Why not replace the Space Shuttle with a ....... Space Plane

[mark_d_s]

Ok, as a Brit I have no right to comment on a foreign space policy. But I'm going to...

It seems that one major requirement going forward (no matter the destination) is cheap, easy, safe human transportation off the earth's surface. How about this...

First, picture the current Space Shuttle stack on a launch pad.
Now, remove the SRBs (solid rocket boosters).
Move the SSMEs (space shuttle main engines) to the bottom of the ET (External fuel Tank - the big orange bit).
Add jet engines the the rear of the shuttle.
Lay Horizontal.
Shrink to 45%.

What you are left with is a new shuttle about the size of a Learjet, which has the capability for powered flight in the atmosphere. This would be launched from a 'mothership' (like virgin galactic is doing already) from an altitude of around 55,000 to 60,000 feet. All thrust would be provided by the ET - which in this configuration would be slung underneath the space plane. The ET would remain attached until after re-entry, at which point it would be dropped from low altitude over a target area (hence the need for jet engines on the space plane), where it would descend using parachutes, thereby being totally resuable. No Science experiments would take place on board - leaving only life support, navigation and a loo! This would massively reduce the mass.

There could be many configurations of this plane, for example :-

1. Two man crew, plus up to 8 passengers. At the rear would be an opening 'roof', like a smaller version of the shuttle, just big enough to expose a docking port. Any unoccupied passenger slots would have the seats replaced by custom fitted containers - e.g. for two passengers, there would be six storage containers large enough for all the food and water each needed for a six month stay on the ISS.

2. Two man crew, plus two payload specialists. The cabin would be reduced in length, and the free space at the back would be converted to a cargo area - such as new instuments for hubble etc. A small robotic 'Canadarm' could easily be included here. Spacesuits would also remain in the cargo area - with astronauts climbing into them similar to NASA's next gen rover (see http://www.engadget.com/2008/10/26/nasa-demos-2020s-12-wheeled-pressurized-lunar-rover-concept-ca/). For these longer stays in space, you'd obviously need to sleep on board - some funky reclining seats would be adequate for a week or so (reclining vertically, not horizontally).


Now, maybe I'm just a bit mad (!) but doesn't the above make a lot of sense? Surely it would enable manned fligh to the ISS & Hubble for a fraction of the cost of all current and propsed systems. And best of all, it requires no leap in technology to acheive.

Any thoughts?
Mark

 

[docm]

A spaceplane that could be launched from an Atlas V has been around for a long, long time: the HL-20 - AKA DreamChaser. Gleaned from the Russian BOR-4 then re-engineered by NASA it was canceled before flying then the concept, and the prototype, moved to newspace company SpaceDev. If they ever get enough funding and work out a deal for a ride....

http://spacedev.com/spacedev_advanced_systems.php

Horizontally launched single stage to orbit spaceplanes will have to wait for a new combined cycle engine - the US Vulcan (jet + scramjet) (PDF file) or the UK SABRE (jet + rocket).

 

[mark_d_s]

Thanks docm, but I think you missed the point of my post - I propose a horizontal takeoff (via a 'mothership') without requiring a combined cycle engine, but with (essentially) a two stage to orbit launch - namely a small shuttle with an underslung 'rocket'. In other words using 1970's technology but without the prohibitive cost of a vertical launch.

In other words, I propose using the most efficient tool for the job - a small human rated space plane/shuttle/taxi (whatever terminology you prefer) simply to ensure manned space flight to the ISS/Moon/Mars vehicles without the need to carry significant cargo. The ultimate stop gap which also happens to have applications for many, many years to come.

All the best
Mark

 

[Fomalhautian]

That's funny Mark. I have a buddy I've worked with for some time who has been building something along those lines in his garage for the last 5 years (in reality, it's been his obsession for at least 20 years). It's getting exciting because he's getting close to completion. I'm hinting around that if he's looking for volunteers for the maiden test voyage...... I'd make a great lab rat.

Anyways, here's a link to an article that came out recently in Phoenix Magazine:

http://www.phoenixmag.com/lifestyle/valley-news/200902/space-cowboy/

 

[Booban]

I think he means your mother ship or whatever it was won't have enough power to throw your learjet into space, until they get scram jets, which don't have to carry fuel and dead weight with them. Horizontal space flight doesn't work, you're burning alot of energy going horizontal rather than just straight up. That's why they use vertical rockets now. Otherwise Virgin Galactic would do it.

Well, I think, I'm not a rocket scientist.

Why should you carry the weight of a jet engine all the way into space when you don't use it until the return.
Then you carry an empty fuel tank too and keep it with you in space.

The shuttle system is pretty good, everything you don't need just drops off then it glides back down.

I don't think the idea for the shuttle is so bad, just in practice it costs so much maintenance to be 100% sure everything is in good working order it would've been cheaper just building a whole new rocket from scratch each time.

One can wonder with today's technology why they can't just build a better shuttle with low maintenance and high reliability. Machines today have all these sensors you just plug in a computer and it tells you whats wrong. Perhaps were just throwing away the shuttle carelessly like we did the Saturn V rocket rather than learning from it and then making it better.

We are using today's off the shelf technology to make the Ares when it should have been the Saturn V technology making all the off the shelf technology we have today.

USA constantly does this, invest billions in the presidential helicopter, F-22, Saturn V, buy a few of them then change your mind and buy something else so the industrial base has a new project that can go over budget once again. But now I'm rambling...