Slashdot Mirror
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.
Before discussion about SpaceShipThree occurs, perhaps we should wait until SpaceShipTwo is actually constructed and tested
Why would anyone pay for a suborbital flight when they expect the next version to be orbital? There will be a few no doubt who think its worthwhile to spend a hundred grand on an e-ticket to nowhere, but probably not enough to cover costs.
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.
I wonder what the re-entry strategy will be for an orbital version. Somehow, I can't imagine Rutan going with thermal tiles.
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
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.
And assuming that they start on the ground. The lift they get by the "white knight" is a very big saver on fuel and engine weight since they do not have to go through the first layers of the atmosphere.
My wife's sketchblog Blob[p]: Gastrono-me
http://www.2r2s.com/irdt_concept.html
My wife's sketchblog Blob[p]: Gastrono-me
"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!"
Actually, the changes aren't that hard to make. The problem with the current engine design is that the hybrid rocket`s isp isn't high enough. Simply changing to another type of rocket doesn't help much though, the spacecraft needs to be an egg-shell filled with fuel in order to get to orbit, if there is no staging.
. html
The problem is that the exhaust gases from a rocket are moving at the speed of sound. You can get much more thrust from the same fuel if only that exhaust were moving faster. It turns out that Rutan has been working on a new type of engine (pulse jets) which does just this, see http://www.pw.utc.com/shock-system/flightsoffancy
for more details. Now if you work out the isp from these new power plants, they are just amazing. It cuts the mass fraction for fuel from 90% down to something like 50%, or even lower. (Remember, the rocket equation has an exponential term in it, so even small changes in thrust per unit fuel mass make a huge difference.)
Burt Rutan said in a recent conference that it requires three breakthroughs for orbital craft to be viable, and that he already has made one of them. It wouldn't surprise me at all if this is that one. (With the others being related to reentry.)
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.
we are building a spacecraft which should be better then our current one, and if we find out it actually works, then we will try to build one which is even better!!! seesh, talk about vapourware...
10 ?"Hello World" life was simple then
I take issue with the tone of this article, not the content. I do not doubt the accuracy of the information in the article at all, but there's a prevailing sense of: "NASA Knows Best".
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, of course they do, but if those individual bright people we're allowed to bring their own ideas to fruition there would be much more innovation. Not to mention that government agencies the world over are generally stifled by administration, that just further compounds things.
Again, the article is probably right in it's facts, but claiming that "Why SpaceShipOne Never Did, Never Will, And None Of Its Direct Descendants Ever Will, Orbit The Earth" (the article title) is like saying that linux would never be more popular on desktops than windows, or that desktop pc's would never outperform mainframes, or any other flippant claims about how the current way of doing things is the best.
In every industry I've bothered to look into there's is always at least one example of a small set-up coming up with something innovative that breaks all the established rules.
SS1 may have been it, it may not, but saying that it'll never happen is just asking to be proven wrong.
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.
Or, to put it another way (and miss-quote The Simpsons):
"It's just rocket science, not brain surgery."
Unfortunately, I am not Wil Wheaton
Getting the craft back down to earth in one piece is going to be the capability I am most interested in seeing them solve. Will it be ablative or something reusuable like the tile system but more robust? Being Rutan I full expect it to land like a plane on return so that alone will limit some of the choices he can make.
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
* Winners compare their achievements to their goals, losers compare theirs to that of others.
The writeup you quote compares the Shuttle engines with the Scaled Composites engine, and says the former are complex enough to do the job, whilst the latter is too simple. But don't the Shuttle's two strap-on solid fuel boosters supply 75% of the thrust at launch? In other words, the Shuttle has three wildly complex engines and a whopping external fuel tank supplying 25% of the thrust, and two relatively simple solid boosters supplying the other 75%. So, in that context, the Shuttle's engines can't do the job by themselves either.
$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
Who said it wasn't possible? Getting to 100km may have been an engineering challenge, but it was clearly achievable. There were about 20 companies competing for the X-prize. That was pretty good evidence for it being possible.
Who's saying that this isn't possible?
All people are saying is that the technology to get to LEO and back is considerably different from that needed to get to 100km altitude and back.
and oh, yeah .. it made me think of Farenheit 451 (the book), where every book was banned, because there was always someone who would object to it contents or get hurt by it or so ...
-- Technology for the sake of technology is as pathetic as eschewing technology because it's technology.
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.
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.
http://michaelsmith.id.au
The business plans of these companies... to fund billion-dollar operations with the wallets of monied space geeks... is nothing more than Heinlein-addled wishful thinking. Most of the bazillionaires would much rather spend their spare time at the French Riviera, or their private Greek island or shopping in Hong Kong. There just aren't enough people willing to shell out megabucks to fund the R&D and operating costs of space tourism.
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
An interesting article, but it seems to make a fundamental mistake in comparing Rutan's task to building a Space Shuttle, when reaching orbit will merely require building something that can do the job of Vostok 1, which was early 60s Russian technology.
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 along too, the task is a lot simpler.
A pizza of radius z and thickness a has a volume of pi z z a
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).
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.
Agreed - the Falcon people are much further along the road towards engines (in particular) of the type needed to actually make orbit. When Rutan has a Falcon-1 equiv engine (covered on Slashdot a while back), *then* I'll pay attention to the press releases.
"None are more hopelessly enslaved than those who falsely believe they are free." -- Goethe
It is a big fuel saver. The use of the fuel is non-linear, So when you can save some fuel by having a higher starting point with less drag, it also has a non-linear saving as result.
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)
My wife's sketchblog Blob[p]: Gastrono-me
"When Rutan has a Falcon-1 equiv engine (covered on Slashdot a while back), *then* I'll pay attention to the press releases."
Why develop an engine from scratch when you're not an engine developer and there are dozens of proven engines you can just buy?
How to make money with space tourism:
Don't charge much up front. People could ride for beans on one condition. Their life insurance policies get made out to you.
As I understand it the third working design in the series was always intended to be an orbital craft. First an X-Prize winner, then a larger passenger version for sub-orbital tourism, and then an orbital design. I've been hearing this pretty much from the beginning. So how is this in any way recent?
I'll tell you what they ought to do...they need to go back to all of the Sci-Fi books written in the sixties and collect the ideas promoted by the authors. Most of the authors were scientists in their own right and spent quite a lot of time researching what the actual details would have to be (within the then known facts and limitations of future tech). Spaceport location, for example, was a common topic that was investigated. I'm not saying that all of the ideas in those old stories are feasable but there's lots of good starting points. Might give one a leg up on the competition :)...
The NSA: The only part of the US government that actually listens.
Difference in notation systems: Dutch: The dot is a thousands seperator, the comma is the decimal seperator.
My wife's sketchblog Blob[p]: Gastrono-me
I hope you're not talking about SS3 because you could not be more wrong.
The reason SS1 was so simple was because it didn't have reach the speeds needed for orbit. It went up and fell back down. Simplicity.
An orbital craft will need to reach much higher speeds. As a result when it reenters the atmosphere, it will have to bleed off that high speed somehow. Most reentry vehicles trade their speed for heat energy by using the atmosphere for braking.
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 massive per-flight costs that devastate the NASA budget year after year.
the shuttle has been for some time (15+ years) now been known to be a massive failure. It came nowhere near its putative objective to provide cheap, routine space transport. It is neither cheap nor routine, and so has not found a market.
Let's compare apples and apples - could NASA have built and flown SpaceshipOne for $25M? No. They would still be working on it and would spend that much on paper studies easily. Is spaceship 1 and orbital craft? No. Is it possible to do much, much beter than NASA has done with the shuttle? Yes. Is machinery as complicated as the SSME at all necessary for cheap, reliable space transport? No.
Rutan has several things working for him: he has a small, talented team. He has few or no political constraints. Theirs is a low-ceremony culture (NASA thinks in terms of paper reviews). SC are masters at materials and airframe design, and they are very good and experienced at flight test - both strategy and tactics. I'm optimistic that they (or someone following after them) can take spaceflight to the next level - routine space tourism.
Space Elevators are probably necessary for the next cost plateau, but they are realistically 30 years away. Routine Virgin Galactic flights are probably 4-5 years away.
Helium balloons want to be free.
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.
The feather won't work. It needs an atmosphere to orient the vehicle, it won't have that until about 100,000 feet or so. And at very high mach numbers it will rip off instead of working. I think Burt knows that. At the AIAA Joint Propulsion Conference (addressing a bunch of aerospace engineers) he said it would be awhile before anyone could do orbital, and his suborbital craft obviously couldn't be upgraded to do the job.
So parent is obviously talking out of his ass when the man who designed the craft said it can't be done.
Plus, you'd have to throw thermal protection system (TPS) on it, and engines probably an order of magnitude larger to achieve the delta-v to hit orbit.
In order to keep the same model (slung-under-aircraft single stage rocket) you'd need a much bigger aircraft - Boeing 747 or one of those Russian (i forget the names). Sling load a rocket, sans feather. Most of your volume is going to be fuel. Get up to your service ceiling and pich up, release your rocket and BOOM.
(Also remember t/space = Burt Rutan & Scaled, and a few other companies ) Personally I favor SpaceX for orbital capacity although remember they only produce launch vehicles, not human-rated vessels. A second company will need to do that and purchase the launch services from SpaceX.
-everphilski-
a-rat? Old fashioned. e-rat is the modern way to go, or if you are a mac fan: i-rat coming out soon.
My wife's sketchblog Blob[p]: Gastrono-me
Plus a 4 hour checkin and a body-cavity search at customs...
And they send your luggage to Saturn.
It's good to use your head, but not as a battering ram.
Just about every rocket is orbital for some portion of its journey (unless it turns into a glider immediately after its engines shut off). It's just that the orbit intersects the surface of the earth - no big deal, really.
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
SpaceShipOne is currently at the Udvar-Hazy Center at Dulles airport. I went there a couple of days ago and recognized it under a blue tarp by the hangar doors near the Concorde. It's a shame they don't uncover it, you can get pretty close to it. I guess they want to have a big unveiling when they move it downtown. http://www.spacealumni.com/index.php?option=com_co ntent&task=view&id=218&Itemid=9
My boy, my boy!
SS1 performs worse than the V-2 (V2 had roughly twice the payload (counting SS1's cockpit as payload as well as its passengers, and assuming a combined mass around 500kg), and twice the delta-V), let alone Vostok. Yet, the V-2 was at the birth of modern rocketry, and was pumped out in huge numbers. Not that a determined small private company can't reach orbit (determined large private companies reach orbit all the time :) ). SpaceX is pretty darn close at this point, for example (although they don't have to worry about reentry). Scaled isn't, however, and SS1 is completely the wrong direction for reaching orbit.
There is nothing fundamentally stopping Scaled from reaching orbit; on the other hand, there's nothing fundamentally stopping Pizza Hut from reaching orbit either, and the only major thing that Scaled has over them is general avionics experience (which they excel at, mind you, even if they're a bit risk-prone with their testing regime). What technical knowledge can Scaled take away from the SS1 program to an orbital craft that they didn't already have from aircraft work? Part of their flight control software, a bit more experience on pressurized cockpits, and validation of their CFD models. Anything else? I suppose if SS3 is air-drop, some of the craft-separation knowledge might be applicable, although they'll need far better ISP if they want to air-drop to orbit (even better than they'd need from the surface, since carriers can't scale infinitely well). Perhaps if they can demonstrate some reentry technology, or partner with a serious orbital contender like SpaceX, they might be able to be taken more seriously.
As for the article: the Shuttle comparison exists primarily because most slashdotters compare SS1 to the Shuttle. Notes about how an SSME isn't needed to reach orbit (but an engine more complicated than SS1's SpaceDev hybrid is) were added specifically to address this issue.
Mind you, I take issue (as do most of the people here) with the design of a man-rated craft that caries tens of thousands of kilograms of payload, but only a little over half a dozen people. Part of this design issue was overoptimism when the program began - not realizing how high maintenance would be on a first-generation reusable, the numbers predicted for launch price per kilogram made it seem like they'd want to use the shuttle for everything, and since they only had the budget for one craft (underbudget at that...)
Are there any deer in the theater tonight? Get 'em up against the wall.
Burt Rutan born in 1943. The X-15 project started in 1953. The X-15 first flew in 1959.
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?
http://lkml.org/lkml/2005/8/20/95
Different people use different punctuation to separate digit groupings. In North America, commas are used to separate groupings of three digits and periods separte integers from decimals (100,000.00 USD). In Europe, it tends to be the other way around (100.000,00 EUR).
The "more correct" way, IIRC, is to separate groups of three with spaces and use commans or periods for the decimal point as you see fit (100 000.00 or 100 000,00).
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 benfit from the rocket scientists that Burt is growing.
2) low cost reusable ablators: The ablators on the leading edges of SS1's wings are a propritary Scaled design that is far cheaper, lighter, and more effective than any other system. It is useable for an orbital system? No. Is it scaleable for an orbital system? No.
The correct answer is of course 'yes' to both questions. Keep in mind that Rutan is a materials engineer. He's forgotten more than most materials engineers ever know about making composite aero-structures.
3) "Flight test experience is irrelevant". WTF?
Is the flight test program of an orbital craft anything like that of an aerodynamic craft? No.
Wrong again. Both the X-15 and SS1 were a whole lot like oribital spacecraft, and the infrastructure and experience to test either of those is all directly relevant to testing higher performance craft. Certainly the test pilot community has recoginized the Scaled Composite test team with multiple awards and recognition. The Scaled chief pilot, Doug Shane, is president of the The Society of Experimental Test Pilots.
The obvious design change is a swing wing. You need the wings to not produce too much drag during launch in order to get up to the speeds needed, so you'll probably have them folded back most of the way.
During landing, AFAIK, the larger the surface area, the more gradual the descent angle should be, and thus the less heating you'll get. (This assumes you descend quickly enough that you don't end up skpping off the atmosphere like a stone across a pond, of course, but....) Anyway, if you can slow the descent angle enough... say a dozen times around the planet before you enter usable air space instead of---what does the shuttle do... about half an orbit from deorbit burn to the ground, give or take?---less than one time around, you would see a lot less surface heating... I think....
Just a thought.
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