Identical twin US astronauts to serve as research subjects

CAPE CANAVERAL, FLORIDA, Aug 10:  NASA’s only identical twin astronauts are planning to serve as guinea pigs for studies investigating the genetic impacts of long-duration spaceflight. Astronaut Mark Kelly, who commanded four space shuttle missions including the final flight of Endeavour, is set to be a test subject on Earth while his twin undergoes studies in orbit. (agencies)