Heavy SSTO lifter (~40 ton payload to LKO) prototype

[1greywind]

I want to share my undergoing project:

This is 220 ton launch weight unmanned reusable SSTO lifter able to deliver ~40 ton payload to 75x75 LKO. Parts count is not yet optimized - 345.

Craft is powered by 28 R.A.P.I.E.R. engines, grouped into 4 wing mounted clusters.

I have plans to create family of SSTO lifters (delivered as subassembly and standalone crafts) with payload range 10-60 ton based on this design. What do you think?

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[Camaron]

Its absolutely incredible. I would never dream of creating such a massive aircraft for lifting uses.

My only question, however, is "Why?" Does it do something better than a typical disposable heavy lift rocket? Wouldn't a reuseable ship, serviced as a load- lifter actually be more difficult to deal with, since you have to re-land and refuel the craft each time instead of just preparing the next launch?

All that said, I'll bet something like this would be an absolute godsend once a proper economy gets put in motion, and all these parts actually start costing something.

[Tank Buddy]

In real life it costs a hell of a lot less to use the same ship over and over again.

[1greywind]

@Camaron - I've started this design as challenge: As your skill with the game grows It is feels to easy to launch thing into space using "conventional" methods. And I also dream about building modular space stations using only one or two reusable launchers: Just imagine how cool (but may be a little hardcore) is to design SS module in VAB, mate it with wheeled platform, launch it, move on wheels to lifter on runway, mount, decouple transporter, liftoff, reach orbit, randevu with space station, dock module at place, and then deorbit and land in KSC. Then repeat this as many times as you want, making screenshots, notes, record video, then edit everything together and create massive report and post it to forum

[Camaron]

Sure would be a big show of power.

[Captain Sierra]

1greywind, have you considered using a blended wing body design? For KSP purposes, this is really just paneling the thing with structural wing panels. Also, have you considered using more powerful, lightweight, and efficient engines (LV45s) instead of RAPIERs and then using turbojets? The weight savings of no RAPIERs would probably make up for the extra engines.

[1greywind]

@Captain Sierra: I've played with Blended wing body concept but found that it forces top-down approach of design: When wing is actually your craft body, you can't freely move wing around to align CoL with CoM. So you first need to place engines and fuel tanks somewhere, and then build wing around so CoL will be where you need. And if your engines are not powerful enough, or if your want to change fuel tanks placement, you need to start over - becouse your wing was built for diffirent CoM placement.

And I start from R.A.P.I.E.R. engines becouse if I can get plane to orbit with only such inefficient engines, I will get big performance boost then switching to more effective combination (I like turbo-jets + LV-N combo).

[Claw]

Very nice design! I haven't built anything this big yet, but I think I'm on my way.

My only question, however, is "Why?" Does it do something better than a typical disposable heavy lift rocket? Wouldn't a reuseable ship, serviced as a load- lifter actually be more difficult to deal with, since you have to re-land and refuel the craft each time instead of just preparing the next launch?

That's the beauty of this game. It doesn't have to be better than any other thing. It just is what it is, because you like it that way.

[Levelord]

In real life it costs a hell of a lot less to use the same ship over and over again.

I thought it was paradoxically more expensive to re-use the same ship, because of retrofitting and repairs. It was one of the primary reasons why the space shuttle program was decommissioned in favor of more traditional rockets to ferry people to the ISS.

[Captain Sierra]

I thought it was paradoxically more expensive to re-use the same ship, because of retrofitting and repairs. It was one of the primary reasons why the space shuttle program was decommissioned in favor of more traditional rockets to ferry people to the ISS.

I think the other half of that equation is that the space shuttle is one of the most complex reusable spacecraft and is also one of the most expensive to maintain, because it is not fully reusable. SRBs are a pain to retool. You have to not only drill out the burnt propellant, but you have to go through and make sure the entire thing is still structurally sound. And the external tank, and all the expensive turbopump equipment (I believe was on the tank), have to be replaced every launch.

A fully reusable craft is much more economical. If your statement is true, then why is SpaceX throwing so much into making the Falcon 9 fully reusable? And why would Reaction Engines Ltd. be working to develop a fully reusable cargo carrying SSTO spaceplane?

[Rune]

I think the other half of that equation is that the space shuttle is one of the most complex reusable spacecraft and is also one of the most expensive to maintain, because it is not fully reusable. SRBs are a pain to retool. You have to not only drill out the burnt propellant, but you have to go through and make sure the entire thing is still structurally sound. And the external tank, and all the expensive turbopump equipment (I believe was on the tank), have to be replaced every launch.

A fully reusable craft is much more economical. If your statement is true, then why is SpaceX throwing so much into making the Falcon 9 fully reusable? And why would Reaction Engines Ltd. be working to develop a fully reusable cargo carrying SSTO spaceplane?

The turbopump machinery is an integral part of the SSMEs (Space Shuttle Main Engines, A.K.A. RS-25), in fact responsible for much of its awesome performance, and as such it stays attached to the shuttle, but yeah, refurbishing costs did in fact make the shuttle MUCH more expensive to fly than an expendable rocket.

It had to do with manpower, though. Not only were the SRBs a stupid thing to reuse (as you have pointed out, reusing a SRB means basically rebuilding it), the heat protection system for example took a lot of man-hours to inspect and replace after every flight. Costly, aerospace engineer-grade man-hours. Ditto for the inspections of the incredibly complex SSMEs with their thousands of parts. In all documents during shuttle design, you can see that NASA consistently underestimated the amount of work it would take to process one shuttle stack after flight. They were talking about 15 days between flights right up to a few years before the first flight!

Then again, if the Shuttle had been flown often enough (something impossible in the end due to the constrains introduced early in the design like SRBs and the fragile composite thermal tile heatshield), those costs (salaries, infrastructures,...) would have spread somewhat and the cost per flight would have ended up being much, much lower. As the Shuttle engineers put it, the first shuttle flight each year costs six billion, all the others after that one are free.

Rune. STS gives reusability a bad name.

[Captain Sierra]

-snip, snip-

Rune, did you ever give my Grand Tour mission a lookover? I recall you asking about it. Speaking of which, I did one of the fuel tank launches today and was gonna do at least two more tonight.

Back on topic, 1greywind, I'm gonna steal that awesome looking engine cluster i you don't mind.

[1greywind]

Back on topic, 1greywind, I'm gonna steal that awesome looking engine cluster i you don't mind.

Of course I'll not mind. Instead I will be pleasured if someone will use part of my design. It is "The Sacecraft Exchange" not "Oh look on my patented-don't-even-think-to-duplicate-or-reverseengeneer craft" forum

And on "reusable craft doesn't mean economical craft" debate: it is just sad, that soviet "Buran" flew only once. And we will never know will this approach be cheaper than Space Shuttle operations cost or not. It was intresting combination of semi-reusable multi-purpose launch vehicle (Energia) and less complex (and thus teoreticaly cheaper to reuse) orbiter.