The phrase "astronaut required" is correct and usable in written English.
It can be used in contexts such as job postings, advertisements, or any situation where there is a need for an astronaut.
Example: "We are looking for a qualified candidate to fill the position of astronaut required for our upcoming space mission."
Alternatives: "astronaut needed" or "astronaut sought".
It was also only the second time that the space station would have been unmanned, because both astronauts were required to go outside for repairs.
While NASA estimated that each astronaut would require 32 liters per day, the FMARS crew, instituting strict rules for water use, got it down to closer to 12 liters per day per person.
Getting into the astronaut core requires enormous dedication and drive, and candidates are selected from a huge pool of highly qualified people.
Although it is still expected that the lunar version of Orion will still be able to orbit the moon untended while it's crew descend to the surface, it is likely that at least one astronaut will be required to bring the capsule back to Earth from space.
To add astronauts would require significant work and rejiggering.
Also in March 2008 shuttle astronauts brought the Canadian robot Dextre, which was so sophisticated that it would be able to perform tasks that previously would have required astronauts to make space walks, and the first part of Kibo.
Astronauts are now required to conduct routine water checks inside their helmets during spacewalks.
Space agencies are concerned with this issue because in order to send humans farther out into the solar system, like to Mars for example, astronauts will be required to survive long journeys floating inside their spacecraft.
Methods for rapidly assessing astronaut exposure are therefore required.
At the time Nasa required all astronauts to be test pilots, which was something no woman was allowed to do.
