Sunday, July 1, 2018

GRACE

 2002-012A


The second ESSP mission is the Gravity Recovery and Climate Experiment (GRACE), a joint NASA/DLR mission. Two GRACE satellites in 450 x 450 km x 90 deg orbits will measure gravity field variations and maintain a 200 km distance. The two satellites, each with a mass of 475 kg, will be launched on a single Rokot rocket in 2001 Jul. The satellites will be built Astrium (Dornier)/Friedrichshafen, and the project is a joint effort between NASA and DLR, run by the U Tex. Austin and GFZ (GeoForschungsZentrum) in Potsdam with project management by JPL. It uses the Astrium FlexBus platform, like CHAMP.

3.1 x 0.77 x 1.9m, 475 kg each, stacked vertically on either side of an MSD (Multi Satellite Dispenser) aboard Briz-M. MSD is built by Krunichev and Astrium RST/Rostock. FM1 and FM2 nicknamed 'Tom' and 'Jerry' during integration.

Sats to be spaced 220 km apart. GRACE 1 swapped with G2 to become the trailing satellite in Dec 2005. Separation was reduced to 70-170 km for one month.


GRACE 1 
 

DateTimeEventOrbit  

2002 Mar 17  0921:27  Launch by Rokot  PL LC133/1 
  T+2:16 St 1 sep 
  T+3:05 Fairing sep
  T+5:19 St 2 sep 
  T+5:19 Bris MES-1 
 0936:28 T+15:01 Briz MECO-1  300 x 300 x 86.4? 
 1042 T+1:20:38 Briz MES-2 34s  300 x 500 x 86.4 
  T+1:20:54 Briz MECO-2 
 1047 T+1:25:38 GRACE sep  500 x 500 x 90 
  T+1:41 CCAM burn 
2005 Apr 6   Small inclination diff added 
2005 Dec 3   OTM-1 Grace-2 Orbit trim for swap burn at -203 km  
2005 Dec 10  0347 GR-2 pass GR-1 at 406m 
2005 Dec 12   GR-2 OTM-2, +58 km, 3.3 km/d 
2006 Jan 11   GR-2 OTM-3 at +170 km, 0.5 km/d  
2017 Dec   Out of prop 
2017 Dec 13   Last contact 
2018 Mar 10  0610? Reentered 

Payload:

  • GPS system

  • Microwave intersatellite link



2002-012B

The second ESSP mission is the Gravity Recovery and Climate Experiment (GRACE), a joint NASA/DLR mission. Two GRACE satellites in 450 x 450 km x 90 deg orbits will measure gravity field variations and maintain a 200 km distance. The two satellites, each with a mass of 475 kg, will be launched on a single Rokot rocket in 2001 Jul. The satellites will be built Astrium (Dornier)/Friedrichshafen, and the project is a joint effort between NASA and DLR, run by the U Tex. Austin and GFZ (GeoForschungsZentrum) in Potsdam with project management by JPL. It uses the Astrium FlexBus platform, like CHAMP.

3.1 x 0.77 x 1.9m, 475 kg each, stacked vertically on either side of an MSD (Multi Satellite Dispenser) aboard Briz-M. MSD is built by Krunichev and Astrium RST/Rostock. FM1 and FM2 nicknamed 'Tom' and 'Jerry' during integration.

Sats to be spaced 220 km apart. GRACE 1 swapped with G2 to become the trailing satellite in Dec 2005. Separation was reduced to 70-170 km for one month.


GRACE 1 
 

DateTimeEventOrbit  

2002 Mar 17  0921:27  Launch by Rokot  PL LC133/1 
  T+2:16 St 1 sep 
  T+3:05 Fairing 
  T+5:19 St 2 sep 
  T+5:19 Bris MES-1 
 0936:28 T+15:01 Briz MECO-1  300 x 300 x 86.4? 
 1042 T+1:20:38 Briz MES-2 34s  300 x 500 x 86.4 
  T+1:20:54 Briz MECO-2 
 1047 T+1:25:38 GRACE sep  500 x 500 x 90 
  T+1:41 CCAM burn 
2005 Apr 6   Small inclination diff added 
2005 Dec 3   OTM-1 Grace-2 Orbit trim for swap burn at -203 km  
2005 Dec 10  0347 GR-2 pass GR-1 at 406m 
2005 Dec 12   GR-2 OTM-2, +58 km, 3.3 km/d 
2006 Jan 11   GR-2 OTM-3 at +170 km, 0.5 km/d  
2017 Sep 3   Partial battery failure 
2017 Sep 8   Mission recovered 
2017 Oct 27?  End of science mission 
2017 Dec 24  0016?  Reentered 

No comments:

Post a Comment

These Are Not My Beautiful Stories

  Summary: The chapters within are outlines for both future stories I’ve got planned (in the case that I never get around to writing them) a...