NASA Plans to Build Two New Shuttle-derived Launch Vehicles

[wvbraun]

Substantial update from nasawatch:<br /><br /><i>According to sources familiar with the study's final recommendations, the heavy lifter will be a "stacked" or "in line" configuration (one stage atop another) and not a "side-mounted" configuration as is currently used to launch the space shuttle. The first stage will be a modified shuttle external tank with rocket engines mounted underneath. The first configuration will use 6 existing shuttle (SSME Block II) engines.<br /><br />A growth version for lifting heavier cargos will use three RS-68 engines. The RS-68 engines, manufactured by Boeing, are currently used in its Delta IV family of launch vehicles. Additional engines would be clustered for launching heavier loads such as those needed for Mars missions.<br /><br />The second stage will have a liquid engine capable of restarting multiple times. The payload will sit atop this second stage inside a large aerodynamic payload shroud.<br /><br />During the study several shuttle-derived heavy launch vehicle options were considered. An old favorite, based on so-called Shuttle-C NASA designed in the late 1980's would have replaced the shuttle orbiter with a payload canister which would more or less replicate the existing orbiter's payload interfaces - sans the orbiter. Existing launch infrastructure would stay mostly the same. This configuration has its limitations in terms of the size of payload that could be launched and was rejected in favor of the in-line design, which has greater capacity for growth and performance.<br /><br />The in-line option resembles the "Magnum booster" that was designed by NASA JSC in the mid-1990s. This will be a rather immense vehicle more on the scale of a Saturn-V. It will require substantial modifications to the existing launch pads and payload handling facilities at the VAB.<br /><br />The second vehicle to be pursued is based on a 5 segment Solid Rocket Booster (SRB). Atop the SRB will be a new liquid-fueled upper stage and the CEV. While this vehi</i>

 

[wvbraun]

It seems Griffin's team is designing the in-line SDHLV with manned Mars missions in mind...<br /><br />Glad to hear that they took into account the workforce issues associated with a shuttle derived approach.

 

[vt_hokie]

I'm glad to hear they're choosing the inline configuration for the heavy lift launch vehicle! That thing is going to be a monster! With a Saturn V class launch vehicle back in the arsenal, we can really start to talk about going back to the moon and beyond.<br /><br />I'm less thrilled about the idea of using a single SRB to launch the CEV. It's definitely the simplest way to go, but is it the safest? Even the the escape tower, is this really going to be much safer than the shuttle?

 

[mikejz]

I would much rather perfer a RP-1 based 1st stage as opposed LH2. It just seems that LH2 is just too much of a hassle and cost to make it effective as a first stage. <br /><br />Does it say it it will fly with 2 or 4 SRBs? It seems that if it was an inline booster you could use 4 SRBs. <br /><br />

 

[henryhallam]

Hoo boy! 6 SSMEs! No wonder it can lift 120 tonnes!

 

[mikejz]

I just really hope they plan on recovering the SSMEs otherwise that would be one costly booster

 

[mikejz]

I just realised, with one of those you could finish the ISS in one shot!

 

[botch]

Well this is sounding...I think the word i'm looking for is audacious <img src="/images/icons/cool.gif" /> <i>Six</i> ssme's? I'd imagine the the tank will have to be heavily modified to accept loads from underneath.

 

[vt_hokie]

That's an interesting point about the SSME's. Might they be recoverable? I doubt it...how would you get them back from orbit? <br /><br />

 

[henryhallam]

The ET will have to be stretched quite a bit to hold that much extra propellant, too.

 

[wvbraun]

This rocket would make Mars Direct missions possible. Zubrin will like it. <br /><br />But I would really like to know how NASA plans to pay for the development program, pad and assembly building mods etc.

 

[mikejz]

Well what are the possibility to do all shuttle launches off of just one of the pads?

 

[botch]

I guess you'd still have the problem of funding the shuttle whilst simultaneously funding the shuttle-derived stuff.

 

[botch]

I seem to remember that the US components are designed for the side mounted shuttle cargo bay instead of having the mountings on the base like conventional launch vehicles. Also the modules would probably have to be stress tested all over again if they were to go up on a different vehicle.

 

[mikejz]

Well just because its inline does not need to mean that the SSME will not be recoverable. Afterall just because the SSMEs will be under the ET does not mean that they have to one structure. You could put the SSMEs in a pod that can seperate and be recovered.<br /><br />That said I am generally unhappy with the choice to use the SSMEs, they are just so complex and expensive as compared to the alternatives. I wonder how hard it would be to remove the regenerative cooling aspects of the design and how much simplification that would result in.

 

[mikejz]

Are they still actually making SSMEs?

 

[spacester]

All shuttles off of one pad even with the so-called rescue mission requirement? <div class="Discussion_UserSignature"> </div>

 

[mikejz]

Question: in theory, what would it take to make the ET carry Lox/Rp-1?

 

[mikejz]

So we are looking at a ~$1.5 billion dollar booster in other words.

 

[spacester]

SG, can you tell us if, in the discussions you were privy to, the big picture strategy accounted for the various possibilities offered by Private concerns?<br /><br />IOW, is the overall plan at all tied in with the availability of private capability for crew and/or cargo to LEO and / or ISS?<br /><br />IOW, is there hope that the growth version might not be needed if someone else builds a big friggin rocket? Or that CEV on a stick might be strictly an interim solution until Orbital Tourism establishes the crew-to-LEO capability NASA needs? <div class="Discussion_UserSignature"> </div>

 

[mrmorris]

Of course we've all focused on the SSMEs being thrown away (or not). In this new in-line SDHLV, what happens to the stretched ET? Surely they don't plan to do the same 'maneuver-and-drop' that is currently the case. I can only see two reasonable alternatives:<br /><br />1. The ET hits 'Empty' out at an earlier stage in the flight trajectory (i.e. while still at suborbital velocity). The fact this system has true upper stages makes that feasible. It also answers how it could support 6 SSMEs without being massively larger than the current ET (i.e. it's <b>supposed</b> to run out sooner, dummy)<br /><br />2. My second alternative doesn't seem so reasonable after I finished writing the first. I was thinking that it'd just be left in a higher orbit (i.e. to become more debris), but surely that can't be the case. If option one isn't the answer, heckifIknow what is.<br /><br />Of course that would rule out any possibility of the new stretch ET becoming the basis for an instant 'wet-lab' space station. <img src="/images/icons/frown.gif" />

 

[wvbraun]

"I'm still for a space-based CEV."<br /><br />All indications are that NASA has settled on a LSR architecture.

 

[spacester]

A private rocket carrying basic commodities can get to $500 per pound if they have somewhere to go on a regular basis. That's what the SDHLV is for: give everyone else places to go. <div class="Discussion_UserSignature"> </div>

 

[vt_hokie]

"hey will finish the ISS in only 15 flights? That is the published number of remaining flights. Is that still the case?"<br /><br />Well, it's going to take 8 more flights to get to "U.S. core complete" with the installation of Node 2. Seven additional flights could get you through installation of the European Columbus module, the two Japanese lab modules, and the final Hubble servicing mission with a couple of flights to spare.

 

[mikejz]

It seems like everything I read only speaks to 2 SRBs. Is there a reason, or is a 4 SRB an option later down the road?