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Life Investigation For Enceladus (LIFE) is a proposed astrobiology mission concept that would capture icy particles from Saturn's moon Enceladus and return them to Earth, where they could be studied in detail for signs of life such as biomolecules. The LIFE orbiter concept was proposed by Peter Tsou to NASA's Discovery Program.〔 In September 2016 NASA will announce the winner of the competition and fund its development for launch by the end of 2021. ==Mission concept== Enceladus is a small icy moon with jets or geysers of water erupting from its surface that might be connected to active hydrothermal vents at its subsurface water ocean floor,〔(Ocean Within Enceladus May Harbor Hydrothermal Activity ). March 11, 2015.〕 where the moon's ocean meets the underlying rock, a prime habitat for life. The geysers could provide easy access for sampling the moon's subsurface ocean, and if there is microbial life in it, ice particles from the sea could contain the evidence astrobiologists need to identify them. The 15-year LIFE mission would use a 'Tanpopo' aerogel collector〔 similar to the one NASA used in the ''Stardust'' sample return mission to return cometary dust in 2006. The proposed spacecraft would enter into Saturn orbit and enable multiple flybys through Enceladus's icy plumes. After spending about two years in orbit as slow as 2 km/s around Saturn,〔 LIFE would use its propulsion system to escape Saturn and begin the ~4.5 year long voyage back to Earth with the collected particles in a return capsule. The spacecraft may sample Enceladus's plume, the E ring of Saturn, and the Titan upper atmosphere.〔 In June 2015 NASA will announce a list of finalists for the current Discovery Program competition, followed by NASA's announcement of the winner in September 2016. The selected mission must launch by the end of 2021. If selected, it would have a $425 million development cost cap, and it would reach Saturn after a series of gravity assists past Venus and the Earth. Samples from Enceladus's plume would make it to Earth about 14 years later.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Life Investigation For Enceladus」の詳細全文を読む スポンサード リンク
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