In as few as five manned space flights from now, the US could be sending astronauts to the moon.
But whether the round-trip moon mission comes that soon—and "soon" means at least 1968—depends on what happens in early launches of the upcoming Apollo series. The first manned Apollo flight could be as early as next month.
Summing up the nation's space effort to date and looking ahead for JAMA Medical News, medical programs chief Charles A. Berry, MD, of the US Manned Spacecraft Center noted:
"Our (Mercury and Gemini) space flights have provided approximately 2,000 manhours of weightless exposure. In general, both the environmental hazards and the effects on man appear to be of less magnitude than anticipated.
"Principal physiologic changes noted are orthostatism for some 50 hours post-flight as measured with a tilt table, reduced red cell mass (5% to 20%), and reduced x-ray density ( calcium) in the os