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Session 5: Focused Discussions—Missions in Definition Mars Telecommunications Orbiter 2009. Chad Edwards Mars Chief Telecommunications Engineer Roger Gibbs MTO Project Manager. Mars Telecommunications Overview.
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Session 5: Focused Discussions—Missions in DefinitionMars Telecommunications Orbiter 2009 Chad Edwards Mars Chief Telecommunications Engineer Roger Gibbs MTO Project Manager
Mars Telecommunications Overview • Telecommunications relay orbiters offer high-rate, energy-efficient links for Mars exploration • Enabling and enhancing support for surface science operations • Robust capture of critical event communications • Communications is a key challenge for in situ exploration • Earth-Mars link is 108 times further than a GEO comsat link
1- Surface Operations Relay Support Increased Data Return • Low-gain DTE: 3 kb/sol • MER-class DTE: 30 Mb/sol • ODY-class relay: 100 Mb/sol • MTO-class relay: 1-10 Gb/sol • Enables high-resolution in situ science instruments Increased Connectivity • Multiple comm contacts per sol • Visibility to night side and to poles (when Earth out of view) • Supports complex in situ operations Increased Energy Efficiency • Low-gain DTE: 500 W-hr/Mb • MER-class DTE: 5 W-hr/Mb • Relay: <0.1 W-h/Mb • Enables small scout-class mission concepts; increases energy available for science
Relay Performance for MER • The MER mission has clearly demonstrated the value of relay telecommunicaitons • Over 75 Gigabits of data have been returned from Spirit and Opportunity (as of 3 Nov, 2004) • 96% of data return has been via UHF relay through ODY and MGS “Cohokia” Panorama image, acquired by the Spirit Pancam instrument (588 Mbit compressed data volume)
2- Critical Event Communications Orbiter Mars01 Lander Sun SPK To Earth • In response to loss of Mars Polar Lander (‘98) during EDL (w/out any communications), MEP established a policy to require capture of engineering telemetry during future mission critical events • Provides critical feed-forward information in the event of a mission anomaly • Requires communications link availability under specific spatial and temporal constraints • Data rate driven by bandwidth, complexity of engineering systems
Critical Event Communications Challenge:At the Right Place, Right Time • Direct-to-Earth communications provides coverage of half of planet, but at extremely low (~1 bps) data rates • Science orbiters can support high-rate telemetry, but with extremely limited visibility • 400 km, polar orbit • Constrained orbit node • Higher altitude telesat can provide greatly increased coverage
Program Strategy • Provide evolutionary infrastructure growth at low cost by flying standardized proximity link payload on every Mars science orbiter • MGS, ODY, MRO science orbiters • Interoperability with international assets (e.g., Mars Express) • Communications capabilities largely defined (i.e., constrained) by science-driven orbit characteristics • Establish revolutionary infrastructure capabilities by deploying first dedicated Mars relay satellite: 2009 Mars Telecommunications Orbiter • Orbit selected to optimize communications figures-of-merit
Telecommunications Capability 5 W Laser: 1 - 30 Mbps Ka-band: 0.35 - 4 Mbps X-band: 35-350 kbps X-band: up to 4 Mbps (28 Gb/2 hrs) Critical Event Monitor UHF: 1 - 16 kbps Directional X-band: 1 Mbps (10 Gb/sol) MER-Class UHF: 128 kbps (1 Gb/sol) Small Lander UHF: 128 kbps (150 Mb in 20 minutes)
MTO as Technology Development Platform In addition to its primary objective of serving as the Mars telecommunications satellite, MTO also provides a platform for two technology experiments: - Optical communications from deep space - Deep space autonomous rendezvous
Mars Laser Communication Demonstration • Flight Terminal • 5W Laser • Data rate 1 to 30 Mbps • Inertial / beacon pointing • Command at 10 bps • Ground Terminal • 5m mirror at Mt Palomar • 4 element array (80 cm each) • Transmit a beacon and uplink commands • Daylight operations
Rendezvous and Autonomous Navigation (RAN)Technology Demonstration Deimos Landmark Phobos Orbiting Sample RAN is composed of two linked elements: • Rendezvous: • Perform a rendezvous demonstration with an Orbiting Sample Canister. • Provides critical feed-forward to Mars Sample Return Mission. • AutoNav: • Demonstrate autonomous Orbital Nav using Mars landmarks, Phobos and Deimos. • Supports Mars unmanned and manned safe and low-cost operational infrastructure.
MTO Status • Mission Concept Review successfully completed May 2004 • Contractor selection in progress: • Industry day conducted June 2004 • Released Draft RFP, Final RFP • Proposals due December 3, 2004 • Contractor selection, factfinding, negotiation and on contract: May 2005 • MLCD completed Mission Concept Review and System Requirements Review; Flight Terminal Peer Review; PDR scheduled for May 2005. • Preliminary Mission System Review scheduled for September 2005. • Launch in 2009 requires significant coordination with MSL. • Design life of 10 years