Gravity and Extreme Magnetism
Artist's impression of GEMS.
|
|
| Names |
SM X-13 |
|---|---|
| Mission type | X-ray astronomy |
| Operator | NASA |
| Website | gems |
| Mission duration | 9 months (primary) 15 months (extended) |
| Spacecraft properties | |
| Bus | LEOStar-2/750 |
| Manufacturer |
Orbital Sciences Alliant Techsystems |
| Launch mass | 288.7 kg (636 lb) |
| Dimensions | 7.12 m × 2.73 m (23.4 ft × 9.0 ft) |
| Start of mission | |
| Launch date | Cancelled |
| Rocket | Pegasus XL |
| Launch site |
Stargazer Cape Canaveral AFS |
| Contractor | Orbital Sciences |
| Orbital parameters | |
| Reference system | Geocentric |
| Regime | Low Earth |
| Eccentricity | 0° |
| Perigee | 575 km (357 mi) |
| Apogee | 575 km (357 mi) |
| Inclination | 28.5° |
| Epoch | planned |
| Instruments | |
| X-ray Polarimeter Instrument | |
|
|
|
SM
The Gravity and Extreme Magnetism SMEX (GEMS) mission was a cancelled space observatory mission. The main scientific goal of GEMS was to be the first mission to systematically measure the polarization of cosmic X-Ray sources. GEMS would have provided data to help scientists study the shape of space that has been distorted by a spinning black hole's gravity and the structure and effects of the magnetic fields around Neutron stars. It was cancelled by NASA in June 2012 for potential cost overruns due to delays in developing the technology.
GEMS was managed by the National Aeronautics and Space Administration NASA, the United States space agency, at the Goddard Space Flight Center. The project was an astrophysics program reporting to NASA's Science Mission Directorate (SMD) in Washington, D.C..
The spacecraft would have been launched on in July 2014 on a nine-month mission with a possible 15-month extension for a guest observer phase; but the mission was terminated at the Confirmation Review stage on May 10, 2012 due to expected cost overruns.
Cancelled missions can be reinstated— for example NuSTAR was cancelled in 2006, but reinstated a year later and launched in June 2012. However, NuSTAR was not cancelled due to project overruns, but rather due to changes in the overall NASA budget, so the circumstances for cancellation were very different. Of course small missions of the Explorer program offer a lot of flexibility and launch opportunities, and the lessons learned can be applied to the same missions goals, but on a different mission (Compare Vanguard 1 to Explorer 1) Just a couple years later two new X-ray polarimetry mission won a NASA award to develop a X-ray polarimetry missions.
The GEMS X-ray telescope was designed to indirectly measure the regions of distorted space around spinning black holes through a measurement of the polarization of X-rays emitted. It will thereby probe the structure and effects of the magnetic field around magnetars and dead stars with magnetic fields trillions of times stronger than Earth's.
...
Wikipedia