GRACE 1

GRACE= Gravity Recovery and Climate Experiment
Also called ESSP 2A or Tom

Prime contractor	Jet Propulsion Laboratory (NASA)/Space Systems/Loral/Astrium GmBH
Platform
Operator	GeoForschungsZentrum (GFZ)/Center for Space Research, University of Texas
Mass at launch	480 kg
Dry Mass	445 kg
Basic shape
Dimension (m)
Equipment
Solar array
Stabilization
Propulsion
DC power	150 W

Re-entered date:	10 March 2018
Lifetime:

Map gravitational mini-variations caused by sea-level changes, glaciers and melting/freezing of ice sheets by measuring distance between satellites.

The GRACE 1 satellite reentered on March 10, 2018 ending the GRACE mission that began in 2002. The identical GRACE 1 and 2 satellites, built by Astrium/Bremen, were operated by the GeoForschungsZentrum Potsdam for the German space agency DLR and by JPL and UT Austin for NASA. They were launched together on a Rokot from Plesetsk into a 450 x 466 km x 89 deg orbit, which decayed to around 300 km by late 2017. The satellites flew in the same orbit about 200 km apart, measuring slight changes in acceleration over space and time due to uneven distribution of mass on the Earth, sensitive enough to detect changes in ocean currents, ice sheets and aquifers. The GRACE science mission ended on 2017 Oct 27, with a battery failure on GRACE 2.
GRACE 2 reentered on Dec 24, 2017. GRACE 1 continued transmitting until Dec 13, by when it had run out of propellant and had been passivated.
A similar dual-satellite mission, GRAIL, carried out analogous gravity mapping of the Moon.

Ref: #3(SD545), #7(JR747), #226 - update: 08.09.18