Nasa mulling over proposals for jupiter icy moons orbiter

NASA's Jet Propulsion Laboratory is evaluating industry proposals for the preliminary design of the Jupiter Icy Moons Orbiter (JIMO) spacecraft, in anticipation of awarding a contract by October, Aerospace Daily said.

Teams led by Boeing, Lockheed Martin and Northrop Grumman submitted their final proposals last month, according to Ray Taylor, acting director for Project Prometheus at NASA's Office of Exploration Systems. In collaboration with JPL, the winning team will create a preliminary design for the spacecraft, which NASA plans to launch sometime next decade.

JIMO will be the first flight demonstration of the space nuclear power and propulsion technology being developed under Project Prometheus. Such technology is essential to in-depth study of the outer planets, according to NASA, where solar power is of little use, Aerospace Daily said.

Using ion-electric thrusters powered by the heat from an onboard nuclear fission reactor, JIMO would orbit Jupiter's three icy moons in succession, investigating their composition, history and potential for sustaining life. NASA's earlier Galileo mission found evidence that these moons may feature subsurface oceans, making them prime targets for science.

After launch no earlier than 2011, JIMO would cruise to the Jovian system under steady but slow acceleration from its electric thrusters. The spacecraft then would orbit Callisto for at least 60 days, then move on to orbit Ganymede for at least 120 days, and finally orbit Europa for at least 30 days. NASA also is considering the possibility of a Europa lander that would be deployed by JIMO. At the end of its mission, the spacecraft would enter a "quarantine orbit" and not return to Earth.