Low delta-V near-Earth asteroids: A survey of suitable targets for space missions

摘要

In the last decades Near-Earth Objects (NEOs) have become very importanttargets to study, since they can give us clues to the formation, evolution andcomposition of the Solar System. In addition, they may represent either athreat to humankind, or a repository of extraterrestrial resources for suitablespace-borne missions. Within this framework, the choice of next-generationmission targets and the characterisation of a potential threat to our planetdeserve special attention. To date, only a small part of the 11,000 discoveredNEOs have been physically characterised. From ground and space-basedobservations one can determine some basic physical properties of these objectsusing visible and infrared spectroscopy. We present data for 13 objectsobserved with different telescopes around the world (NASA-IRTF, ESO-NTT, TNG)in the 0.4 - 2.5 um spectral range, within the NEOSURFACE survey(http://www.oa-roma.inaf.it/planet/NEOSurface.html). Objects are chosen fromamong the more accessible for a rendez-vous mission. All of them arecharacterised by a delta-V (the change in velocity needed for transferring aspacecraft from low-Earth orbit to rendez-vous with NEOs) lower than 10.5 km/s,well below the Solar System escape velocity (12.3 km/s). We taxonomicallyclassify 9 of these objects for the first time. 11 objects belong to theS-complex taxonomy; the other 2 belong to the C-complex. We constrain thesurface composition of these objects by comparing their spectra with meteoritesfrom the RELAB database. We also compute olivine and pyroxene mineralogy forasteroids with a clear evidence of pyroxene bands. Mineralogy confirms thesimilarity with the already found H, L or LL ordinary chondrite analogues.