Juno at Jupiter
An illustration of NASA's Juno spacecraft in orbit around Jupiter. Credit: NASA/JPL-Caltech

WASHINGTON — NASA released an announcement of opportunity (AO) for the agency’s next New Frontiers planetary science mission Dec. 9, kicking off a multi-year competition at least a month earlier than widely expected.

The AO, as planned, seeks proposals for missions to one of six destinations in the solar system, from Venus to Saturn. Missions have a cost cap of approximately $850 million, excluding launch and operations, and must be ready for launch by the end of 2025.

The release of the AO took many in the planetary science community by surprise, as they were not expecting NASA to have the final document ready until January. NASA officials speaking as recently as a Nov. 29 meeting of the Venus Exploration Analysis Group (VEXAG) at NASA Headquarters here were still giving a January date for the release of the AO.

Jim Green, director of NASA’s planetary science division, did suggest at the meeting that the AO could come out sooner, although he didn’t indicate its release was imminent. “After we establish a schedule, we want to be able to get it through the signature cycle,” he said, referring to a process of reviews prior to release. “Once it’s through the signature cycle, there’s no reason for us to hold it, so we will issue it. It’s making its way through the signature cycle as we speak today.”

At that time, agency officials said that initial proposals to the AO would be due to NASA 90 days after its release in January. Despite the earlier date, though, the AO calls for proposals by April 28, additional time that agency officials said they would try to provide if they were able to release the AO early. “If the AO comes out earlier [than January], we’ll keep it in April. I want to give you guys as much time as possible,” said Curt Niebur, New Frontiers program scientist, at the VEXAG meeting.

The AO restricts the New Frontiers proposals to six categories of missions, established in an earlier draft version of the announcement. They include:

  • Comet Surface Sample Return: a mission to visit a comet and acquire a “macroscopic” sample of its nucleus for return to Earth;
  • Lunar South Pole-Aitken Basin Sample Return: a mission to land in a deep basin near the south pole of the moon and collect samples for return to Earth;
  • Ocean Worlds: any of a variety of missions to study Saturn’s moons Enceladus and Titan, including searching for evidence of life in the subsurface liquid water ocean believed to exist on Enceladus;
  • Saturn Probe: a mission to deploy one or more probes into the atmosphere of Saturn to study its chemistry and structure;
  • Trojan Tour and Rendezvous: a mission to the “Trojan” asteroids sharing the orbit of Jupiter; and
  • Venus In Situ Explorer: a mission to study the atmosphere and surface of Venus, including a search for “evidence of past hydrological cycles, oceans, and life” that might have existed on the planet.

NASA plans to select several proposals for Phase A concept studies by the end of 2017, with those reports due back to NASA by late 2018. NASA plans to provide $4 million for each concept study awarded, Niebur said at the VEXAG meeting. NASA will then select a mission from those finalists by mid-2019.

The winning mission will be the fourth mission in the New Frontiers program, intended for missions too ambitious to fit into the cost cap of the smaller Discovery program but which don’t require a larger flagship-class mission.

New Horizons, the first New Frontiers mission, launched in 2006 and flew past Pluto in July 2015, and is now en route to a January 2019 flyby of a Kuiper Belt object. Juno, the second New Frontiers mission, launched in 2011 and entered orbit around Jupiter in July. The OSIRIS-REx asteroid sample return mission, the third New Frontiers mission, launched Sept. 8.

Jeff Foust writes about space policy, commercial space, and related topics for SpaceNews. He earned a Ph.D. in planetary sciences from the Massachusetts Institute of Technology and a bachelor’s degree with honors in geophysics and planetary science...