Doug Messier wonders if Scaled and Virgin bit off more than they can chew with SpaceShipTwo.
I agree with him that it was a mistake to not fly SpaceShipOne more (and perhaps even commercialize it). I think that they made two misjudgements (well, actually, three). Their determination to stick with a hybrid, the initial decision to develop it within Scaled instead of subcontracting, and an overabundance of faith in Burt (which wasn’t helped by his health problems a couple years ago, though he’s reportedly much better now). The explosion cost them at least a year, and probably more, now that they’ve let a new subcontract to SpaceDev for the propulsion. They would have been a lot better off to just go with a liquid from the beginning (as some of us suggested to them). It might have been too risky to rely on XCOR for SpaceShipOne, because they didn’t yet have the track record, but they should have considered them (or someone else, such as Armadillo) for the new vehicle.
I wonder if they’ve been schedule constrained by budget? If not, a 2011 service date (six years after program start) puts into question the ability of private industry (at least this particular team) to do things much faster than the government.
Hmm. But is there a size between SS1 and SS2 that would be commercially viable? If not, then scaling up SS1 more moderately would just leave them with another very expensive test vehicle. Sounds like something only the government can afford.
Who knows? Their chosen size was somewhat arbitrary, though they no doubt convinced themselves it was commercially optimal. They could have sized for four instead of six passengers. They could have had a little less floating room. Of course, given their high marginal costs with the hybrid, I can understand why they would want to maximize passenger capacity. But they’ve made the choice now, and they’ll have to live with it.
The nice thing, of course, is that they will have competition from XCOR, Armadillo and (hopefully) others, so the market will figure it out.
“commercially viable”
Well we won’t know if SS1 could have been commercially viable since they never attempted to use it in the capacity.
I’m surprised that Scaled has done as well as it has. With the big WK2 flying already.
Of course, the real problems of rocket propulsion and finally, the routine operation are ahead.
There are many companies that in my view have much more sensible ways of approaching the suborbital tourism market.
Rand,
SS2 is going to use an engine in the 60klbf range. While XCOR and Armadillo might eventually be doing stuff that big, that’s way beyond the size of the biggest thing either of them have done. I think you’re forgetting Orion Propulsion. Heck at 60klb, you’re running at a decent fraction of a Merlin engine. This is not a trivial development by any stretch. Now, had they taken SS1, and done a liquid replacement for that, just to get the bugs worked out, then that would’ve been a much smaller first step.
I’m not saying that liquids aren’t a good idea (I think they’re a great idea), just that SS2’s scale has kind of painted them in a corner where hybrids might start looking interesting again.
~Jon
There are many companies that in my view have much more sensible ways of approaching the suborbital tourism market.
Perhaps you could name a few of them, mz? I’m just aware of XCOR’s Lynx and Astrium (Space Liner? FAST? something like that). Neither strike me as being obviously more sensible than the Scaled vehicle.
I’m not saying that liquids aren’t a good idea (I think they’re a great idea), just that SS2’s scale has kind of painted them in a corner where hybrids might start looking interesting again.
Just another reason to question their scale.
If not, a 2011 service date (six years after program start) puts into question the ability of private industry (at least this particular team) to do things much faster than the government.
My own personal issues aside, budget seems the obvious choice, particularly with the costs associated with the engine accident. However, given the size and complexity of the project it’s possible that it’s a combination of the two.
Government/big aerospace projects aren’t necessarily always slow because they’re Government or Big Aerospace. Sometimes projects are slow because of the nature of the project.
I suspect that this is one of those projects where the timeline and critical path looked fine going into it and then a cascade of seemingly minor things built up over time.
It wasn’t too long ago that Boeing were determined they’d have the 787 in service by now and they’re not delaying things out of choice nor is it entirely due to strike action.
After winning the X Prize, I was surprised that Burt didn’t use SS1 or a clone to do some systems development that would’ve been useful for SS2. For example, SS1 exhibited some “interesting” flight characteristics (excessive dihedral effect, manual flight controls) that would be unsuitable for repeated customer-carrying flights. With a smaller test vehicle, they could’ve worked out some of the bugs and developed improved systems for SS2. If you watch the excellent Dark Sky documentary, you’ll see that several of SS1’s flight tests were pretty ragged edge flying. I would’ve like to have seen them take some of the roughness out of the design before going ahead with SS2 but it didn’t happen.
It didn’t happen, though.
It looks to me like a relatively sound choice. A bad accident with the SS1 would taint the SS2. While if you discontinue the SS1 when they did, it has a 100% success record.
It is tough to judge really without knowing the dynamics. A couple things stand out:
– Hybrid engines don’t make sense, and Burt has alluded to the fact in several talks that this will be their last hybrid. The safety of the engine is not nearly what they thought at first – with their particular combo they have all the drawbacks of both solid (clogged nozzle, low Isp, need for significant turnaround work), coupled with the significant safety drawbacks of detonable monoprops. The *especially* didn’t make sense when they dropped their prime engine contractor. I would not be surprised to see development move in the direction of a SS2.1 with a biprop liquid replacement once (if) SS2 is flying and making money, especially if there is competition.
– Air-launch is a great idea for a low-Isp (read: cheap) fuel, and it would have made almost as much sense with a kero-lox or similar liquid system. However, air-launch from an entirely new vehicle the size of a small airliner is highly questionable. I would be interested to see the man-hour breakdown on SS2 vs. WK2 – I suspect there is a lot more design time in the latter. In other words, I’m not convinced that WK2 was a strategically necessary or beneficial addition to the program, especially in the “strike while the iron is hot” atmosphere from about 2004-2008. I get the feeling that Virgin held up their end of the deal, building a global sales network, finding space suit and training vendors, and now they’re kind of wondering what else they can do to keep customers happy while the spacecraft is built.
– Going from prototype to production. Few people, even (or especially) in the aerospace industry, appreciate how much more difficult and expensive it is to make lots of a thing versus one of a thing. Scaled has never turned out a series like this before, let alone two at the same time. It’s a company with a prototype mentality, trying to make a production vehicle, and running into problems along the way. If they had just gone ahead and built a straight-up prototype system, and then waited to design the assembly line until after that was well on its way, they might be flying something to space right now. It might not be carry passengers, but it wold be proving out technology and it would be good PR.
How useful is WK2 for the USAF responsive launch needs?
That, it seems, might be a part of Virgin’s business model.