A Look at How NASA Decides Where next to Boldly Go with New Frontiers
published during a waxing crescent moon.

Last month, NASA released an announcement of opportunity for its next New Frontiers mission. There have only been three previous such missions—New Horizons, Juno, and OSIRIS-REx—an esteemed group by any measure, bound by cost yet wildly ambitious in their pursuit of science. Scientists are now racing to meet an April deadline, at which time proposals must be submitted for a new spacecraft to explore a pre-determined spot in the solar system.

To understand New Frontiers is to understand how NASA’s planetary science division works. From the outside, it sometimes seems that NASA is like the Pentagon and that somewhere on Kennedy Space Center is a building where all of the agency’s missions are hatched, planned, built, and launched. Scientists in white lab coats walk into the administrator’s office, slap a coiled set of schematics onto her desk and unroll them in dramatic fashion. A scientist points to the target and reveals the name of the ship that will take us there.

In fact, spacecraft missions in the Discovery and New Frontiers-class are proposed by scientists from government, industry, and academia, and are eventually chosen by NASA through competition. (Flagship missions are a special case, generally directed by the agency rather than competed.) Discovery missions have a cost cap of around $450 million, and scientists have a free hand in mission objectives and destinations, provided they track with the Planetary Science Decadal Survey. (A good example of this is the MESSENGER spacecraft, built by the Johns Hopkins University Applied Physics Laboratory and sent to Mercury.) The targets for New Frontiers missions are, for the most part, stated explicitly by the Decadal, and the cost cap for the most recent “New Frontiers 4” announcement is $850 million.

NASA Decides

The OSIRIS-REx spacecraft, enclosed in a payload fairing, is hoisted before being mounted to a rocket. Credit: NASA


So what is this “Decadal Survey,” why is it so influential, and where does it come from? It is a document produced every ten years (hence the name) by the National Academy of Sciences at the request of NASA and the National Science Foundation. NASA foots the bill, with additional funding provided by the NSF. (The National Academy is itself a non-profit organization.) The purpose of the survey is to capture the science community’s priorities for the robotic exploration of the solar system. Space travel is, of course, an expensive endeavor indeed, and though there are an infinite number of things to explore and a commensurate number of questions unanswered, NASA can only afford to build and fly a small number of spacecraft at a time. As such, the agency needs to know the questions that burn brightest in the hearts of scientists. This impartial and peer-reviewed document is the answer.

To produce the Decadal, the National Academy establishes a steering committee that in turn empanels multiple groups of subject matter experts from around the world. The most recent Decadal had five committees, each of which focused on one of the following areas: the inner planets, the giant planets, satellites, Mars, and primitive bodies. (The number and focus of those groups are not fixed, but rather, determined by the steering committee and its chair.) Community input is essential, and comes from oral presentations made to the committees; webcasts; public forums and town halls at universities and national conferences; and through a call for white papers.

The committees sift through the community input and produce reports for the steering committee, which in turn produces its own report characterizing NASA’s progress in scientific exploration; summarizing planetary science for policy-makers and other stakeholders; characterizing the planetary science community’s current state of knowledge of the solar system; and identifying the top-level science questions that should guide NASA’s flight and research programs. This report is a massive doorstopper of a book, the most recent of which was titled Visions and Voyages for Planetary Science in the Decade 2013-2022, or in the parlance, “the Decadal.” This is the bible that NASA uses to determine where it should invest its resources and where next it should explore. Though NASA is not bound by law to follow the Decadal, it generally does so.

As it relates to New Frontiers 4, the Decadal directly states five of the six possible targets of a New Frontiers-class mission. The consensus destinations are: the surface of a comet; the surface of Venus; the south pole of the Moon; a Trojan asteroid; and Saturn. NASA used this list in its recent announcement of opportunity. Partly because of congressional legislation, and partly in keeping with the intent of the Decadal, a sixth candidate was also listed by NASA: a visit to an “ocean world” such as Titan or Enceladus.

NASA Decides

Rendering of the OSIRIS-REx spacecraft. Credit: NASA


Scientists interested in sending a spacecraft to one of these destinations aren’t simply dashing off a two-page email message and hoping for the best. Though they have less than five months from the announcement to the deadline, the proposals must be drafted with astonishing detail. Dante Lauretta, the principal investigator of OSIRIS-REx, tells me that a primary proposal document for a candidate mission will be hundreds of pages long. “The step one proposal document for OSIRIS-REx was 129 pages long, with another 248 pages making up the appendices,” he says.

“I always felt like the science was the easy part.”

Crafting a technical document of such length might seem like an impossible task, but the missions most likely to make the final cut have been in development for quite some time. “Teams that I feel are serious about bidding on New Frontiers 4 started immediately after New Frontiers 3 was selected,” says Lauretta. That was in 2011 when OSIRIS-REx was selected after having been submitted to NASA on three separate proposal solicitations. For teams actively preparing mission proposals, the hard part right now isn’t the science, but rather, is the engineering design required to meet the scientific objectives. Moreover, the teams must put together credible cost estimates to actually develop the program.

“I always felt like the science was the easy part,” Lauretta says of his own experience running the gauntlet. “The science is compelling. If you’ve already made it to a Decadal Survey level of a New Frontiers mission, writing the science story should not be the challenge. The challenge is answering how are you going to get that done, and who is going to do it, and how much is it going to cost.”

One look at the objectives for a prospective mission and the magnitude of the engineering and cost problems become clear. In the case of the Venusian surface, one of the six candidate environments in the announcement, NASA expects a mission to do such things as “constrain the coupling of thermochemical, photochemical, and dynamical processes in Venus’s atmosphere and between the surface and atmosphere to understand radiative balance, climate, dynamics, and chemical cycles,” and “search for evidence of past hydrological cycles, oceans, and life and constraints on the evolution of Venus’s atmosphere.” The announcement hardly mentions the kicker: that to do that, they’re going to have to land something on the surface of Venus.

NASA Decides

Artist’s rendering of the surface of Venus. Credit: NASA


The proposal deadline for New Frontiers 4 is April 29th, at which time NASA-convened committees will begin their own process of peer review. Science panels will evaluate the merit and feasibility of proposals that were submitted, and management and cost panels will have their say. Each proposal will be considered independently of one another. The evaluations produced by these panels will be handed off to a subcommittee of the full Announcement of Opportunity Steering Committee. This ad-hoc subcommittee will weigh the mission proposals and divide them each into one of four categories, with Category I boiling down to “recommended for acceptance” and Category IV being “recommended for rejection.”

Once each of the missions has been categorized, the subcommittee will send its recommendations to the full steering committee. If the steering committee is satisfied with what it finds, will then send the recommendations to the associate administrator for the Science Mission Directorate at NASA, who will have the final say in which proposals move forward in the competition. These “step one selections” will be announced by the agency in November. They will each be given a certain budget in the small millions of dollars and will have one year to fully develop their mission concepts in a highly detailed report. The OSIRIS-REx concept study report was almost 2,000 pages long.

From the finalists, only one will likely be selected as the next New Frontiers mission. NASA will make the announcement in July 2019. For most of us, that means reading about it in the news or on a press release. For the principal investigator of the selected mission, it means getting a life-changing phone call from the selection official. “It’s probably one of the greatest feelings in the world,” says Lauretta. “I honestly felt like I won the lottery. I still feel that way.” Soon the mission team is activated, and the hard work resumes. NASA expects the team to turn those thousands of pages into a robotic explorer. As Lauretta puts it, “They write a contract with you for whatever hundreds of millions of dollars and tell you to show up at the launch pad five years later—with a spacecraft!”

That spacecraft will launch in 2025.