
A depiction of how the ARM vehicle could perform an asteroid deflection. (Image credit – NASA)
On Sept. 14, the White House Office of Science and Technology Policy (OSTP) and NASA held an event
In his remarks, Holdren first outlined four components of the administration’s vision for human space exploration: working with the private sector to develop cost-effective means of expanding human presence in space, developing new technologies for space exploration, extending use of the International Space Station into the mid-2020s so that it can serve as a test-bed for these new technologies, and executing a series of increasingly ambitious missions to take humans beyond low Earth orbit. Holdren then explained that the ARM is a key part of this vision as it provides a destination for humans to conduct operations near the Moon and demonstrates advanced electric propulsion capabilities key to the ultimate goal of sending humans to Mars.
Holdren also stated that ARM serves as an important demonstration of asteroid deflection techniques that could one day help prevent an asteroid from striking the Earth. He noted that the meteor that exploded above Chelyabinsk, Russia in 2013 had the power of 400-500 kilotons of TNT (about 30 times the power of the nuclear bomb dropped on Hiroshima), and that a 1908 meteor impact, dubbed the “Tunguska event,” was equivalent to a multiple megaton explosion.
Given that the Chelyabinsk impact is estimated to be a 1 in 100 year event and the Tunguska impact is estimated to be a 1 in 1,000 year event, Holdren asserted that asteroid deflection is a capability worth developing. “We have to be smarter than the dinosaurs,” Holdren said, a reference to the theory that a large meteor strike near the Yucatán peninsula led to the extinction of dinosaurs.
A depiction of how the ARM vehicle could perform an asteroid deflection. (Image credit – NASA)
Holdren then summarized the ARM’s rationale by pointing to five distinct benefits of the mission:
The Asteroid Retrieval Mission makes sense in about five ways: it makes sense for science, for better understanding of the composition of asteroids and what they can tell us about the origins of the solar system. It makes sense from the standpoint of technology demonstration, demonstrating technologies we’re going to need for the mission to Mars. It makes sense in terms of human operations in cis-lunar space, again the most appropriate stepping-off point for Mars. And it makes sense for the possibilities for using asteroids for sources of materials, potentially sources of fuel, sources of water, to resupply space missions, and ultimately, to meet needs on Earth. So this is a multi-purpose mission, but the planetary defense aspect is one important part of it.
Yesterday, the Senate Commerce, Science, and Transportation Committee announced
Section 435 of the Senate’s new authorization bill is specific to the ARM. It begins by noting that the projected cost of the mission has grown from $1.25 billion to $1.4 billion and that the estimated launch date has slipped from December 2020 to December 2021. It then points out that the NASA Advisory Council concluded that “maneuvering a large test mass is not necessary to provide a valid in-space test of a new solar electric propulsion stage” and that “other possible motivations for acquiring and maneuvering a boulder, such as asteroid science and planetary defense, do not have value commensurate with their probable cost.”
The bill then expresses the Senate’s overall skepticism about the mission:
It is the sense of Congress that the technological and scientific goals of the Asteroid Robotic Redirect Mission may not be commensurate with the cost; and alternative missions may provide a more cost effective and scientifically beneficial means to demonstration the technologies needed for a human mission to Mars…