TheRealHocusLocus writes: The Emergency Asteroid Defence Project has launched a crowdfunded IndieGoGo campaign to help produce a set of working blueprints for a two-stage HAIV, or Hypervelocity Asteroid Intercept Vehicle. This HAIV paper (PDF) describes the use of a leading kinetic impactor to make a crater — a following nuclear warhead would detonate in the crater for maximum energy transfer. The plans would be available for philanthropists to bring to prototype stage, while your friendly local nuclear weapon state supplies the warhead. This may be a best-fit solution. But just ask Morgan Freeman: these strategies could fail. What — if any — backup strategy could be integrated into an HAIV mission as a fail-safe in case the primary fails? Here is a review of strategies (some fanciful, few deployable) if we have to divert an asteroid with very short lead time. A gentle landing on the object may not be feasible, and we must rely on things that push hard or go boom. For example: detonating nearby to ablate surface materials and create recoil in the direction we wish to nudge. Also, with multiple warheads and precise timing, would it be possible to create a "shaped" nuclear explosion in space?