For many space enthusiasts, a new mission to Jupiter’s ocean moon Europa is high up on their wishlists. Yesterday, July 15, NASA announced that they are seeking proposals for science instruments for just such a mission, bringing it one step closer to reality.
In the Announcement of Opportunity, NASA states that they are looking for science instrument proposals which could help answer the question of whether there is, or was, life on this fascinating world. As John Grunsfeld, associate administrator for NASA’s Science Mission Directorate explained: “The possibility of life on Europa is a motivating force for scientists and engineers around the world. This solicitation will select instruments which may provide a big leap in our search to answer the question: are we alone in the universe?”
NASA wants science instruments which would be compatible with a spacecraft either orbiting the moon or making multiple flybys, such as the Europa Clipper. A lander or even probe into the ocean itself would still be further in the future. The mission would be part of the National Resource Council’s (NRC) Planetary Decadal Survey.
Initially, 20 proposals will be accepted in April 2015. About $25 million will then be awarded for the selectees to further advance instrument development for this stage of the process, Phase A. From these, 8 instruments will be chosen to actually be built.
There are five key science objectives for the mission, as outlined by The Decadal Survey:
• Characterize the extent of the ocean and its relation to the deeper interior
• Characterize the ice shell and any subsurface water, including their heterogeneity, and the nature of surface-ice-ocean exchange
• Determine global surface, compositions, and chemistry, especially as related to habitability
• Understand the formation of surface features, including sites of recent or current activity, identify and characterize candidate sites for future detailed exploration
• Understand Europa’s space environment and interaction with the magnetosphere.
While characterizing landing sites for future exploration is the fourth scientific priority in the Planetary Decadal Survey, NASA places high priority on this goal to enable a potential future lander mission to Europa. Current data does not provide sufficient information to identify landing sites and to design a landing system capable of safely reaching the surface. In the AO, NASA included a reconnaissance goal to characterize scientifically compelling sites, as well as hazards, for a potential future, landed mission to Europa.
“Proposals must be responsive to one or more of the five objectives,” said Curt Niebur, Outer Planets Program scientist at NASA Headquarters in Washington. “Plans could be adjusted to programmatic decisions made by NASA in the future.”
The entire Announcement of Opportunity can be viewed here.
Other mission proposals include the Jupiter Europa Orbiter (JEO), which would have had a very impressive instrument payload, but was deemed to be too expensive. The Europa Clipper, a lower-cost orbiter, and an eventual lander are still under consideration.
The original Clipper concept calls for 32 low-altitude flybys of Europa over 2.3 years, with repetitive science operations and a detailed study of global regions of Europa’s surface. The original Orbiter concept would have an orbiter spend 30 days in a 62 mile (10o km) polar orbit above Europa. The orbiter would also conduct repetitive science operations, including detailed mapping and gravity and magnetic field measurements. Probably further into the future the original Lander concept calls for a lander to spend 30 days studying the surface of Europa, as well as measurements of the surface and subsurface composition and morphology. The estimated costs for the Clipper, Orbiter, and Lander concepts are $1.98 billion, $1.7 billion, and $2.8 billion respectively. More details are available here.
The harsh radiation hitting Europa’s surface would mean that any spacecraft in that environment for a long time would require suitable protection. Also, as a matter of protocol, the spacecraft must meet strict planetary protection requirements to avoid possibly contaminating the water below the surface with earthly organisms.
There is still a lot of work to do, but a return mission to Europa now seems both doable and more likely to be implemented in the relatively near future (depending on budgets of course). Let’s go!