A Robotic Penetrator for the Main Belt Comet 133P/Elst-Pizarro Exploration
Abstract
Comparing the isotopic composition of the D/H ratio of the water ice in the main belt comets (MBCs) to that of the oceans on the Earth can enhance the understanding of where the water comes from and how the distribution of the water ices in our early solar system. Since 133P/Elst-Pizarro is the first observed MBC and has been confirmed as active at repeated perihelia, it has been selected as one of the two potential targets in China's next asteroidal exploration mission. As scheduled, asteroid (2016HO3) will be detected first around 2024 then after almost 7 years of flight the mother ship will arrive at 133P/Elst-Pizarro finally. By analyzing the D/H ratio of possible eruptive volatiles with several remote-measuring payloads on the mother ship, it is expected to determine whether MBCs were a major contributor to the water delivered to the early Earth, however, when the mother ship arrives 133P/Elst-Pizarro still stays inactive, making the expected volatiles hard to detect. Herein, a robotic penetrator with a turbo-blasting explosion subsystem has been proposed to realize a 1m class in-situ subsurface detection and create an artificial crater. After dethatching from the mother ship, this penetrator will be propelled by a small rocket to over 150m/s, meanwhile, the mother ship quickly moves to a safe zone. During the penetrating process, an inner accelerator records the online penetrating loads that can be applied to recognize the mechanical properties of the in-situ rubble pile material. Under the above high speed penetrating interactions, volatiles around the penetrator will be heat-induced from the rubble pile cavities and be diffused into an ion-trap mass spectrometer inside the penetrator. After that, a helium type turbo-blasting subsystem will be delayed to detonate, making a non-contamination explosion on the surface. Under the rapid turbo-blasting interaction, the surrounding rubble piles will be definitely blown away, leaving an artificial crater for further remote observation. Currently, preliminary system design and validation tests on the penetrator have been finished. To realize a final deployment, the system's total mass and peak power should be controlled within 6.5kg and 12.5W, respectively. Future work in the autonomous detection will look at the integration of the penetrator system, the optimization of penetrating ability, and the measurement of volatiles' abundance.
- Publication:
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43rd COSPAR Scientific Assembly. Held 28 January - 4 February
- Pub Date:
- January 2021
- Bibcode:
- 2021cosp...43E.153T