WASHINGTON – As NASA grows up a decade-long attempt to return samples from Mars, some scientists are concerned that the campaign may not provide any funding available for other robotic missions to the planet.
The only future NASA mission to Mars under development is Mars 2020, a rover that is currently completing assembly and is scheduled to launch in July 2020. The rover, based on the Curiosity rover that has been on Mars for seven years, will cache Martian rock and soil samples for later return to Earth.
While NASA has not formally undertaken the additional missions needed to retrieve the samples and return them to Earth, both NASA and the European Space Agency have begun planning for them. That method includes a NASA-led mission to land on Mars, retrieve the specimens and launch them into orbit around the planet, and an ESA-led mission to grab the orbital sample container and return it to Earth. Both missions started in 2026 and returned the samples in 2031
But when participants in a meeting last month in the Mars Exploration Program Analysis Group (MEPAG) in Pasadena, California, noted, there are almost no other Mars robot missions to be produced. The only exception is Escape and Plasma Acceleration and Dynamics Explorers (EscaPADE), a proposed smallsat mission to study the interaction of the solar wind with the Martian atmosphere chosen by NASA in June as part of a new planetary science smallsat program. NASA is funding additional studies of EscaPADE, but without the guarantee, the mission will be approved for development and launch.
This has led to concern that Mars is returning to test other research that scientists want to conduct on Mars. "Our highest priority is Mars return, but we have other priorities as well," R. Aileen Yingst, MEPAG chairman, said in comments at the beginning of the group's July 26 meeting. “We should address outstanding scientific issues in parallel with or as part of the sample. Right now, there are no aviation opportunities that look ahead that way. "
She noted that in addition to the lack of flagship Mars missions such as March 2020, scientists cannot propose medium-sized New Frontiers missions since such missions, while contested, are limited to only a handful of selected destinations that currently exclude Mars. The smaller Discovery program, which also selects missions in a competition, can be used for the Mars mission, like the InSight lander. But she said, "Getting to Mars during the Discovery cost cap is problematic."
"There is some concern in society that new information may not be forthcoming soon," she concluded.
Later during the meeting, researchers asked NASA officials present for alternatives to address this, such as flying additional scientific instruments on the test returning landers and orbiting missions that began in 2026.
Jim Watzin, NASA's Mars Exploration Director Program, said that NASA did consider flying additional scientific payloads on these missions early in its development. However, he argued that it did not fit into the "lean" Mars return architecture announced nearly two years ago by Thomas Zurbuchen, NASA's associate scientist for science, who is trying to perform sample return as quickly and as cheaply as possible. "It was the right decision," he said. These, for example, recurring missions face "very, very intense propulsion requirements" to get to Mars and back. "Each time I add an extra kilo of mass to it, it makes the problem harder and harder to implement."
Some asked for another orbiter to handle surface communication and other roles, such as imaging, given the age of existing paths. Watzin said that launching the other two parts of the 2026 sampling campaign means that there is a "reasonable probability" that existing paths will still be able to function at least as communication relays.
When it came to an orbiter doing science, Watzin was more pessimistic. "Unfortunately, we live in a world of limited budgets," he said, acknowledging the need for a new remote analysis mission to support science and, possibly, future human exploration.
"Do I have a plan today? No," he said of a new orbiter.