Acta Astronautica vol. 220 (Jul 2024) is a good one:
Nath, A. Developing algorithms to determine an Asteroid’s physical properties and the succ… p. 62 2024.04.019
Schulc, M. Czakoj, T. Novák, Even et al. Validation of SiO2 neutron cross sections for aster… p. 88 2024.04.006
Chabot, N. Adams, E. Rivkin, A. et al DART: Latest results from the Dimorphos impact and… p. 118 2024.04.001
Guidi, C. Becatti, G. Bernazzani, L. et al. Study on the compatibility between iodine and co… p. 392 2024.04.027
Conway, B. A. Speziale, A. Malagni, L. Optimal combined impulsive/low-thrust trajectories… p. 516 2024.04.021
Nath examines the ability to gauge an asteroid with incomplete information. Only a spacecraft gives the full picture, with “diameter” (that is, 3D shape, for nonspheres), at least some spectra (giving asteroid type), and mass (with a good transmitter and a favorable flyby speed), plus unambiguous determination of the orbit, spin state, (in)homogeneity, any asteroid moons, etc. But there’s no way we can send a probe to +1 million asteroids, plus comets as necessary. We then need to piece together what we can from remote sensing (telescope) data. Should we need to deflect that incoming asteroid, we would then need new information, on the post-deflection state of the body.
Schulc et al. then consider the big blow: how do asteroids respond to nuclear deflection? A hydrogen bomb releases a lot of its energy as neutrons, which are highly penetrating. How does asteroid-typical rock respond to such neutron irradiation?
And while we’re on the subject of deflection, what’s the latest from DART? The project scientists put out the paper.
Less dramatically, electric thrust is an enabling technology. Cubesats are a vital piece of the NewSpace new world. Iodine unites electric propulsion for Cubesats, since iodine packs readily into these limited volumes, and is approved for launch as such secondary payloads (iodine is no real threat to the rocket or primary payload). Iodine propulsion, therefore, enables many, new, cheap missions. Missions like… asteroid probes!
Somewhat related/somewhat not: Conway et al. examine trajectories for deflector spacecraft. If we had all the warning in the world, an electric thruster would get us pretty much anywhere a threatening asteroid would be. But we don’t assume infinite warning time. We haven’t found and tracked most of the smaller (~100 to several hundred meters diameter) threats, nor do we have years and years of warning for a long-period comet that has a bad orbit. We then need some amount of rapid (chemical) propulsion in the mission, and perhaps some Electric Prop (EP) for efficiency and flexibility. What does a mixed-mode trajectory to a threatening asteroid shape up as?
Sorry if I’m dwelling on bad news, bad sub-topics. These are questions we’re asking ourselves now, so we don’t have to rush an answer in some putative crisis moment.