Letter | Setting Up Straw Men To Hit Asteroid Plan
Setting Up Straw Men
To Hit Asteroid Plan
Robert Zubrin’s column “NASA’s Asteroid Absurdity” [Commentary, May 20, page 19] deftly attacks self-made straw men, but fails to deal with the reality of the Obama administration’s proposed asteroid initiative.
The first straw man Zubrin sets up is a scheme no one proposed: deflecting a potentially hazardous asteroid with a solar-electric propulsion spacecraft. For years the principal recommendation of planetary defense advocates was not building deflection systems but completely observing near-Earth space to find all the potentially hazardous objects. This is precisely what is proposed in the asteroid initiative and why it is a valuable first step for planetary defense.
The next straw man is Zubrin’s statement that “this initiative will cost many billions of dollars.” This initiative might cost $1 billion or $2 billion over the next eight years — a rather small portion of the approximately $40 billion to $50 billion planned for human spaceflight. It makes that human spaceflight exciting and purposeful, going beyond the Moon and leading the world into the solar system. We will create new achievements instead of dwelling on past ones, doing so with a new synergy between robotic and human missions.
Achieving “vastly more science” by robotic spacecraft is another straw man. The human asteroid mission is not about asteroid science — it is about developing human capability for interplanetary flight, i.e., it is about life science. That said, I expect that when astronauts really get to asteroids and conduct experiments and measurements there and bring back a diversity of samples, the science will not be “vastly” less.
Another straw man is about resources from “the 3.5-meter rock.” The size asteroid to be retrieved is about double that — important to the development of astronaut exploration capabilities and operations in deep space. But no one is proposing that this asteroid be used for fuel manufacture (despite Zubrin’s painstakingly simple calculations). Instead, this mission will provide knowledge and experience for putative future use.
A last straw man is Zubrin’s claim that bringing the asteroid to lunar orbit instead of sending astronauts to one way out there in its interplanetary orbit is cheating on the president’s goal of reaching an asteroid by 2025. The fact is that no asteroid in its natural interplanetary orbit can be reached by 2025 — we have neither crew support vehicles nor rockets capable to that end. We can wait for those (one or two more decades?), doing missions to nowhere in the meantime. But will that generate a more meaningful or valuable space program?
Like Zubrin, I wish we could jump to Mars — but no one has the money or capability to do that now. Wishing is not a good plan. The Augustine committee on human spaceflight grappled with the problem posed by the distant goal and limited resources — and came up with the flexible path. We can’t jump to Mars, so instead we’ll do it step-by-step, and asteroids will provide the steppingstones. That is the real “Mars Direct.”
The writer is executive director emeritus of the Planetary Society.