Planetary Decadal Embraces Planetary Defense, Endorses NEO Surveyor

Planetary Decadal Embraces Planetary Defense, Endorses NEO Surveyor

The new National Academies Decadal Survey for planetary science weighs in on NASA’s planetary defense program for the first time, fully endorsing it. In particular, it strongly supports the NEO Surveyor mission to accelerate the search for potentially hazardous Near Earth Objects to comply with congressional direction to locate and catalog NEOs 140-meters or more in diameter. However, NASA’s FY2023 budget request proposes a two-year delay.

Planetary defense refers to protecting Earth from comets and asteroids — Near Earth Objects (NEOs) — that could impact Earth with devastating consequences. The extinction of the dinosaurs 65 million years ago is thought to have been caused by a large NEO hitting Earth and spewing dirt and dust high in the atmosphere, cooling the planet and dooming the cold-blooded animals.

Concerns in policy circles about the NEO threat date back almost 25 years. In 1998, Congress directed NASA to find and catalog 90 percent of NEOs 1-kilometer or more in diameter within 10 years. NASA accomplished that task and Congress then set a new mandate in the George E. Brown Jr. Near-Earth Object Survey Act, part of the 2005 NASA Authorization Act, to find 90 percent of NEOs 140-meters or more in diameter within 15 years.

NASA funding for ground-based NEO searches increased substantially in the Obama Administration, which wanted to move an asteroid into lunar orbit and send astronauts to study it, but it was the explosion of a meteor over Chelyabinsk, Russia in 2013 that galvanized interest in the threat NEOs pose to Earth.

NASA created a Planetary Defense Coordination Office (PDCO) in 2016 within the Planetary Science Division of the Science Mission Directorate. Over the next two years, the Obama and Trump Administrations issued a U.S. NEO Preparedness Strategy and Action Plan assigning roles and responsibilities to a number of government agencies including NASA.

PDCO still oversees ground-based searches for NEOs and has been trying, with some success, to expand its role to space-based searches and technology demonstrations to deflect asteroids. It’s hard because PDCO has to compete for funding against planetary science missions like Europa Clipper and Mars Sample Return and some scientists don’t consider searching for or diverting asteroids to be “science.”  That’s the main reason planetary defense was not considered in previous Decadal Surveys, which are conducted by the National Academies of Sciences, Engineering, and Medicine to identify key science questions and recommend missions to address them over the next 10 years (a decade).

This time, NASA explicitly included planetary defense in its charge to the planetary science Decadal Survey committee. The report was released last week.

PDCO’s first flight project, the Double-Asteroid Redirection Test (DART), was launched in November and will impact the tiny moon of the small asteroid Didymos on September 26, 2022.

Illustration of how DART’s impact will alter the orbit of Dimorphos about Didymos. Telescopes on Earth will be able to measure the change in the orbit of Dimorphos to evaluate the effectiveness of the DART impact. Credit: APL

DART is a test of a potential method for deflecting a threatening asteroid, but first one must find them.

That gets back to the 2005 congressional mandate. The 15-year time frame elapsed two years ago, but NASA is still working on finding those small, dark, 140-meter diameter objects. It is much more difficult than locating their 1-kilometer cousins using only ground-based instruments.

The solution is a space-based infrared telescope designed specifically for that task. PDCO has struggled to get funding for it, however. Linda Billings, a communications consultant to NASA’s planetary defense and astrobiology programs, speaking for herself on her personal blog, traces the history and points out that a 2019 study by the National Academies explicitly endorsed NEO Surveyor.

That report plus former NASA Administrator Jim Bridenstine’s enthusiastic support broke the logjam, at least temporarily. In September 2019, NEOCam, an ongoing effort led by Amy Mainzer, then at JPL, was reformulated as NEO Surveyor.

Illustration of the NEO Surveyor space telescope. Credit: University of Arizona.

Jonathan McDowell, an astrophysicist with the Harvard-Smithsonian Astrophysical Observatory, told that “getting a better handle” on the NEO population is “critical for planetary defense, and long overdue,” and NEO Surveyor will “also provide some characterization of the asteroid type and physical properties.”

Until a month ago, NEO Surveyor seemed to be on solid footing and headed towards launch in 2026, but on March 28 NASA submitted its FY2023 budget request to Congress proposing a two-year delay with near-term funding cut dramatically.

In the FY2022 request, projected funding for FY2023 was $174.2 million, with $184.0 million in FY2024, $181.7 million in FY2025, and $128.1 million in FY2026. In the FY2023 request, it is cut to $39.9 million. The projections now are $75.0 million in FY2024, $140.0 million in FY2025, $200.0 million in FY2026, and $200.0 million in FY2027.

Mainzer, now at the University of Arizona and Survey Director for NEO Surveyor, told that achieving the congressional mandate of finding 90 percent of NEOs 140-meters or more in diameter will take about 10 years once NEO Surveyor is launched. Without NEO Surveyor “it will take decades.” She said the FY2023 request was “a complete shock. ” The project is “not experiencing any technical difficulties.”

“NEO Surveyor promised to speed up the discovery process. But, for now, it may be on hold,” Billings wrote.

Speaking to Women in Aerospace today, NASA Deputy Administrator Pam Melroy said the decision to delay NEO Surveyor was based on priorities. “We’re working through it. There’s always the potential for making more progress and realigning the science portfolio if we can, but we just had to set our priorities for the ’23 budget.”

The FY2023 budget request was formulated while the Decadal Survey was underway, so its recommendations do not reflect the proposed delay. Instead, it strongly endorses NEO Surveyor and NASA’s planetary defense role more broadly, recommending a “rapid-response” mission to demonstrate a capability to quickly send a spacecraft to investigate a newly-discovered potentially hazardous NEO.

Source: Origins, Worlds, and Life: A Decadal Strategy for Planetary Science and Astrobiology 2023-2032. National Academies of Sciences, Engineering, and Medicine. April 2022.

During a press conference last week, study co-chairs Robin Canup of the Southwest Research Institute and Philip Christensen from Arizona State University addressed the intersection between planetary science and planetary defense.

Christensen said the Decadal Survey committee “felt there is a very strong synergy between what NASA does both on the science of understanding these objects and its capability for sending missions to these objects.” NEO Surveyor “falls between this boundary … because it does great science, but also fills this societal need to understand these objects.” Canup called NEO Surveyor a “scientifically rich mission.”

Implementing the Decadal Survey’s recommendations will be challenging at the budget levels proposed in the FY2023 request, not only for NEO Surveyor but the rapid-response mission. The report does not specify a target asteroid for that flight, but Billings thinks the close approach of Apophis in 2029 would be an excellent opportunity. That would mean starting another mission while trying to complete NEO Surveyor, however.

NASA’s overall budget request for FY2023 is $26 billion, a roughly 8 percent increase over its $24 billion FY2022 appropriation.

The FY2023 request for the Science Mission Directorate is the highest in history, $7.988 billion.

The challenge is that NASA has a lot of expensive programs underway in its five science disciplines: astrophysics, biological and physical sciences, earth science, heliophysics, and planetary science. The planetary science request is $3.16 billion, the largest of the five, to fund probes like Europa Clipper and three more missions to Mars, in cooperation with the European Space Agency, to retrieve samples being collected right now by the Perseverance rover and bring them back to Earth.

The Decadal Survey endorses all of those, too, and many more.

Hence the need to prioritize. NASA decided NEO Surveyor was a lesser priority, but the ultimate decision is up to Congress. It continues to have a strong interest.

For FY2022, the House Appropriations committee directed NASA to allocate no less than $143.3 million for NEO Surveyor (the same as the request) and “welcomes NASA’s commitment to the NEO Surveyor mission and to a 2026 launch date.”  The Senate Appropriations Committee directed NASA to “include in future budget requests the amount required for Planetary Defense to ensure … development of NEOSM that pursues a launch date in 2025 while maintaining the mission’s current instrument architecture, to the extent that it is scientifically justified and cost effective.” The Decadal Survey report seems to settle the question of whether it is scientifically justified.

Both also required a report from NASA within 180 days of enactment on progress in meeting the requirements of the 2005 law. The FY2022 appropriations bill was enacted on March 15 so it will be due in about 5 months.

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