NASA Considers Public Values in its Asteroid Detection Program
NASA’s Asteroid Initiative encompasses efforts for the human exploration of asteroids—as well as the Asteroid Grand Challenge—to enhance asteroid detection capabilities and mitigate their threat to Earth.
October 2015 | by David Delaney
The human space flight portion of the initiative primarily includes the Asteroid Redirect Mission (ARM), which is a proposal to put an asteroid in orbit of the moon and send astronauts to it. The program originally contemplated two alternatives for closer study: capturing a small 10m diameter asteroid versus simply recovering a boulder from a much larger asteroid. Late in March, NASA offered an update of its plans. It has decided to retrieve a boulder from an asteroid near Earth’s orbit—candidates are the asteroids 2008 EV5, Bennu, and Itokawa—and will place the boulder on the moon’s orbit to further study it.
This mission will help NASA develop a host of technical capabilities. For instance, Solar Electric Propulsion uses solar electric power to charge atoms for spacecraft propulsion—in the absence of gravity, even a modicum of force can alter the trajectory of a body in outer space. Another related capability under development is the gravity tractor, which is based on the notion that even the modest mass of a spacecraft can exert sufficient gravitational force over an asteroid to ever so slightly change its orbit. The ARM spacecraft mass could be further increased by its ability to capture a boulder from the asteroid that is steering clear of the Earth, enabling a test of how humans might prevent asteroid threats in the future. Thus, NASA will have a second test of how to deflect near-Earth objects on a hazardous trajectory. The first test, implemented as part of the Deep Impact Mission, is a kinetic impactor; that is, crashing a spacecraft on an object to change its trajectory.
The Asteroid Initiative is a partner of the agency’s Near Earth Object Observation (NEOO) program. The goal of this program is to discover and monitor space objects traveling on a trajectory that could pose the risk of hitting Earth with catastrophic effects. The program also seeks to develop mitigation strategies. The capabilities developed by ARM could also support other programs of NASA, such as the manned exploration of Mars.
NEOO has recently enjoyed an uptick of public support. It used to be funded at about $4 million in the 1990s and in 2010 was allocated a paltry $6 million. But then, a redirection of priorities—linked to the transition from the Bush to the Obama administrations—increased funding for NEOO to about $20 million in 2012 and $40 million in 2014—and NASA is seeking $50 million for 2015. It is clear that NASA officials made a compelling case for the importance of NEOO; in fact, what they are asking seems quite a modest amount if indeed asteroids pose an existential risk to life on earth. At the same time, the instrumental importance of the program and the public funds devoted to it beg the question as to whether taxpayers should have a say in the decisions NASA is making regarding how to proceed with the program.