Commercial  Spaceflight  and   Advanced  Propulsion    

Commercial  Crew     Development  (CCDev1)   •  Sierra  Nevada   Corpora>on  (SpaceDev)  

–  Development  of  the   Dream  Chaser  spaceplane   –  $20M  for  building  and   tes>ng  Engineering  Test   Ar>cle   –  Leverages  NASA  HL-­‐20   airframe   –  Launch  vehicle:  Atlas  V   –  Hybrid  Rocket   –  Seven  crew  members  

•  Robert  Bigelow   •  Expandable  Space  Sta>on  Modules   –  Inflatable  modules  are  easier  to   launch   –  Based  on  technology  developed  at   NASA:  TransHab  Program  

•  Prototypes:   –  Genesis  I  

•  1/3  size  inflatable  structure   •  Launched  July  12,  2006   •  Expanded  to  twice  its  diameter  (4.4  m)  

–  Genesis  II   •  •  •  •  • 

Same  size  as  Genesis  I   Launched  June  28,  2007   Enhanced  sensors   Addi>onal  layer  for  thermal  control   Increased  reliability  

Sundancer/BA  330   •  Occupancy  

–  3  people  –  long  term   –  6  people  –  short  term  

•  Protec>on  

–  Radia>on   –  Ballis>c  

•  •  •  • 

Four  large  windows   Environmental  Systems   Solar  Power   Propulsion   –  Manuevering   –  De-­‐orbi>ng  

•  Es>mated  launch:  2014?  

Space  Ship  Two   •  Spaceplane  

–  VSS  Enterprise   –  VSS  Voyager  (planned)  

•  Hybrid  Rockets   •  Peak  Al>tude:  110  mi   White  Knight  Two   •  Jet  powered  aircrac   –  VMS  EVE   –  VMS  Spirit  of  Steve   Fossed  

•  Launch  Al>tude:  9.5  mi  

•  Suborbital  Space  Tourism   –  Ticket:  $200  K   –  Down  payment:  $20  K  

•  Spaceport   –  Partnership  with  New  Mexico   –  $200  million   –  Training  ground  for  tourists  

Lynx   •  Two  person   •  $95k  ($20k  deposit)  >cket  price   •  Al>tude  100  mi.   •  Take  off/lands  like  airplane   •  Mark  I  test  flight:  2014?   •  Poten>ally  four  flights/day   •  Kerosene  and  LOX  engines     X-­‐Racer   •  Designed  for  Rocket  Racing  League   •  Two  seats   –  Pilot   –  Flight  Engineer  

•  230  mi/hr  

Advanced  Propulsion/Concepts  

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Surface  Reactors   •  Need  power  for  astronauts  on   Moon  or  Mars   •  Nuclear  power  is  the  only   viable  solu>on  for  powering   manned  missions   •  NASA  Glenn  is  currently   working  on  developing  a  40   kW  fission  reactor   •  Small  scale  compared  to   terrestrial  power  plants   •  Design  must  be  very  different   (heat,  size,  materials…)   •  Test  (without  nuclear   material)  is  expected  2012-­‐13  

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Innova>ve  Nuclear  Space  Power      and  Propulsion  Ins>tute     •  Research  space  nuclear   reactor  concepts   •  Research  space  nuclear   thrusters   •  Research  materials/ components  for  space  nuclear   power   •  Mixture  of  theore>cal,   computa>onal,  and   experimental  work   10  

What  we’re  going  to  talk  about   We’re  going  to  talk  about   propulsion  that  involves  physics   that  is  understood.         This  does  not  mean  that  all  of  the   engineering  problems  are  solved     We  will  not  discuss  propulsion  that   requires  new  physics  to  be   discovered  or  invented.       If  you  are  interested  in  “new   physics”  propulsion:   hdp://www.daviddarling.info/ encyclopedia/A/ advanced_propulsion_concepts.html    

•  •  •  •  •  •  •  • 

Bussard  Ramjet   Solar  Sails   Magne>c  Sails   Beamed  Energy  Propulsion   Laser  Propulsion   Tethers   Space  Elevator   An>mader   11  

Fuel-­‐less  Propulsion   We’ve  talked  a  lot  about  chemical,  electric,  and  nuclear  rockets.   In  all  of  these  systems,  you’re  rocket  must  accelerate  its  fuel  for   later  parts  of  the  mission.      

This  led  us  to  the  rocket  equa>on.    Remember  that  the  fuel  mass   has  an  exponen>al  dependence  on  the  spacecrac  velocity.  

If  we  could  leave  the  fuel  behind,  this  would  improve   performance  drama>cally.    This  is  an  exponen>al  mass  savings.   12  

Bussard  Ramjet   The  Bussard  Ramjet  picks  up  fuel  from  interstellar  space  as  it  flies  that  it  then   “burns”  in  a  nuclear  reac>on  to  provide  power  and  thrust.   Ini>al  design  was  mechanical  structure.   However,  for  a  1000  ton  spacecrac,  a   ramjet  needed  to  be  over  104  km2  

Magne>c  fields  can  be  used  instead,  but   we  can  only  collect  ionized  H  and  not   atomic  H   Technical  challenges  remain:    difficult  to   get  H  into  engine;  collec>ng  p  not  D   13  

Solar  Sails  

A  solar  sail  uses  a  large  sail  and  is  pushed  by  photons  from  the  Sun.   Photons  carry  momentum  and  transfer   their  momentum  to  the  spacecrac   when  they  collide  with  the  sail.  

No  fuel  is  required.   Conceptually  simple  design.   Can  move  spacecrac  towards  and   away  from  the  sun   Photon  pressure  at  Earth:  10-­‐5  N/m2   Large  scale  structure  required  in   space  (several  square  km)   Thrust  decreases  as  you  move   farther  from  the  Sun  since   intensity  falls  off  like  1/r2  

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Solar  Sails  

A  solar  sail  uses  a  large  sail  and  is  pushed  by  photons  from  the  Sun.  

Research  is  currently   underway  to  develop   solar  sail  technology.  

NASA  JPL:  Nano  Sail  D  tested  in   large  vacuum  chamber  ()  

JAXA  in  space  solar  sail   deployment  (7.5  µm  thick)  

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Recent  Solar  Sails   •  Japanese  Ikaros  Project   –  Launch:  May  2010   –  Diagonal  20  m   –   Thickness:  7.5  µm   –  Next  step:  50m  sail  to   Jupiter/Trojans  

•  NASA  Nanosail-­‐D   –  Cubesat   –  Nov  2010   –  Area:  100  m2   16  

Magne>c  Sails   A  magne4c  sail  uses  a  large  extended  magne>c  field,  which  interacts  with  the   solar  wind.  The  force  of  the  solar  wind  plasma  on  the  sail  provides  thrust.  

Mini-­‐Magnetosphere   Plasma  Propulsion  (M2P2)   Uses  plasma  to  “inflate”  magne>c  field     Only  small  structures  and  no   superconduc>ng  magnets  are  required  

Magne>c  field  and  plasma  pressure   balance.    As  spacecrac  gets  farther   away,  size  of  the  sail  changes,  but  the   thrust  does  not  decrease     Genera>ng  a  large  scale  magne>c   field  has  challenges:   1.  requires  superconduc>ng  magnets     2.  large  structures  in  space  

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M2P2  Research   Dipole  magne>c  field  generated  by  large   current  loop     Magne>c  field  looks  like  a  mini-­‐ magnetosphere     Test  M2P2  constructed  here  at  UW     Tested  at  NASA  Glenn     Ini>al  results  on  magne>c  field  infla>on   look  promising     Currently  unfunded     Similar  research  currently  funded  by  E18  SA  

M2P2  

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MagBeam  

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ISS  to  Mars?   •  Plans  to  deorbit  the  ISS  pushed  back  from   2016  to  2020   •  ISS  cost  approximately  $150  billion  to   construct  in  total   •  Unclear  what  it  would  require  or  cost  to  move   the  ISS  out  of  orbit   •  Thermal,  radia>on  issues  designed  for  being   at  Earth  

Laser  Propulsion  

A  laser  pushed  lightsail  is  similar  to  a  solar  sail,  except  the  photons  come   from  a  laser  on  a  sta>on  instead  of  the  Sun.   Idea  proposed  and  analyzed  by  Robert  Forward  in  1989.     No  fuel  or  large  quan>>es  of  onboard  power  are  required.     More  control  of  system  since  laser  is  controlled  on  Earth.     Similar  issues  as  solar  sail:  large  structures  in  space;  light   falls  off  like  1/r2;  low  force  

A  lightcra>  has  a  parabolic  mirror  that  is  hit  by  a   laser  on  the  ground.    The  laser  causes  the  air  under   the  crac  to  heat  violently,  which  generates  thrust.     Requires  high  power  lasers  (100  kW  for  sounding   rocket  capabili>es).     hdp://www.youtube.com/watch?v=LAdj6vpYppA  

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Tethers   Tethers  Unlimited  is  currently  inves>ga>ng  use  of  space  tethers  for   propulsion,  power  genera>on,  orbital  transfers,  launch  assist…   Microsatellite  Propulsionless  Electrodynamic  Tether  (µPET):   How  it  works:   1.  Long  tether  is  deployed   2.  Current  is  run  along  the  tether  (on   board  power  is  required)   3.  Current  in  the  tether  interacts  with  the   Earth’s  magne>c  field   4.  That  current  can  be  used  to  power   something  to  provide  thrust   Tether  deployment  has  been  successfully   tested  on  shudle  missions     hdp://www.youtube.com/watch? v=pCAEFocoVdM  

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Tethers   Tethers  Unlimited  is  currently  inves>ga>ng  use  of  space  tethers  for   propulsion,  power  genera>on,  orbital  transfers,  launch  assist…   Tether  Assisted  Launch:  

Tethers  are  constructed   with  mul>ple  fibers  to   be  a  robust  design  

How  it  works:   1.  Spacecrac  is  launched  by   low  power  rocket.     2.  Satellite  in  orbit  reaches   down  with  tether  and   grabs  the  spacecrac   3.  Tether  swings  the   spacecrac  into  a  higher   orbit   4.  The  orbital  al>tude  of  the   satellite  is  decreased   5.  Can  use  µPET  to  increase   the  orbit   24  

Space  Elevator   A  space  elevator  stretches  from  the  surface  of   the  Earth  to  geosynchronous  orbit  and  higher   to  a  counterweight     A  “climber”  ascends  the  cable  to  bring  payloads   from  Earth’s  surface  to  orbit     Concept  of  space  elevator  was  first  invented  by   Konstan>n  Tsiolkovsky  1895   Currently,  material  technology   is  not  available  to  construct  a   space  elevator     There  is  specula>on  that   carbon  nanotube  material   could  be  used  in  the  future  

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Space  Elevator   Base  sta>ons  come  in  two  varie>es:   1.  Mobile  plaworms   2.  Sta>onary  Plaworms  

Climber:   •  Not  a  tradi>onal  elevator   •  Must  be  able  to  climb  variable  cable  size   •  Speed  and  mass  must  be  carefully   adjusted  to  minimize  oscilla>ons  and   cable  damage   26  

When  will  we  build  one?   “The  space  elevator  will  be  built   about    50  years  acer  everyone   stops  laughing.”        -­‐Arthur  C.  Clarke    

Tether  Strength  Compete>>on:   •  Breaking  strength   •  Strength  to  weight  ra>o   •  Tether  length   Power  Beaming  Climber  Compe>>on:   •  The  level  1  (2  m/s)  challenge:  LaserMo>ve     ($900,000).     •  The  level  2  (5  m/s)  challenge  remains   unclaimed  ($1,100,000).   “This  is  no  longer  science  fic>on.  We  came  out  of  the  workshop  saying,  ‘We   may  very  well  be  able  to  do  this.’”    -­‐David  Smitherman  (2000)  NASA/Marshall’s  Advanced  Projects  Office   27