ESA Document - Emits - ESA

More documents

Recommendations

Info

s 3.4.3 Thermal 3.4.3.1 Requirements and design drivers HMM Assessment Study Report: CDF-20(A) February 2004 page 238 of 422 3.4.3.1.1 TMI The propellants considered for Trans Mars Injection are liquid hydrogen and liquid oxygen. Main requirement is to control the evaporation of these cryogenic liquids during their operational life service (from launch till the end of the trans Mars injection firing). The requirement is • to maintain a boil-off (BO) below 70 kg per month for the liquid hydrogen and 430 kg per month for the liquid oxygen (system requirement) It is assumed that no orbital servicing capability will be available for refilling (improbable hypothesis) and that compliance of this requirement can only be done per design. 3.4.3.1.2 MOI and TEI For both injection, chemical propulsion is retained with the propellant UDMH / NTO • to maintain the propellant tanks, support structure and tubing above liquid freezing points (between 0 and 40C with margins) • to maintain the integrity of the thermal protection if close to the thrusters nozzle • to optimise the ratio efficiency over mass 3.4.3.2 Assumptions 3.4.3.2.1 TMI • The envelope sizing of the tanks is based on the Russian launcher Energya capability (80T and fairing maximum diameter). The mass of the propellants needed depend on the overall vehicle mass and the number of tanks / stacks is the result of a system level trade-off provided as an input. • Maximum life service is estimated at system level on the basis of a possible logistic for the delivery flights (build up of the assembly). 3.4.3.2.2 Heat loads Cryogenics lifetime depends on the heat loads absorbed by the vessel, basically the result of the relative attitude between the vessel, the sun and the planet. Lifetime therefore can be drastically extended by the choice of suitable orbits (high orbit to reduce Earth radiative load) or specific orientation of the vessel (low projected surface to sun or planet). The following hypothesis are done: • No attitude control capability of the tank. A worst case illumination is assumed (normal incidence) • LEO is assumed (500 km) for the assembly (launcher capability) • Influence of others other tanks and assembly (heat loads per infrared or reflection) is not considered.
s HMM Assessment Study Report: CDF-20(A) February 2004 page 239 of 422 • Standard illumination (1400 W/m2) and Earth thermal characteristics (albedo 0.4, infrared 273 W/m2) are assumed 3.4.3.3 Baseline thermal design 3.4.3.3.1 Hydrogen storage Given that hydrogen storage is essential for fuel cells, life support and propulsion (Chemical, solar or nuclear), the efficiency of its storage is shown in Table 3-66: Type Features Compressed hydrogen in a gaseous state, can be stored under high pressure (up to 700 bars) within pressure vessels (aluminium, composite) increasing the hydrogen storage density Liquid hydrogen in a liquid state, is subject to boil-off (evaporation of liquid caused by heat leaks) depending on the vessel size, shape and thermal insulation. Density depends on saturated temperature Metal hydrides per absorption on transition metal, hydrogen storage density reach maximum 7% of metal weight (200-300C), 2-5% (alanates) under normal temp. and pressure. Investigations focus on more performance and lighter metal density, but so far weight is a problem for space applications Chemical hydrides per chemical reaction. A hydride solution (sodium borohydride for example) combined to water and catalyst produces hydrogen Carbon nanotubes per adsorption on activated carbon structure, hydrogen storage density could theoretically approach storage density of liquid hydrogen but mechanisms for adsorption/desorption are still under investigation (nanotubes) Glass microspheres per physical adsorption on micro glass sphere. Permeability is controlled per temperature chemical hydrides complex hydrides LH2 GH2, 700 bar GH2, 350 bar 0 0.5 1 1.5 2 2.5 Table 3-66: Hydrogen storage options kWh/kg kWh/L Figure 3-75:Comparative storage technology (L), Hydrogen phase diagram (R) For propulsive applications, storage in the liquid state is currently the most efficient technique available (shall remain so at least in the mid term) and has been retained for this study. The performance of this type of storage is related to the thermal design capability to maintain cryogenic temperature (20.2K at 1 bar). Condition of storage is a trade-off between the different constraints from the system and available thermal hardware. For example, supercritical storage eases the refrigeration requirement (higher efficiency at higher temperature) but lowers the density of the liquid (by a factor of 2.6 from triple point to critical point) and increases the pressure (by a factor of 170 from triple point to critical point).
Page 1 and 2:
s HMM Assessment Study Report: CDF-
Page 3 and 4:
s STUDY TEAM HMM Assessment Study R
Page 5 and 6:
s T A B L E O F C O N T E N T S HMM
Page 7 and 8:
Page 9 and 10:
s L I S T O F F I G U R E S HMM Ass
Page 11 and 12:
Page 13 and 14:
Page 15 and 16:
s L I S T O F T A B L E S HMM Asses
Page 17 and 18:
Page 19 and 20:
s 1 INTRODUCTION 1.1 Background HMM
Page 21 and 22:
s 2 GENERAL ARCHITECTURE 2.1 Study
Page 23 and 24:
Page 25 and 26:
s 2.2.4.2 Accelerations HMM Assessm
Page 27 and 28:
s 2.2.4.4 Temperature and relative
Page 29 and 30:
Page 31 and 32:
Page 33 and 34:
s Figure 2-10: Trajectory Overview
Page 35 and 36:
s 2.4.3.5 TEI and planetary protect
Page 37 and 38:
Page 39 and 40:
Page 41 and 42:
Page 43 and 44:
Page 45 and 46:
s Mars Excursion Vehicle Transfer H
Page 47 and 48:
s 2.7.5.1 Mission elements dry mass
Page 49 and 50:
s 2.7.5.8 MEV release The MEV is re
Page 51 and 52:
s Total mission time (days) 1200 10
Page 53 and 54:
Page 55 and 56:
Page 57 and 58:
s stack 9 Propellant mass of the ne
Page 59 and 60:
Page 61 and 62:
Page 63 and 64:
Page 65 and 66:
s The core supporting structure has
Page 67 and 68:
s 2.7.7.1.3 Mars excursion module S
Page 69 and 70:
s 2.7.7.1.4 Earth return capsule HM
Page 71 and 72:
s Mission Phase Description Event s
Page 73 and 74:
s Mission Phase Description Event s
Page 75 and 76:
s 2.7.10 Mission performance Table
Page 77 and 78:
s Days on Martian surface 450 400 3
Page 79 and 80:
Page 81 and 82:
Page 83 and 84:
s Maximum manoeuvre duration 6 mont
Page 85 and 86:
s % of loss from baseline 20 18 16
Page 87 and 88:
s 2.7.15 Sensitivity analysis HMM A
Page 89 and 90:
s 2.7.15.4 Influence of the mass of
Page 91 and 92:
Page 93 and 94:
s Parameters used: • No Shuttle
Page 95 and 96:
s 2.8.3.3 Launch 3- Front node Figu
Page 97 and 98:
Page 99 and 100:
Page 101 and 102:
Page 103 and 104:
Page 105 and 106:
Page 107 and 108:
Page 109 and 110:
s 2.10.1.4 Communications HMM Asses
Page 111 and 112:
Page 113 and 114:
s 2.10.2.2.2 LEO assembly HMM Asses
Page 115 and 116:
Page 117 and 118:
s Basic RF link Four 70-m Ka-band s
Page 119 and 120:
Page 121 and 122:
Page 123 and 124:
Page 125 and 126:
s 3 TRANSFER VEHICLE 3.1 Systems…
Page 127 and 128:
s Operational Requirements It shall
Page 129 and 130:
s Trans Mars Injection Module Mars
Page 131 and 132:
s Figure 3-2: Parallel configuratio
Page 133 and 134:
s Figure 3-6: Global dimensions com
Page 135 and 136:
s Front Node 3.2.3.1.3 EVA systems
Page 137 and 138:
s Trans Mars Injection (three stage
Page 139 and 140:
s Figure 3-16: Recommendations for
Page 141 and 142:
s Factors to be considered Impacts
Page 143 and 144:
Page 145 and 146:
Page 147 and 148:
Page 149 and 150:
s Figure 3-24: Baseline design back
Page 151 and 152:
s Figure 3-26: Baseline design priv
Page 153 and 154:
s Module part 3............= 0 m 3
Page 155 and 156:
s 3.3.2.1 Requirements and design d
Page 157 and 158:
Page 159 and 160:
Page 161 and 162:
Page 163 and 164:
Page 165 and 166:
Page 167 and 168:
Page 169 and 170:
Page 171 and 172:
Page 173 and 174:
Page 175 and 176:
Page 177 and 178:
s flux [W/m2] 250 200 150 100 50 0
Page 179 and 180:
s Figure 3-38: Power required to ma
Page 181 and 182:
Page 183 and 184:
Page 185 and 186:
s 3.3.4.3 Assumptions and trade-off
Page 187 and 188: s 3.3.4.3.3 Power conditioning and
Page 189 and 190: s 3.3.5 AOCS HMM Assessment Study R
Page 191 and 192: s HMM Assessment Study Report: CDF-
Page 193 and 194: s Configuration Length (m) Total ma
Page 195 and 196: s 3.3.5.5 ACS for TMI 1 st HMM Asse
Page 205 and 206: s 3.3.6.2 Baseline design HMM Asses
Page 209 and 210: s 5 Reduce 2dB pointing precision t
Page 211 and 212: s 70-m antenna 70-m antenna 3.3.7.5
Page 213 and 214: s Angular separation SEM > 10º SEM
Page 215 and 216: s Figure 3-63: Communications MEV/M
Page 225 and 226: s Element 1: Transfer Habitation Mo
Page 229 and 230: s Radiation Shielding Shielding Req
Page 233 and 234: s The propulsion system and its cha
Page 237: s Item Nr. Mass [kg] Margin [%] Mas
Page 247 and 248: s 3.4.4 Mechanisms HMM Assessment S
Page 249 and 250: s 4 MARS EXCURSION VEHICLE 4.1 Syst
Page 253 and 254: s Figure 4-2: Option 2: Vertical co
Page 257 and 258: s 4.3 Surface habitation module Fig
Page 259 and 260: s Figure 4-11: Section through the
Page 267 and 268: s 4.3.1.5.3 Top level Figure 4-20:
Page 271 and 272: s Schedule in hours for the most ac
Page 273 and 274: s 4.3.3.6 Waste production HMM Asse
Page 275 and 276: s Figure 4-26: Total pressure vs. O
Page 277 and 278: s ECLS system mass: Figure 4-27: Ma
Page 281 and 282: s Figure 4-28: Mars albedo (L), ars
Page 285 and 286: s sun flux (W/m2) 450 400 350 300 2
Page 289 and 290:
s Insulation structure (external) F
Page 291 and 292:
s cryocooler heat lift [W] cryocool
Page 293 and 294:
Page 295 and 296:
Page 297 and 298:
s • a duty cycle value (duration
Page 299 and 300:
s Figure 4-48: MAV Power Inputs HMM
Page 301 and 302:
Page 303 and 304:
s 4.3.5.4.2 Power storage HMM Asses
Page 305 and 306:
s Figure 4-52: Regenerative Fuel Ce
Page 307 and 308:
s Figure 4-54: Solar irradiance on
Page 309 and 310:
s 450.00 400.00 350.00 300.00 250.0
Page 311 and 312:
s 4.3.6.1 Budgets HMM Assessment St
Page 313 and 314:
Page 315 and 316:
Page 317 and 318:
Page 319 and 320:
Page 321 and 322:
Page 323 and 324:
s Surface Surface Container MAV Con
Page 325 and 326:
Page 327 and 328:
s 4.3.9.3 Baseline design 4.3.9.3.1
Page 329 and 330:
s Bio-Lock Masses: Core Samples No.
Page 331 and 332:
Page 333 and 334:
Page 335 and 336:
s Figure 4-72: Entry Velocity (L) a
Page 337 and 338:
Page 339 and 340:
Page 341 and 342:
Page 343 and 344:
s 2 3.9 233 923.1 347 923 12.3 352
Page 345 and 346:
s Figure 4-85: Communications MEV/M
Page 347 and 348:
Page 349 and 350:
s 4.4.5.3.2 GNC equipment HMM Asses
Page 351 and 352:
s 4.4.5.4 Control laws generation H
Page 353 and 354:
Page 355 and 356:
s Finally, the Figure 4-97 shown th
Page 357 and 358:
Page 359 and 360:
Page 361 and 362:
s velocity (m/sec) altitude (km) 50
Page 363 and 364:
s 4.5 Mars Ascent Vehicle 4.5.1 Tra
Page 365 and 366:
s Term Value Unit Radius of equator
Page 367 and 368:
Page 369 and 370:
Page 371 and 372:
Page 373 and 374:
s Inclination (deg) 47.5 47 46.5 46
Page 375 and 376:
Page 377 and 378:
Page 379 and 380:
s 4.5.3 Structures HMM Assessment S
Page 381 and 382:
Page 383 and 384:
s 4.5.5 Thermal HMM Assessment Stud
Page 385 and 386:
s 4.5.5.3 Baseline thermal design H
Page 387 and 388:
Page 389 and 390:
s Crew Ingress/Egress Hatch: HMM As
Page 391 and 392:
s Element 3: Mars Ascent Vehicle HM
Page 393 and 394:
s 4.5.7.5 Budgets Characteristic Va
Page 395 and 396:
s PER DAY PER MISSION DRINKING WATE
Page 397 and 398:
Page 399 and 400:
Page 401 and 402:
s 5 OVERALL CONCLUSIONS HMM Assessm
Page 403 and 404:
s 6 APPENDIX A - MARTIAN SURFACE NU
Page 405 and 406:
Page 407 and 408:
s Figure 6-1: Example of buried rea
Page 409 and 410:
Page 411 and 412:
s 7 APPENDIX B - REFERENCES [RD1] C
Page 413 and 414:
s [RD26] IES2, Phase A0: Final Repo
Page 415 and 416:
Page 417 and 418:
s [RD85] Mars Transportation Enviro
Page 419 and 420:
s 8 APPENDIX C - ACRONYMS AAA Avion
Page 421 and 422:
s MLI Multi-Layer Insulation MMH Mo
show all

ESA Document - Emits - ESA

Create successful ePaper yourself

Delete template?

Save as template?