Moon & Mars Orbiting Spinning Tether Transport - Tethers Unlimited

More documents

Recommendations

Info

-Commercial Tether Transport AIAA 2000-3842with the grapple and a secure, high-strength connectionmust be made between the payload and grapple within arelatively short period of time Ð typically 5-15 seconds.While this is a much shorter time period than has beendemonstrated in space to date, other systems have demonstrated rendezvous and capture on equivalent or evenshorter timescales. One example would be the landingof jets on an aircraft carrier; this maneuver occurs withhigh relative velocities, unpredictable relative accelerations, and small physical windows for successful capture of the aircraftÕs hook by the arresting rope, yet it isperformed successfully many times every day. A second example would be the mid-air capture of film cannisters dropped by surveilance satellites. This systemagain had short (~2 seconds) rendezvous windows andhigh relative velocities, yet this maneuver was performed many times with a 100% success rate.• Tether Dynamics Control and StabilizationThe dynamics of flexible tethers in orbit are complex,and system that utilize electrodynamic propulsion mustbe controlled to avoid problems with dynamical instabilities. TUI has already developed a simple methodfor stabilizing the dynamics of the Terminator Tether ª ,an electrodynamic tether drag system. 10A momentumexchange/electrodynamic-reboosttether facility, however, will require a more complex dynamics controlsystem to maintain optimum performance of the tetherthrusting and ensure that tether dynamics do not adversely impact the rendezvous and capture maneuvers.• High-Strength Survivable Tether with IntegratedElectrodynamic TetherTUI has already demonstrated fabrication of multikilometerlengths of conducting multiline tethers andnonconducting tethers made of high-strength fibers suchas Spectra 2000. However, a tether boost facility willrequire a very high strength-to-weight micrometeoroidsurvivable tether structure that has both high-strengthfibers and conducting elements for electrodynamicthrusting. Furthermore, the electrodynamic componentof this tether must be designed to reliably operate atmany kilovolts of potential relative to the tether facilityand ambient plasma.• High-Power, High-Voltage SystemsIn order to perform electrodynamic thrusting on aTether Boost Facility that has a tether length of many10Õs of kilometers, the power system on the facilityÕscontrol system must be capable of processing manykilowatts of powers and converting them to voltages onthe order of 20 kV, while ensuring that no electricalarcing can occur to threaten the integrity of the tether orother systems.• Tether Orbit Propagation & Collision AvoidanceA Tether Boost Facility will be a very large objectmoving through altitudes where there are many existingsatellites and space debris objects. Although a survivable space tether structure such as the Hoytether ª canenable the tether to withstand degradation by impactswith small pieces of space debris, the tether system willstill have to deal with large objects that may get in itsway. One of the significant issues for this is developing accurate and fast methods for propagating the orbitand dynamical behavior of a tethered system so that thetether system controllers can reliably predict closeencounterevents and command avoidance maneuvers.Working to our advantage, however, is the fact that amomentum-exchange/electrodynamic-reboost tetherfacility will have significant ÆV capabilities using itselectrodynamic thrusting. Thus if close encounters canbe predicted with sufficient advanced notice, the tetherfacility can avoid these encounters.Suggested Technology Development Efforts:In order to address the technology needs listed above,there are several development efforts that could significantly advance the technology readiness levels of appropriate solutions with relatively low investment requirements.Grapple Mechanism Develo p mentThe payload-tether rendezvous is the most significantchallenge for a momentum-exchange tether system.There are, however, several grappling concepts thatcould make this problem more tractable. One concept,originally suggested by Tillotson and recently improvedby Sorenson, 11 is illustrated in Figure 2. In thisconcept, the tether grapple assembly at the end of thetether would open a net structure, providing a very largetarget area for the payload. The task for the payloadwould then be to intersect this net and secure itself tothe net. To minimize chances of the net damaging thepayload, rather than intersecting the net, the payloadmight instead maneuver to come within a short distanceof the net and shoot a tethered ÒharpoonÓ into the net.The payload would then ride the net for half a revolutionof the tether. To release itself from the net, thepayload would retract the barbs on its harpoon, therebyinjecting itself into its transfer orbit.GRASP DemoSome of the methods for achieving the rendezvousbetween the payload and the rotating Tether Boost Facilitycould be demonstrated in a low-cost ground experimentthat would utilize existing Automated Ren-Figure 2. SorensenÕs ÒNet and GrappleÓ concept forfacilitating payload-tether rendezvous.4
Commercial Tether Transport AIAA 2000-3842dezvous and Capture (AR&C) laboratory test facilities.Several organizations, including the LawrenceLivermore National Laboratory (LLNL) and NASA/MSFC have AR&C air-table test facilities. Figure 3shows the LLNL facility. This facility could be usefulfor tests such as a ÒGrapple Rendezvous and SecurePickupÓ (GRASP) experiment to demonstrate that apayload could perform the required terminal rendezvousmaneuvers and securely dock with a tethered grapplewithin the short (
Page 2 and 3: Tethers Unlimited, Inc.MMOSTT Final
Page 24 and 25: NIAC Funded Tether Research• Moon
Page 26 and 27: Electrodynamic Reboost• Power sup
Page 28 and 29: Cislunar Tether Transport System•
Page 30 and 31: MXER Tethers Included in NASA’sII
Page 32 and 33: 5mt Payload Tether Boost Facilityfo
Page 34 and 35: LEOGTO Boost Facility• Initial Fa
Page 36 and 37: Tether Boost FacilityControl Statio
Page 38 and 39: LEOGTO Boost Facility• TetherSim
Page 40 and 41: Rendezvous• Rapid AR&C Capability
Page 42 and 43: Proposed RETRIEVE TetherExperiment
Page 44 and 45: µTORQUE on Delta IV• Delta-IV Se
Page 46 and 47: Opportunities for NASATechnology De
Page 48 and 49: AIAA 2000-3842COMMERCIAL DEVELOPMEN
Page 50 and 51: --Commercial Tether Transport AIAA
Page 54 and 55: Commercial Tether Transport AIAA 20
Page 56 and 57: Commercial Tether Transport AIAA 20
Page 58 and 59: Momentum Exchange/Electrodynamic Re
Page 60 and 61: DESIGN AND SIMULATION OF A TETHER B
Page 62 and 63: Tether Boost Facility Design AIAA 2
Page 70 and 71: Tethers Unlimited, Inc.Cislunar Tet
Page 82 and 83: Interim Report Outline- Configurati
Page 84 and 85: Mission Definition¥ Payload Capaci
Page 86 and 87: Baseline Control Station DetailsTET
Page 88 and 89: Baseline Grapple AssemblyCAPTURES A
Page 90 and 91: LEO Facility System ArchitectureGRA
Page 92 and 93: Payload Adapter Assembly Subsystems
Page 94 and 95: Potential Reeling FunctionsReeling
Page 96 and 97: LEO Control Station Weights16
Page 98 and 99: Payload Adapter Assembly Weights18
Page 100 and 101: Tether Boost FacilityRequired Power
Page 102 and 103:
Electrical Propulsion Voltage´ Spe
Page 104 and 105:
Potential Reeling FunctionsReeling
Page 106 and 107:
Preliminary Reeling AnalysisθθAss
Page 108 and 109:
Tether Boost FacilitySystem Require
Page 110 and 111:
Table of Contents1 Scope ..........
Page 112 and 113:
2 ReferencesThis section lists docu
Page 114 and 115:
The system shall measure and contro
Page 116 and 117:
4 Ground Rules & AssumptionsThis se
Page 118 and 119:
Appendix F: Tether Boost Facility D
Page 120 and 121:
Appendix F Tether Boost Facility De
Page 122 and 123:
Appendix F Tether Boost Facility De
Page 124 and 125:
Page 126 and 127:
Page 128 and 129:
Page 130 and 131:
Page 132 and 133:
Page 134 and 135:
Page 136 and 137:
Page 138 and 139:
Page 140 and 141:
Page 142 and 143:
Appendix L: Tether Boost Facility D
Page 144 and 145:
Page 146 and 147:
Page 148 and 149:
Page 150 and 151:
Page 152 and 153:
Page 154 and 155:
Page 156 and 157:
Page 158 and 159:
Page 160 and 161:
Page 162 and 163:
Page 164 and 165:
Page 166 and 167:
Page 168 and 169:
Page 170 and 171:
Page 172 and 173:
Page 174 and 175:
Page 176 and 177:
Page 178 and 179:
Page 180 and 181:
Page 182 and 183:
Page 184 and 185:
Page 186 and 187:
Page 188 and 189:
Page 190 and 191:
Page 192 and 193:
Page 194 and 195:
Tethers Unlimited, Inc.Tether Rende
Page 196 and 197:
Page 198 and 199:
Page 200 and 201:
Page 202 and 203:
Page 204 and 205:
Page 206 and 207:
Ongoing Tether Work Under NIAC Fund
Page 208 and 209:
Cislunar Tether Transport System•
Page 210 and 211:
Rapid Earth-Mars Transport• Reusa
Page 212 and 213:
EarthMars Launch Windows• MMOSTT
Page 214 and 215:
Incremental Development Path1. TORQ
Page 216 and 217:
LEOGTO Boost Facility• TetherSim
Page 218 and 219:
Tether Boost FacilityControl Statio
Page 220 and 221:
Modular Design• Design Components
Page 222 and 223:
Payload Accommodation AssemblyConfi
Page 224 and 225:
Electrodynamic Thrusting• Drive c
Page 226 and 227:
Tether Facility Reboost• Use Elec
Page 228 and 229:
Rendezvous• Rapid Automated Rende
Page 230 and 231:
Rendezvous Method: Preparation• P
Page 232 and 233:
Development Issues• Automated Ren
Page 234 and 235:
Potential Flight Experiments• Hig
Page 236 and 237:
Opportunities for NASATechnology De
Page 238 and 239:
Acknowledgements• Boeing/RSS - Jo
Page 240 and 241:
IAF-99-A.5.10RAPID INTERPLANETARY T
Page 242 and 243:
Rapid Interplanetary Tether Transpo
Page 244 and 245:
Page 246 and 247:
Page 248 and 249:
Page 250 and 251:
Page 252 and 253:
Page 254 and 255:
Page 256 and 257:
Page 258 and 259:
Page 260 and 261:
Page 262 and 263:
Page 264 and 265:
Page 266 and 267:
Page 268 and 269:
Page 270 and 271:
Page 272 and 273:
IAF-00-S.6.04TETHER SYSTEMS FOR SAT
Page 274 and 275:
IAF-00-S.6.04controlled very precis
Page 276 and 277:
IAF-00-S.6.04Perigee Altitude (km)3
Page 278 and 279:
IAF-00-S.6.04The LEO⇒GTO Tether B
Page 280 and 281:
IAF-00-S.6.04AcknowledgmentsThis re
Page 282 and 283:
Tethers Unlimited, Inc.Appendix K:
Page 284 and 285:
Page 286 and 287:
Tethers Unlimited, Inc.at a rate of
Page 288 and 289:
Page 290 and 291:
Tethers Unlimited, Inc.Appendix L -
Page 292 and 293:
Page 294 and 295:
Page 296 and 297:
Tethers Unlimited, Inc.Appendixm M:
Page 298 and 299:
Page 300 and 301:
Page 302 and 303:
Appendix N. MXER Tether for Deployi
Page 304 and 305:
Page 306 and 307:
Page 308 and 309:
Electrodynamic Thrustingto Reboost
Page 310 and 311:
100000 95000 90000 85000 80000 7500
Page 312 and 313:
Momentum Exchange/Electrodynamic Re
Page 314 and 315:
NOMENCLATURESymbol MeaningA payload
Page 316 and 317:
DepartureangleA = 1.5π - (ω + u
Page 318 and 319:
Tether material has a "characterist
Page 320 and 321:
Rendezvous of Grapple with PayloadT
Page 322 and 323:
adius vector to the new center of m
Page 324 and 325:
days from payload pickup at one pla
Page 326 and 327:
"JupiterandBeyond"Tether cut CUT:<
Page 328 and 329:
Tethers Unlimited, Inc.Appendix Q:
Page 330 and 331:
Tethers Unlimited, Inc.Appendix R:
Page 332 and 333:
Page 334 and 335:
Page 336:
show all

Moon & Mars Orbiting Spinning Tether Transport - Tethers Unlimited

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?