14 - 1 nasa’s goddard space flight center lro operations concept richard saylor jr. htsi/code 444...

14 - 1NASA’s Goddard Space Flight Center

LRO Operations Concept

Richard Saylor Jr.

HTSI/Code 444

August 16-17, 2005


Operations Concept Development

Level 1 RequirementsLevel 2 Requirements

(MRD)(431-RQMT-000006)

LRO Concept of Operations(431-OPS-000046)

LRO Level 3 Requirements

LRO Project Database

Management Plan

LRO Flight Operations Plan

LRO Mission Operations Support

Plan

LRO Flight Operations

Contingency Plan

LRO Flight Procedures Documents

• Level 1, 2, and 3 requirements are used in the development the mission operations concept• The operations concept describes the operational plan which will be used around the

framework of the requirements– Document will be updated as the mission designs evolves

• Initial version of the Lunar Reconnaissance Orbiter Concept of Operations is available• From the operations concept, lower level operational support documents will be developed


LRO Mission Phases

No Phase Sub-Phases Description

1 Pre-Launch/ Launch readiness

Space Segment Readiness Ground Segment

Readiness

Includes instrument I&T, spacecraft/orbiter I&T, space/ground segment testing as well as operations preparation and ground readiness testing leading up to launch.

2 Launch & Lunar Transfer

Launch and Ascent Separation and De-spin Deployment and Sun Acq. Lunar Cruise Lunar Orbit Insertion

Includes all activities & operations from launch countdown sequence to Lunar Orbit Insertion (LOI). LOI includes all maneuvers necessary to obtain the temporary parking orbit for Orbiter activation and commissioning. During the cruise phase, initial spacecraft checkout will be performed to support activities for mid course correction (MCC) and LOI.

3 Orbiter Commissioning Spacecraft Commissioning Integrated Instrument

Commissioning

Configure and checkout the spacecraft subsystems and ground systems prior to instrument turn-on. Instrument integrated activation will be developed to complete instruments turn-on and commissioning. Instrument commissioning includes any calibration activities needed in the temporary orbit.

4 Routine Operations Measurements (Routine Ops)

Station-keeping Momentum Management Instrument Calibrations Lunar Eclipse Yaw Maneuver Safe Mode

One year of nominal science collection in the 50 (+/- 15) km orbit.

5 Extended Mission Operations

After 1-year of science observations, orbiter may be boosted into a higher orbit to reduce maintenance requirements. Potential goals for extended mission are:

– Perform relay comm. operations for 2nd RLEP mission.– Collect additional measurement data at the nominal mission orbit– Take additional measurement operations in a higher orbit.

6 End-of-Mission Disposal Includes planning and execution of end-of-life operations.


Mission Phase Summaries

Launch and Cruise PhasePhase Begins: Approximately L-18-hrs (start of launch vehicle countdown procedure

Phase Ends: Completion of Lunar Orbit Insertion (LOI) maneuvers. Orbiter is captured in commissioning orbit.

Sub-Phases: Launch and Ascent, Separation, Deployment and Sun Acquisition, Lunar Cruise, Lunar Orbit Insertion

Key Orbiter Activities:

• C&DH monitors and detects separation from launch vehicle, triggers separation sequence which controls activities through Deployment and Sun Acquisition sub-phase.

• Deploy solar array boom and panel.• Acquire Sun and perform ground acquisition for telemetry and commands.• Start spacecraft bus commissioning activities.• Perform mid-course correction (MCC) maneuver within 24 hours of launch.• Turn on CRaTER and LEND for early calibration activities during the flight to lunar orbit.• Deploy high gain antenna.

Key Ground Activities:

• Use all networks including DSN to support early mission objectives.• Provide S-Band tracking data to flight dynamics for MCC planning.• Dump and analyze orbiter housekeeping data.• Verify ground system configuration (use different S-Band telemetry rates).• Process real-time housekeeping data for engineering team.• Execute pre-define sequence of events.

Support Plan: • Mission Operations Team (MOT) staffs the MOC 24x7 until LRO captures into commissioning orbit.• Spacecraft engineering team staffs the MOC• Instrument engineering team staffs the MOC for CRaTER and LEND. Other instrument team staff depends on

potential instrument contingencies defined later.• Goal is to perform prime commissioning activities during prime shift. Backup shift will mostly monitor orbiter

operations and prepare for next day activities.


Key Early Mission Activities


Mission Phase SummariesOrbiter Commissioning Phase

Phase Begins: After orbiter insertion into the commissioning orbit of 30x216 km.

Phase Ends: Completion of instrument commissioning and insertion into the mission orbit of 50 km.

Sub-Phases: Spacecraft Commissioning, Integrated Instrument Commissioning


• C&DH commissioning• Test and calibrate solar array and high gain antenna pointing• Verify Ka downlink telemetry• Perform sensor and alignment calibration activities• Configure the spacecraft fault detection and handling components• Power instruments according to the integrated instrument commissioning plan• Perform functional checks with each of the instruments• Execute instrument calibration activities according to the instrument calibration/validation plan• Perform series of thruster maneuvers to capture into the mission orbit


• Use primary ground network stations for support (White Sands, Australia, Belgium, Kiruna, and Hawaii). DSN will be used for backup and contingency activities.

• Flight dynamics will analyze commissioning orbit and verify whether frozen orbit exist at the 30x216 orbit. Data could be used later for planning of extended mission.

• Verify file data delivery concept and distribution links to each of the instrument science operations center.• Backup MOC will be checked out.

Support Plan: • MOC will be staffed approximately 16-hrs/day during commissioning phase. Non-critical automation tools will be verified prior to reduced staff hours.

• MOC will be staffed will spacecraft and instrument engineering teams to support planning and real-time monitoring of the orbiter.

• Most activities will be performed on the prime shift, backup shift will monitor and prepare for next day activities.


Mission Phase SummariesRoutine Operations Phase

Phase Begins: Starts after insertion into the mission orbit of 50 km and completion of instrument commissioning.

Phase Ends: Ends after 12 months from the start of routine operations phase.

Sub-Phases: Measurement Operations, Station-Keeping, Momentum Management, Instrument Calibrations, Lunar Eclipse, Yaw Maneuver, Safe Mode


• Spacecraft will nominally be nadir pointing.• Momentum management will be performed every 2-weeks while in contact with the ground.• Station-keeping maneuvers are done every month, requires two burns during 1 orbit.• Once a month, around the station-keeping maneuvers, instrument calibrations will be coordinated with

instrument science teams. Currently allocated approximately 3 orbits for calibrations activities.• Roughly twice a year, LRO may be affected by lunar eclipse, orbiter might be commanded to low power mode.• Twice a year, near the beta angle condition, the spacecraft will perform a 180° yaw maneuver.• Once a month, operate mini-RF technology demonstration. Operating times will be perform around monthly

station-keeping maneuvers.


• Use primary ground network stations for support (White Sands, Australia, Belgium)• Back network S-Band support will be provided by Kiruna, Hawaii, and DSN.• Ka-Band measurement data will be dumped during the White Sands Ground Station view period each day.

Roughly 4 contacts each day.• Data will be distributed to each instrument SOC for level 0 and higher data processing.• Ground will use reliable transfer protocol to verify data files from the spacecraft recorded is received on the

ground.

Support Plan: • MOC will be staffed 5 days a week (Monday-Friday), 8-hr shift. Automation will monitor ground and orbiter health and safety.

• Flight operations team will also perform parallel/proficiency activities using the backup MOC.• Flight operations team will call upon the development spacecraft engineers for anomaly support.• Instrument SOCs will be responsible for all instrument maintenance.


LRO’s View of the Universe

• Twice a year, LRO will be in full Sun for roughly one month for each event. The full Sun condition occurs when the orbit Beta angle reaches ~76°.

• During the eclipse season (the shaded portion of the Sun circle), LRO is expected to have a maximum lunar occultation of 48 minutes. The maximum duration lunar occultation will occur when the orbit beta angle reaches 0°.

• Twice a year, LRO will be required to perform a 180° yaw maneuver. The yaw maneuvers will be performed as the orbit approaches the beta 0° condition.

• Twice a month, LRO’s orbit will be in full view of the Earth for a period of ~2 days. During the 2 days, ground stations on the Earth will have continuous view of LRO. However, due to the HGA range of motion limitation, the HGA ground contacts will still be limited to approximately 56 minutes. The omni antennas can provide continuous coverage.

• Twice a month, LRO will perform momentum management. The maneuver will occur when the ground has complete coverage of the orbit.

• Once a month, LRO will perform station-keeping (SK) maneuvers to maintain the mission orbit. The station keeping maneuver will be performed when the ground stations has complete coverage of the orbit.

• Twice a year (on average), the Earth will pass between the Moon and the Sun (Lunar Eclipse).


Integrated Instrument Operations

Moon’s Pole

Moon’s Pole

Non Sun Lit, Total time ~56.5 minutes

Non Sun Lit, Total time ~56.5 minutes

LRO Baseline Instruments Operating Modes

NAC 1 (Each Image ~256 MB)

WACWAC (1 Mbit Image/Sec)

NAC 2 (Each Image ~256 MB)

LROC Operating Mode

Constant data rate ~10 kbpsLOLA Operating Mode

LROCPower Cycle

Constant data rate ~0.035 kbpsLEND Operating Mode

Constant data rate ~10.6 kbpsDiviner Operating Mode

Constant data rate ~100 kbps (During Flares), Non flares ~0.2 kbpsCRaTER Operating Mode

Constant Data Rate ~20.2 kbpsLAMP Operating Mode Constant Data Rate ~20.2 kbpsHV Disable HV Enable

Sun Lit ~56.5 minutes

Instrument Avg. Orbital Power ~90 W ~90 W

~88 W ~88 W

~96 W~105 W

~105 W~103 W

Instrument Avg. Data Rate

~0.14 Mbps ~0.14 Mbps

~6.35 Mbps


Predicted Daily Data Volume

Data SourceRaw Rate

(kbps)

Data Rate w/OH (kbps)

Op Time per Orbit

(min)

Raw Data per Orbit (Mbits)

Orbit Data w/CCSDS OH (Mbits)

Daily Data w/CCSDS OH (Mbits)

Daily Data w/CFDP OH

(Mbits)

Daily Data w/R-S OH

(Mbits)

Min Per File

File Size (Mbits)

File Size (kBytes)

Files per Orbit

Files per Day

LOLA 10 10.50 113.0 66.21 69.52 885.94 912.52 1,049.39 10.0 6.15 787.50 11.3 144.0LEND 0.6 0.63 113.0 3.97 4.17 53.16 54.75 62.96 113.0 4.17 533.93 1.0 12.7LAMP Sci 20.2 21.21 56.5 66.87 70.22 894.80 921.64 1,059.89 10.0 12.43 1,590.75 11.3 144.0LAMP HK 0.8 0.84 113.0 5.30 5.56 70.88 73.00 83.95 113.0 5.56 711.90 1.0 12.7CRaTER 100 105.00 113.0 662.11 695.21 8,859.38 9,125.16 10,493.93 1.3 8.00 1,023.75 86.9 1,107.7Diviner 10.6 11.13 113.0 70.18 73.69 939.09 967.27 1,112.36 10.0 6.52 834.75 11.3 144.0LROC WAC 598 598 56.5 1,979.71 1,979.71 25,228.13 25,984.97 29,882.71 5.0 175.20 22,425.00 22.6 288.0LROC NAC N/A N/A 56.5 38,550.59 38,550.59 491,264.13 506,002.06 581,902.37 N/A 1,204.71 154,202.35 32.0 407.8Spacecraft HK 32 32 113 211.88 222.47 2,835.00 2,920.05 3,358.06 10.0 18.75 2,400.00 11.3 144.0

188.7 2,405.0

SSR Daily Storage w/CCSDS OH: 518.58 GbitsSSR Daily Storage w/CCSDS & CFDP OH: 534.14 GbitsSSR Orbit Storage w/CCSDS OH: 40.69 GbitsSSR Orbit Storage w/CCSDS & CFDP OH: 41.92 GbitsTotal Data to be dumped daily w/all OH & Coding: 1,228.53 Gsymbols

LRO Data Calculation Summary


Predicted Data Downlink Concept

Data Volume w/CCSDS OH (Min): 308.69 Gbits 24.22 GbitsData Volume w/CCSDS OH (Max): 518.58 Gbits 40.69 GbitsData Volume w/CCSDS & CFDP OH (Min): 317.95 Gbits 24.95 GbitsData Volume w/CCSDS & CFDP OH (Max): 534.14 Gbits 41.92 Gbits

Pass Length: 45 minutes 45 minutes 45 minutes 45 minutesTime Since Last Pass: 1044 minutes 113 minutes 113 minutes 113 minutes

Orbits Since Last Pass: 9.24 orbits 1 orbits 1 orbits 1 orbitsData Recorded (Min): 223.80 Gbits 24.22 Gbits 24.22 Gbits 24.22 GbitsData Recorded (Max): 375.97 Gbits 40.69 Gbits 40.69 Gbits 40.69 Gbits

Data to be Dumped (Min): 230.52 Gbits 24.95 Gbits 24.95 Gbits 24.95 GbitsData to be Dumped (Max): 387.25 Gbits 172.20 Gbits 41.92 Gbits 41.92 Gbits

Symbols (Min): 544.02 Gsym 58.88 Gsym 58.88 Gsym 58.88 GsymSymbols (Max): 913.92 Gsym 406.39 Gsym 98.92 Gsym 98.92 Gsym

D/L Capacity: 606.45 Gsym 606.45 Gsym 606.45 Gsym 606.45 GsymRemaining Data (Min): 0.00 Gbits 0.00 Gbits 0.00 Gbits 0.00 GbitsRemaining Data (Max): 130.28 Gbits 0.00 Gbits 0.00 Gbits 0.00 Gbits

Minutes Remaining (Min): 4.63 minutes 40.63 minutes 40.63 minutes 40.63 minutesMinutes Remaining (Max): -22.82 minutes 14.84 minutes 37.66 minutes 37.66 minutes

Contact #3 Contact #4

LRO 1-Ka Ground Station (White Sand) Dump Scenario

Daily Orbit

Contact #1 Contact #2Min. View Period at White Sands


Daily Operations Timeline


One Week Operations Profile


Ground System Architecture


Data Flow Discussions

• All commands will originate from the mission operations center– Instrument SOCs will delivery request and timelines as required– MOC will process and generate command loads or incorporate

request into the daily pass activities

• White Sands receives S/Ka downlinks– Ka-Band measurement data is transferred to MOC for processing.

MOC distributes the data to each of the instrument SOCs.– MOC also will distribute mission planning products to ground system

elements as required

• Real-time housekeeping data is received at the MOC for monitoring orbiter health and safety


Mission Phase SummariesExtended Mission Operations Phase

Phase Begins: Starts after nominal mission phase ends, approximately 14 months after launch.

Phase Ends: Ends when disposal phase begins.

Sub-Phases: None


• Activities will be dependent on objectives during phase:– Communication relay for next lunar mission– Extended measurement operations in mission orbit or higher lower maintenance orbit.


• Use primary ground network stations for support (White Sands, Australia, Belgium)• Back network S-Band support will be provided by Kiruna, Hawaii, and DSN.

Support Plan: • MOC will be staffed 5 days a week (Monday-Friday), 8-hr shift. Automation will monitor ground and orbiter health and safety.

• Flight operations team will call upon the development spacecraft engineers for anomaly support.• Instrument SOCs will be responsible for all instrument maintenance.


Mission Phase Summaries

End-of-Mission Disposal PhasePhase Begins: Starts when extended mission operations is declared over.

Phase Ends: Orbiter impact on the Moon and mission closeout activities are completed.

Sub-Phases: None


• Remaining fuel will determine when mission will impact. Plan is to continue until all fuel is used.• Depending on discovery during the mission, the impact zone may be selected otherwise, there is no requirement

on impact location.


• Plan to support end-of-mission activities. Develop end-of-mission plans and define closeout activities.• Tracking, if possible, the orbiter trajectory as it impacts the Moon.

Support Plan: • MOC will be staffed according to the detailed de-orbit plans.• Closely supported by flight dynamics and spacecraft engineers.


Mission Operations Team Staffing

• Mission Operations Center will be located at GSFC• The mission operations team will support ground system and orbiter

development prior to launch– Operations team will augment ground system test team, useful in providing

training to the operations team– Operations team will provide test engineers for instruments, spacecraft box

level, spacecraft bus, and orbiter level integration and test.• Help develop test procedures, command & telemetry databases, develop Users

Guide and other related operations documentation• Provide ground system expertise

– I&T will use the same Command and Telemetry system– Other systems will be shared such as the anomaly system

• Staffing plan calls for gradual decrease in operations staffing level as the mission progress from commissioning to routine.– Rate of decrease will be dependent on mission activities and verification of

automation


Summary

• Initial operations concept has been developed for the mission– Lunar Reconnaissance Orbiter Mission Concept of Operations

Document is available for review

• Operations defined in document have been and continue to be included as part of the mission design– The operations document will continue to mature in preparation for

mission PDR, but existing requirements are compatible with the concept.