Recent letters about cranky lighthouse keepers suggest that long space trips may prove psychologically impractical (5 March, p 33). Could a possible solution be a female-only crew? With a few notable exceptions, women generally coexist with less friction than men. They also appear to use less oxygen - for instance, women use 30 to 50 per cent less air than men when diving. For really long interstellar trips, they could also reproduce to maintain crew numbers.
With these advantages it seems odd that such an obvious resource is often dismissed, as illustrated by the quote from the Chinese spacecraft designer (12 March, p 8). Or could it be that women see the futility of Mars trips, and allow deluded male flight planners to skirt the issue?