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SpaceShipThree to be Orbital Spacecraft
Posted by
samzenpus
on Thu Aug 25, 2005 04:03 AM
from the space-class-flight dept.
from the space-class-flight dept.
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."
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Why SpaceShip[One|Two|Three] will not reach orbit (Score:4, Interesting)
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.
Only assuming thye use the same design (Score:5, Insightful)
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.
Parent
I am interested on how he gets back down (Score:4, Interesting)
Unless he revolutionizes rocket propulsion I don't see how they are going to get anyone into orbit at reasonable costs, by reasonable I mean in the $1,000,000 range.
If space tourism would generate a good return on investment I am pretty sure the Russians would be all over it. They already have the technology to get there and have proven they would take paying customers. Since they haven't moved more aggressively I have seriously doubts if it is doable on todays technology. Look at the Kliper, the estimated costs are nearly $3 billion just to develop it! It can take 6 people and 750kg of cargo to LEV. The other issue that stands out with Kliper is that the module may only be used 25 times before retirement.
If the Russians are having such issues with LEV on that budget it will take a miracle for anyone else.
Wiki link to Kliper
http://en.wikipedia.org/wiki/Kliper [wikipedia.org]
Parent
Re:Only assuming thye use the same design (Score:5, Interesting)
Fuels that are used in space must carry their own oxygen, but when going at high speeds in the earth's atmosphere, why not make like a jet engine and get oxygen from the atmosphere? Perhaps there could be two fuels, one for use in the atmosphere and one for use in space. The engine would start using one, then as pressure dropped would slowly switch to the other. But of course with an air intake that must work from zero to hypersonic speeds, you run into some pretty nasty physics in designing the thing. End result is you end up with a non-constant flow of oxygen to your engine, no matter how well you design your system. Thus the engine must be designed with this tolerance in mind.
So, anyone trying this: good luck!
Parent
Re:Only assuming thye use the same design (Score:4, Informative)
Because rockets generally don't 'go at high speeds in the earth's atmosphere'. Typically the job of the first stage is to lob the second stage pretty much out of the atmosphere so it can accelerate to orbital velocity with very low drag and vacuum-optimised engines.
You really don't want to be flying at Mach 20 in an atmosphere thick enough to provide oxygen to your engines: I believe the NASP design would have required active cooling with liquid hydrogen to keep the skin from melting. Developing such a system is a lot more expensive than throwing some more liquid oxygen in the tanks, and fatal if the cooling fails.
Parent
Re:Only assuming thye use the same design (Score:4, Informative)
There are ways around it - raise the chamber pressure [yarchive.net] like in the shuttle or use an altitude compensating nozzle like an aerospike [yarchive.net] or plug nozzle [wikipedia.org] but the kinks are yet to be worked out of these approaches.
There are problems with using air-breathing launchers. [yarchive.net] That said the most interesting idea I've seen for a cheap launcher includes them [yarchive.net].
Parent
Re:Only assuming thye use the same design (Score:5, Interesting)
It is probably more effective, from a mass-fraction standpoint to use multiple rocket stages rather than using an airbreathing stage over a small fraction of the trip.
IMO, the real "holy grail" is not reducing the stages to 1, but increasing the stages to infinity: a rocket that consumes its own structural mass as its usefulness is spent. No piece of structural mass should be lofted higher than it needs to be. Continuous staging would be the ultimate extension of that principle. In fact, I believe I have seen engines for sounding rockets that are designed to do just that.
Parent
Re:Only assuming thye use the same design (Score:3, Informative)
The feather won't work (Score:3, Interesting)
So parent is obviously talking out of his ass when the man who designed the craft sai
Re:Why SpaceShip[One|Two|Three] will not reach orb (Score:4, Insightful)
Parent
Re:Why SpaceShip[One|Two|Three] will not reach orb (Score:5, Interesting)
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.
Parent
Re:Why SpaceShip[One|Two|Three] will not reach orb (Score:4, Informative)
Just calculate the needed potential energy to lift the crafts total mass for 10km up in the air, and you know what basic savings you get.
I also can not seem to find an image of a rocket trajectory, so a description will have to suffice: The first few kilometer the trajectory is as straight up as possible. The trajectory in the densist air layers is the shortest possible. Since speeding up in that part is costly (drag=speed^2), the speed is kept down, in multistage rockets by coasting, or with solid fuel rockets by designing the thrust in such a way that you do not spend to much fuel on speed. Once the air density is low enough (less drag), you will speed up again, and adjust the trajectoy to get to escape velocity. For a decaying orbital trajectory, you do not necessarily need escape velocity, you just need to be able to make it around the earth like one time. So going orbital is also still pretty free in interpretation and goal.
New designs for suborbital planes with ramjets almost all use this design principle for this reason (and they need to get up to speed to make the ramjet work).
The main problem stays though that the design is complex, the take-off of a combined craft like this is slow, and the payload the combined craft can take is low, not higher than current rocket techniques if you really want to get into orbit (Imagine the shuttle+fueltank minus thrusters being lifted to sufficient height)
Parent
Re:Why SpaceShip[One|Two|Three] will not reach orb (Score:3, Insightful)
Just because an organisation employs thousands of the brightest people it can find doesn't make their end product the best, it simply does not follow.
Beurocracy, design constraints, budgetary constraints and pure "can't think out the box" attitudes in large organisations tend to quash innovation. Not that NASA don't innnovate,
Re:Why SpaceShip[One|Two|Three] will not reach orb (Score:3, Insightful)
Re:Why SpaceShip[One|Two|Three] will not reach orb (Score:3, Insightful)
The shuttle is big, expensive and hugely complex, with a very compact engine, but that's because it's a 10-seater spaceshiip, and has a *huge* payload bay. If all you want to do is get a small crew up there, and not take a 60ft by 15 ft 28,800kg satellite alo
Re:Why SpaceShip[One|Two|Three] will not reach orb (Score:3, Insightful)
Re:Why SpaceShip[One|Two|Three] will not reach orb (Score:5, Insightful)
This as got to be one of the most stupid posts/pages that I've seen so far this year.
Parent
Re:Why SpaceShip[One|Two|Three] will not reach orb (Score:3, Insightful)
This article implies a non-sequitur conclusion - that since Spacecship 1 didn't go into orbit, it's not possible to do it better or ceahper than NASA has done with the Shuttle. Yes, it will cost much more than $26M to develop SS3, but I can't see how anyone could have built a "reusable" vehicle less efficiently. BAsed on blindly optimistic and untested assumptions (wich many knew were spurious), NASA went from drawing board to operational system in one jump, so we are stuck with 1970s technology and massi
Re:Why SpaceShip[One|Two|Three] will not reach orb (Score:3, Interesting)
Wrong. What makes you think hybrid couldn't be used as part of an orbital system? And the bottom line is that its a rocket motor that required real rocket science to design and implement. SS3 may or may not use a hybrid motor, but it will certainly benfi
premature (Score:3, Insightful)
Doesn't make much sense to me (Score:3, Interesting)
Seems to me the whole idea of suborbital flight as a stepping stone to bigger things is a bad one. Its like expecting DOS to scale up to a multi-threaded multi-user graphical operating system. Maybe it can be done, but is the final product safe to use? Starting with technology designed from the ground up to do the mission makes a lot more sense to me.
Here's why (Score:5, Insightful)
2. Because I'll be dead before they get the orbital vehicle ready for commercial passengers.
Parent
Re:Here's why (Score:3, Funny)
Re:Doesn't make much sense to me (Score:3, Insightful)
Yeah. Because it's not, you know, riding in a freaking spaceship into honest-to-God SPACE. You'll take whatever chance you get.
Interesting.. (Score:3, Interesting)
-jcr
Link to IRDT (Score:3, Informative)
news at eleven (Score:4, Funny)
On private spaceflight... (Score:5, Insightful)
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.
Re:On private spaceflight... (Score:4, Insightful)
Agreed. NASA has blazed the trail that private space entrepreneurs are walking now. None of this would have been possible without the knowledge that NASA had to learn the hard way using lots of taxpayer dollars.
But virtually all the atmospheric, space and rocket propulsion knowledge which was required for the design and construction of SpaceShip1, the SpaceX Falcon 1, the t/Space launcher and other private space vehicles in the works was acquired before 1965.
Parent
NASA vs Scaled Composites (Score:4, Insightful)
Not really. I heard Burt and Mike speek at Airventure in 2004. Burt breifly mentioned one of their prototype aircraft built for NASA. It was a very high altitude plane, and required a pressure suit for the pilot. The NASA team to support the "spacesuit" was larger than the Scaled team who designed, built, and supported the aircraft.
And while others here are bashing Scaled for simply repeating what NASA did back in the 60's I have a few words to say:
1) I don't see anyone else making real progress getting the public into space. NASA won't take you suborbital for 200K. Sure, only the rich can afford it now, but it is progress, and it is supposed to get cheaper.
2) Rutan does innovate: Carefree Reentry was never done before - in fact, the X-15 crashed because it reentered with improper attitude.
3) Scaled is making significant progress in a short time. Yes, they are on the shoulders of giants, but did you expect them to start with a moon shot or what?
4) If I ever get to space in my lifetime, even briefly, it's more likely to be in a vehicle designed by Scaled Composites than NASA. NASA can't afford it the way they operate.
5) When did NASA ever express any intention of taking ordinary people into space for fun? Oh right, never.
I still respect the research that NASA does, but someone has to put that to practical use and that's where they fall down.
Parent
Re:NASA vs Scaled Composites (Score:3, Insightful)
No money in Space Tourism (Score:4, Insightful)
I mean, the Renaissance-era European explorers weren't wealthy sightseers who wedged themselves into tiny wooden deathtraps to sight-see. They were businessmen after profitable trade routes. Money lauched the Nina the Pinta and the Santa Maria, not tourism. Explorers werre invested in with the expectation that the money spent would return with a huge profit, not a nice story about the local food and colorful customs.
But! Sending techs up to deploy, retrieve or even fix sattelites in orbit... now that's real money.
That sort of work requires an orbital spacecraft with a decent payload capacity. So, this is a very good step in the right direction to making private space enterprise possible.
SoupIsGood Food
SS1 and the x-15 (Score:4, Insightful)
It's amazing how easy the SS1 folks make the achivement appear. Clearly the SS1 team had done their homework and benefited from what was learned in the X-15 program. Whereas the X-15 program built up speed and altitude flights slowly, with each pilot getting experience at every point, the SS1 made large jumps on each flight, often trading off pilots along the way. No doubt Mike Adams was smiling down on the SS1 flights.
It's great to see the private sector advancing technologies like this; what was so hard in the 1950/60's is easier with 21st century materials, engine technology and computer controls (BTW the X-15 was one of the first air/spacecraft to depend on 1st generation flight controls).
Re:SS1 and the x-15 (Score:4, Interesting)
Parent
At the age of 10? (Score:3, Insightful)
So, if Burt was one of the engineers on the original X-15 team, he was 10 (perhaps 9) when he joined.
He's quite a remarkable man, isn't he?
Here's a suggestion (Score:4, Funny)
Don't charge much up front. People could ride for beans on one condition. Their life insurance policies get made out to you.
Re:Here's a suggestion (Score:3, Funny)
None. Try thinking more like a Merck or Firestone executive.
One thing I *NEVER* see ... (Score:4, Interesting)
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!
FYI - SpaceShipOne update (Score:3, Informative)
Re: Slashdot bullshit (Score:5, Insightful)
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.
Parent
Re: Slashdot bullshit (Score:3, Insightful)
My guess is that Rutan won't be building SS3, though he may build WK3. The turbine powered first stage is a great success.
The orbiter will presubably be a pure rocket SSTO, carrying passengers only. Rutan doesn't have any demonstrated skills in this area so I don't think he will be involved.
Re:PR bullshit (Score:5, Interesting)
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) [skyramp.org]
Parent
Re:PR bullshit (Score:3, Insightful)
Re:PR bullshit (Score:5, Insightful)
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.
Parent
Re:PR bullshit (Score:3)
Re:PR bullshit (Score:3, Insightful)
Why develop an engine from scratch when you're not an engine developer and there are dozens of proven engines you can just buy?
Re:Ticketprizes? (Score:5, Funny)
Plus a 4 hour checkin and a body-cavity search at customs...
Parent
Re:Ticketprizes? (Score:3, Funny)
And they send your luggage to Saturn.
Re:Ticketprizes? (Score:3, Informative)
Re:Ticketprizes? (Score:3, Funny)