P54A-05
The New Horizons Radio Science Experiment: Performance and Measurements of Pluto's Atmospheric Structure, Surface Pressure, and Surface Temperature
Friday, 18 December 2015: 16:54
2007 (Moscone West)
Ivan Linscott1, David P Hinson2, Michael Keith Bird3, Alan Stern4, Harold A Weaver Jr5, Catherine Olkin4, Leslie Ann Young6, Kimberly Ennico Smith7 and Atmospheres Science and Composition Theme Teams, (1)Stanford University, Stanford, CA, United States, (2)SETI Institute Mountain View, Mountain View, CA, United States, (3)Univ Bonn, Bonn, Germany, (4)Southwest Research Institute, Boulder, CO, United States, (5)Applied Physics Laboratory Johns Hopkins, Laurel, MD, United States, (6)Southwest Research Institute Boulder, Boulder, CO, United States, (7)NASA Ames Research Center, Moffett Field, CA, United States
Abstract:
The New Horizons (NH) spacecraft payload contained the Radio Science Experiment (REX) for determining key characteristics of Pluto and Charon during the July 14, 2015, flyby of the Pluto/Charon system. The REX flight equipment augments the NH X-band radio transceiver by providing a high precision, narrow band recording of high power uplink transmissions from Earth stations, as well as a record of broadband radiometric power. This presentation will review the performance and initial results of two high- priority observations. First, REX received two pair of 20-kW signals, one pair per polarization, transmitted from the DSN at 4.2-cm wavelength during a diametric radio occultation by Pluto. REX recorded these uplink signals and determined precise measurement of the surface pressure, the temperature structure of the lower atmosphere, and the surface radius of Pluto. The ingress portion of one polarization was played back from the spacecraft in July and processed to obtain the pressure and temperature structure of Pluto’s atmosphere. Second, REX measured the thermal emission from Pluto at 4.2- cm wavelength during two linear scans across the disk at close range when both the dayside and the night side are visible. Both scans extend from limb to limb with a resolution of one-tenth Pluto’s disk and temperature resolution of 0.1 K. Occultation and radiometric temperature results presented here will encompass additional data scheduled for playback in September.
