No. It is plain economics. Feasibility for re usability is determined by flight rate. For launch vehicles, the break over point is around 40 launches per year.
Quote from: OV-106 on 12/15/2009 03:11 pmQuote from: Robotbeat on 12/15/2009 02:57 pmRLVs are not just a good idea, they are the only sensible idea. ...And I guess we could have stopped after the Wright Flyer too and went to work directly on developing the 747. What would you think if the state-of-the-art of airplanes in the 1950s was still the biplane? See? Analogies can go both ways. I never said we should develop the 747 of spacecraft, only that we have to design in a sensible manner... i.e. reusable spacecraft should be the default except for rare exceptions with very good reasons... expendable should not be the norm. If it costs too much to refurbish something, then we need to find out how to reduce those refurbishing costs instead of just going back to expendables. Perhaps NASA is poorly suited to cost-reduction. I don't think that has to be the case, but if it is, then NASA should be restructured or perhaps a new agency formed to work along with NewSpace and the aerospace primes to develop a sustainable space infrastructure.
Quote from: Robotbeat on 12/15/2009 02:57 pmRLVs are not just a good idea, they are the only sensible idea. ...And I guess we could have stopped after the Wright Flyer too and went to work directly on developing the 747.
RLVs are not just a good idea, they are the only sensible idea. ...
No. It is plain economics. Feasibility for re usability is determined by flight rate. For launch vehicles, the break over point is around 40 launches per year.It has nothing to do with NASA as an organization. NASA doesn't fly enough missions to justify development of an RLV. NASA in itself does not drive the need for sustainable space infrastructure nor should NASA (or any gov't agency) be in charge of one. Market forces are what should drive the need for a sustainable space infrastructure
I know what you are saying in the strictest sense, however, the analogy on your end is flawed. You are equating time we have been sending objects in space to airplane development and expecting the same pace of development. The two can't be compared in that way because of the physics and where our state of the art currently is at with regards to reaching space.
What you are suggesting is that we don't do anything until some group, somehwere, at some point has agreed that we have a sufficiently reusable vehicle and that everything is now sustainable.
However, I ask you to define that since you are proposing it.
Remember, at this point expendable does not automatically equal unsustainable.
What you suggest is essentially a single stage to orbit vehicle with such low recurring costs and a high flight rate that it revolutionizes everything (X-33 and VentureStar come to mind). ...
Furthermore, you suggest we should stop everything until we reach that panecia moment,
If it costs too much to refurbish something, then we need to find out how to reduce those refurbishing costs instead of just going back to expendables. Perhaps NASA is poorly suited to cost-reduction. I don't think that has to be the case, but if it is, then NASA should be restructured or perhaps a new agency formed to work along with NewSpace and the aerospace primes to develop a sustainable space infrastructure.
It has nothing to do with NASA as an organization. NASA doesn't fly enough missions to justify development of an RLV.
NASA in itself does not drive the need for sustainable space infrastructure nor should NASA (or any gov't agency) be in charge of one. Market forces are what should drive the need for a sustainable space infrastructure
The one flawed pseudo-RLV we do have doesn't do too bad compared to expendables, even at a far less than 40-per-year flight rate. Even just using larger tiles would make a measurable difference in its cost for refurbishment.NOTE: I didn't say NASA should be shuttered. I said that, if NASA is unable to build sustainable space infrastructure, it might be a good idea to form a new agency (not necessarily eliminating NASA, which is effective in science and exploration) that can.
This is quite a likely point, but there is no empirical proof, since there isn't a RLV yet. The one flawed pseudo-RLV we do have doesn't do too bad compared to expendables, even at a far less than 40-per-year flight rate. Even just using larger tiles would make a measurable difference in its cost for refurbishment.
Quote from: Robotbeat on 12/15/2009 04:54 pmThe one flawed pseudo-RLV we do have doesn't do too bad compared to expendables, even at a far less than 40-per-year flight rate. Even just using larger tiles would make a measurable difference in its cost for refurbishment.NOTE: I didn't say NASA should be shuttered. I said that, if NASA is unable to build sustainable space infrastructure, it might be a good idea to form a new agency (not necessarily eliminating NASA, which is effective in science and exploration) that can.Interesting on the TPS. Where is your data to support this?
Finally, you want to create another government agency that essentially competes with NASA for resources and has all the overhead a separate government agency would require? This will essentially drive down the purchasing power of the money available for space as a whole.
Quote from: Robotbeat on 12/15/2009 04:54 pmThis is quite a likely point, but there is no empirical proof, since there isn't a RLV yet. The one flawed pseudo-RLV we do have doesn't do too bad compared to expendables, even at a far less than 40-per-year flight rate. Even just using larger tiles would make a measurable difference in its cost for refurbishment.It is many times costly than expendables. The tiles do not account for that much of the refurb time or cost
I agree. I don't propose such an agency, but if you measure the purchasing power of money invested in NASA for reusable launch vehicles in the last three decades (not counting Shuttle), then you have very, very little purchasing power indeed. I am not saying this is necessarily the case for NASA as a whole, I am merely saying what is plain to everyone: we cannot develop a RLV (or reusable spacecraft) at NASA the same way it has been attempted with VentureStar, etc.... with billions invested and little to no results. Partly this is just technical difficulty and at least as much it was poor management decisions and overly compromised, ambitious, and design-by-committee designs. I don't think that it'll take a new agency to fix this, but if the problem is endemic to NASA (as is evidenced by frustrations faced with scientists seeing an overbearing bureaucracy to get their experiments flown even during the early 1970s), then perhaps a new agency is warranted. I completely realize that if someone were to attempt to do this, they would most likely end up with a much smaller budget for space across the board, so it may be unrealistic to attempt such a restructuring (assuming you care about space).
It has been mentioned on this board, quite frequently, that NASA should be replaced with something along the line of its predecessor, the NACA in order to simplify the bureaucracy and to work better with the NuSpace companies.But NASA has grown into an immense beast and it requires a lot of feeding. I think it will require an impossible amount of political will to accomplish putting it on such a diet.
They certainly do cost more, and they cost a few times more for delivering cargo, but are comparable for delivering crew, since it is a (manned) spacecraft as well as a launch vehicle (and as such it is not quite fair to compare it to expendables without a capsule when talking about reusable launch vehicles).How much do the tiles account for in terms of refurb time and costs versus the rest of the refurb process? How much do things like poorly thought-out placement of access panels cost in time and money, things that could be fixed if you were to build a Shuttle version 1.5?I know that even transporting the Space Shuttle via air is something like $65 million. You'd want to be able to safely transport a next-gen reusable vehicle via something cheaper, like road or rail or barge. The Shuttle is probably just too huge to ever be moved inexpensively.Is there are break-down of the various costs of Shuttle refurb anywhere that you can link to? Thanks!
An expendable capsule would also be cheaper for the few flights per year that CxP is going to do.Reusable does not necessarily mean cheaper.