Vowing to continue Mars exploration at a more measured, affordable pace after pulling out of a joint sample return program with Europe, the head of NASA's science directorate said Monday the space agency is launching a feverish study to lay the groundwork for a robotic mission to the red planet in 2018.

Artist's concept of InSight, a proposed Discovery-class mission to land on Mars and study the planet's internal structure. Credit: NASA/JPL
 
It was welcome news at a meeting of Mars scientists outside Washington this week, but researchers may have trouble crafting a Mars mission to their liking at a cost cap of about $700 million, the figure floated by NASA science chief John Grunsfeld.

The planetary science decadal survey, a report prepared by an independent panel of researchers, recommended last year NASA should pursue a mission to select, gather and store rock samples on the surface of Mars in the coming decade, but only if it fit within the space agency's budget.

With NASA's budget outlook yielding little money for such an ambitious Mars mission, scientists went back to the drawing board.

The budget blueprint proposed by President Barack Obama on Feb. 13 would slash NASA's Mars budget from $587 million in fiscal year 2012, to about $361 million next year, then dropping to less than $189 million by fiscal 2015.

NASA named Orlando Figueroa, a veteran Mars program manager, to head a planning board to create a new framework for the space agency's Mars strategy. An interim report is due March 15, and the committee will complete its work this summer.

Time is of the essence.

Michael Meyer, the lead Mars scientist at NASA Headquarters in Washington, said prospects are dimming rapidly for a Mars orbiter in 2016, even if Congress restores planetary science funding.

"There's a limit to what we can do because these missions take many years," Grunsfeld said Monday. "2018, from where I'm sitting, is right around the corner."

Figueroa's team will report to Grunsfeld, who is chairing NASA's overall strategy revamp, which will seek significant inputs from the agency's human spaceflight, science and technology divisions.

NASA picked Orlando Figueroa, a veteran Mars program manager, to head the agency's planning committee for the red planet. Credit: NASA
 
The $700 million expected to be available for a 2018 mission will likely limit NASA to flying an orbiter. Opportunities to launch toward Mars come about every two years when the planets are in the proper position.

The 2018 launch opportunity is especially favorable, and the mechanics of the trajectory to Mars that year will allow rockets to boost more mass toward the red planet. The 2020 window is desirable for the same reason, but not as much so as 2018.

NASA's latest agreement with the European Space Agency called for Europe to build a rover for launch in 2018, while NASA would have provided a launch vehicle and entry, descent and landing system. The space agencies were already working on instruments for a European-built orbiter due for launch on a U.S. rocket in January 2016.

Amid the red planet replan, and despite bleak budget numbers, scientists are pushing for a mission to advance the Mars research community's No. 1 goal: Mars sample return.

Steve Squyres, who chaired the decadal survey study, described the report's recommendation in intentionally specific terms Monday.

"Per the recommendations of the planetary decadal survey, new missions to Mars that lead directly to sample return, and I'm choosing those words carefully ... have very high priority," Squyres said. "It was the single highest priority in the decadal survey. New Mars missions that do not lead directly to sample return should be openly competed via the Discovery program."

The Discovery program is how one mission, named InSight, may be approved for launch to Mars in 2016. If selected by NASA this summer from among three candidate missions, InSight would land on Mars and study its internal structure.

The Discovery program was designed to offer a high flight rate for small-scale planetary missions. NASA competitively selects Discovery missions from research proposals, then funds the development and flight of the spacecraft at cost caps of about $500 million. For the last two decades, Mars has received special attention from NASA, which maintained a vibrant series of strategic missions launching nearly every two years since the 1990s.

But the Discovery program puts Mars on an even footing with proposed missions to other planets, moons, comets and asteroids. InSight is up against probes to Saturn's moon Titan and comet Wirtanen for a single flight opportunity.

The Mars sample caching rover topping last year's decadal survey recommendations would have stored surface samples for later missions to retrieve and return to Earth. The three-part Mars sample return effort was expected to cost $8.5 billion.

With the sample-collecting mission now off of NASA's manifest, the agency is moving to immediately plan and implement a new Mars strategy, one which will incorporate goals of the agency's technology and human spaceflight programs.

Steve Squyres, a researcher from Cornell University, headed the decadal survey panel. Credit: NASA
 
Some scientists are weary of a restrained Mars program, claiming the most valuable research can only come from returning pieces of the planet to Earth for analysis in a laboratory.

"We have accomplished so much at Mars in the last 15 or 20 years of exploration that we are now ready to make the next crucial step in Mars exploration, which is to bring samples back," Squyres said.

NASA's Mars Science Laboratory, a $2.5 billion flagship-class mobile robot launched in November, is en route to the red planet now, heading for a parachute- and rocket-assisted touchdown in August. Its suite of instruments will help determine whether was ever habitable for life.

The decadal survey typically influences NASA's strategic direction, and the report's emphasis of Mars sample return is a feather in the caps of scientists still hopeful for the start of the multi-billion dollar, three-mission campaign.

Grunsfeld said NASA is not dictating the scope of a potential 2018 mission, adding it does not have to be a sample caching mission, a rover, or a lander. The Figueroa team will lay out a tentative framework for review by NASA, the science community, Congress and the White House.

Adding color and ambiguity to the decadal survey's preference for sample return, Squyres said: "Maybe that means caching, maybe that means something else. For example, there are technologies that could be used in Mars sample return."

Other planetary scientists, mostly absent from this week's Mars conference, lament the White House budget's zeroing out of NASA's funding for an outer planets flagship mission.

Studies tasked with defining a less costly robotic mission to Jupiter's icy moon Europa will finish up in May. Other reports on probes to Uranus and Saturn's moon Enceladus will wrap up in a few years, then there is no funding in NASA's budget profile for new outer planets flagship missions.

Speaking to a NASA Advisory Council subcommittee Feb. 23, Jim Green, the agency's planetary science director, said there were simply no funds projected in NASA's budget to pay for any multi-billion-dollar planetary probes to any destination.

"This budget does not provide any funds for a flagship-level activity," Green said. "So that would mean we would need a new start. That would mean we would need the approval of the administration. That would mean we would need the approval of Congress. That would mean the economy would have to really rebound."