. customary units, mass vs force in “pounds,” and the practical challenges of high‑Mach flight and recovery in amateur rocketry.
Measurement Units and Conversions
- Long tangent on units: people convert the rocket specs to metric, then joke with absurd units (parsecs/sec, light‑years, etc.).
- Debate over whether “pounds” are mass or force; clarification that both pound-mass and pound-force exist and context matters.
- Several note SI’s clarity (kilogram vs newton) and criticize over-precise conversions (too many significant figures).
- Distinction between US customary vs British imperial systems is emphasized; examples from UK, Canada, NZ of mixed-unit everyday use (stones, ounces, PSI, feet/inches, etc.).
- Note that displays (TVs) and aerospace hardware are engineered in metric even if marketed or displayed in inches/feet.
US Space Dominance, History, and Units in NASA
- Argument that US “dominance” in space comes from post‑WW2 position and massive ICBM/Cold War spending, not imperial units.
- Counterpoints about periods where US human launch capability relied on Soyuz, and about strong non‑US contributions (e.g., Germany pre‑WW2, ESA, others).
- Discussion of Wernher von Braun’s influence and the V2 → Saturn V lineage.
- Disagreement over whether Apollo was primarily imperial or metric internally; one cited source claims AGC computed in metric but displayed imperial.
Student vs Amateur vs Civilian Rockets
- Original question: why can’t a determined civilian group “beat” the student team?
- Answers: money, materials, tooling, and especially experience and iteration are the main constraints, not legality.
- USC’s advantage is long-running institutional support, sponsors, in‑house composite solid motors, and strong documentation/knowledge transfer.
- College teams offer a rare mix of time, talent, motivation, and university resources that is hard to replicate in adult hobby groups.
- Distinction drawn between “amateur,” “civilian,” and government/contractor rockets; some skepticism that “first civilian” is an accurate label.
Regulation and Safety
- FAA requires waivers above 18,000 ft and defines “amateur rocket” (suborbital, under 150 km, impulse limit, no humans).
- High‑altitude launches use remote sites like Black Rock Desert; clubs and events (e.g., BALLS, FAR) provide structured environments and standing clearances.
- Motor suppliers and hobby orgs self‑regulate via certification and hazmat rules.
- ITAR/export‑control concerns mean experts and YouTubers sometimes avoid giving fully detailed “how‑to” guidance.
Technical Difficulty and Orbital Mechanics
- Clarifications: record altitude ~143 km; far above aircraft but much below orbital regimes.
- Multiple comments explain that orbit is about achieving ~7.5–8 km/s horizontal velocity, not just height; geostationary orbit is far higher and faster.
- Going Mach 5+ in dense atmosphere is described as exceptionally hard without the rocket disintegrating; solid motors, heating, guidance, and recovery are all nontrivial.
- Educational value of working through the full design–build–test cycle is repeatedly highlighted.