Europa. Credit: NASA

GREENBELT, Md. — One day after the White House unveiled a 2015 NASA budget request that funds new designs for a robotic probe to Jupiter’s ice-covered moon Europa, space agency officials said they would be requesting ideas soon for a mission with a price tag of $1 billion or less. 

“My desire, to be quite honest, would be a … Europa mission that we could fly for a billion dollars or less,” NASA Administrator Charles Bolden said here March 5 at the American Astronautical Society’s Robert H. Goddard Memorial Symposium. “That may or may not be possible,” Bolden conceded, but it will not stop the agency from trying. 

“Something we’re going to do post-haste is put out [a request for information] for ideas,” John Grunsfeld, associate administrator for NASA’s Science Mission Directorate, said at the symposium. NASA will ask for Europa mission concepts that could be done “for around a billion dollars.” 

Grunsfeld did not say when the request for information would be released. Asked for clarification about the release date, NASA spokesman Dwayne Brown wrote in a March 6 email that it would be “soon.” NASA is “still discussing when it will be officially released,” Brown wrote.

A $1 billion price tag would appear to rule out one of the most mature Europa mission concepts developed by NASA in recent years, a flyby probe called Clipper that would cost an estimated $2.1 billion, excluding launch. That cost estimate was validated by the government-funded Aerospace Corp. of El Segundo, Calif., according to a presentation given by Clipper project manager Barry Goldstein in January at a meeting of the NASA-chartered Outer Planets Assessment Group. Clipper’s mission concept review is slated to take place by Sept. 30, Goldstein said at that meeting.

Teams at NASA’s Jet Propulsion Laboratory in California and the Johns Hopkins Applied Physics Laboratory in Laurel, Md., have been refining Clipper instrument concepts since October using about $15 million of NASA funding.

Congress appropriated $70 million and $80 million, respectively, in 2013 and 2014 for Europa mission studies. However, most of that money was not used for instrument risk reduction, which is one of the greatest hurdles for an infant mission, Curt Niebur, program scientist at NASA Headquarters in Washington, said in January at the assessment group meeting. Instead, the bulk of that money was used to refine the mission concept and draw up rough blueprints for a small but resilient Clipper spacecraft that could carry science instruments into a heavily irradiated environment. 

Although the Clipper concept nominally calls for using a nuclear battery known as a radioisotope thermo-electric generator — the Cassini Saturn orbiter and Mars Curiosity rover use these — teams were required by law to spend money studying whether the mission might instead use solar power. 

At the Goddard symposium, Grunsfeld hinted at a possible focus of a lower-cost mission to Europa, referencing the recent discovery of suspected liquid-water plumes gushing from the jovian moon’s icy surface by an astronomer using the Hubble Space Telescope. 

“Perhaps we can fly through [the plumes] with something like the Mars Organic Molecular Analyzer … and see if there’s signs of organics,” Grunsfeld said. 

The Mars Organic Molecular Analyzer is an instrument the European Space Agency plans to include on its ExoMars rover, which is tentatively slated to launch in 2018. NASA is building a mass spectrometer for the instrument at the Goddard Space Flight Center here.

In the $17.5 billion NASA budget request released March 4, the White House asked for $15 million for preformulation studies on a robotic mission to Europa. Some scientists believe Jupiter’s sixth moon may be hiding the ingredients for life — an energy source, organic materials, and a relatively warm, salty ocean — beneath an exterior ice crust estimated to be about 20 kilometers thick.


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Dan Leone is the NASA reporter for SpaceNews, where he also covers other civilian-run U.S. government space programs and a growing number of entrepreneurial space companies. He joined SpaceNews in 2011.Dan earned a bachelor's degree in public communications...