Ultra-Low Delta-v Objects and the Human Exploration of Asteroids

TL;DR

This paper highlights the significance of ultra-low delta-v near-Earth objects for human exploration, emphasizing the need for dedicated surveys to identify more accessible targets before 2025.

Contribution

It underscores the importance of ultra-low delta-v NEOs for mission feasibility and proposes a dedicated survey strategy from a Venus-like orbit to discover more such objects.

Findings

Only 65 of 6699 known NEOs have delta-v <4.5 km/s

Ultra-low delta-v NEOs are rare and hard to recover

A dedicated optical or mid-IR survey from Venus-like orbit is needed

Abstract

Missions to near-Earth objects (NEOs) are key destinations in NASA's new "Flexible Path" approach. NEOs are also of interest for science, for the hazards they pose, and for their resources. We emphasize the importance of ultra-low delta-v from LEO to NEO rendezvous as a target selection criterion, as this choice can greatly increase the payload to the NEO. Few such ultra-low delta-v NEOs are currently known; only 65 of the 6699 known NEOs (March2010) have delta-v <4.5 km/s, 2/3 of typical LEO-NEO delta-v. Even these are small and hard to recover. Other criteria - short transit times, long launch windows, a robust abort capability, and a safe environment for proximity operations - will further limit the list of accessible objects. Potentially there are at least an order of magnitude more ultra-low delta v NEOs but, to find them all on a short enough timescale (before 2025) requires a dedicated survey in the optical or mid-IR, optimally from a Venus-like orbit because of the short synodic period for NEOs in that orbit, plus long arc determination of their orbits.