Space SHuttle Main Engine

[dj13]

Todays headlines being about the SSME replacement, it occurred to me that the best, and probably fastest way to develop a replacement, might be to publish the blueprints of the original SSME on the web.<br /><br /> Sacriledge you say? <br /><br /> It has been out of patent for 8 years at least. As with small computer technology, which avoided patent issues for the first 10 years or so, releasing the blueprints for the SSME might allow serious improvements in both efficiency, and manufacturing costs, and these improvements might happen at a very increased pace. <br /><br /> NASA says the manufacturing costs are too high. I think perhaps the monopoly of specialized contracts, and contractors might play into the puzzle. <br /><br /> Few would disagree that the SSME might be the most powerful engine, pound for pound, available. Imagine the worlds brains at work improving the cost benefit ratio in keeping with most other technologies.<br /><br /> Current price tag on the SSME is about $50 million. I'd bet, within 5 years, there could be fire sales on better versions, mass produced in China unfortunately. Maybe 3 for 10 million?<br /><br /> Just a teaser for the day...<br /><br />DJ

 

[trailrider]

Unfortunately, I don't think you understand what drives the cost of something like a SSME. It isn't just a matter of machining the parts and assembling them. There is the matter of quality control and verification. The paperwork alone cost a LOT in terms of manhours. Could it be done more cheaply elsewhere? Sure. But would you want to risk your life or the lives of others on the work of some group that does NOT have a track record? The other thing that drives costs is the number of units produced. Generally, but not always, mass production will drop the UNIT cost of an item. But you still have to have and maintain test facilities, train skilled workers, etc.<br /><br />So until we see launch vehicles produced in quantities like commercial airliners, I doubt we will be able to reduce the costs of SSME's very much.<br /><br />Going to NON-reusable SSME's (RS-25's) might get the unit costs down...but...you still have to qualify them and the new production methods will have to be verified.<br /><br />I'm not saying that won't happen someday...I hope it will! But it will be a long time coming.<br /><br />Ad Luna! Ad Ares! Ad Astra!

 

[CalliArcale]

Yep. The real expense comes in quality assurance -- change management, formal qualification testing, supplier management....there are whole disciplines in engineering that have nothing to do with actually designing or building the thing, yet which are critical to success. They are often overlooked, but they're important.<br /><br />I think RS-68 might be a good choice. It'll be interesting to see how the trade study comes out. (Remember, nothing's decided yet; NASA might yet stick with SSME. It all depends on how the numbers and the risk analysis come out.) <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[propforce]

Let's not forget the SSME drawings maybe export controlled. It can be used as weapon technology.<br /><br />Let's also not forget that there are countries out there who wants to copy our technologies without spending their own money developing them, and some may want to use our technologies against us. <br /><br />Always be vigilant. <div class="Discussion_UserSignature"> </div>

 

[scottb50]

I would think it would be much simpler for Boeing to develop a commercial version of the engine, if a market could be found for it. With all the requirements in place now they would be in the best position to build a new engine based on the production SSME and it's extensive flight experience. <div class="Discussion_UserSignature"> </div>

 

[barrykirk]

Most powerful engine pound for pound?<br /><br />If your referring to thrust to weight ratio for LOX/LH2 that may be true. <br /><br />However most LOX/RP1 engines have a much higher thrust to weight ratio.

 

[barrykirk]

Sorry, my post was confusing... I was referring to thrust to weight ratio for the engine, not the fuel.<br /><br />Doh, there is no thrust to weight ratio for the fuel.

 

[drwayne]

Although you can figure in fuel density into performance calculations for a fuel / engine combination.<br /><br />That was actually where I thought you were heading with things - but then again, I haven't been on more than a couple of minutes at a time today, and with work and getting started on the move - I am an ad for short attention span theater...<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[ragnorak]

<br />Reusability is the issue here and that involves coatings and the use of materials that can withstand repeated launch environments. The question is, with this whole RS-68 idea, is is it less expensive to man rate a RS-68 than alter the SSME to make less expensive, expendable and still meet its man rating requirements. Both engines have to be certified with new materials for new uses and that is going to cost big money. SDLV is no quite as simple, safe, soon as some people suggest.