rumor of no more winged space craft

[Bill Thmpson]

Well I am back.

Like many computer programmers I lost my job #-o But the Trazadone and the Prozac have just kicked in 8-[ and I am able to actually type a message here.

Anyway, what is this rumor that soon there will no longer be any winged space craft going up into orbit because the safty cannot be garanteed?

[Avatar28]

Sounds like just that, a rumor. We MIGHT go back to capsules for a time for certain things, but ultimately they will need something larger like the shuttle. So I wouldn't expect them to permanently go away. Nor do I think it there is especially anything that makes winged craft inherently less safe than capsules. Well, other than that they're more complex which I suppose could add some element to it.

[Bill Thmpson]

Let's go back the origional HG Wells plan.

Launching people in a giant cannon ball at the moon.

[informant]

Jules Verne's plan! (http://lit4lib.artshost.com/wells.htm#sf) Wells used antigravity.

[Bill Thmpson]

Jules Verne's plan! (http://lit4lib.artshost.com/wells.htm#sf) Wells used antigravity.

oooooo, my bad

[russ_watters]

A winged spacecraft/lifting body is the only way to bring a sizeable payload back to earth and will never be completely abandoned.

[kenneth rodman]

Unless we figure out a way to produce antigravatinos then wings will become a safety item in case the antigrav fails =D>

[Zamboni]

Didn't they use to employ parachutes to slow down the craft?

[SirThoreth]

Didn't they use to employ parachutes to slow down the craft?

Capsules use their flat underbellies for the primary bit of decelleration, as the resistance from the atmosphere slows them down. The shuttle, for the first phase of reentry, do the same - that's where Columbia broke apart.

Parachutes come into play on capsules as they slow down enough to use them, in order to slow down further still to a safe speed for landing. Winged craft, meanwhile, glide or fly to a landing.

As for abandoning the winged spacecraft concept, I'd like to point out that Scaled Composite's entry for the X-Prize is winged. The problem is making a large, structurally sound winged spacecraft, as the shuttle indicates.

Once in space, wings are so much dead weight. That's one of the reasons the capsule concept for the Orbital Space Plane is making so much headway right now, because it can be used for things outside of low-Earth orbit. Hell, the Apollo Command Module, it turns out, was structurally sound enough and well protected enough to be able to handle reentry from a return-trip velocity from Mars, according to some articles I read recently. The plan is to do something similar with a capsule-based OSP, so it can be used to ferry people to the ISS, or even to and from a future space station at the Earth-Moon Lagrange Point.

I expect to see lots of suborbital winged spaceplanes like Spaceship One (by Scaled Composites) in the near future, with a larger, winged Shuttle replacement 10-15 years away or more, once we get some of the materials problems worked out.

[TinFoilHat]

A winged spacecraft/lifting body is the only way to bring a sizeable payload back to earth and will never be completely abandoned.
There are several options for non winged or lifting body spacecraft capable of returning large payloads to the ground.

One is the Delta Clipper concept, where you light landing engines and make a powered vertical landing. Another is the Roton design, which uses helicopter blades powered by peroxide rockets in the tips to make a safe landing. Both have been proven in flight tests, although on non-orbit-capable prototypes.

There's also the option of landing a large payload in the ocean, but that adds recovery cost and time, and exposes your ship to salt water on every landing.

[Bill Thmpson]

but why not use:

A. The teleport.

B. The Star Gate

C. or The Martrix (and don't tell me that humanity would have to be forced into a virtual reality where there is no blindness or pain etc etc)

[Doodler]

If we're at the point of launching permanently orbital space stations (with a touch of boosting here and there), why not a permanently orbital spacecraft? A three stage launch vehicle, stage one being the launch booster, stage two a replacement boost engine for the spacecraft, and the last being a crew return vehicle that docks to the orbital vessel. The vessel itself needs to be nothing more than a living quarters, solar power generation, science/cargo bay and control unit, with the rest being brought up with each flight. Resupply occurs both as a part of the crew arriving and possibly a second launch.

As far as winged spacecraft go, I think the concept should be shelved for mainstay spacecraft until they can get the turnaround costs down under the replacement costs of a capsule. Lets face it, when was the last time the space shuttle carried anything back to Earth from space? Its an unneeded capability.

[Glom]

Erm, Doodler. STS 111 last June. It carried back Expedition 4's gear in the Leonardo MPLM. And let's not forget that it would have brought back the SPACEHAB RDM on STS 107 if it hadn't run into the snag of disintegrating.

Wow, I posted in ATM! :o

[Doodler]

I wasn't aware they had brought a Leonardo back, I thought those were disposed of via re-entry. I'll call "Uncle" on STS-107's science payload as well as the others that have been carried up now that I am reminded of them. I was thinking of satellite retrieval when I posted, not science payloads carried inside the shuttles.

[Glom]

I wasn't aware they had brought a Leonardo back, I thought those were disposed of via re-entry.

Of course they brought them back. That's the whole point. They're reusable cargo modules.

[Ikyoto]

A winged spacecraft/lifting body is the only way to bring a sizeable payload back to earth and will never be completely abandoned.

Uhmm... I thought that gravity was a pretty good way to bring a sizable anything to Earth...

Ok, so it won't be in pristine condition, but it works.

[Madcat]

Well that depends on your definition of WORKS... the matter is still present in some shape or form I guess... it's not going to do what you designed it to do...

[Ikyoto]

Oh no, the PROCESS works. The ship, item, person, collection of old rocks, whatever, will more than likely be charred and splintered into so many charcoal like items roughly the size of the brain of the average field mouse and then merrily scattered over several thousand miles as the mass of most stuff we've put up isn't enough to have anything survive uncontrolled re-entry.

But the "get it back to the surface" bit of the process sure works!

[Simon]

Hahaha.... And once again, ill-defined concepts end up causing unexpected results.

Let's rephrase the idea as "bring a sizable amount of material back to earth, intact". :D

[Ikyoto]

Oh bother...

Ok - One of the things I have always wondered about is why use a powered flight? The decent of items can be plotted out fairly well and a ablative shield and parachute got many Russian back to Earth just fine and they didn't use the ocean as a landing zone.

OR - The shuttle used wings to control it's flight path coming in - Why not a newer design that is more in line witht the concept of a "lifting body" where the wings are replaced by a entire body - for more stucturally sound and still does the same thing.

The "one way to do things" concept in NASA needs to be let go of. A combination of ways to get things around always works best. There is no ONE type of shipping here on Earth. There are hundreds of smaller systems that are allowed to evolve and grow. The entire US space program has always been "fix it fast and showey and then let that solution be the end fo the line" while other nations have been slower but more consistant.

(ok, rant off)

[Glom]

Good points, Ikyoto. The Space Shuttle was indeed supposed to be an all-things-to-all-people vehicle and failed to live up to expectations. The idea was STS would launch everything for America, which was a stupid notion.

The notion was one of the things that seperates today from the Era of Cool. Then, there was a whole line of boosters designed to be used for specific purposes. Consider: the Saturn V was used to launch Skylab while the Saturn IB shipped crew up to it. But, to be fair, the original idea for the Space Shuttle was that it would simply be a freight vehicle, resupplying and recrewing the Skylab superstation.

[man on the moon]

There's also the option of landing a large payload in the ocean, but that adds recovery cost and time, and exposes your ship to salt water on every landing.

what about one of the great lakes? they're a heck of a lot smaller, but fresh at least. maybe the risk of over shooting is too high or something. there is also a lot of grassland (empty) as someone else pointed out that could be used for such a purpose.

[Ikyoto]

Yeah! The Great Lakes!

I live in one of the burbs of Buffalo and being close enough to both see AND potentially benifits from the job influx that would bring would be a great idea.

But the winds out there on the lakes and the lack of ability to use them during the winter would make such a proposal a dead issue.

[Richard of Chelmsford]

Here's a bit of Rico-Chelmsfordian science for you blokes.

How about this for a way of launching space vehicles. Sort of the 'pump-up' method.

In England, (and probably the U.S. and elsewhere too) in some factory sites we have steam engines to ferry goods around the site. The engines are powered by super-heated water which is a by-product of the industrial process. That is, water which is held under pressure in the loco at a temparature above that of boiling point. So when you release the pressure, the water boils and creates steam to drive the engine. Simple.

So, suppose we have something like the space shuttle sitting on its pad with no boosters. We feed in the fuel similarly superheated and under pressure, heated from an outside heat source. So when we fire it up we get the chemical burn power, plus the boiling power from the now boiling fuel.

It might work.

Of course, the downside is that you would have to increase the weight of the vehicle to make the tanks strong enough to hold this stuff and that might cancel out any advantage you might get, but with an advance of materials science we might be able to balance the forces and take advantage of this principle.

What say you science punters? 8-[

[TinFoilHat]

The problem with the boiling-fuel rocket is in figuring out how to keep the engines from melting. One advantage to rockets using cold liquid fuels is that you can use the fuel as a coolant fluid before burning it; the fuel circulates through tiny channels in the nozzle wall before being fed into the combustion chamber. This pre-heats the fuel and cools the engine for free. If you start with the fuel already hot and boiling, what are you going to cool the rocket nozzle with?

[wedgebert]

I think we're just better off finding some way to use oxygen from the atmosphere rather than using boiling fuel.

Just cutting the amout of O2 necessary by 25% would result in over a 6.25% decrease in the shuttle's takeoff weight. And that translates to over 37,500 kilograms in LOX alone. That's not counting the decreased mass from smaller fuel tanks. (The Shuttle carries 600,000 kg of LOX which makes up 25% of it's takeoff weight).

Or you could live an extra 37 tons into orbit. Maybe use the extra mass to modify the shuttle to allow for higher orbits or even trips to Luna.

[TinFoilHat]

Using O2 from the atmosphere has its own set of tradeoffs. It gets less energy-efficient to use outside air the faster you go, because you have accelerate the air out the back faster than it's coming in the front. You add a lot of weight in scoops and engines - air-breathing engines have nowhere near the power-to-weight of rocket motors. And most rockets try to get out of the atmosphere as quickly as possible because doing any significant portion of your acceleration to orbit while still in the atmosphere is a bad idea. You can't just compare the reduces weight of the oxygen without also factoring in all the extra weight of additional systems you'll need.

The only way I could see airbreathing assist for rockets being a good idea is on a two-stage in which the airbreathing first stage never leaves the atmosphere, but flies as high and fast as it can before launching the non-airbreathing second stage.

[Doodler]

Whoa whoa whoa. Full stop. Dropping stuff into the Great Lakes???Software ain't perfect, so the odds of a screw up killing people on the ground is pretty substantial in a worst case scenario. Heck, even before the Columbia accident, NASA had hemmoroids over flying hardware into the atmosphere over population. If we go back to a capsule spacecraft, we are simply going to have to build science experiments to fit the lab or get the shuttles up to snuff for an occassional launch. But it will be a cold day in Hades' heart before anyone is allowed to return spacecraft into the Lakes.

[russ_watters]

Just cutting the amout of O2 necessary by 25% would result in over a 6.25% decrease in the shuttle's takeoff weight. And that translates to over 37,500 kilograms in LOX alone. That's not counting the decreased mass from smaller fuel tanks. (The Shuttle carries 600,000 kg of LOX which makes up 25% of it's takeoff weight). Its a little better than that, since reducing the takeoff weight means you need less thrust and less fuel for the same launch profile, and reducing the amount of fuel means you need even less fuel which reduces the weight even more so you can reduce the amount of fuel more making you need even less fuel and so on and so on and so on. Tough to calculate exactly though.Using O2 from the atmosphere has its own set of tradeoffs. It gets less energy-efficient to use outside air the faster you go, because you have accelerate the air out the back faster than it's coming in the front. You add a lot of weight in scoops and engines - air-breathing engines have nowhere near the power-to-weight of rocket motors. There are tradeoffs, but those two aren't among them. The first you have precisely backwards - All jets get more efficient the faster they go and a ramjet engine gets more efficient the faster it goes almost without boundary. The SR-71 is a great example of that - it took forever to take off since it was a turbo-ramjet and very inefficient at low speed.

Power to weight ratio of the engine hardware itself is probably a little worse on the jet, yes, but thats irrelevant since what you are really interested in is the power to weight ratio of the whole ship - and the weight of fuel you save for a jet far outweighs the loss from the engine's weight.

The main concern is the 3rd thing you listed - the fact that the space shuttle (for example) effectively gets out of the atmosphere in the first 2 minutes of flight. So you'd only really get a benefit from integrating it into the first stage of boosters.

[TinFoilHat]

The first you have precisely backwards - All jets get more efficient the faster they go and a ramjet engine gets more efficient the faster it goes almost without boundary.
I don't think so. Airbreathing engines are optimized for particular speed and altitude ranges, but the effective ISP of any airbreathing engine decreases with increasing airspeed and decreasing pressure. The losses from friction grow faster than the benefits from increasing airflow. A rocket engine doesn't care about outside airspeed, and gets better ISP the lower the outside pressure becomes.
Power to weight ratio of the engine hardware itself is probably a little worse on the jet, yes, but thats irrelevant since what you are really interested in is the power to weight ratio of the whole ship - and the weight of fuel you save for a jet far outweighs the loss from the engine's weight.
The power to weight of the engine is much worse - pound for pound, a good rocket engine produces four or five times the thrust of a good jet engine, and that's not including the weight of air scoops/inlets, or the weight of the *extra* fuel you have to carry to offset the extra drag and weight. You'll have to carry less oxidizer, but more actual fuel and lots of extra dry weight, which is what you really want to avoid. I've seen enginnering analysys showing that in the end, air-breathing first stages end up being lots of complexity and cost for little benefit.

Take a look at the following page:

http://www.islandone.org/Propulsion/SCRAM-Spencer1.html

Remember, fuel and liquid oxygen are cheap; transsonic ramjet engines and supersonic spaceplane designs aren't.