Asteroid Hunting Space Telescope Finally Gets a Break

NASA’s Near Earth Object (NEO) Surveyor is finally getting a break. A decade in the planning, the asteroid-hunting space telescope was just approved to move into preliminary design and NASA’s FY2022 budget request includes enough money to pay for it. Now it is up to Congress. The outlook should be promising since NEO Surveyor’s purpose is to meet a congressional mandate to find 90 percent of NEOs more than 140 meters in diameter.

Congress has a long-standing interest in locating and tracking NEOs — asteroids and comets in orbits that could bring them close enough to Earth to pose a threat.

In 1998, Congress directed NASA to find 90 percent of the largest ones, 1 kilometer or more in diameter, within 10 years. A NEO that size is thought to have hit Earth 65 million years ago and caused the extinction of the dinosaurs as debris billowed up high in the atmosphere, blocking sunlight and altering the climate.

As NASA neared completion of that goal, Congress set a new mandate. The George E. Brown Jr. Near-Earth Object Survey Act, part of the 2005 NASA Authorization Act, told NASA to find 90 percent of  NEOs 140 meters or more in diameter within 15 years. That size NEO might not wipe out entire species, but would have significant regional effects.  The meteor that exploded over Chelyabinsk, Russia in 2013, for example, was about 20 meters wide.

NASA has been trying, but the 15-year deadline expired in 2020 and the agency is still far short of the goal.  Not surprisingly, the smaller asteroids are much more difficult to find. Not only are they smaller, but dark. Ground-based optical telescopes used to search for NEOs can see only part of the sky, only at night, and operate in less effective wavelengths for objects that can best be found by looking for heat signatures. The solution is an infrared (IR) telescope based in space where it can search day and night in a much larger sphere.

Amy Mainzer proposed such a mission, NEOCam, in 2011 while working at the Jet Propulsion Laboratory (JPL).  The biggest challenge turned out not to be technology or money, but nomenclature.

Some scientists do not consider searching for asteroids to be “science,” but “planetary defense.” Hence it historically has not been included in the Decadal Surveys conducted by the National Academies of Sciences, Engineering, and Medicine every 10 years that set NASA’s science priorities or a category for consideration in NASA’s Discovery series of competed mid-sized space missions.

NEOCam could never get past the “Phase A” concept phase, although it had enough support to get small amounts of funding for “extended Phase A studies.”

Defending Earth from NEOs does get a lot of attention outside the science community, however. The Chelyabinsk event galvanized public interest, including in the White House and Congress. The Obama and Trump Administrations issued a NEO preparedness strategy and action plan to coordinate government roles and responsibilities.

NASA created a Planetary Defense Coordination Office (PDCO) in 2016. Congress has substantially increased funding for NEO searches using ground-based systems over the past decade and also allocated funds for PDCO’s first flight project, the Double Asteroid Redirection Test (DART) scheduled for launch later this year. But not enough for the pricier NEOCam.

NEOCam’s future began to change in 2019. First, NASA Administrator Jim Bridenstine threw his support behind it in a keynote address at a Planetary Defense Conference. Then a report from a National Academies’ committee endorsed building a space-based IR telescope specifically to search for NEOs. The committee agreed with fellow scientists that it is not science, but said the solution was to create a planetary defense category of missions separate from NASA’s science projects.

With the head of NASA and the Academies behind it, Thomas Zurbuchen, NASA’s Associate Administrator for Science, soon announced the agency would go ahead with a “NEO Surveillance Mission” (NEOSM).  NEOSM basically is NEOCam with a new name, NEO Surveyor, plus a program to integrate the spacecraft data with that from other sources like ground-based telescopes.

Mainzer left JPL in 2019 and now is with the University of Arizona’s Lunar and Planetary Laboratory. Individuals who lead NASA science missions are given the title Principal Investigator (PI), but since this is not science, her title instead is Survey Director.

Whatever the project name or project leader’s title, a space-based IR telescope dedicated to searching for asteroids is now closer to reality. NEO Surveyor went through its Key Decision Point-B (KDP-B) review on May 25.  On Friday, June 11, NASA officially deemed the review a success and approved NEO Surveyor to move into Phase B, preliminary design.

Anticipating the positive outcome, earlier in the week Lindley Johnson, NASA’s Planetary Defense Officer and head of PDCO, told NASA’s Small Bodies Assessment Group that “this is the best position we’ve ever been in,” not just getting through KDP-B, but having the money included in NASA’s FY2022 budget request. The total request FY2022-2026 is $811.2 million.

Without NEO Surveyor, NASA estimates it will take 30 more years to meet Congress’s mandate to find 90 percent of NEOs 140 meters or more in diameter. With the spacecraft, it will take just 10 years.

Entering preliminary design is a promising step, but just a step.  JPL is in charge of building the spacecraft with the next review, KDP-C, in two years. If all goes well, launch will be in the first half of 2026.

But it is all dependent on Congress appropriating the funds. Action on the FY2022 budget request will be the next giant leap to watch.