Don’t weaponize space

On the Planetary Society  website, the normally responsible and pro-science Planetary Society has posted an opinion piece by Louis Freedman and Tom Jones asking NASA to reconsider its refusal to fund the Asteroid Redirect Mission.  In short, this is a mission to kidnap a small asteroid from elsewhere in the inner solar system, and redirect it towards the earth, hopefully parking it in the most stable lunar orbit they can find (the Moon’s uneven gravity, and the tidal interactions between the Earth and Sun, tend to make most lunar orbits unstable).  Once there, the asteroid can do three things:

1. Fall into the Moon.

2. Fall into the Earth.

3. Be ejected into an Earth-crossing orbit around the sun.

One of the goals of this project is to give manned space missions a target that is easier to get to and from than either a wild inner solar system asteroid, or the Moon.  Because this will give them a stepping stone to Mars. 

The prospect of asteroid redirection technology being used to crash asteroids into the Earth doesn’t seem to faze Drs. Freedman and Jones; they don’t lay our any risk assessment or amelioration plans.    But an asteroid strike on Earth, especially a targeted asteroid strike, could be extremely damaging, as only nuclear weapons are capable of putting as much energy into the atmosphere in a comparable amount of time. And any asteroid-fetching spacecraft could be communicated with by a dish pretty much anywhere on Earth at some points during its flight. 

Amateurs often build radio receivers, point them at the sky, and listed to NASA spacecraft.  To date, nobody has managed to hack one, but there has been very little incentive to do so.  Putting a asteroid redirecting spacecraft into the inner solar system that is a computer hack away from becoming a weapon of mass destruction seems like a pretty rash thing to do, so I am surprised that the Planetary Society is advocating this.