WASHINGTON โ€” NASA expects to contribute up to $1.5 billion to a 2018 Mars mission with the European Space Agency (ESA) provided the two sides can agree on a plan to drill the martian surface and collect samples with a single combined rover instead of the previously envisioned pair.

Jim Green, director of NASAโ€™s Planetary Science Division, said ESA member states are expected to decide by late May whether to proceed with a new mission concept that would combine science objectives planned for NASAโ€™s Mars Astrobiology Explorer-Cacher (MAX-C) rover with Europeโ€™s ExoMars rover, both of which were slated to launch atop a single United Launch Alliance Atlas 5 rocket in 2018.

โ€œBoth agencies are sitting down at the table and trying to chart a new course that fits the budget realities that we both have,โ€ Green said during an April 22 meeting of the NASA Advisory Councilโ€™s Science Committee here.

Green said NASA could contribute roughly $1.2 billion to a revised joint mission plus an estimated $300 million for launch costs, or roughly $700 million less than the agency signed up for under the original dual-rover plan.

But with the White House under pressure to rein in spending, NASA says it will be unable to meet its roughly $2.2 billion commitment to the dual-rover mission, forcing the two sides back to the drawing board and prompting ESA in mid-April to halt work on its Mars program, which in addition to the ExoMars rover includes a joint ESA-NASA Mars Trace Gas Orbiter slated to launch on an Atlas 5 in 2016.

While ESAโ€™s contractors have been ordered to stop all ExoMars work, Green said NASA will continue to fund development of the science instruments that agency has agreed to contribute to the ESA-led Mars Trace Gas Orbiter. NASA and its contractors are building four of the orbiterโ€™s five instruments and paying for the spacecraftโ€™s launch as part of a $500 million contribution to the 2016 mission.

โ€œWe are working in good faith with ESA and therefore we cannot stop work on our instruments because they deliver early, so our approach is weโ€™re continuing to develop them,โ€ Green told Space News April 22.

Looking ahead to a combined 2018 rover mission, Green said NASA hopes to lower the roverโ€™s overall development cost by leveraging existing designs, including the entry, decent and landing capability that will be used for the agencyโ€™s $2.4 billion Mars Science Laboratory (MSL) mission launching in November.

โ€œThereโ€™s no reason to invent a new one,โ€ he said. โ€œWe have worked very hard to make sure MSLโ€™s entry, descent and landing plans, blueprints and drawings are all available for us to turn around and remanufacture and make a duplicate.โ€

Green said NASA could also equip the new rover with a nuclear power source by utilizing a spare Multi-Mission Radioisotope Thermoelectric Generator that was designed for MSL.

โ€œThatโ€™s part of the trade space,โ€ Green said, adding that the plutonium-fueled battery could power the Mars rover if it is required to traverse dark areas of the red planet where solar arrays would prove useless. โ€œIt gives us great flexibility, and we may need it, but we have to do the basic mission architecture first.โ€

In the meantime the two sides have yet to determine who will lead the mission.

โ€œRight now, NASA is the mission lead for 2018,โ€ Doug McCuistion, head of NASAโ€™s Mars exploration program, said during a meeting of the NASA Advisory Councilโ€™s planetary science subcommittee here April 18. However, under the revised 2018 mission, โ€œthereโ€™s a very good possibility that the ESA team will be the rover lead.โ€

For the moment, McCuistion said ESA and NASA are more concerned with deciding which combination of existing assets and capabilities should contribute to the revamped Mars campaign.

โ€œItโ€™s not going to look like ExoMars, itโ€™s not going to look like MSL; itโ€™s going to be something new,โ€ McCuistion said.

 

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