HEND has finished the measurements of  3-D cloud of neutrons around Mars

During the month (November 19 – December 19, 2001) of Odyssey aerobraking flight the Russian instrument HEND has accumulated very large volume of data for the flux of neutrons at the totality of about 70 shrinking orbits for distances from 250 km up to 20 000 km from the surface of Mars. These data allows to build up the 3-D model of neutrons cloud of the planet. The model will provide the necessary background for the circular 400 km orbit of the future mapping stage of the mission, when HEND has to measure the variations of neutrons albedo over the surface. The detection rates of neutrons with energies about several MeV are presented below for different distances from the surface of the planet, which are averaged for regions with North latitudes around 70° and with longitudes 210°-300° and 30°-120° (red and blue dots, respectively).

Instrument HEND has been developed in the Institute for Space Research by the order from Russian Aviation and Space Agency, and it has been implemented on the US spacecraft in accordance with the Implementing Agreement between the US National Aeronautics and Space Administration and the Russian Aviation and Space Agency.

HEND Principal Investigator  I.G. Mitrofanov

December 21, 2001