SSTO

JoshNH4H · 2008-02-18 16:27:49

It's a good idea. however, I regard a stage as a clearly seperate factor contributing height or speed to a craft going to orbit. There are two factors in your design- the mass driver, and the chemical rocket.

Don't get me wrong, this is a very good idea, worth trying. It's just not ssto.

dicktice · 2008-02-18 16:56:53

Why are you such a stickler for all-up, self-contained, definition of single-stage-to-orbit? What's the point? An airborne, airbreathing flyback first stage would be much preferred to a Saturn-like first stage, with reuseability making it commercially viable to start from airports anywhere in the world. If you really want to be picky, using the rotation of the Earth as a form of boost invalidates your ssto rocket claim, unless you launch it in a westerly direction to make your point--which would be just plane silly, right?

GCNRevenger · 2008-02-18 17:58:00

Amen, short of next-next-generation supermaterials or the semi-exotic fuels like slushed/spiked Hydrogen or cyclic ozone, two stages make the most sense.

The whole vehicle doesn't need to be built to reenter, saving heat shield mass, the lower vehicle doesn't need to carry all its oxidizer, and you can use denser fuels than liquid hydrogen to keep the vehicle size small.

Terraformer · 2008-02-19 04:28:46

How fast can a Jet Plane go (I mean possibly, excluding the plane shaking itself apart, structural problems, etc. Those can be dealt with.)

neviden · 2008-02-19 05:10:55

How fast can a Jet Plane go (I mean possibly, excluding the plane shaking itself apart, structural problems, etc. Those can be dealt with.)

About 2-3 mach. Orbital speed is 25 mach.

I agree that the SSTO is just not practical at the moment. A good TSTO design, with high flight rate would be almost as good and is much more practical and cheaper to build.

noosfractal · 2008-02-19 05:14:22

http://en.wikipedia.org/wiki/Scramjet

GCNRevenger · 2008-02-19 11:41:15

Ordinary turbofan/jet engines do top out around Mach 3 or so, but if you inject water liquid oxygen into them they can be pushed up to Mach 4 or 5. Or, if were to add ramjets or ramjet functionality (1960's technology really, SR-71 plane or USN missiles) this could be bumped up to Mach 5 or 6 with a modest increase in maximum altitude to boot.

The airframe shouldn't be too hard either, it is rumored that the old SR-71 could theoretically handle Mach 5 with sufficient cooling.

Another trick is combining jet and rocket engines into a single unit, like Reaction Engines' concept http://www.reactionengines.co.uk/sabre.html . While I doubt their SSTO plane would be practical, it might make a great first stage engine.

Terraformer · 2008-02-19 12:38:42

So, excluding the possiblity of advances in Scramjets, the fastest we can get up to is Mach 5-6 with a Ramjet. Am I right?

Could the Ramjet be included as part of the rocket (RocketplaneKistlers method), or would it have to be part of a reusable 1st stage?

GCNRevenger · 2008-02-19 12:50:31

So, excluding the possiblity of advances in Scramjets, the fastest we can get up to is Mach 5-6 with a Ramjet. Am I right?
Could the Ramjet be included as part of the rocket (RocketplaneKistlers method), or would it have to be part of a reusable 1st stage?

A spiffy modern ramjet, possibly with injected coolant/oxidizer for kick, would probably be the easiest air-breathing method, yeah. Probably pretty reliable too. An "enhanced" turbine engine probably wouldn't be that hard either, though possibly heavier.

It would definitely ride on the first stage, there is no reason to bring the engine into orbit. In fact, the upper stage probably doesn't need anything but rockets. However, some form of rocket power on the lower stage might be desirable to keep the upper stage as small as possible even at the expense of a bigger lower stage.

GCNRevenger · 2008-02-19 12:56:29

http://www.bristolspaceplanes.com/proje … ecab.shtml Here is another example of a two-stage system which is a simple plan, which is to just make a really big traditional jet and add rockets to it for the "sprint" phase. Probably the most low-tech solution, but don't knock it, low tech means easy tech.

Terraformer · 2008-02-19 13:36:37

How about a Souped up 'WhiteKnightThree' with Ramjets

GCNRevenger · 2008-02-19 16:15:44

Bah, Rurtan and those rubber & laughing gas rockets lofted by suped up weeny LearJet jet engines are pitiful toys in any configuration, and the fraudulently named "SpaceShipNumber" blah blah blah are by no means approaching true orbital flight.

Austin Stanley · 2008-02-22 18:51:39

Are there any catalysts that would turn H2 into 2H?
Not to my knowledge: one problem is that the 2H would immediately recombine into H2 upon leaving the catalyst (as they are in close proximity), and the second is the rather large amount of energy needed to break the H-H bond.
Making monoatomic Hydrogen isn't so much the difficulty, the trouble is with storing it so that it doesn't spontaneously recombine to H2 before you can use the stuff as fuel.

As I hear it most of the hope is for metallic hydrogen to turn out to be meta-stable at somewhat reasonable pressures and temperatures (in this case I mean still very cold and high pressure). As there really isn't any hope at keeping plain old hydrogen monoatomic for any appreciable length of time. You have to keep to it to cold to be practical.

Another rather far-out their idea talked about is meta-stable helium (that is helium with one its electrons energized to a higher orbital). Which theoretically would be a room temperature solid in some configurations. The ISP of this would be ridiculous, like 2200 sec. Which beats out most everything short of a NSWR. Of course no one has made this substance yet.

There are a couple other odd ones, like N20. But cyclic ozone does appear to be the one with the best chance of seeing fruition in the short term. Of course even this is a distant hope as we are still not certain that cyclic ozone can actually exists.

GCNRevenger · 2008-02-22 23:14:19

As I hear it most of the hope is for metallic hydrogen to turn out to be meta-stable at somewhat reasonable pressures and temperatures (in this case I mean still very cold and high pressure). As there really isn't any hope at keeping plain old hydrogen monoatomic for any appreciable length of time. You have to keep to it to cold to be practical.
Another rather far-out their idea talked about is meta-stable helium (that is helium with one its electrons energized to a higher orbital). Which theoretically would be a room temperature solid in some configurations. The ISP of this would be ridiculous, like 2200 sec. Which beats out most everything short of a NSWR. Of course no one has made this substance yet.

Yeah the weird excited Helium is verry far out, if possible at all.

JoshNH4H · 2008-03-12 20:16:23

say you have an engine with an Isp of 850. WWhat would the SSTO look like?

GCNRevenger · 2008-03-12 20:29:48

With 850sec, then something like a chubby delta wing plane or maybe even a Delta Clipper style VTOL rocket.

cIclops · 2008-03-13 01:16:58

And a lot of radiation shielding because only a nuclear engine has enough thrust and can deliver an Isp of 850

GCNRevenger · 2008-03-13 07:32:58

Yeah basically,

And the fuel tanks would be huge for a nuke-powered SSTO.

Terraformer · 2008-03-14 12:32:10

I've come up with a defination for an SSTO: anything launching into orbit using only one stage from a permanent stable platform like the ground or a blimp.

GCNRevenger · 2008-03-14 13:34:24

I've come up with a defination for an SSTO: anything launching into orbit using only one stage from a permanent stable platform like the ground or a blimp.

The blimp would be a first stage.

Terraformer · 2008-03-14 14:06:23

I was refering to if the blimp was a permanent platform. Like the DSS.

GCNRevenger · 2008-03-14 18:47:44

I was refering to if the blimp was a permanent platform. Like the DSS.

It would be well above the ground, and would hence be an additional stage.

Gregori · 2008-03-14 20:50:44

How Come Mass Driver don't work?

GCNRevenger · 2008-03-14 21:06:04

Mass drivers? As in going directly to orbit? Or just as a boost for a launch vehicle?

Terraformer · 2008-03-15 04:05:37

If someone lived in an Airship, and launched to Orbit from there, it would be an SSTO for them.

I's a good thing we don't live underwater; we'd be having discussions about whether launching from a boat would count as a first stage.

Anyway, the lower air resistence should help somehow.

New Mars Forums

Announcement

#26 2008-02-18 16:27:49

Re: SSTO

#27 2008-02-18 16:56:53

Re: SSTO

#28 2008-02-18 17:58:00

Re: SSTO

#29 2008-02-19 04:28:46

Re: SSTO

#30 2008-02-19 05:10:55

Re: SSTO

#31 2008-02-19 05:14:22

Re: SSTO

#32 2008-02-19 11:41:15

Re: SSTO

#33 2008-02-19 12:38:42

Re: SSTO

#34 2008-02-19 12:50:31

Re: SSTO

#35 2008-02-19 12:56:29

Re: SSTO

#36 2008-02-19 13:36:37

Re: SSTO

#37 2008-02-19 16:15:44

Re: SSTO

#38 2008-02-22 18:51:39

Re: SSTO

#39 2008-02-22 23:14:19

Re: SSTO

#40 2008-03-12 20:16:23

Re: SSTO

#41 2008-03-12 20:29:48

Re: SSTO

#42 2008-03-13 01:16:58

Re: SSTO

#43 2008-03-13 07:32:58

Re: SSTO

#44 2008-03-14 12:32:10

Re: SSTO

#45 2008-03-14 13:34:24

Re: SSTO

#46 2008-03-14 14:06:23

Re: SSTO

#47 2008-03-14 18:47:44

Re: SSTO

#48 2008-03-14 20:50:44

Re: SSTO

#49 2008-03-14 21:06:04

Re: SSTO

#50 2008-03-15 04:05:37

Re: SSTO

Board footer