Paving the Way for an Effective Deflection Mission: State of the Art NEO Precursor Missions

Abstract

In the event of the detection of an asteroid in a collision course with the Earth, numerous efforts would be made to gather as much data as possible on the hazardous object before an effective fully-fledged deflection mission can be developed. In the same way as ground and space–based telescopes will certainly be used towards this goal, a mission to collect in-situ information on the asteroid properties and to test the technologies required to perform the deflection will be mandatory. Such mission should be largely based on already existing space technology and /or hardware at time of asteroid threat detection (with the few exceptions of any novel technologies that being necessary to perform the asteroid deflection need to be tested for the first time), in order to reduce technological risk and enable the shortest possible development time. The mission proposed in this paper, which has been called Don Quijote, will consist of two spacecraft, which would be injected into separate interplanetary trajectories by the same Soyuz launch vehicle. The first spacecraft, called Hidalgo, would impact on the asteroid at a relative speed of at least 10 km/s. A second spacecraft, called Sancho, would have previously performed a rendezvous manoeuvre with the asteroid and would remain in orbit about it, observing the impact and analysing any changes in the asteroid internal structure, shape, orbit and rotation state as a consequence of the collision. The objectives of the mission would be to determine the asteroid internal structure, to constraint its mechanical properties, to determine the feasibility of coupling devices onto its surface and measure the orbital deflection of the asteroid as a result of the impact of the Hidalgo spacecraft. As an illustration of the mission concept and its versatility, a candidate mission has been selected considering one of the proposed DEFT, Athos, with optimum spacecraft masses and delta-v, compatible with the asteroid detection and estimated Earth impact date. Hidalgo arrival at Athos on 2012 would take place more than four years before the Earth impact, that could be time enough to allow the adaptation of a second mission -according to Don Quijote mission results - in order to enable an optimal asteroid deflection