Really ... BDBs ... how much would it cost?

[nacnud]

OK here is a bunch of links to info on possible SRB derived CEV launcher:<br /><br />From the planetary scocities report: Extending Human Presence into the Solar System, page 20<br /><br /><font color="yellow">As mentioned earlier, we have concluded that in addition to Atlas and Delta, another CEV launch option merits further consideration. This option is based on the development of a new launch system that combines a cryogenic upper stage with a single Shuttle SRM. This approach has several attractive features. It allows us to take advantage of the existing Shuttle human space flight assets at the Vehicle Assembly Building (VAB) and Launch Complexes 39A and B that would otherwise become idle upon termination of Shuttle operations. Furthermore, the SRM has proven to be the most reliable launch vehicle in the history of manned space flight, with no failures in 176 flights following the modifications implemented in the aftermath of the Challenger accident. Finally, the reusability of the SRM when operated independently of the Space Shuttle could result in significant cost savings relative to fully expendable vehicles. A sketch of such a new launch vehicle is provided in Fig. 1, courtesy of ATK Thiokol.</font>(image below)<br /><br />From SRB CEV [astronautix.com]<br /><br /><font color="yellow">Several proposals were made in 2004 for a shuttle-derived booster to launch cargo payloads of 18 tonnes, or the manned CEV Crew Exploration Vehicle into low earth orbit. A single shuttle solid rocket booster would be mated with an upper stage in the 100 tonne class. <br /><br />Astronaut Scott Horowitz specifically proposed using the Apollo-era J-2 100 tonne thrust engine for the upper stage (12 remained in storage or museums). ATK Thiokol proposed using several new generation AJ-60/MB-60 27 tonne thrust engines. Advantages of the sc</font>

 

[georgeniebling]

176 flights with post-Challenger mods .... how many total Shuttle flights have there been (with the change in the coding system (STS, etc) and the flights out of order I can never remember the exact number.

 

[najab]

No, even the 5-segment booster would only get you about 60-70% of the way to orbit. The numbers depend on a lot of things (thrust profile, mass of the CEV, etc), but I recall reading (and a rough estimation suggests) that the staging velocity would be about 10,000mph or so.

 

[najab]

><i>how many total Shuttle flights have there been?</i><p>There have been 113 launches. 112 Crews have made orbit. 111 Have landed.<br /></p>

 

[ve7rkt]

So, 176 RSRM flights on 88 shuttle launches post-Challenger (100% success), and 48 or 49 SRB flights on 25 shuttle launches up to and including Challenger depending on whether you count Challenger as one or two SRB failures (96% or 98%).

 

[drwayne]

I can't get over the attitude of the Marshall team which shifted around to asking Thiokol to prove that it was NOT safe to fly. I know you can never prove for certain that is IS SAFE to fly, but if the contractor expresses serious doubts, I think you should err on the side of caution.<br /><br />But hey, who cares what I think.... <img src="/images/icons/wink.gif" /><br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[ve7rkt]

<font color="yellow"> For these purposes, you could count that as a 0% rate of SRB faliure. That failure mode was known and fully avoidable, even though it introduced added launch constraints. I still can't get over that. </font><br /><br />Fair enough. :/<br /><br /><font color="yellow"> "You can change the mixture, add inhibitors, etc. to change the burn rate on APCP solid fuel. So they could make a fuel load for an SRB that burned twice as long at half the thrust, or whatever else it takes."<br /><br />Yes, they could however that is not required to launch a CEV and upper stage, see above posts. </font><br /><br />I figured a CEV plus upper stage would mass more than the 25-30t the CEV would have to be under to be lifted by an EELV, but but would the upper stage really bring it all the way up to 400,000 pounds (~180t)? My uneducated wild guess wouldn't have been half that.

 

[najab]

They don't cost more, but the savings is minor - something like $75 million reused, versus $80 million new.

 

[tap_sa]

<font color="yellow">"probably cheaper the either the Atlas V or the Delta Heavy"</font><br /><br />According to Astronautix.com Atlas V 500 series sells at $192M, and that's the inflated price because of commercial market collapse. Something is seriously wrong if NASA couldn't negotiate a good deal considerably below that, especially if they ink a deal for 10+ launches for CEV development and moon exploration.

 

[tap_sa]

$75-80M for the SRB but how much for the new 2nd stage plus R&D for the whole concept? Original estimate for Atlas 500 series launches were $110M. If NASA would agree to order 100 launches the price might be that or even lower.

 

[najab]

><i>According to Astronautix.com Atlas V 500 series sells at $192M...</i><p>Yes, but the CEV would probably require a heavy version which, if they offered it, would likely cost well in excess of $250M.</p>

 

[tap_sa]

SRB CEV 18t to ISS, Atlas V 551 20t to 28 degree 185km LEO or 17t to polar LEO. Doesn't say how much Atlas would deliver to ISS orbit that I'd guess it's close to the polar figure.

 

[smradoch]

To SG,<br />there was lot of discussion about SDV, how difficult is to modify STS infrastructure? I think that SDV should be able to launch both piloted and cargo missions or be very very cheap cargo. <br /><br />Some options for Moon or Mars mission:<br /><br />Ares: 2 ASRM, modified ET, 3 SSME, completely new upper stage, new big fairing for cargo mission, new EDS for Lunar mission or upper stage would be used? Modified STS infastructure. Payload 120t to LEO or so. Possibly human rated. <br /><br />Smaler SDV: 2 SRB, modified ET, 2 RS-68, new fairing for cargo mission, new upper stage serving as EDS, possibly upgradeable, modified STS infrastructure. Payload cca 80t to LEO. Why not human rated? <br /><br />Shuttle C: 2 SRB, ET, 3 SSME, new design of cargo pod, new EDS necessary, slightly modified STS infrastructure. Payload cca 77t to LEO. Not easily upgradeable (maybe ASRM?) Not human rated.

 

[henryhallam]

There are various other proposals too, here's one I'm quite keen on:<br /><br />http://www.ssdl.gatech.edu/main/ssdl_paper_archive/aiaa_2004-3735_paper.pdf<br /><br />Called "Centurion", it isn't quite so shuttle-derived but does use the five-segment SRBs.<br /><br />Could somebody with relevant experience take a look and let us know whether the numbers look feasible?

 

[mikejz]

Thats an intresting idea. Of course I ask the question of why bother with a liquid core for the first stage. Why not just another SRB?

 

[drwayne]

Generally an upper stage will require more flexibility than a solid provides to tailor in its flight profile (thrust levels,firing times, multiple firings etc.) to get things where they need to be.<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[henryhallam]

<i>"Thats an intresting idea. Of course I ask the question of why bother with a liquid core for the first stage. Why not just another SRB?"</i><br /><br />So that the "light" version can be man-rated easily, with no solids at all.