It's a severe challenge for mid-long term space flight to assure astronauts in sound body and mind and have good working capability.

随着载人飞行逐渐进展，保障航天员在航天中的身心健康和良好的工作能力是中长期飞行最严峻的挑战。

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And NASA is also being called on to develop new technologies to solve problems involved in long-term space flight for humans and robots.

VOA: special.2010.04.28

Also on board is a new exercise machine, which is part of ongoing studies into the effects of long-term space flight on muscle and bone loss in astronauts.

VOA: standard.2010.04.05

Most impressively, it has helped construct an orbiting laboratory that offers the prospect of long-term research into the effects of space flight, research that can not just improve the health and safety of our astronauts but also of people on Earth.

CNN: Commentary: Let's aim for Mars