Mars Odyssey PSG

1
Mars Odyssey PSG Mission Status Gaylon W.
McSmith Robert A. Mase June 9, 2003
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Mars Odyssey Mission Status

• Spacecraft operations are nominal
• All Science payload suites are collecting data in
  a nominal fashion
• April 7, 2003 marked the 2-year anniversary of
  Odyssey launch
• On this date, we completed our 5000th mapping
  orbit
• Mission Statistics (May 2003)
• Day 443 of the 917-day science mission (48
  complete)
• Day 338 since GRS Boom Deploy (49 of one
  Mars-year)
• Total Mapping Orbits 5380 (6196 since MOI)
• 761 days past Launch (61 of mission complete)
• Launch April 7, 2001 End of Primary
  Mission August 24, 2004
• Science Data Return
• Total Science Data Returned to Date 155 Gbytes
• Planned Data Volume for 917-day Science Mission
  126.5 Gbytes
• DSN allocations better than planned, operations
  enhancements

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Mars Odyssey Propellant Budget
Total Fuel in the Tanks (Feb 2002) 46.2 kg 3
kg Unusable 2.4 kg Total Fuel Available for
Mapping (Feb 19, 2002) 43.8 kg Expected A
ctual Usage Allocation Usage to Date (1 May
2003) Contingency 8.2 kg 2.6 kg 0.0 kg Safe
Mode 5.0 kg 1.6 kg 0.2 kg Momentum Mgmt 11.5
kg 3.7 kg 2.0 kg Orbit Maintenance 3.7 kg 1.2
kg 0.0 kg Extended Science 1.9 kg - 0.0 kg PQ
Orbit Raise 3.4 kg - 0.0 kg Unallocated 10.1
kg - 0.0 kg Total 43.8 kg 9.1 kg 2.2 kg Total
Usable Propellant Remaining 41.6 kg 3 kg
Allocations for 1374-day mission
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Mars Odyssey Recent Spacecraft Activity
Recent Spacecraft Activity Jan-Apr Executed 14
NSP Demo Passes (18 Scheduled) Jan 7 Activated
the MARIE auto-download/erase block Jan
15 Increased THEMIS APID30 packet buffer
allocation Jan 24 Uplinked Safe-Mode emergency
desat parameters Jan 27 Multi-Spacecraft DDOR
demo pass (w/ MGS) Feb 4 Solar Array gimbal
cycle and reposition Feb 4 110 kbps data rate at
70m stations Feb 13 Updated DPT for small-packet
issue Feb 22 Multi-Spacecraft DDOR demo pass (w/
MGS) Apr 7 Completed 5000th Mapping Orbit Apr
10 Demonstration of 124 kbps data rate Apr
28 Solar Array gimbal cycle
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Mars Odyssey Plans for Next Quarter

• Plans for the next 3 months
• Continue UHF relay capability development and
  testing
• UHF testing with MER test-set at LMA (May 5-9)
• Complete UHF Stanford test plans
• Execute tests in June - Sep 2003
• Continue OTM planning for Sun-synchronous
  maneuver (Oct 2003)
• Plan for Demo tracks to prepare for Asset
  Contention Period (ACP)
• DEMOs with Parkes and New Norcia
• Arraying in an MSPA configuration
• 2-MSPA with uplink swaps
• Continue DDOR campaign to support MER (thru Nov
  2003)
• Study phasing ODY orbit to support MER SOL-1
  overflight

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Mars Odyssey Schedule
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Mars Odyssey Network Simplification Project (NSP)

• Transition to NSP is complete
• All stations are now transitioned to NSP or down
  for NSP upgrade
• During Feb - April, up to 4 of 10 stations were
  down at once for upgrade
• ODY had less tracking, more MSPA than usual
• ODY impacted by stations not returning to service
  on schedule
• And by changing DEMO tracks
• Future Capability Upgrades that will impact
  Odyssey
• All will require ODY demonstration tracks in the
  fall to prepare for the Asset Contention Period
  (ACP)
• 2-MSPA with multiple uplink swaps
• Array capability with MSPA
• Alternate Assets - in case of spacecraft
  emergency during ACP
• Parkes and New Norcia, both in Australia

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Mars Odyssey UHF System Test with Stanford

• Program desire to characterize ODY UHF system
• Discovered 6dB (forward) and 2dB (return) losses
  in cruise tests
• Can still meet MER requirements if system has not
  degraded further
• Avoid last-minute surprises, time to re-plan if
  negative result
• Major challenges have been addressed
• Instrument FOV constraints
• Test in three phases
• Power-on test - does not involve Stanford - early
  June (completed)
• Nadir-point test (no attitude change) - late June
• Earth-point test - mid-August
• Project continues to work implementation details
• Scope/goals of each test
• Test timeline and scheduling of Stanford antenna
• Identification of backup opportunities

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Mars Odyssey UHF System Test with Stanford

• Likely Scenario for Earth-point test
• Test tentatively scheduled for 25 Aug 2003
• Would perform one activity to point UHF at Earth
• Accommodates all S/C and instrument FOV
  constraints throughout
• 10 minute slew to Earth-point attitude
• Dwell at Earth-point for 20 minutes
• 15 minute dogleg-slew to return to nadir-point
• Dogleg to avoid Mars in GRS cooler FOV during
  slew
• Would dedicate an orbit to this activity
• May possibly be repeated a few days later
• Will identify backup opportunity to perform test
  again a few weeks later
• Only re-test if necessary

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Mars Odyssey OTM for Extended Mission

• Plan for the Extended Mission
• Perform an inclination-change maneuver to change
  the LST drift
• Propellant Budget Allocation 1.9 kg (10 m/s of
  DV)
• Design Constraints
• Sun-synch at the earliest LMST that would provide
  a solar beta angle lt -52.5 with 1.5 margin
• Margin analysis performed by ACS (D. Shafter)
• Any change/perturbation in orbit drift can be
  trended and accommodated by an OTM in the future
  if necessary
• To maintain Solar Beta Angle lt -54.0 -gt OTM
  Sept 23, 2003
• Implementation
• Flight team has gone through one iteration of OTM
  design
• Attitude very close to nadir-point attitude
• Issue Telecom during the burn
• If required attitude change would negatively
  impact GRS

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Mars Odyssey 5 PM Sun-Synchronous Orbit
All dates approximate
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Mars Odyssey MER and Beagle2 UHF Relay

• Landing Dates
• Beagle2 Dec 25, 2003
• MER-A Jan 4, 2004
• MER-B Jan 25, 2004
• Impacts to Odyssey
• MER requested ODY orbit phasing to cover post-EDL
  deployments
• Assessing ability to predict/control orbit
  phasing
• Would likely alter the ground track repeat cycle
• UHF relay data requires change to packet buffer
  allocations
• Possibly in 2 stages, prior to relay, just prior
  to MER-B
• DSN allocations actually improve
• Nearly continuous downlink
• Lots of MSPA, sharing of uplink within a pass

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Backup Slides UHF Relay Packet Buffer Allocations
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Mars Odyssey Onboard Memory Allocations (Apr
2002)

• Old Onboard Configuration (April 2002)

• Original Proposal (April 2002)
• Change GRS allocation from 30 MB to 12.5 MB
  allowed for 15 hours of data collection on-board
  Odyssey (assuming 1500 b/s collection with 30
  margin)

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Mars Odyssey Onboard Memory Allocations (Current)

• Current Onboard Configuration

• Current On Board Configuration

• Proposed (New)
• Change GRS allocation from 30 MB to 8.5 MB allows
  for 12 hours of data collection on-board Odyssey
  (assuming 1500 b/s collection with 10 margin)
• Current average data rate of 990 bps equivalent
  to 18 hours on board

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Mars OdysseyPacket Buffer Changes

• THEMIS Change from Original Baseline
• Packet buffer allocation increased at the
  beginning of mapping due to 2 min. data latency
  issue
• Current allocation of 1500 packets (3.3 Mbytes)
  supports 110 kbps or 124 kbps
• Reduction to 1200 packets (2.6 Mbytes) supports
  110 kbps
• MARIE Change from Baseline
• MARIE Changed from 40 file equivalent (2000
  packets, 4.4 Mbytes) to 80 file equivalent (4000
  packets, 8.8 Mbytes)
• Reduction in Frequency of MARIE Mode Changes
  Desired
• Auto-Download Block Supports 80 file equivalent
  packet buffer
• New 40 file Auto-Download Block Required
• MER/Beagle Packet Buffer Allocation (32.5 Mbytes
  Proposed)
• 15 MBytes per MER supports 120 Mbits per pass
  (6820 packets)
• 2.3 Mbytes for Beagle-2 supports 18.8 Mbits per
  pass (1050 packets)

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Mars Odyssey2005 Average Daily Tracking Pass