WASHINGTON — A constellation of commercial satellites could serve as a communications relay system for future NASA missions, such as an orbiter later this decade to search for subsurface ice on Mars.
In recent presentations to advisory committees, NASA officials have discussed the possibility of working with industry to place several satellites into orbit around Mars that would serve as relays for other missions, notably the proposed Mars Ice Mapper. Such satellites, they said, could greatly increase the amount of data missions can return to Earth and end reliance on aging science missions that also serve as data relays.
One proposal presented at those meetings features three satellites in equatorial orbits at altitudes of 6,000 kilometers. The satellites would be equipped with radio links for communicating with other spacecraft in orbit and on the surface as well as to and from Earth. The satellites may also include laser intersatellite links to allow them to communicate with each other.
“This will be an opportunity to provide great relay assets” for various Mars missions, said Eric Ianson, director of the Mars Exploration Program at NASA Headquarters, during a Nov. 30 meeting of NASA’s Planetary Science Advisory Committee, or PAC.
That constellation, he said, would be a “commercial contribution” of some kind, although the exact nature of the arrangement between NASA and industry had yet to be worked out.
“We intend to do this as a commercial contract that will be solicited and competed,” said Jim Watzin, former director of the Mars Exploration Program who is now a senior adviser supporting human Mars exploration planning at NASA Headquarters, at a Nov. 23 meeting a panel of the ongoing planetary science decadal survey. “This is an opportunity space that is an enabler for exploration.”
NASA hasn’t disclosed how much it foresees spending on such a system, either by owning and operating the satellites or buying services from commercially provided satellites. “It’s a non-trivial expense to move in this direction, but we believe it’s a really big opportunity for the agency and Martian science,” said Rick Davis, assistant director for science and exploration in NASA’s Science Mission Directorate, at the decadal panel meeting.
Language in the report accompanying the Senate version of a fiscal year 2021 appropriations bill that funds NASA hinted at the agency’s interest in commercial communications at Mars. “The Committee is aware that NASA is investigating possible new models for using commercial services for future communications with Mars surface assets in the late 2020s and early 2030s, though no such services exist today,” the report stated. It called for a report within 180 days of enactment “outlining the Science plan for securing such commercial services for future Mars surface assets.”
Davis said that planning for the satellite system involves NASA’s Space Communications and Navigation program, which handles spacecraft communications through systems such as the Deep Space Network, as well as the commercial crew and cargo programs. “We are essentially trying to leverage their experience on how to do this very efficiently,” he said.
While agency officials said the constellation could be used for any number of future Mars missions, the one it’s most closely tied to is Mars Ice Mapper, a mission included in NASA’s fiscal year 2021 budget request to fly an orbiter to Mars no earlier than the mid-2020s. The orbiter, equipped with a synthetic aperture radar provided by the Canadian Space Agency, would search for subsurface ice deposits that could be resources for future human missions. The Japanese space agency JAXA and Italian space agency ASI are also expected to collaborate on Mars Ice Mapper.
Davis said a communications system like the one proposed could increase the data returned from Mars by a factor of 100, which would be valuable for Mars Ice Mapper, whose radar will generate large volumes of data. “That is revolutionary, potentially, in terms of being able to flow total data and also being able to do time histories of things we’re looking at,” he said.
In addition, he noted a communications network at Mars would mean future missions would not need their own powerful direct-to-Earth communications systems, and can instead fly with smaller and less expensive systems that can work with the data relay satellites. “We see significant dividends for the science community going forward that really opens up an envelope of opportunity that we have not had before with Martian exploration.”
“Experimenting with commercial communications was brought up as an opportunity as we examined the bandwidth limitations of Ice Mapper,” Watzin said, citing advances in commercial communications satellites. “Is the time right that one could exploit the derivation of that technology and deploy it Mars at an affordable cost such that we can make a paradigm shift in how we do communication and increase the effectiveness of how we do our missions?”
However, Watzin and others emphasized that Mars Ice Mapper is not dependent on that communications network. “If it turns out not to be affordable, not to be timely, or the risk is too high, then the Ice Mapper mission proceeds without it,” Watzin said.
Ianson made the same point at the PAC meeting. “My understanding is that it’s not an absolutely must-have,” he said. “It would help with the relay of data and it would also provide a better relay network around all of Mars.”