Minisat-1 (LEGRI)
Mission OverviewThe Minisat-1 mission was a Spanish-led mission with a primary instrument being the Low Energy Gamma-ray Imager (LEGRI), a coded masked prototype instrument. The satellite was launched on April 21, 1997 from a Pegasus XL rocket (a “winged” rocket dropped from an aircraft) and the LEGRI instrument onboard was activated on May 19, 1997. The instrument was a collaboration between the University of Valencia, University of Alicante, Centro de Investigaciones Energeticas, Medioambientales y Technologicas (CIEMAT), Instituto Nacional de Technica Aerospacial (INTA), University of Southampton, University of Birmingham, and the Rutherford Appleton Laboratory. Minisat-1 was the first operational mission in the Minisat series. It was planned with a two year mission span, but ultimately operated sucessfully for five years before re-entry into the Earth’s atmosphere. LEGRI was not the only instrument on MiniSat-1, but is the primary one of interest to high-energy astrophysics. InstrumentationLEGRI was a coded mask array gamma ray detector. The detector plane was a mosaic of 10 x 10 of 80 HgI2 and 20 CdZnTe crystals 0.5 cm thick with an active area of 1 cm2: the mixed detectors were intended to test differing technologies under identical conditions. The detector was passively shielded on the back and sides by the mechanical assembly and by a tantalum collimator and aluminium window in the pointing direction. The coded mask was mounted 540 mm in front of the instrument and was made of tungsten elements attached to a honeycomb plate and support structure. A start sensor allowed precise tracking of attitude of the spacecraft to permit ground-based analysis without blurring from spacecraft motion. The instrument has a spatial resolution of 20 arcminutes, and could perform moderate spectroscopy (with 4 keV resolution at 30 eV). ScienceLEGRI was primarily a proof-of-concept mission for coded-mask gamma-ray imaging. Having shown the concept worked, LEGRI detected and characterized gamma-ray burst sources in particular. Page authors: Lorella Angelini Jesse Allen HEASARC Home | Observatories | Archive | Calibration | Software | Tools | Students/Teachers/Public Last modified: Thursday, 24-Sep-2020 17:21:49 EDT HEASARC Staff Scientist Position - Applications are now being accepted for a Staff Scientist with significant experience and interest in the technical aspects of astrophysics research, to work in the High Energy Astrophysics Science Archive Research Center (HEASARC) at NASA Goddard Space Flight Center (GSFC) in Greenbelt, MD. Refer to the AAS Job register for full details. |