Developing a new Single stage to orbit craft

[J_Aerospace]

Hi there i want to start a thread regarding ideas and designs for a new single stage to orbit spacecraft.

I have been thinking of this for a while but cannot decide on a realistic design. I have googled for many hours and just keep coming up with the same concept stuff of which really i think better stuff is possible.

I want to propose a thread where none developers can post ideas sketchs pics etc.. in a hope that a variaty of new vessels will emerge.

Here are a few ideas i have come across.

 

[Scarecrow]

Not that I'm an expert, but it could be that you can't come up with a realistic design because there is no realistic design (with current technology that is).

 

[J_Aerospace]

I have been playing around and i think i have found a decent design.

 

[n0mad23]

I've been frequenting the NASA forum a lot lately, and the buzz there for the single stage approach is basically to do an intermittent step.

Much of the problem here is how much propellant is needed to get into the upper atmosphere. Even from the standpoint of 'hypothetical' tech like our Delta-Glider, this initial sequence is really energy consuming.

It seems the air-drop is where most of the thinking is directed. Kind of like the White Knight-SpaceShipOne approach, but scaled WAY UP.

If this is an interest, do a search for the Crossbow platform.

I'm really thinking (especially with my interest in tether-sling networks) that getting to LEO cheaply and efficiently is the way to go.

 

[Director]

The Director's Delta V

Hi there i want to start a thread regarding ideas and designs for a new single stage to orbit spacecraft.

I have been thinking of this for a while but cannot decide on a realistic design. I have googled for many hours and just keep coming up with the same concept stuff of which really i think better stuff is possible.

I want to propose a thread where none developers can post ideas sketchs pics etc.. in a hope that a variaty of new vessels will emerge.

Here is my design :

http://webpages.charter.net/tsiolkovsky/designs/DeltaV.zip

Here is the paper to go along with it :

http://webpages.charter.net/tsiolkovsky/proposal/IPO.doc

I'm more interested in second generation Orbiter based flight control for this, the design is more or less fixed by reality, nature and the laws of physics.

 

[J_Aerospace]

Hi there i a have done some more research and the way to go is ssto read this
http://en.wikipedia.org/wiki/Single-stage-to-orbit

so i have been playing around and come up with this. There is still alot of work with the mesh and textures to do. i am planning a series of vessels along this line, this one is just a mule unmanned iss resupply further vessels in the series will include a passenger and payload launchers.

 

[n0mad23]

J_Aerospace,

I'm looking forward to seeing what you do with this project. I'd vaguely remembered a thread along these lines, but couldn't find it. Originally, my intent was to put the SSTO images here.

I'll see about having the threads merged as they really connect.

Thanks for tackling this one! The possibilities are really attractive.

 

[Urwumpe]

Not that I'm an expert, but it could be that you can't come up with a realistic design because there is no realistic design (with current technology that is).

You can in todays technology build a SSTO. It would just never become economic. But two stages with a reusable first stage is also already a good cost saving.

 

[n0mad23]

Yes, I think TSSO's have a bit more viability in terms of development and economic attraction at this stage.

It's quite astounding how much energy's required getting a rocket into the upper atmosphere, and a reusable first stage (especially as a air launch platform) is a good solution.

 

[Urwumpe]

Yes, I think TSSO's have a bit more viability in terms of development and economic attraction at this stage.

It's quite astounding how much energy's required getting a rocket into the upper atmosphere, and a reusable first stage (especially as a air launch platform) is a good solution.

What is a TSSO? I looked for the definition of the acronym, but can't find something useful except a greek organisation.

If you mean Twin-Stage To Orbit, it would be a TSTO.

Also, the energy for getting to 150 km altitude is quite low actually - it is "only" 46% of the the energy required for reaching orbit, when you go to 150 km in a suborbital hop, and even less when you launch for orbit, 40%.

For getting to 17 km altitude and mach 0.85, a rocket uses only about 28% of the energy for getting into Orbit. But to have 28% less or not to have, that is the question.

 

[n0mad23]

You see what happens when I don't follow my own advice?

I've noticed another mistake and two typos I've done as well.

Yes, TSTO is the acronym I meant. It's interesting that in some discussions I've been following, many people are referring to air launched systems as SSTO's - which seems problematic as it ignores the fact that the airplane is in fact a 'first stage.'

There really are advantages to launching at attitude. Gravity loss is number 1. If you launch a rocket pointing straight up, fully 1.0 g of its thrust to weight is pure loss. By launching at altitude you avoid this loss all together.

Launching at altitude also eliminates engine pressure loss incurred at sea-level. While this isn't nearly as significant as gravity loss, launching at 1/4 the air-pressure allows more thrust and a higher ISP (and I think a significantly lower engine pressure as well).

While atmospheric drag is the least significant issue, launching at altitude becomes a bonus here as well.

 

[Urwumpe]

Yes, but you also get more problems to solve regarding handling the rocket. Also, air launches are directly on the border between where hi-tech single stage rockets can reach orbit and where modest technology air-launched twin-stage rockets are better.

A reusable hydrogen-oxygen air-launched rocket for example is technologically pretty cool,
but the volume of it's tanks would make the first few km from the surface ugly.