The journal Acta Astronautica for Sep 2025 (vol. 234) has:
Hosonuma, T. Miyabara, T. Ozaki, N. et al. Autonomous optical navigation for DESTINY*: Enhancing misalignment robustness in flyby observations with a rotating… Pgs. 117 .2025.04.023
Li, Y-H. Lien, W-C. Liu, S-W. Development of a hanging pendulum thrust stand for pulsed plasma thrusters Pgs. 368 .2025.05.003
Arnold, W. Becker, M.M. Fischer, H.-H. et al. Complete CASSE acceleration data measured upon landing of Philae on comet 67P at Agilkia Pgs. 480 .2025.03.044
The DESTINY+ mission will fly by “asteroid” (3200) Phaethon (now an exemplar along the comet-asteroid transition). But Phaethon’s orbit is very elliptical, one of the things that make it comet-like. To orbit around it would take ridiculous fuel mass (and therefore cost), or a torturous trajectory of many planet flybys (also incurring mission costs). JAXA opted for a flyby only, at a steep crossing angle, and thus high relative speed. DESTINY+ will cross so fast, it will only get a brief span to take data. At issue: maximize science results, and lower the chances of spoiled shots (images with Phaethon framed poorly, or not in frame at all). Hosonuma et al. ponder it: the probe has some ability to pan and frame its target, without commands (and their delays) from the ground.
Li et al. is more straightforward, but also involves turning. All thrusters must be well-tested on the ground; no one’s going to risk a mission (and possibly their career) by unproven systems. But with electric propulsion, thrusts are so low as to be negligible versus Earth conditions (mostly gravity, plus others). One might cynically say you can’t fly without testing, but you can’t test without flying. The circle has to be broken by building thrust chambers that can replicate space conditions, starting with gravity. Li et al. do so, hanging thrusters on a pendulum, with low friction.
And now we turn to space conditions, in hindsight instead of forward planning. The Rosetta mission’s Philae lander (arguably) botched its landing, failing to ‘stick’ it, and ending up settling on its side. This caused several experiments to fail (they got pointed to empty space, not the comet). We now make the best of what we got: what were the bounce properties, as measured by the lander’s accelerometers? With accelerometer data, we might at least derive properties of the comet surface at the (multiple) bounce sites. Fertile ground, metaphorically (and literally?).