SSTO - Single Stage To Orbit

[John_S4x4]

Looks like ARCA Space Corporation are looking to get their HAAS 2CA SSTO rocket to launch in 2018.
It's a 16,000Kg Aerospike rocket powered by hydrogen peroxide and RP-1. Launching a 100Kg payload into low earth orbit at cost of $1 million dollars.

http://newatlas.com/single-stage-rocket/48710/

https://www.youtube.com/watch?v=30LBEyFdWmE

[Fugazi]

Nice to see an aerospike nozzle finally get used for something other than small research rockets. Although to be fair, an aerospike nozzle is probably the only feasible method for a SSTO vehicle. There are other methods of extendible nozzle sections that slip down as the pressure ratio between the chamber and the atmosphere changes but I doubt the weight penalty and added complexity is worth it compared to the small efficiency loss of an aerospike.

[Eric Mc]

Back in the very early days of the space race (1958), the US managed to launch an entire Atlas rocket into orbit. These early Atlases were very lightweight being made of very thin steel.

It wasn't quite single stage to orbit, but it was an impressive feat for the time.

https://www.youtube.com/watch?v=KTOpjhL1430

[Einion Yrth]

There have been a number of launch vehicles capable of SSTO, Atlas was one as Eric notes, and I think Falcon 9 is too; with no useful payload capacity however, it's rather pointless. Reusable boosters make more sense.

[Fugazi]

Einion Yrth said:

There have been a number of launch vehicles capable of SSTO, Atlas was one as Eric notes, and I think Falcon 9 is too; with no useful payload capacity however, it's rather pointless. Reusable boosters make more sense.

Agreed, there's a significant penalty of having to accelerate a lot of unused mass to orbital velocity and just thinking about it from the Tsiolkovsky rocket equations and an ideal mass fraction (propellent/rocket mass), I think there will only be a narrow size/weight range where such a vehicle could feasibly operate. Too small and you haven't got enough volume to store the required propulsive energy to reach orbit, too large and you'll never be able to carry enough fuel to get there either.

[Einion Yrth]

If only someone could come up with a high thrust, high ISP engine that doesn't involve irradiating small countries...

[eharding]

Einion Yrth said:

If only someone could come up with a high thrust, high ISP engine that doesn't involve irradiating small countries...

You can get impressive results with chemical motors, no need to resort to nuclear.

As has been observed elsewhere, dimethylmercury as the fuel and dioxygen diflouride as the oxidiser would yield some deeply impressive results. The namby-pamby brigade would bang on about the side effects, and you probably wouldn't want to get any of it on you...but hey, with Trump in charge, who knows?.

Edited by eharding on Monday 3rd April 21:17

[Simpo Two]

eharding said:

As has been observed elsewhere, tri-methyl-mercury as the fuel and dioxygen diflouride as the oxidiser would yield some deeply impressive results.

How does that compare thrustwise with C-Stoff and T-Stoff...?

[eharding]

Simpo Two said:

eharding said:

As has been observed elsewhere, tri-methyl-mercury as the fuel and dioxygen diflouride as the oxidiser would yield some deeply impressive results.

How does that compare thrustwise with C-Stoff and T-Stoff...?

I think the specific impulse of the C-Stoff / T-Stoff ME 163 engine was around 400 seconds - dimethylmercury / FOOF would be a lot higher, on account of the mercury in the fuel and the unholy beast of an oxidiser - but I don't think anyone has been mad enough to measure it. Yet.

[Einion Yrth]

dimethyl mercury and FOOF!?

I think I'd rather take my chances with the nukes.

[Eric Mc]

British rockets often used HTP (High Test Peroxide) which I think was derived from the German T-Stoff/C-Stoff technology.

It was a bugger to handle. I sometimes chat with a guy who worked on Blue Steel missiles and he said they were handled with EXTREME care.

[eharding]

Einion Yrth said:

dimethyl mercury and FOOF!?

I think I'd rather take my chances with the nukes.

You big Jessie. It isn't as if you're going to live long enough to suffer a lingering, excruciating death from the mercury when you're dealing with FOOF.

The concept was a bit of whimsy by Charlie Stross, but he did reference "Ignition! An informal history of liquid rocket propellants" by John D Clark, which is a great read - and a great insight into how nasty some of the fuels they tried in the early days were.

[Einion Yrth]

eharding said:

You big Jessie. It isn't as if you're going to live long enough to suffer a lingering, excruciating death from the mercury when you're dealing with FOOF.

The concept was a bit of whimsy by Charlie Stross, but he did reference "Ignition! An informal history of liquid rocket propellants" by John D Clark, which is a great read - and a great insight into how nasty some of the fuels they tried in the early days were.

Yes, I have a PDF of Ignition!, a very entertaining read.