# Why don't they just fly the space shuttle out into space like a plane? **URL:** \ **Category:** Factual Questions\ **Created:** [June 14, 2011, 6:16am UTC](https://boards.straightdope.com/t/why-dont-they-just-fly-the-space-shuttle-out-into-space-like-a-plane/585406 "2011-06-14T06:16:55Z")\ **Posts on this page:** 7\ **Page:** 2
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 14, 2011, 6:08pm UTC](https://boards.straightdope.com/t/why-dont-they-just-fly-the-space-shuttle-out-into-space-like-a-plane/585406/21 "2011-06-14T18:08:02Z")
A better example than the X-15 or SpaceShipOne might be the [Pegasus](http://en.wikipedia.org/wiki/Pegasus_%28rocket%29), which is launched the same way but does reach orbit (but can’t carry humans). ---
**Author:** ![MarcusF](https://avatars.discourse-cdn.com/v4/letter/m/67e7ee/32.png) [@MarcusF](https://boards.straightdope.com/u/MarcusF)\ **Post date:** [June 14, 2011, 6:14pm UTC](https://boards.straightdope.com/t/why-dont-they-just-fly-the-space-shuttle-out-into-space-like-a-plane/585406/22 "2011-06-14T18:14:11Z")
> [@lazybratsche](#): > > Wasn’t trying to correct you, just furthering your illustration. I.e. here’s an example of a suborbital rocket carried by a plane, what would it take to make it from there to orbit? No problem! One thought that has always interested me is how would space travel developed if there hadn’t been the pressure to match the USSR - no Man in Space Soonest and Project Mercury followed by the Moon within the decade but a sensible progression from the X15 to reusable orbital craft. Not sure if there is such a route or if you end up back with the Shuttle. Maybe \*\*Stranger \*\*could comment? ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [June 14, 2011, 6:29pm UTC](https://boards.straightdope.com/t/why-dont-they-just-fly-the-space-shuttle-out-into-space-like-a-plane/585406/23 "2011-06-14T18:29:55Z")
> [@Stranger\_On\_A\_Train](#): > > The other problem with spaceplanes in general, and HTOL vehicles in particular, is that the design that allows for lift (large wings) also substantially complicates thermal protection design for reentry. I’m sure that all readers are aware of the issues with the American STS/Orbiter after the tragic loss of _Columbia_, but they may not be aware of just how many times the Shuttles have come close to the same degree and type of damage, and how little can be done, even using more recent technology in thermal protection, to enhance the basic design of the Shuttle or other winged orbiter against this type of damage. The best materials for thermal protection are not robust against shock and impact, and the best materials that withstand shock and impact not not generally good insulating materials. The best thermal material for this has existed for a long time (Starlite). Due to various vagaries trying to get it into production it isn’t being used but frankly this stuff seems magical and the perfect answer for thermal protection. > [@](#): > > Two decades ago amateur scientist Maurice Ward invented a material that could resist the force of 75 Hiroshimas. So why haven’t we all heard about it? > > \ > > The defence establishment was watching. In July that year, Ward was invited to the British Atomic Weapons Establishment at Foulness, and the egg went nuclear. ‘They’d been trying to get something to withstand a nuclear flash for 45 years, and we did it in five minutes.’ Ward was reluctant to take part at first. ‘I was happy with my egg. It was just a challenge and I didn’t want to lose.’ This was a different league. Starlite-coated eggs were subjected to light-energy sources that simulated a nuclear flash, equivalent to a temperature of 10,000 C. ‘They did it twice and it was still there. Charred, but intact.’ The Foulness equipment couldn’t keep up. ‘I said to one scientist, “Are we doing all right?”, and he burst out laughing. He said, “Normally, we do a test every couple of hours because we have to wait for it to cool down. We’re doing it every 10 minutes, and it’s sat there laughing at us.”’ Most materials vaporise beyond 2,000 C. Pure carbon, which has the highest melting point of all elements, melts at 3,500 C. Starlite was withstanding temperatures and forces that physics and thermodynamics dictated it shouldn’t. Even with tests from unquestionable authorities like AWE, people were sceptical. ‘Some people called me a shyster. But they are blinkered. We’ve got video: We can show you.’ > > \ > > But Greenbury also thinks that Starlite’s potential has been, so far, its biggest handicap. ‘It’s difficult to think of another invention that is bigger in its implications. If it had been less important, I think it would have been much easier.’ Ward certainly believes in his product, claiming publicly that it could have prevented the space shuttle disasters. ‘Starlite has a Q-value [an energy absorption rating] of 2,470. The space shuttle tiles have a Q-value of 1.’ Not only that, but because Starlite is so lightweight – 1mm thick, compared to 75mm for the space tiles – it’s actually ‘2,470 x 75 times better’. > > SOURCE: [http://www.telegraph.co.uk/technology/5158972/Starlite-the-nuclear-blast-defying-plastic-that-could-change-the-world.html](http://www.telegraph.co.uk/technology/5158972/Starlite-the-nuclear-blast-defying-plastic-that-could-change-the-world.html) ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [June 14, 2011, 6:39pm UTC](https://boards.straightdope.com/t/why-dont-they-just-fly-the-space-shuttle-out-into-space-like-a-plane/585406/24 "2011-06-14T18:39:10Z")
> [@Whack-a-Mole](#): > > The best thermal material for this has existed for a long time (Starlite). Due to various vagaries trying to get it into production it isn’t being used but frankly this stuff seems magical and the perfect answer for thermal protection. Well, it’s magical because it’s made out of uni-directional Unicorn horn… More discussion [here](http://boards.straightdope.com/sdmb/showthread.php?t=612169&highlight=starlite). ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [June 14, 2011, 6:48pm UTC](https://boards.straightdope.com/t/why-dont-they-just-fly-the-space-shuttle-out-into-space-like-a-plane/585406/25 "2011-06-14T18:48:41Z")
> [@beowulff](#): > > Well, it’s magical because it’s made out of uni-directional Unicorn horn… > More discussion [here](http://boards.straightdope.com/sdmb/showthread.php?t=612169&highlight=starlite). I see nothing there to suggest the claim is false. It may not live in the core of a nuclear explosion and be subject to shock damage but I think repeated tests by Britain’s Atomic Weapons Establishment lends it a distinct air of credibility to its claims. Can you name another material that will survive 10,000 C temperature hits…repeatedly? Aerogel maybe but I doubt aerogel is suitable to cover a Space Shuttle. As mentioned in the other thread it seems this guy’s eccentricity is what is preventing it from being marketed. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [June 14, 2011, 8:49pm UTC](https://boards.straightdope.com/t/why-dont-they-just-fly-the-space-shuttle-out-into-space-like-a-plane/585406/26 "2011-06-14T20:49:45Z")
> [@md2000](#): > > One design I read about was a jumbo jet with a small rocket motor in the back; the idea was to get a bit more speed and substantially more height out of the mothership (\>60,000 feet) before releasing the rocket. Plus an empty Jumbo had really good lift capacity to carry a very heavy orbiter. Orbital Sciences does this with their commercial [Pegasus](http://www.orbital.com/spacelaunch/pegasus/) family of launch vehicles, which are launched from beneath an L-1011. The Pegasus air launch vehicle can be compared directly with a ground launch vehicle, as the OSC [Taurus](http://www.orbital.com/SpaceLaunch/Taurus/) is a Pegasus stack on top of the 92 inch Castor 120 “Stage 0”. For instance, the Taurus 3210 launching from Kwajalein Atoll on the Reagan Test Site can achieve a 200 nmi circular orbit at an 11° inclination with a \>1200 kg payload (and larger fairing), while the air launched Pegasus XL launched from RTS can only deliver a payload of about 430 kg to the same orbit. Part of the difference is the level of thrust available from the Castor 120, but the efficiencies gained by air launch from a relatively slow moving aircraft are just not that great. The real advantages are the ability to locate your point of launch to the most efficient azimuth (within the constraints of the range and ground hazards) and increased launch availability (you don’t have to worry about the impact of ground winds and weather conditions on launch constraints, as well as not having to cope with things like ground facility conflicts, environmental impacts (every government-owned space launch range in the continental United States is located in or near a nature preserve or controlled habitat) or protesters. I think part of the appeal of plane-type space launch vehicle concepts is that they seem familiar to what we already know and use on a daily basis. However, the environments, conditions, and functions of space launch vehicles and spacecraft–which spend most of their time at very high Mach conditions or outside of the atmosphere–is nothing like airplanes, which spend all of their time in a substantial atmosphere which provides both oxidizer and a fluid medium to develop lift, and the attempt to marry the two functions in a single vehicle result in pretty severe compromises. The anticipated reusability, reliability, and short turnaround time of the STS/Orbiter (shuttle) turned out to be hopelessly optimistic, as were estimates of the cost savings by consolidating all launches into the one vehicle, even compared to the fixed costs of purely expendable vehicles. I would tend to disagree that the development of a workable SSTO vehicle is actually all that distant, at least in terms of the technical feasibility. There are several vehicles in the former US inventory that are practically SSTOs, albeit with a negligible payload, indicating that developing an SSTO vehicle with a practical payload capability is really a matter of increasing performance marginally rather than requiring revolutionary new propulsion technology. The biggest hurdle to an SSTO is an engine that provides good performance at a range from sea level to exoatmospheric. On multistage vehicles nozzles on stages are optimized for the range in which they operate, so that nozzles for lower stages are smaller and lighter than nozzles for upper stage motors/engines which attempt to capture the additional momentum from plume expansion. For an SSTO, you would like a nozzle that can provide variable performance to provide optimal thrust at different altitudes without adding a lot of weight like an extendable nozzle. Nozzle designs that do this (plug and aerospike nozzles) do exist, and while not at a production-ready level of technical maturity have been demonstrates in full scale static fire tests. An aerospike version of the RL-10 in a Saturn S-IVB-based vehicle should provide adequate performance to achieve low Earth orbit with a reasonable payload, even given the fairly heavy metallic structure. A vehicle like the Delta Clipper concept making substantial use of lightweight composite structures for tankage and main structure could conceivably deliver a payload to orbit with just minor improvements of conventional engines, and developing aerospike or plug nozzle engines that can manage even a small percentage in total impulse improvement would allow you to fly even a very large vehicle like the [Chrysler SERV](http://www.pmview.com/spaceodysseytwo/spacelvs/sld034.htm) to orbit with a heavy payload or separable personnel shuttle, and even recover and reuse the launch vehicle. (As with the shuttle, I question the turnaround time–aerospike engines would likely have to be replaces or refurbished between flights due to erosion of the nozzle spire–but even given that there is still more of the vehicle that is reusable than the STS, and the complexity of thermal protection systems with this concept is greatly reduced compared to a spaceplane design. We could be ten to fifteen years away from a working SSTO with the same budget that was used to build a Shuttle-based expendable launch system, with comparable payload capability, lower costs and (likely) higher reliabilities. But not with spaceplane concepts, which still press the limit in thermal protection technology. Stranger ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [June 14, 2011, 10:11pm UTC](https://boards.straightdope.com/t/why-dont-they-just-fly-the-space-shuttle-out-into-space-like-a-plane/585406/27 "2011-06-14T22:11:04Z")
> [@MarcusF](#): > > No problem! One thought that has always interested me is how would space travel developed if there hadn’t been the pressure to match the USSR - no Man in Space Soonest and Project Mercury followed by the Moon within the decade but a sensible progression from the X15 to reusable orbital craft. Not sure if there is such a route or if you end up back with the Shuttle. I question that without the Cold War strategic race that we would have had heavy lift capability to support the space race, and without a competition to put people in orbit and to the Moon, I doubt there would have been the impetus to develop manned space launch capability, especially given the massive cost of such a program. The X-15, despite being a rocket-powered vehicle, is really an aircraft, and as a general concept lacks many features required for an orbital vehicle, nor do I think it could evolve into an orbit-capable spacecraft. > [@Whack-a-Mole](#): > > The best thermal material for this has existed for a long time (Starlite). Due to various vagaries trying to get it into production it isn’t being used but frankly this stuff seems magical and the perfect answer for thermal protection…I see nothing there to suggest the claim is false. Although I’ve heard snippets about this technomagical “StarLite” material for years, I have yet to see a documented test of the material despite claims, and I see several indications that the asserted property and testing of the material is false, including that it was tested by AWE in a nuclear explosion-like environment or [“Ward refused even to allow the formula to be written down; only he and a couple of family members knew it, and it was kept only in their heads,”](http://itotd.com/articles/653/starlite/) as if it were a recipe for cheesecake. As for the use in a spacecraft thermal protection application, we’d need to know more than just what its combustion or degradation temperature (presumably what is meant by “10,000 °C”, such as thermal and mechanical properties (thermal conductivity, emissivity, specific heat capacity, density, tensile and shear strength, fracture toughness, surface finish, corrosion and chemical reactivity, et cetera). If this material is an aerogel-like substance, it may provide good thermal insulation but lack the mechanical properties to withstand flight environments or thermal mass to absorb the heat flux incurred during reentry. An unprotected human could withstand an environment in which the ambient temperature of 10,000 °C if the heat flux is low enough (though you’d probably want an air supply). Stranger [Previous page](https://boards.straightdope.com/t/why-dont-they-just-fly-the-space-shuttle-out-into-space-like-a-plane/585406.md?page=1)