The TEMPEST technology demonstration (TEMPEST-D) mission is in development to raise the TRL of the instrument and spacecraft systems from 6 to 9 as well as to demonstrate radiometer measurement and differential drag capabilities required to deploy a constellation of 6U-Class satellites in a single orbital plane. The TEMPEST-D millimeter-wave radiometer instrument provides observations at five frequencies from 89 to 183 GHz using a single compact instrument designed for 6U-Class satellites. The direct-detection topology of the radiometer receiver substantially reduces its power consumption and eliminates the need for a local oscillator and mixer, thereby decreasing complexity compared to heterodyne receivers. The TEMPEST-D instrument is self-calibrating, using a cross-track scanning reflector to view an ambient blackbody calibration target and cosmic microwave background every scan period, enabling precision end-to-end calibration of the millimeter-wave radiometers. The TEMPEST-D radiometer instrument has been fabricated and successfully tested under environmental conditions (vibration, thermal cycling and vacuum) expected in low-Earth orbit.
The top-level requirements for the TEMPEST-D mission are to: (1) demonstrate precision inter-satellite calibration between TEMPEST-D and one other orbiting radiometer (e.g. GPM or MHS) measuring at similar frequencies; and (2) demonstrate orbital drag maneuvers to control altitude to 100 m or better, as verified by GPS, sufficient to achieve required temporal spacing in a constellation of 6U-Class satellites.
TEMPEST-D began in August 2015, with a rapid 2.5-year development to deliver a complete flight system with integrated payload by February 2018. TEMPEST-D has been manifested by NASA CSLI and is planned for launch on ELaNa-23, a commercial resupply service to the ISS on a Cygnus Antares II, in March 2018. The TEMPEST-D satellite is expected to be deployed into a 400-km orbit at 51.6° inclination several months after arriving at the ISS.