The National Aeronautics and Space Administration on Monday published a Request for Information (RFI) seeking ideas for low-cost missions to explore one of Jupiter’s moons. Europa is interesting to scientists because there is evidence of liquid water beneath a thick layer of ice.
John Grunsfeld, associate administrator for the NASA Science Mission Directorate, called the RFI an opportunity to hear from creative outsiders who can help NASA do the most for the least cost. Europa, he said, is one of the most interesting places to search for life beyond Earth. The drive to explore Europa has spurred curiosity and ingenious thinking by scientists and engineers.
NASA has studied a number of possible Europa missions, and is now funding development of some technologies that science instruments built for exploring Europa would require. Congress approved $80 million dollars for this work, for Fiscal Year 2014. NASA’s 2015 budget request includes an additional $15 million.
Previous scientific research suggests that Europa has a liquid ocean under a thick crust of ice. The ocean probably encircles the moon and contains more water than all of Earth’s oceans. This new NASA effort seems ideas for a Europa mission aimed primarily, though not exclusively, at learning more about that subsurface ocean.
The RFI focuses on concepts that cost less than $1 billion, not counting the cost of the launch vehicle. Each concept has to meet most or all of the scientific priorities mentioned in the 2011 Planetary Science Decadal Survey, a report from the National Research Council.
The Decadal Survey designated a mission to Europa as one of the highest priorities for NASA in the coming years. The document lists five specific objectives for research on Europa. The Europa mission would characterize the extent of the ocean, study the crust and subsurface water, determine surface composition and chemistry, characterize the moon’s immediate space environment, and study the formation of surface features.
While Europa and Jupiter’s other moons have been visited by spacecraft on several occasions, the visits have been restricted to quick flyby investigations. NASA’s Galileo spacecraft, launched in 1989, passed close to Europa more than a dozen times. The Galileo spacecraft, which reached Jupiter in 1995, found “strong evidence” of a liquid ocean under Europa’s surface. This fact increases the odds that life or some sort could exist under the moon’s icy crust.
In 2011, NASA’s Hubble Space Telescope detected water vapor above Europa’s south pole. That observation suggested that plumes of water vapor were erupting from the surface, though this possibility still needs to be analyzed.
Missions to Europa will need to be designed to cope with not only the harsh environment of space, but to protect Europa’s environment from contamination. High radiation near Jupiter will require special protective measures. Landers would need to meet numerous requirements intended to protect Europa’s ocean from contamination including the introduction of terrestrial microorganisms.
Icy moons like Europa may be common in the universe, as astronomers have discovered many Jupiter-like planets orbiting other stars. Other moons in our own solar system also seem to have liquid water under the surface. Saturn’s tiny moon Enceladus appears to have a partial ocean of water under a thick crust of ice.
Proposals will be accepted through May 30, 2014. This is just a request for information, not a solicitation of products or services.
The potential of a mission to explore Europa in depth is part of NASA’s long-term exploration plans. Now, the agency wants to recruit creative outsiders to generate mission ideas.
By Chester Davis
NASA Jet Propulsion Laboratory