Technical Budgets Mass Power Pointing knowledge and accuracy

Technical Budgets Mass Power Pointing knowledge and accuracy Data downlink Fairing envelope Orbit (Heat)

Mass Budget (1) - Launcher, Observatory, S/C, LAT, GBM -

Mass Budget (2) - Current Status of LAT Mass -

Mass Budget (3) - Center of Mass above the S/C Interface Max Height off the S/C interface for Center of Mass = 185 mm

Mass Budget (4) - History and Release of Contingency -

Mass Budget (5) - How well do we know? -

Power Budget (1) - LAT and GBM -

Power Budget (2) - Current Status and Breakdown - * * ACD estimate under review May vary slightly

Power Budget (3) - History and Release of Contingency -

Power Budget (4) - How well do we know? Big uncertainties: ²Size of the radiator panels to dump the heat ²Heater to maintain the minimum temperature during Safehold mode ²Number of CPUs required for on-board data processing

Pointing Knowledge (1) - Nomenclature -

Pointing Knowledge (2) - Allocation -

Pointing Knowledge (3) - Absolute Pointing Accuracy -

Pointing Knowledge (4)

Pointing Knowledge (4) LAT Alignment 18 March 2002 S. Ritz version 1. 1 The total numbers of the track required for the inner- and inter-tower alignments are 2000 x 16 = 8. 0 M tracks and 230 K x 16 = 3. 7 M tracks, respectively. The total data size is (8. 0 M + 3. 7 M ) x 2 k. B/event = 23. 4 GB (2 k. B/event is tentative number and to be determined). 300 kbps, it takes 9 days to send data to the ground. Tracker Alignment. Assuming and Pointing Accuracy Eduardo do Couto e Silva and Hiroyasu Tajima SLAC February 26, 2002 (ver. 0. 1) March 5, 2002 (ver. 0. 2)

Data Downlink (1) - Latency -

Data Downlink (2) - Volume From: Bartels, Arlin [mailto: abartels@staac-mail. gsfc. nasa. gov] Sent: Sunday, February 17, 2002 14: 09 To: Steve Ritz Subject: RE: LAT IRD rev. A - final review copy prior to draft SC RFO Steve, I'm removing the TBR because I don't see the point of leaving it "unresolved". Since I'd be writing a CCR anyway at some point, either to remove the TBR or to change the number, the only reason to leave this as a TBR is to imply some uncertainty in the number being the correct one in the first. I'm not aware of any GLAST Project plans to ask the LAT to lower the LAT output below 26 Gb/24 h, so the TBR doesn't really apply. -Arlin LAT Science gets 300 kbps but may not be more.

Data Downlink (3) - Storage -

Fairing Envelope (1) - Specification -

Fairing Envelope (2) - LAT Size -

Fairing Envelope (3) - LAT in Delta II Capsule See next page 1 -zone Radiator Cut-outs for possible S. A. launch locks Hole to accommodate Solar Array mast VCHP reservoirs GLAST rotated 45 deg to clear PAF mounting bosses LAT with updated Radiator package, 6935 PAF, and SC stayclear volume in the Delta-II fairing Radiator Mount Bracket at 4 corners of Grid

Fairing Envelope (4) - Constraints from GBM and Star trackers ACD+MLI+MMS stay clear Radiator panel Star tracker FOV? Shortest clearance 12. 5 mm 1851 mm 2743 mm ? mm 1796 mm 1990 mm Delta-II H Fairing

Orbit and Attitude (1) - Coordinate Systems (1) -

Orbit and Attitude (2) - Coordinate Systems (2) -

Orbit and Attitude (3) - Specification -

Orbit and Attitude (4) - Body Coordinate System -