Famed US astronaut and politician John Glenn has said that that NASA's planned return to the Moon will be of no use to a future manned Mars mission.
"It seems to me the Moon is questionable as a way station," the former space ace and Senator told congressmen on Wednesday.
"If that's what we're doing - which I don't believe it is - but if that's what we're thinking about doing, that is enormously expensive," he added. The House Science and Technology Committee were debating NASA's first 50 years and the future challenges faced by the space agency.
In recent years NASA has laid out plans to return to manned space exploration with a vengeance, following general direction from President George Bush. In outline, America is expected to establish some form of permanently manned Moonbase, and then to send a manned mission to Mars. Spaceplane Shuttles will be replaced by Orion rocket stacks and capsules like those of Glenn's early spacefaring days.
However, the veteran spaceman said that there was no advantage to be gained by moving the personnel and equipment for a Mars mission down and then up again through the lunar gravity well. Glenn contended that it would be better and easier to assemble an interplanetary craft above Earth.
"That to me would be the cheapest way to go," he said.
Glenn himself was the first American in Earth orbit. After an early career as a Marine fighter pilot, he joined NASA's original "Mercury Seven" astronaut group (stigmatised as "spam in a can" living freight by legendary test pilot Chuck Yeager), and was first to orbit aboard a Mercury capsule in 1962.
Retiring from NASA and the Marines afterwards, Glenn became a US Senator. At the age of 77, he returned to space aboard the shuttle Discovery in 1998. This was said to have provided valuable information on the effects of microgravity on the elderly.
Glenn later criticised the Russian space agency for allowing paying space tourists to visit the International Space Station, saying that Roskosmos had done the equivalent of putting "a Greyhound station or hot dog stand on one end".
As it happens, Russia also has plans for manned travel to the Moon and Mars, so the debate over which types of people should be allowed to go - and whether or not they go to the Red Planet via the Moon - may continue.
Glenn's remarks were reported in Aviation Week. ®