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SpaceShipThree to be Orbital Spacecraft
FleaPlus writes "The president of spaceflight company Virgin Galactic has recently
stated that if the upcoming suborbital service with SpaceShipTwo
is successful, the follow-up SpaceShipThree will be an orbital craft.
Although orbital spaceflights would be much longer and could
potentially dock with orbital
space stations, they are also considerably more difficult than
suborbital spaceflights. Other private firms working on orbital
spaceflight (and potentially in the running for Robert Bigelow's $50
million America's Space Prize for orbital flight) include t/Space
and SpaceX."
There's a very interesting writeup about the potential problems related to trying to reach orbit in these "scaled composites" "spaceships" at http://www.daughtersoftiresias.org/misc/ss1.html.
Basically, the biggest problem is that due to the simplicity of the engine design (the are examples of space shuttle engine and the SS1 engine on the page above), the design would never scale enough to reach velocities needed to get into orbit.
I suspect that the engineers involved in Vigin Galactic are not complete morons, and might possibly know a little bit about high altitude flight and rocket engines. Perhaps even more than you do, surprising as that may seem.
If they set about designing an orbital craft, I'd hazard a guess and say that they wouldn't use an engine design that is known not to work. Likely as not, they'd use a different engine design that is known to work.
"There's absolutely no way that White Knight / Spaceship One will scale up to an orbital vehicle."
Sigh. Where did they say it would use the same design as the current vehicles? Ah, they didn't.
"If Rutan thinks he can build a vehicle capable of travelling ten times faster than SS1 with high enough SI and all the rest of that engineering detail, great, let him try"
Putting people into space is 1960s technology: anyone with a few brain cells and enough money can do it. The only question is whether Rutan can do it cheaply enough to make space tourism viable.
1. Because I know the orbital flight will cost 10x the suborbital and I'm not quite rich enough for that.
2. Because I'll be dead before they get the orbital vehicle ready for commercial passengers.
RETURN without GOSUB in line 1050
Then, when the materials tech becomes practical, they build a space elevator on the very same site. Makes perfect sense; at that point, they have the name and a shitload of capital to make it happen. Taxpayers have spent enough on incremental baby steps and aerospace subsidies.
May dreams such as these take wing and I'd be happy just to watch: (link)
"OH SHIT, THERE'S A HORSE IN THE HOSPITAL!"
I have to agree that I prefer to buy products from (and work for) companies that tend to keep their PR under wraps until they actually have something to show for what they have been spending all of their R&D budgets. I have done too many projects that I call "design by press release", where my boss tells me what the product is supposed to do by sending out the press release, and they I have to try and shoehorn the project to meet those expectations (including customer expectations). It is never a good thing.
In the computer software industry, you can sometimes get away with that sort of mentality, but in aviation and especially rocketry I would say that is an absolute mistake. If I were running an aerospace company there is only one way I would dare make that sort of press release, and that would be if I already had the designs "on the drawing board" and had already proven most of the major technological hurdles (at least from a test lab viewpoint). Obviously Scaled Composites hasn't sent anything up besides SS1, and you (as well as others) are correct that SS1 by itself simply won't scale up to orbital velocities without some very substantial structural and raw materials changes. Essentially a whole new spacecraft from the ground up.
SpaceX I think has at least been doing the right thing, and they got a bunch of real rocket scientists that know their stuff. They will get to orbit (unmanned), and if their Falcon I is successful, the Falcon V has a very good chance of success. The Falcon V is also a "next generation" spacecraft, and does demonstrate what scaling in the aerospace industry is really all about. There are also no major "show stoppers" to the Falcon V other than government bureaucracy and idiots in congress calling it a "munition".
I see a number of things that will prevent a scaled up or modified version of SS1 from being successful as an orbital spacecraft. On the other hand, if you compare the DC-3 to the DC-10, there are some similar features between the two aircraft, but it also shows huge leaps of logic as the aeronautical engineers finally figuered out how to build aircraft. I'm willing to do a "wait and see" on this new design by Scaled Composites, but I am very skeptical.
I'm under the impression that the direct speed/altitude benefits are fairly small. Rather, the main benefits are from safer abort methods (you can parachute back down if your engines fail) and being able to build an engine optimized for the upper atmosphere and space. You also don't have to pay launch site fees, and liability insurance becomes easier to deal with. Here's a relevant quote from t/Space's site:
n =projects.view&workid=CCD3097A-96B6-175C-97F15F270 F2B83AA
http://www.transformspace.com/index.cfm?fuseactio
The major benefits of air launch come in safety, simplicity and flexibility. Crew safety is enhanced because abort-at-ignition is easier when the capsule already is high enough for parachute deployment, vs. the on-the-pad challenge of releasing sufficient energy in the correct direction to send the capsule high enough for the parachutes to deploy. Public safety is enhanced because the launch takes place over open ocean, well away from any populated areas.
Air launch also allows simpler engines, which don't need to be designed to operate at both sea-level air pressure and at altitude. The "all-airborne" operation also reduces the performance penalty of using inexpensive low-pressure tanks and engines.
Flexibility and responsiveness is greatly enhanced by air launch. Most winds and precipitation at the airport runway -- launch site -- don't delay a launch; the carrier aircraft simply flies to clear weather. In addition, responsive launch often requires matching a particular inclination and orbit phasing. The carrier aircraft over open ocean can launch the CXV to any azimuth, and by flying across longitudes, can quickly match a desired orbit phasing.
The t/Space version of air launch provides only modest performance gains, in the 10-25% range, compared to a ground launch. It does not attempt technically difficult challenges such as accelerating the launch aircraft to supersonic speeds, or reaching very high altitudes.
$100.000 for flying from LA to Sydney in approx 4 hours?
Plus a 4 hour checkin and a body-cavity search at customs...
http://blog.nexusuk.org
Not really related to the articl, but... I'm getting pretty annoyed by this "look at what this small company is capable of doing, while NASA wastes billions of dollars!". Hell, Rutan himself made some similar comments (was it on 60 Minutes?).
Yes, What Rutan/Scaled Composites did is great, no denying that. But comparing their budget to NASA's is ludicrous. Does Scaled Composites maintain orbiting space-stations? Does Scaled Composites build orbiting space-stations? Do they conduct scientific experiments on other planets and in space? Do they send probes to comets and Mars? Rutan and Co managed to put a spacecraft for a short amount of time in to edge of space. NASA did that in 1961.
Rutan and Co have the advantage of having the knowledge that NASA and others have accumulated over the years at great expense. They use that knowledge, and then make remarks how NASA is "wasting money". Well, without that "waste of money", SS1 would still be nothing but a glimmer in Burt Rutans eye.
Lesbian Nazi Hookers Abducted by UFOs and Forced Into Weight Loss Programs - -all next week on Town Talk.
Hopefully the engineers at Scaled and Virgin know more than you (and the author of the linked page) do. Who's to say that a direct descendant of SS1 wil not (gasp!) change engine technologies?!
This as got to be one of the most stupid posts/pages that I've seen so far this year.
Okay ... every freaking time this subject comes up (which you all know is fairly often) at least part of the thread gets hijacked into a detour on re-entry heating and "how in the heck is Rutan going to solve that problem", etc.
... all you have to do is SLOW DOWN!
... "every action", etc. ... it takes as much energy to slow down as it took to speed up in the first place ... so it would take a LOT of fuel.) An ablative coating (on the Apollo Command Module) or the tile system (on the Shuttles) is a heckuva lot cheaper and easier than managing to get enough fuel on-orbit to slow the dang thing back down to near-zero.
... but that doesn't make it any less true!
... it just isn't so. As is the case with many science problems, there is more than one way to skin the cat.
IANARS, but I do know a thing or two about aerospace principles and technology due to the education I *do* have. What I always find amusing about this particular area of the discussion (re-entry heating) is that everyone posting seems to take for granted that re-entry heating is an axiomatic phenomenon that MUST be faced head-on. (Pun not intended but noticed.)
THIS IS NOT TRUE!
The only reason re-entry heating is an issue for us (NASA, et al) is more a matter of ECONOMICS than technology.
The simple fact is that you can re-enter the atmosphere with little or no heating
The reason we don't slow down is we can't afford to carry enough fuel to get into orbit and still have enough to slow the craft down for a cool re-entry. (Think about it
In a nutshell - if I can slow my craft down enough (think "retro-rockets" here) then I can practically "float back down" into the atmosphere with minimal heating.
There *are* possible solutions, such as *sending* fuel to orbit in a separate un-manned craft, and then re-fueling the manned craft on-station. Or *manufacturing* fuel outside Earth's gravity well so craft can re-fuel. Or having some other means of power to use for "retro-thrust" in orbit.
Now, I am going to cap the preceding comments with a BIG disclaimer:
*Of course* I realize that this opens a different set of problems and perhaps presumes technology developments in other areas
I am just tired of people assuming that no matter what you do you have to have a craft capable of withstanding all of that horrible heat
Me out!
See you space cowboy