Astronomy and Astrophysics – Astronomy
Scientific paper
Sep 2006
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006dps....38.2410j&link_type=abstract
American Astronomical Society, DPS meeting #38, #24.10; Bulletin of the American Astronomical Society, Vol. 38, p.523
Astronomy and Astrophysics
Astronomy
Scientific paper
INTRODUCTION: Measurements from Cassini have determined that warm "tiger stripe” regions on Enceladus are made of water ice that is at a temperature of up to 157 +/-32K (Spencer et al, Science, 311, 1401, 2006). If the tiger stripe region is assumed to be pure polycrystalline water ice, and if liquid water exists below the ice lithosphere, then thermal analyses show that the thickness of the ice is less than 40-m. Two possible means to penetrate the ice are described below.
HARPOON PENETRATOR: Sandia National Laboratories has published reports, which give ground penetration depth as a function of various projectile parameters. Applying the Sandia equations (Young, SAND97-2426, 1997) to an Enceladus penetrator, one example shows that a sharp, steel penetrator, that is 10 cm diameter and 2-m length (132 kg) could penetrate through 40-m of ice with an impact velocity of about 150 m/sec and maximum deceleration of 350 g's. This allows ruggedized science instruments to be carried on the harpoon and tethered to an antenna dropped off at the surface level, as was done in many of the Sandia tests. Larger diameters or shorter rods require higher velocities and higher g's.
SUBLIMATION PENETRATOR: Calculations have also been performed on soft-landed, heated probes. Using power tethered from the surface craft, the penetrator would sublimate down to the liquid layer. Assuming a 3-cm diameter probe with a 50-w heated tip, the probe would descend at the rate of about 1-m per day with descent rates approximately proportional to power/area. An insulated cylindrical area above the heated tip could contain ports for science instruments that could be located on the surface craft with data transmitted by optical fiber.
This research was carried out at Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.
Castillo Julie C.
Jones Jack A.
No associations
LandOfFree
Penetration of Enceladus Ice Tiger Stripes does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Penetration of Enceladus Ice Tiger Stripes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Penetration of Enceladus Ice Tiger Stripes will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-999421