Astronauts could not survive the trip

The argument

Apollo missions so far have been the only manned mission beyond Earth low orbit. In order to reach Moon space-ships had to cross Van Allen belts. The crossing could have been lethal, or at least would have permanently damaged the astronauts. Most astronauts did not develop health problems later on that could be related to that.

Context

There is evidence that outer space radiation would have severely affected the astronauts

Premises

Counter-arguments

The level of radiation of the Van Allen belts can be crossed with proper shielding. Most probes and satellites do this on a regular basis.

Rejecting the premises

[Rejecting P1] The premise misstates the hazard. The Van Allen belts are regions of trapped particles rather than a uniform barrier, and the Apollo trajectories were deliberately plotted to pass through their thinner edges at high speed, giving roughly an hour of transit through the intense region. Combined with the shielding of the spacecraft structure, the resulting exposure was small — total mission doses were of the order of a chest X-ray series rather than anything lethal. The counter-argument on record makes the same point by noting that probes and satellites cross the belts routinely. [Rejecting P2] This premise defeats the argument rather than supporting it. If crossing the belts would have been lethal or permanently damaging, and the astronauts show no such damage, the straightforward conclusion is that the crossing was survivable and the premise about lethality is false. The argument instead preserves the false premise and discards the missions. [Rejecting P3] The reasoning is also unfalsifiable as constructed: any evidence of astronaut health is read as proof the trip did not happen, and evidence of harm would presumably be read as proof of the danger. No observation is allowed to count against the conclusion. [Rejecting C] Independent evidence not controlled by the agency settles the matter in any case. Retroreflectors placed at three landing sites are still used by observatories in several countries for laser ranging to the Moon; the returned samples have been analysed by laboratories worldwide and are unlike terrestrial rock; Soviet tracking followed the missions in real time during a period of intense competition; and later lunar orbiters have imaged the landing sites, descent stages and surface tracks.