Why a capsule?

• Why a capsule? by cozmicray on 23 Jun, 2006 17:24
• Can someone point me to the trade studies or analysis that support the choice of a capsule design?  
  Seems NASA goes from airplane form to capsule form to airplane form to capsule form for no reason.  The X planes to capsule to STS, dyna soar. CRV, VentureStar to now capsule CEV.
  NASA can only have one at a time and NOT a truck to space and a mini to space.  This way no progress is made.  Are the lessons learned from Apollo being applied to CEV, are the lessons learned even captured or known.  Don't take any risk, don't stretch/develop technology, never advance.
  Just baffles me.
  
  Tnx
• #1 by HailColumbia on 23 Jun, 2006 17:49
• I thought this debate had been long settled. (although I'm sure that Vt Hookie guy wouldn't agree)
  The CEV is designed to return from the moon. It is going to hit the atmoshphere much faster then the shuttle does,   the wings would snap off.  Plus, they serve little purpose other then to land on a runway, they are deadweight that you would have to carry all the way to the moon, that means less useful payload.  Dos the capsule look lame? yes, it definatly does, the space shuttle is probably the sexiest space ship we will ever see.  "looking cool" is not a good enough reason to build a spacecraft into an aircraft. Now, if the CEV was only supposed to operate in LEO, then wings start to look good again.  
  
  I would hardly define wings as "progress" The starship enterprise had no wings, and THAT would be progress.
• #2 by Jim on 23 Jun, 2006 18:10
• Quote

  cozmicray - 23/6/2006  1:11 PM
  
  Can someone point me to the trade studies or analysis that support the choice of a capsule design?  
  Seems NASA goes from airplane form to capsule form to airplane form to capsule form for no reason.  The X planes to capsule to STS, dyna soar. CRV, VentureStar to now capsule CEV.
  NASA can only have one at a time and NOT a truck to space and a mini to space.  This way no progress is made.  Are the lessons learned from Apollo being applied to CEV, are the lessons learned even captured or known.  Don't take any risk, don't stretch/develop technology, never advance.
  Just baffles me.
  
  Tnx

  
  Dynasoar was not NASA,  X-33 (Venturestar was Lockheed) was a launch vehicle not a crew carrier.
  
  It was found during OSP that liftingbody/winged vehicles could not provide unccntrolled aborts.  They needed active control.    The CEV has requirement for this.  Also to save time and money and use the wealth of the info from the  Apollo program, the CEV shape was dictated to be the same as Apollo.  
  
  Lesson learned:  separate crew from cargo.   CEV only carries the crew ( the "cargo" it carries with the crew amounts to luggage).  The CEV is the mini.  
  
  The Truck is the CaLV and it carries the cargo.  The Ca stands  for cargo.
  
  The CEV is not to "stretch/develop technology" but to get people to and from LEO (soon as possible) so that we can "advance" by going to the moon and Mars later.    The CEV, in concept, is the cheaper way to go because the flight rates don't support RLV's
• #3 by quark on 23 Jun, 2006 22:01
• Quote

  HailColumbia - 23/6/2006  11:36 AM
  
  I thought this debate had been long settled. (although I'm sure that Vt Hookie guy wouldn't agree)
  The CEV is designed to return from the moon. It is going to hit the atmoshphere much faster then the shuttle does,   the wings would snap off.  Plus, they serve little purpose other then to land on a runway, they are deadweight that you would have to carry all the way to the moon, that means less useful payload.  Dos the capsule look lame? yes, it definatly does, the space shuttle is probably the sexiest space ship we will ever see.  "looking cool" is not a good enough reason to build a spacecraft into an aircraft. Now, if the CEV was only supposed to operate in LEO, then wings start to look good again.  
  
  I would hardly define wings as "progress" The starship enterprise had no wings, and THAT would be progress.

  
  In the original CEV proposal a year ago, LM proposed a lifting body design---not exactly wings, but not a capsule.  The NG/Boeing team proposed a capsule.  The current capsule was dictated by NASA after ESAS.  The lifting body has several advantages.  Among them is the ability to take out more velocity when hitting the atmosphere, very important coming back from Mars, not so much from the moon.  It also has a substantial cross range capability which allows better control over landing sites, planned and abort.
  
  The "requirement" for uncontrolled abort is curious considering it doesn't exist today (within STS) and all systems have to be dual fault tolerant.
• #4 by Jim on 23 Jun, 2006 22:21
• The STS didn't meet a lot of requirements  and had waivers and that is why it is being retired.  Lessons learned.   Just because it didn't meeting the requirements doesn't mean its ok or right.  (sounds like your father)
  
  The lifting body caused a lot more problems wrt to abort than it solved.
• #5 by zinfab on 23 Jun, 2006 22:59
• Quote

  The "requirement" for uncontrolled abort is curious considering it doesn't exist today (within STS) and all systems have to be dual fault tolerant.

  Challenger proved the error in this strategy. Had there been a capsule/abort, the crew would still be with us.
• #6 by quark on 23 Jun, 2006 23:57
• Quote

  zinfab - 23/6/2006  4:46 PM
  
  

  Quote

  The "requirement" for uncontrolled abort is curious considering it doesn't exist today (within STS) and all systems have to be dual fault tolerant.

  Challenger proved the error in this strategy. Had there been a capsule/abort, the crew would still be with us.

  
  
  I am not defending STS or its level of safety.  However, I think there needs to be a balance between a reasonable level of safety and a reasonable level of mission capability.  To me, uncontrolled abort---in addition to "anytime abort", in addition to "dual fault tolerance", all above and beyond STS---tips the balance.  No airplane or automobile meets an "uncontrolled abort" requirement.  Maximum safety is not getting out of bed...
  
  I liked the idea of a fly-off, where different ideas could be tested and compared.
  
• #7 by nacnud on 24 Jun, 2006 00:23
• Quote

  I liked the idea of a fly-off, where different ideas could be tested and compared.

  
  Great idea, want to pay for it? It is very very hard to try and justify space planes over capsules on safety grounds. There might be operational advantages but a lifting capsule and a steerable parachute can land with pin point accuracy and RLVs have the flight rate problem.
  
  Small capsules for people and big dumb rockets for cargo seem like a very good option at the moment, only once there is demand for high flight rate and significant down mass do space planes look economically attractive.
  
• #8 by astrobrian on 24 Jun, 2006 01:41
• Then why not go with unmanned "planes" and keep the capsules manned. sounds like the best of both worlds. We can fly UAVs all over the place, and run rovers all over mars, why not the shuttle. That would be able to keep the ISS partners happy and keep our astronauts safer in the process
• #9 by hyper_snyper on 24 Jun, 2006 01:56

• Quote

  astrobrian - 23/6/2006  9:28 PM  Then why not go with unmanned "planes" and keep the capsules manned. sounds like the best of both worlds. We can fly UAVs all over the place, and run rovers all over mars, why not the shuttle. That would be able to keep the ISS partners happy and keep our astronauts safer in the process

  What do you mean by unmanned planes?  Cargo launch with spaceplanes?  If so, then you're limiting the amount you can haul to space because a straight up expendable rocket will always be able to lift more than a cargo only spaceplane.   

• #10 by Jim on 24 Jun, 2006 15:12
• Quote

  quark - 23/6/2006  7:44 PM
  
  
  I am not defending STS or its level of safety.  However, I think there needs to be a balance between a reasonable level of safety and a reasonable level of mission capability.  To me, uncontrolled abort---in addition to "anytime abort", in addition to "dual fault tolerance", all above and beyond STS---tips the balance.  No airplane or automobile meets an "uncontrolled abort" requirement.  Maximum safety is not getting out of bed...
  
  

  
  Most manned spaceflight accidents/incidents have occurred during reentry.  We know the accidents but there were many more incidents.  I don't have the list with me at home.  But one was Soyuz 5? where the descent module reentered upside down.  STS-9 GPS shutdown and APU fires.  A wing burnthru on STS-XX.  I will get the list later.
  
  This is requirement for "robust" (maybe that is a better word) abort.
  
  Cars and Planes don't have "aborts"  They don't deal the potential, kinetic or stored energies involve with space launch or entry
• #11 by cozmicray on 24 Jun, 2006 19:10
• Hey I just wanted to see some hard analysis and trade studies that show capsule is the choice.  Not dictation by NASA.
  Why then are a lot of very good designers and engineers with Russians and the rest of the world building a lifting body --- Kliper?
  
• #12 by Jim on 24 Jun, 2006 19:45
• Rest of the world is not building anything(except for Spacedev).  Kliper is not a firm program, just a proposal by Energia.  the RSA did not ask for it.  It has yet to go forward with funding.  Kliper does not go to the moon.  
  
  All the OSP studies showed it.   Look at the ESAS, it states the reasons.  Look at other threads on the this website, there are posts with links to studies., Also to save money, NASA said use the Apollo outermold line, since there was a lot of data on it.
• #13 by astrobrian on 24 Jun, 2006 20:20
• The Kliper was canned in favor of a capsule
  http://www.flightglobal.com/Articles/2006/06/13/207228/Kliper+dropped+for+lunar+capsule.html
• #14 by kraisee on 24 Jun, 2006 21:21
• Jim points out the two most overpowering decisions to go with the capsule - the extensive data library available on the Apollo-capsule mouldline, and the cost savings.
  
  Another few points to keep in mind is that a simple capsule is just that:  "simple".   Winged space-planes and lifting body designs require a host of additional subsystems, such as aerodynamic control surfaces and landing gear.   All these additional systems add more mass to the vehicle, which cause restrictions in numerous other ways (all added mass needing to be sent to the moon is a very bad thing), and also quite bluntly; the more subsystems you have, the more that can possibly go wrong.
  
  Further, lifting body designs create a lot more complexity during the development cycle.
  
  During the OSP program a huge amount of effort, money and man-hours had to go into solving the complex aerodynamic and loading issues of ensuring the highly complex shaped craft on top did not exceed the designs of the launcher during ascent.   This sort of developement requirement is *vastly* reduced if you use a simple conical capsule, and this ultimately boils down to a safer design.
  
  It seems to boil down to a change in philosophy following the loss of Columbia.
  
  Much of the space program's prior history was been about "What are the limits of what we can design?".   CEV changes that philosophy to "Use our extensive knowledge to create the safest possible craft to do the job?"
  
  The "pushing the limits" focus is still there within NASA though - but it has changed direction towards the missions instead of the vehicle hardware.   NASA is now focussing on "How far can we GO out there?"   I for one, hugely welcome this change.
  
  Ross.
• #15 by kraisee on 24 Jun, 2006 21:28
• Oh and also the simple capsule will obciously be quicker to design and make than a more complex shaped craft - and reducing the time gap between Shuttle and CEV as much as possible is a critical requirement stipulated by Congress & the WHite House to NASA.
  
  Ross.
• #16 by cozmicray on 25 Jun, 2006 00:04
• Thank you for showing me the analysis that shows the capsule design is the best!
  Now show me where the Apollo lessons learned document or database is kept?
  Please show me where in the CEV RFP that the  Apollo lessons learned or any other lessons
  learned must be used?    The "Not invented here" permeates ALL NASA projects.
  All the lessons learned from Apollo have died with the old engineers.
  
• #17 by Jim on 25 Jun, 2006 00:14
• Quote

  cozmicray - 24/6/2006  7:51 PM
   The "Not invented here" permeates ALL NASA projects.
  

  
  NASA ran Apollo.  So how can it be NIH?
  
  Where is your proof for "ALL NASA projects"?
  
  

  Quote

  cozmicray - 24/6/2006  7:51 PM
  All the lessons learned from Apollo have died with the old engineers.
  

  
  Says who?  They are still around.  And there lessons to
  
  Unfortunately you don't have access to the database NASA (windchill) is using for Constellation.  Even the lessons from OSP are being used.
  
  There is a whole lot of Apollo info being used.  I have downloaded some of it for my own personal reading.
  
  You are making a lot of accusations without showing any info to back them up
• #18 by mlorrey on 25 Jun, 2006 02:48
• Quote

  zinfab - 23/6/2006  5:46 PM
  
  

  Quote

  The "requirement" for uncontrolled abort is curious considering it doesn't exist today (within STS) and all systems have to be dual fault tolerant.

  Challenger proved the error in this strategy. Had there been a capsule/abort, the crew would still be with us.

  
  FIRST was proven to have uncontrolled abort capability (that was its purpose: as an inflatable winged space station escape and reentry pod). Wings or lifting bodies does not mean no uncontrolled abort capability.
  
  And why is uncontrolled abort so important? With human pilots and autopilot controls, there is no event in which an uncontrolled abort is needed. Such capability would NOT have saved Challenger or Columbia.
• #19 by mlorrey on 25 Jun, 2006 02:58
• Quote

  kraisee - 24/6/2006  4:15 PM
  
  Oh and also the simple capsule will obciously be quicker to design and make than a more complex shaped craft - and reducing the time gap between Shuttle and CEV as much as possible is a critical requirement stipulated by Congress & the WHite House to NASA.

  
  OSP was designed and ready to be built years ago.
  
  X-33 was designed and under construction more than a decade ago.
  
  GTX demonstrator was ready to be built in 2004, with its RBCC engines proven in test cells.
  
  Don't bring up the "it will save time" gambit. NASA had multiple opportunities prior to the VSE to start construction on various launch vehicle projects. Building capsules is like going back to the Model T.