Bridenstine Embraces Planetary Defense, Endorses NEOCam

NASA Administrator Jim Bridenstine showed his support for planetary defense today by giving the keynote address at the Planetary Defense Conference (PDC).  Protecting the Earth from asteroids and comets is not “Hollywood” and he wants to dispel any “giggle factor” the topic may evoke.  In addition to existing ground-based facilities to identify and track these Near Earth Objects (NEOs), he agreed a dedicated spacecraft is needed and said NASA is committed to building NEOCam, a program that has struggled to win support against competing priorities.

The PDC underway in College Park, MD this week is the sixth in a series organized through the International Academy of Astronautics (IAA).  In addition to providing updates on NEO projects in countries around the world, it features a table-top exercise on how to respond to a hypothetical incident in which a large asteroid might collide with Earth.

Asteroids are rocks travelling through space and they collide with Earth all the time.  Most are small and delight the public when they scream through Earth’s atmosphere as meteors.  Sometimes remnants survive to the surface and are collected as meteorites.

Planetary defense addresses the issue of large asteroids that could cause damage on Earth, like the 20-meter diameter meteor that disintegrated over Chelyabinsk, Russia in 2013.  In that case, people were injured by flying glass as windows were blown out from the accompanying sonic boom.  A more powerful blast occurred in Tunguska, Russia in 1908, leveling trees for 200 kilometers, but it was in a remote area and no one was injured as far as anyone knows.

The point is that large asteroids do impact Earth with grave consequences.  The extinction of the dinosaurs 65 million years ago is thought to have been caused by an asteroid impact.

Planetary defense involves the full scope of detecting and tracking NEOs, characterizing them, mitigating threats posed by Potentially Hazardous Asteroids by deflecting them before they reach Earth, and what to do if one will, in fact, hit the planet.  The White House released a NEO preparedness strategy and action plan last year.

Congress passed laws n 1998 and 2005 directing NASA to detect and track first 90 percent of NEOs 1 kilometer or more in diameter, and then 90 percent of those greater than 140 meters in diameter.  NASA fulfilled the assignment for the 1 kilometer diameter class and has been working on the 140 meter diameter group for many years.  They are much more difficult to find.

The 2005 law called for NASA to achieve that objective by 2020, but at a media briefing yesterday prior to the conference, Amy Mainzer of the Jet Propulsion Laboratory (JPL) estimated it will take another 30 years.

What would help is launching NEOCam, a space-based camera specifically designed for finding NEOs.  That could shorten the time frame to 10 years, she said.

Mainzer is the Principal Investigator (PI) for NEOWISE, a spacecraft that was repurposed for asteroid hunting after its primary astrophysics mission ended.  Mainzer is also the PI for NEOCam, which is in “extended Phase-A” at NASA. That means initial work is progressing, but it has not been approved for development.  Mainzer and NASA’s Planetary Defense Officer Lindley Johnson estimated the life cycle cost of a NEOCam mission, including the instrument, spacecraft, launch, and operations, at $500-600 million.

That’s a hefty pricetag considering that Johnson’s Planetary Defense Coordination Office until recently had a budget of about $50 million a year.  That budget grew substantially in FY2019 reflecting a decision to proceed with a different space mission, Double Asteroid Redirection Test (DART), that will test a kinetic energy method of deflecting an asteroid.  Scheduled for launch in 2021, it will impact a moon of a small asteroid, Didymos, to see if it can alter the moon’s trajectory.  That mission, led by Johns Hopkins University’s Applied Physics Lab, has a life cycle cost of $313 million.  Congress funded DART at $97 million for FY2019.

Congress also supported NEOCam in FY2019.  The House Appropriations Committee specified $10 million for the instrument in its report on the FY2019 appropriations bill and the report on the final version of the bill specified that it receive “no less” than FY2018.

Bridenstine was asked today about what it will take to get NEOCam launched.  Noting that he was asked about NEOCam during a recent Senate Commerce Committee hearing, he said he would talk to the head of the Science Mission Directorate (SMD), Thomas Zurbuchen, and the director of SMD’s planetary science division, Lori Glaze, about how to fund it.

“But know this, we are committed to doing that,” Bridenstine asserted.

Bridenstine also was asked about the possibility of a mission to the asteroid Apophis, which will make a close approach to — but not collide with — Earth on April 13, 2029.  It presents a unique opportunity to study an asteroid up close.

He called the idea “awesome,” and added “I will certainly take it on board.”

The PDC, which is being livestreamed, will have a session devoted to Apophis tomorrow.  In a JPL press release today, Paul Chodas, Director of JPL’s Center for Near Earth Object Studies, said that by observing Apophis in 2029 “we will gain important scientific knowledge that could one day be used for planetary defense.”