NASA and other space agencies have strict health standards for astronauts

The argument

This argument holds that commercial space flight should be restricted to the young and healthy because the established space agencies already operate exactly this restriction: NASA and other national space programmes impose strict health standards on astronauts, and that expert precedent should govern who is sent into space commercially. The agencies' practice reflects hard-won knowledge. Space programmes do not select crews casually; they screen candidates through rigorous medical examination and impose demanding fitness and health criteria, excluding those with cardiovascular conditions, certain chronic illnesses and other vulnerabilities. They do so because decades of spaceflight experience taught them what the human body faces — the G-forces of launch and re-entry, the cardiovascular and physiological stresses of microgravity, and the impossibility of medical rescue once in flight — and which conditions those stresses can turn lethal. The health standards are, in effect, the codified safety knowledge of the people who understand spaceflight best. The argument applies that precedent directly to the commercial case. Commercial passengers will be subjected to the same fundamental physics and the same bodily stresses as professional astronauts; the environment does not become gentler because a ticket was purchased. It would be reckless for a commercial industry to wave aboard anyone able to pay while the expert agencies, facing identical conditions, carefully screen out the unfit — and irresponsible to discard a safety standard built precisely to prevent foreseeable deaths. The sensible course is to mirror the professionals: restrict participation to those whose youth and health give a margin of safety the agencies' own criteria demand. From this standpoint, deferring to the established expert standard is simple prudence. Because NASA and other space agencies impose strict health standards on astronauts, this argument holds, commercial space flight should be available only to the young and healthy.

Premises

Counter-arguments

The analogy misreads what the agencies' standards are for. NASA screens candidates for multi-month orbital missions in which crew perform demanding work, endure prolonged microgravity, conduct spacewalks and have no possibility of medical evacuation — and it selects a handful of people from thousands of applicants, so its criteria function as competitive selection standards as much as safety thresholds. Commercial suborbital flight involves minutes of weightlessness and peak accelerations of a different order. Treating one set of requirements as the standard for the other ignores the difference in exposure. The precedent has also moved against the argument. Agencies progressively relaxed their criteria as evidence accumulated, and conditions that once excluded candidates no longer do; commercial flights have since carried passengers in their seventies and eighties and a passenger with a prosthetic leg, without the outcomes predicted here. "Young and healthy" is in any case the wrong instrument on the argument's own logic, because what the agencies actually do is individualised medical assessment against specific conditions — which admits a fit older person and excludes an unfit young one. Deference to the expert standard therefore argues for screening, not for this position. And the competing positions turn on a question the argument never reaches: who should bear the risk. An informed adult accepting a disclosed medical risk is the ordinary arrangement in other hazardous pursuits, from diving to high-altitude mountaineering.

Rejecting the premises

[Rejecting P1] Agency standards were developed for months-long orbital missions requiring demanding work, prolonged microgravity, spacewalks and no possibility of evacuation, and they double as competitive selection criteria — so they do not transfer directly to minutes of suborbital flight. [Rejecting P2] Deference to expert practice argues for individualised medical assessment rather than for this position, since assessment admits fit older people and excludes unfit young ones — and agencies have themselves relaxed criteria over time, while commercial flights have carried passengers in their seventies and eighties and a passenger with a prosthesis.