MightySat-2.1

MightySat-2.1, also known as P99-1 or Sindri was a small spacecraft developed by the Air Force Research Laboratory to test advanced technologies in imaging, communications, and spacecraft bus components in space.

Design
MightySat II.1 was manufactured by Spectrum Astro in a modular approach, using, e.g., VME-based subsystems, and a planar payload deck for small experimental payloads. The satellite measured 0.67m x 0.83m x 0.86m (WxLxH) and had a launch weight of 123.7 kg (Bus Mass: 87.1 kg). Power was provided by 2-axis articulated Si solar arrays with a designed end-of-life power output of 330 W. The attitude determination and control subsystem featured a 3-axis zero-momentum-bias reaction wheel assembly with a Sun sensor, a star tracker and inertial measurement units, delivering an attitude jitter of 15.7 arcsec/sec, and pointing accuracy and knowledge of 648 and 540 arcsec, respectively. The communication was compatible with the US Air Force space-ground link system with data rates of 1 Mbit/s for payload/experiments data downlink, 2.0 kbit/s for command uplink, and 20 kbit/s for telemetry downlink. Computing and data handling was done by a RAD6000 CPU @ 20 MIPS with an IEEE VME backplane 128 MByte CPU RAM, and a 21.6 MBytes/sec transfer rate, and a 2 Gbit solid state recorder for science data. Among its 10 experiments was a Fourier transform hyperspectral imager.

Mission
MightSat II.1 was launched on July 19, 2000, with a Minotaur I. It deorbited in November 2002 due to natural decay of its orbit, exceeding more than twice its nominal lifetime.

Stand-alone experiments/sensors

 * Kestrel Fourier transform (visible) hyperspectral imager
 * Quad TMS320C40 (QC40) floating point digital signal processor
 * DARPA-Aerospace sponsored PicoSat launcher assembly
 * Shape memory alloy thermoelastic tailoring experiment
 * Starfire optical reflectors for use with Kirtland's Starfire Optical Range

Engineering/experimental bus components

 * NRL miniature SGLS transponder (known as the NSX)
 * Multi-functional composite bus structure
 * Solar array concentrator
 * Advanced composite solar array substrate
 * Solar array flexible interconnect