NASA 2001 Mars Odyssey page 1 Workshop HEND Russian Aviation and Space Agency Institute for Space Research Orbital variation of counts rate in anti-coincidence detector of HEND Workshop “The First year of HEND operations on the NASA Odyssey Mars Orbiter” Moscow, Russia May 20-22, 2002

NASA 2001 Mars Odyssey page 2 Workshop HEND Russian Aviation and Space Agency Institute for Space Research Observations of anomalous signal in interplanetary space Time profiles for S4, S5 and soft channel S6 for all June 2001 CRUISE

NASA 2001 Mars Odyssey page 3 Workshop HEND Russian Aviation and Space Agency Institute for Space Research Spectra and time profile for soft channel S6 in “quiet” and “anomalous” periods area A on previous slide area B on previous slide 2001 June 01 – June 16 – 24 CRUISE

NASA 2001 Mars Odyssey page 4 Workshop HEND Russian Aviation and Space Agency Institute for Space Research Observations of anomalous signal near Mars Time profiles for S4, S5 and soft channel S6 for October 24 – November 29 AEROBRAKING

NASA 2001 Mars Odyssey page 5 Workshop HEND Russian Aviation and Space Agency Institute for Space Research Time profiles for S4, S5 and soft channel S6 for area (1) on previous slide. AEROBRAKING

NASA 2001 Mars Odyssey page 6 Workshop HEND Russian Aviation and Space Agency Institute for Space Research Spectra for “quiet” period (A) and for “anomalous” ones (B) area A on previous slide area B on previous slide 2001 October 24 – October 25 – 26 AEROBRAKING

NASA 2001 Mars Odyssey page 7 Workshop HEND Russian Aviation and Space Agency Institute for Space Research 1. All counts of soft channels of S6 projects on belt mainly between equator and 60 0 degree in north hemisphere without any correlation with topography. Variation of counts rate in anti-coincidence detector during mapping have some peculiar features: MAPPING Map of gamma albedo of Mars. (Data from 18 February to 16 May 2002)

NASA 2001 Mars Odyssey page 8 Workshop HEND Russian Aviation and Space Agency Institute for Space Research MAPPING Typical time profiles for soft channel S6. (Data for 11 March 2002) Illumination of Odyssey by Sun. (Solid angle of Mars minus Angle (Sun,Mars) for 11 March 2002) 2. All time profile of anomalous signal have similar structure: “day” and ” night” peaks.

NASA 2001 Mars Odyssey page 9 Workshop HEND Russian Aviation and Space Agency Institute for Space Research 4. Spectra of “day” and “night” peaks have different form. MAPPING

NASA 2001 Mars Odyssey page 10 Workshop HEND Russian Aviation and Space Agency Institute for Space Research MAPPING 3. All “day” peaks are shorter then “night” ones. Duration of “day” and ”night” peaks. (Data for typical days of March and April 2002)

NASA 2001 Mars Odyssey page 11 Workshop HEND Russian Aviation and Space Agency Institute for Space Research MODEL

NASA 2001 Mars Odyssey page 12 Workshop HEND Russian Aviation and Space Agency Institute for Space Research Red and blue parts of circular orbit of spacecraft are time intervals where “day” and “night” peaks of anomalous signal in soft channel of anticoincidence detector observed. MODEL