CAPE CANAVERAL, Fla. — NASA’s Mars rover Curiosity has barely scratched the surface of a planned two-year mission to assess if the solar system’s most Earth-like planet ever had the chemistry for life, but planners of a bargain-priced 2020 follow-on rover already are eager for any lessons learned.

That assessment, organized by the NASA chief engineer’s office and expected to run about six months, kicked off on March 5, complementing work by a newly formed Mars 2020 Science Definition Team (SDT) to scope out instruments for the new rover that will meet the project’s budget, deadlines and goals.

“Essentially they will be producing a document that we will use to develop the Announcement of Opportunity to select instruments to be on the 2020 mission,” Michael Meyer, lead scientist for NASA’s Mars Exploration Program, said at a webcast Mars program analysis group meeting Feb. 27.

The 19-member SDT, headed by Brown University geologist Jack Mustard, has been told NASA will have about $80 million for rover science instruments, Meyer said, adding that at least one and possibly two more instruments, with a total value of about $20 million, also should be coming from participating international or other partners.

“We are quite interested in international partnering and I believe on the 2020 mission it could be extensive,” said Jim Green, head of NASA’s planetary science division.

That cost estimate does not cover a Curiosity duplicate chassis, operating systems and support equipment; a sky crane entry, descent and landing system; and a robot arm, drill and possible sample cache, if one is included.

Overall, NASA expects to spend about $1.5 billion on a second Mars Science Laboratory (MSL)-type rover, about $1 billion less than the cost of Curiosity, which landed on Mars Aug. 5. The cost also does not include a launch vehicle.

Additional funding and instruments may come from NASA’s human exploration and technology development divisions, Meyer added.

Like Curiosity, the new rover, targeted for launch in 2020, will assess locations around its landing site for geological processes and chemistry that could have supported and preserved microbial life, but scientists also are weighing whether and how to directly search for biomarkers.

A key question is whether the rover will cache samples for an eventual return to Earth.

“One specific question to the SDT is in fact whether or not to cache,” Meyer said.

Although Curiosity’s initial budget for science instruments was $85 million in 2004 dollars, the agency ended up spending roughly twice that amount.

“It may very well be that the current instrumentation on MSL may not work financially for the 2020 mission, particularly since one of the issues is whether or not there’s a cache, which could be a limitation on available volume for instrumentation,” Meyer said.

“We really want open competition for the instrumentation to go on this mission. I don’t doubt that some people will propose instrumentation that they’re already familiar with building. That will be part of the equation when we go through weighing the pros and cons of those instruments that will be put on the mission,” he added.

In addition to taking advantage of engineering, testing and development that went into the Curiosity rover and landing system, NASA is looking to save money by reducing the number of science instruments and the complexity of integrating the payload.

“One of the things we learned from MSL is that adding another instrument, even if it’s free, it’s not free, and it greatly increases the complexity of the mission,” Meyer said.

“Essentially, we are fiscally constrained. We just don’t have the money, and in some ways we don’t have the time, to develop the most sophisticated instruments to go on the 2020 rover,” he said.

The SDT is expected to issue an interim report mid-April. A final report is due May 31. NASA plans to put out a solicitation for rover science instruments this summer.

In addition to its Mars 2020 rover, Maven orbiter and InSight lander, NASA is contributing to the European Space Agency’s 2016 and 2018 Mars missions and the Indian Space Research Organisation’s first Mars mission, which is scheduled for launch this fall.

“They have asked us for support in a number of areas, including tracking and navigation, for which we have agreed to help support them. They’ve done a tremendously successful mission, Chandrayaan, around the Moon and stepping out to Mars is the next huge step,” Green said.