Tether Boost Facilities for In-Space Transportation

Transcription

1 Tether Boost Facilities for In-Space Transportation Robert P. Hoyt, Robert L. Forward Tethers Unlimited, Inc. 97 NE 43rd St., Seattle, WA fax John Grant, Mike Bangham, Brian Tillotson The Boeing Company 530 Bolsa Ave., Huntington Beach, CA (74)

2 NIAC Funded Tether Research Moon & Mars Orbiting Spinning Tether Transport (MMOSTT) Hypersonic Airplane Space Tether Orbital Launch (HASTOL) Objectives: Ð Perform Technical & Economic Analysis of Tether Transport Systems Ð Identify Technology Needs Ð Develop Conceptual Design Solutions Ð Prepare for Technology Development Efforts and Flight Experiments to Demonstrate Tether Transport Technology TUI/MMOSTT 2

3 Momentum-Exchange Tether Boost Facility High-strength tether rotates around orbiting control station Tether picks payload up from lower orbit and tosses payload into higher orbit Tether facility gives some of its orbital momentum & energy to payload Tether facility orbit must be restored to enable it to toss additional payloads TUI/MMOSTT 3

4 Electrodynamic Reboost Power supply drives current along tether Thrust Magnetic Field Current Plasma contactors exchange current with ionosphere Plasma waves close current ÒloopÓ Current ÒpushesÓ against geomagnetic field via JxB Force TUI/MMOSTT 4 Plasma Contactors (Hollow Cathode, FEA, Bare Wire)

5 Momentum-Exchange/Electrodynamic-Reboost Tethers: Summary of Advantages Tether Boost Facilities Can Provide a Fully-Reusable In-Space Propulsion Architecture Ð LEO MEO/GTO Ð LEO Lunar Surface Ð LEO Mars Ð ETO Launch, in combination with Hypersonic Airplane/RLV Momentum Exchange + Electrodynamic Tether Can Enable Propellantless Propulsion Beyond LEO Rapid Transfer Times Ð 5 days to Moon Ð days to Mars Operational Tether System Can Be Tested Before Use With High- Value Payloads Reusable Infrastructure + Low Consumables Lower Cost TUI/MMOSTT 5

6 Cislunar Tether Transport System Developed Orbital Architecture for Round Trip LEO Lunar Surface Transport Whole System Launch Mass = 30x Payload Mass Ð LEO Tether Boost Facility Mass = 3x Payload Mass, Lunar Tether Facility = 7x Payload 3 Payloads/Year Incremental Commercial Development Path TUI/MMOSTT 6

7 Rapid Earth-Mars Transport Reusable Architecture for Round Trip Earth to Mars Transport Rapid Transfer Times (90-30 days) INTERPLANETARY TRANSPORT USING ROTATING TETHERS Earth s gravitational sphere of influence Payload pick-up Tapered tether Loaded Tether Center of mass orbit Patch point Sol Patch point Mars gravitational sphere of influence Loaded Tether Center of mass orbit Payload release Origin Escape trajectory Interplanetary trajectory Payload release Destination Inbound trajectory Tapered tether Payload capture TUI/MMOSTT 7

8 MXER Tethers Included in NASAÕs IISTP Process NIAC Funded MMOSTT and HASTOL efforts have resulted in Momentum-Exchange/Electrodynamic Reboost Tethers being considered in NASAÕs In-Space Integrated Space Transportation Planning Process TUI & NASA/MSFC developed concept designs for Tether Boost Facilities for 4 classes of missions Ð Microsatellite Ð mt Payloads Ð 5 mt Payloads Ð 0 mt Payloads IISTP Process evaluated these designs in trade studies for several different scientific missions ÒHigh-Risk/High PayoffÓ MXER Tethers scored well for several classes of missions Ð High Performance metric TUI/MMOSTT 8

9 Tether Architecture for LEO-GTO-LTO-Mars Transport Tether facility serves as transport hub for multiple destinations Tether serves as a zero-propellant, reusable, high-isp, high thrust ÒThird StageÓ TUI/MMOSTT 9

10 5mt Payload Tether Boost Facility for In-Space Transportation Architecture Reusable In-Space Transportation Infrastructure Payload Launched to 325 km LEO Tether Boosts Payload to Elliptical Orbit Tether Uses Electrodynamic Thrust to Reboost Analysis of Other Propulsion Technologies with MX Tether Assist: Delta-II-Class LV Launches 5,000 kg Spacecraft Tether Boosts Spacecraft to C 3 Ê=Ê-.9 km 2 /s 2 High-Thrust Propulsion Systems: Ð Do Injection Burn at Perigee (570 km, 0.62 km/s) Low-Thrust Propulsion Systems: Ð Use Lunar Swingby to Escape EarthÕs Gravity Well TUI/MMOSTT 0 Tether System Point Design: Boost 0,000 kg to GTO Boost 5,000 kg Vehicle to : Ð Highly Elliptical Orbit (C 3 =-.9) Ð Lunar Transfer Trajectory Ð Escape Via Lunar Swingby Tether Facility Launch Mass: 63 mt Ð Deploy using 3 Delta-IV-H LVÕs Ð Retain Delta Upper Stages for Ballast Ð 200 kw EOL Power Supply for Month Reboost

11 Net Payoff: Reduced Launch Costs To launch 5,000 kg to GTO: Using Rockets: Delta IVM+(4,2) or SeaLaunch ~ $90M Using Rocket to LEO, Tether Boost to GTO: Ð Delta II 7920 (~$45M) or Dnepr (~$3M) /2 to /7 the launch cost TUI/MMOSTT

12 LEOðGTO Boost Facility Initial Facility Sized to Boost 2500 kg Payloads to GTO First Operational Capability Can Be Launched on Delta IV-H Modular Design Enables Capability to be Increased Top Level Mission Requirements: Requirement Payload Mass Pickup orbit Release orbit Release insertion error Payload environment Turnaround time Mission life Collision avoidance Operational orbit lifetime Payload pickup reliability 2500 kg at IOC, can grow to follow market 300 km equatorial GTO < Delta IV/Ariane 5 < Delta IV/Ariane 5 30 days 0 years + 00% of tracked spacecraft 5 days 99% Value TUI/MMOSTT 2

13 Mass Properties Breakdown Control Station Mass: 0,967 kg Tether Mass: LEO Control Station Thermal Control Subsys Qty Redun dancy Mass Contin gency 5% Unit mass (kg) Mass with no margin (kg) Mass with Contingency (kg) Mass Margin (kg) ,274 kg Cabling/Harnesses Structure 33% 25% Grapple Mass: 650 kg GLOW: 9,89 kg Ð 5% margin w/in Delta IV-H payload capacity Electr.Pwr. PV array panels Power Storage PV array drive motors PMAD Downlink Comm Subsys Downlink Transceiver Downlink antennae TFS Net Comm Subsys % 5% 3% 3% 3% 3% Expended Upper Stage 3,467 kg C&DH Comm. antennae Transceiver Computer % 3% 3% TT&C On-Orbit Mass: ADCS transponder 2 3% ,358 kg ED Tether Power Subsys Plasma Contactor (FEAC) 2 25% PMAD/PCUt 2 50% Docking & I/C Subsys Beacon 8% Tether Deploy & Control TUI/MMOSTT 3 Tether reeling assembly 33%

14 Tether Boost Facility Control Station Solar Arrays, 37 BOL Battery/Flywheel Power Storage Command & Control Tether Deployer Thermal Management Total Mass:ÊÊÊÊ 23,358 kg Payload Mass: 2,500 kg Tether (not shown to scale) Hoytether for Survivability Spectra km Long Conducting Portion for Electrodynamic Thrusting Grapple Assembly Power, Guidance Grapple Mechanism Small Tether Deployer TUI/MMOSTT 4 Payload Accommodation Assembly (PAA) Maneuvering & Rendezvous Capability Payload Apogee Kick Capability Payload

15 NIAC Efforts Have Developed Improved Tether Analysis Tools Tether System Design: Ð Tapered tether design Spectra 2000 Ð Orbital mechanics considerations to determine facility mass required Tether operation: TetherSimª Numerical Models for: TUI/MMOSTT 5 Ð Orbital mechanics Ð Tether dynamics Ð Electrodynamics Ð Hollow Cathode & FEACs Ð Geomagnetic Field (IGRF) Ð Plasma Density (IRI) Ð Neutral Density (MSIS Ô90) Ð Thermal and aero drag models Ð Endmass Dynamics Ð Payload Capture/Release Interface to MatLab/Satellite Tool Kit

16 LEOðGTO Boost Facility TetherSim ª Numerical Simulation (0x real speed) Ð Tether Dynamics, Orbital Mechanics TUI/MMOSTT 6

17 Technology Readiness Level Boeing & TUI Performed TRL Analysis of MXER Tether Technologies Many necessary components are already at high TRL TRL Analysis Indicates Areas for Future Work to Address: TUI/MMOSTT 7 Ð Power management subsystem Ð Thermal control subsystem Higher power than previously flown systems Ð Electrodynamic Propulsion Subsystem Plasma contactors Dynamics control Ð Automated Rendezvous & Capture technologies Prediction & Guidance Grapple Assembly & Payload Adapter Ð Some work ongoing in HASTOL Ph II effort Ð Flight Control Software Ð Traffic Control/Collision Avoidance

18 Rendezvous Rapid AR&C Capability Needed Relative Motion is Mostly in Local Vertical Tether Deployment Can Extend Rendezvous Window ÆZ (m) ÆX (m) Payload Capture Vehicle descends towards Payload PCV Deploys More Tether PCV pays out tether and Payload maneuvers to dock with grapple PCV engages tether brake and begins to lift payload Additional Tether Deployment Under Braking Can Reduce Shock Loads Load Level s braking 5 s braking 0 s braking 20 s braking 30 s braking 0.2 TUI/MMOSTT Time (s)

19 Space Debris-Survivable Tether Micrometeoroids & Space Debris Will Damage Tethers Solution approach: spread tether material out in an open net structure with multiple redundant load/current paths Primary Lines Secondary Lines (initially unstressed) Secondary Lines Transfer Load Around Damaged Section Severed Primary Line Effects of Damage Localized 0.2 to 0's of meters 0.- meter TUI/MMOSTT 9

20 Proposed RETRIEVE Tether Experiment Candidate Secondary Experiment for XSS- $800K in Initial Development funds from AFRL Small ED tether system deorbits µsat at end of mission Ð Activated only after primary mission completed Mass: (CBE+Uncertainty): 6.5 kg Demonstrate Ð Controlled orbital maneuvering with ED tether Ð Long life tether Ð Stabilization of tether dynamics TUI/MMOSTT 20

21 µtorque: MX Tether to Boost µsat to Lunar Transfer or Escape Microsatellite Tethered Orbit Raising QUalification Experiment Build Upon RETRIEVE to Create Low-Cost Demo of MXER tether technology Secondary payload on GEO Sat launch µtorque boost microsat payload to lunar transfer or escape 0.4 km/s boost to payload Mass-competitive with chemical rocket Launch vehicle places primary payload into GTO µtorque uses ED drag to spin up tether µtorque releases payload into lunar transfer/swingby µtorque deploys tether & microsat above stage TUI/MMOSTT 2

22 µtorque on Delta IV Delta-IV Secondary Payload ~00 kg weight allocation Boost ~80kg microsat from LEO to low-meo TUI/MMOSTT 22

23 Momentum Exchange/Electrodynamic Reboost Tether Technology Roadmap NIAC Study µtorque Experiment Cislunar Tether Transport System GRASP Experiment LEO GTO Tether Boost Facility ETO-Launch Assist Tether ED-LEO Tug ISS-Reboost ProSEDS RETRIEVE Terminator Tetherª µpet TUI/MMOSTT 23

24 Opportunities for NASA Technology Development Expand AR&C Capabilities for Rapid Capture High Power & High Voltage Space Systems Electrodynamic Tether Physics Debris & Traffic Control Issues Conduct Low-Cost Flight Demo of Momentum- Exchange Tether Boost Modest NASA Investment in Technology Development Will Enable Near-Term Space Flight Demonstration TUI/MMOSTT 24

25 Contributors Boeing/RSS - John Grant, Jim Martin, Harv Willenberg Boeing/Seattle - Brian Tillotson Boeing/Huntsville - Mike Bangham, Beth Fleming, John Blumer, Ben Donohue, Ronnie Lajoie, Lee Huffman NASA/MSFC - Kirk Sorenson Gerald Nordley Chauncey Uphoff TUI/MMOSTT 25