Mission to Mars: the HiRISE camera on-board MRO

Abstract

Following its launch in August, 2005 and a year of interplanetary cruise and aero-braking, the successful Mars Reconnaissance Orbiter (MRO) mission is currently orbiting Mars and down-linking imagery from the High Resolution Imaging Science Experiment (HiRISE) camera. The primary objectives of the MRO mission are to characterize the present climate of Mars, look for evidence of water-related activities, and characterize potential landing sites. After only four months in the Primary Science Phase (PSP) of the mission, MRO has returned more data than any other previous Mars mission. Approximately one-third of this data volume is from the HiRISE camera, built by Ball Aerospace & Technologies Corporation (BATC), for the University of Arizona (UofA), Department of Planetary Sciences. With a 0.5-meter primary mirror, the HiRISE instrument includes the largest optical telescope ever sent beyond Earth's orbit, and is producing images with unprecedented resolution. It has detected objects of less than one meter size from the nominal orbit of 250 x 320 km. The highest resolution images have a scale of 25 to 32 cm per pixel (1.0 microradian IFOV). HiRISE is a "push-broom" camera with a swath width of 6 km in a broad red spectral band and 1.2 km in blue-green and near infrared bands. There are 14 CCD detector chips (2048 x 128 TDI elements each) on the focal plane. The HiRISE camera was designed to minimize use of spacecraft resources. Even with a half-meter primary mirror, through the use of lightweight glass optics and graphite-composite structures the final mass of the instrument is only 64.2 kg. It maintains a nearly uniform telescope temperature of 20°C yet its orbital average power consumption is less than 60 W. An overview is given of the NASA MRO mission and the HiRISE instrument. Pre-launch activities are detailed and the launch time discussed. An account is given of the cruise events, along with a description of aerobraking and the primary science phase. A sample of science results are presented, including a wealth of imagery.