Asteroid missions are now launched about every second or third year. Hayabusa 2 is on the way, Osiris-Rex is about to launch, the AIDA mission will launch in about 5 years and of course the Rosetta comet mission is also relevant for planetary protection against impact events.
Before a mission to actually divert an asteroid on impact trajectory, it would be nice to study it up close with a precursor probe in orbit or at least for a flyby. This would give information about the asteroid's composition and whatnot and greatly help the design of a deflection mission and other mitigation measures.
- Would it make sense to use the regular flow of asteroid science probes as a reserve to double as such precursor probes, in the case that a near term threat is identified?
The idea is that the next asteroid science mission would not launch until the next one is ready to launch, so that there's always an asteroid probe ready to launch within a few months or so. This would delay in situ asteroid exploration by about two years. It would also require that the science probes are equipped to give data which also is useful for planetary protection. A small impactor would certainly be very valuable for that purpose, but heavy. And ground penetrating radar, although it is power hungry. Maybe space agencies could cooperate to finance such add-ons to otherwise purely scientific missions. Compared to having a specialized probe in storage, this has the advantage of free-riding on science missions and might be cheaper. Also, each probe will be newly made and use the latest technologies.
- Are there synergies enough between asteroid science missions and asteroid redirection missions to make sense out of such a strategy, or would the science be compromised and the data wouldn't matter much for the choice of actual deflection mission anyway?
- And what about the orbital mechanics, is it practical to today (8 months before planned launch) decide that Osiris-Rex, instead of launching to Bennu, should fly to asteroid X which is in a harder to reach trajectory? Could for example a planned Atlas V 411 launch be upgraded to a 452 (if that configuration is established) within a few months?
- Osiris-Rex is a sample return mission, a function which cannot be expected to be used in this scenario because of time and velocities. Would it be useful for planetary protection if it instead made a flyby, with its design as it happens to be today?