Abstract:
Access to the surface of the icy moons around Saturn and Jupiter is made difficult by the large ΔV requirements for orbital insertion and subsequent soft landing on the moon’s surface. The ΔV are difficult to reduce because most of the moons have no atmosphere so that aero-braking is not possible. These restrictions can be removed through the development of what we describe as cryo-braking through the generation of a temporary ice-particle atmosphere. In this scheme a hyper-velocity impactor is used to create a collimated high velocity spray that is ejected upwards towards the incoming payload. It is shown that with careful design of the impactor the mass of the ejected ice-particles can be at least two orders of magnitude greater in mass than the impactor. Furthermore, the ice-particles undergo velocity dispersion so that the highest velocity particles but with relatively low density reach the payload first to produce initial slowing. In this way the acceleration and velocity of the payload section can be slowly reduced to levels for which electronics is known to survive, This deceleration requires no propellant and thereby would greatly increase the mass fraction that can be delivered to the surface and survive. The system also has the advantage that it will enable exposure of the sub-surface material without necessarily destroying any organics that might be present in the subsurface material.
About the Speaker:
Professor Winglee received a PhD from the University of Sydney in 1985. He is currently a professor of Earth and Space Science at the University of Washington, Seattle. He has extensive experience in space plasma physics and engineering, particularlyin relation to the space environments around the planets and advanced space propulsionsystems. Significant areas of research include the generation of auroral radiation, heating of ionospheric ions in the auroral zone, the active injection of beams fromspacecraft, reconnection in the magnetotail and magnetopause, ionospheric ion outflows, and planetary magnetospheres, and the development of electrodeless plasma systems for in-space propulsion. He also continues to work with developing opportunities for students in higher education in Science, Technology, Engineering and Math through his activities associated with the Washington NASA Space Grant Consortium.
