Griffin Favors Shuttle SRB for Launching CEV

[erauskydiver]

Griffin Favors Shuttle Solid Rocket Booster for Launching CEV<br /><br />From SpaceNews.com<br /><br />NASA Administrator Mike Griffin said Monday (last week) that he favors launching the proposed Crew Exploration Vehicle (CEV) on a single solid rocket booster based on the ones that for the past two decades have helped lift the space shuttle off the launch pad. <br /><br />The so-called single stick approach, which refers to the use of a single solid rocket booster, has been touted by solid rocket maker ATK Thiokol as the safest and simplest solution to launching the CEV. The solid rocket would require an upper stage engine. Boeing and Lockheed Martin, meanwhile, have been pushing their respective Evolved Expendable Launch Vehicles (EELVs) -- the Atlas 5 and Delta 4 respectively -- as the right choice for CEV. <br /><br />Griffin has said on numerous occasions that he believes a shuttle-derived launcher is the right choice for the agency’s heavy-lift needs -- lofting payloads weighing 100 metric tons or more on their way to the Moon or beyond. But on the issue of launching the CEV, which is expected to weigh 25 metric tons or so, Griffin had so far declined to show a public preference. But in an interview Monday at NASA Headquarters, Griffin said that, all things considered, shuttle-derived looks to be best choice for both heavy lift and CEV. <br /><br />"[T]here would be a bunch of changes that would have to be made to the EELV to human rate it. I don’t know that that would be the most fiscally sound path for NASA to go down, and frankly I don’t know that the EELV community would welcome us getting into their production lines in order to make those kinds of modifications," Griffin said, "so all that would need to be thought through very carefully. Right now [the path] we think is the most favorable is the shuttle-derived path in part because it gives us the best work force transition issues."<br />

 

[shuttle_rtf]

If so, then Griffin's pointing towards the Lockheed Martin Lifting Body design for the CEV. One of the earlier design photos of the Lockmart CEV was shown during assent on top of a SRB. <br /><br />Also, although I get sick of saying this, can you kindly post the URL to the actual place the article is published, thanks.

 

[erauskydiver]

Sorry, the article was copy and pasted from our internal website here at work. URL wouldnt work for you.

 

[shuttle_rtf]

Ok mate, no worries. Just wanted to see if there was any pics with it etc.

 

[shuttle_rtf]

I'll try and find it and post it here, SG.<br /><br />I'm not 100 per cent it was an SRB, could have been a staged liquid engined booster. I'll post it and see what you reckon.

 

[shuttle_rtf]

Here we are:

 

[najab]

Did you mean to say Atlas? <img src="/images/icons/smile.gif" />

 

[najab]

You can't link directly to images. (Thanks to a past user who linked to porno...)

 

[najab]

You can't link directly to images. (Thanks to a past user who linked to porno...)

 

[bpcooper]

Thanks najaB. <div class="Discussion_UserSignature"> <p>-Ben</p> </div>

 

[najab]

You have to save the image to your system, and then upload it on the "Preview Post" page. Then a mod can approve it.

 

[bpcooper]

Here is a small illustration of the SRB version. I have seen better...I used to have a large, realistic drawing of it on the MLP in the VAB.<br /><br />http://images.spaceref.com/news/cev.srb.jpg<br /> <div class="Discussion_UserSignature"> <p>-Ben</p> </div>

 

[najab]

><i>Cowing doesn't allow anyone to download his images so I am just linking it.</i><p>That's always the safe option. (Though, technically, in order to view the image on a website it has to be downloaded. I guess he doesn't want them reposted.)</p>

 

[bpcooper]

He labels the images with a period (cev.srb.jpg) so when it's downloaded it doesn't save as a jpeg properly.<br /><br />However, if you right click on the link above you can save the jpg normally. <div class="Discussion_UserSignature"> <p>-Ben</p> </div>

 

[mikejz]

Humm. Starting to think about buying a few shares of ATK....Hehe

 

[mikejz]

Humm. Starting to think about buying a few shares of ATK....Hehe

 

[no_way]

<blockquote><font class="small">In reply to:</font><hr /><p> technically, in order to view the image on a website it has to be downloaded. I guess he doesn't want them reposted<p><hr /></p></p></blockquote><br /><br />thats OT, but the reason why people dont allow direct linking of images from their websites is that you are basically "stealing" their bandwith. Even posting image links isnt always appropriate ( if so said by the author ) , because you arent generating pageviews for a given site and pageviews = ad money.

 

[bpcooper]

I notice two double posts above...and I have been having problems with this site connecting. Anyone else clicking to post and the page times out? <div class="Discussion_UserSignature"> <p>-Ben</p> </div>

 

[spacefire]

hey at least he's leaning towards a lifting body <img src="/images/icons/smile.gif" /><br />how are they going to stabilize it during ascent? I didn't think the SRBs had movable nozzles.<br />Also, the second stage should have quite a kick to separate the orbiter from the booster in case of a malfunction.<br />Can an emergency shut-off system be implemented for the SRB? We don't want anotehr CHallenger <br />I don't know, to me using the SRB generates more problems than it's worth. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[mrmorris]

<font color="yellow">" I didn't think the SRBs had movable nozzles. "</font><br /><br />You thought wrong. The SRBs are what steer the shuttle.<br /><br /><font color="yellow">"Also, the second stage should have quite a kick to separate the orbiter from the booster in case of a malfunction. "</font><br /><br />There's an escape tower. This would be essential whether the first stage was solid <b>or</b> liquid.<br /><br /><font color="yellow">"We don't want anotehr CHallenger "</font><br /><br />An O-ring leak -- assuming one were still possible with the new seals, wouldn't cause a catastrophic failure for the stick. A loss of thrust, but no explosion. The ET is what exploded.

 

[najab]

><i> The ET is what exploded.</i><p>Cue Mr Pedantic (that's me). The ET didn't explode, if it had there would have been a <b>much</b> more energetic event. What happened was the plume from the SRB leak burned through the lower support structure of the SRB, which then pivoted around the upper support into the ET. The bottom of the LH2 tank fell out as a result of the impact and the rapid expansion of the fuel drove the top of the tank into bottom of the LOX tank. The two mixed with the resulting rapid combustion.<p>As it was, the Orbiter was destroyed by being yawed <i>sideways</i> into the air stream, and aerodynamic forces broke it apart (the crew compartment was seen exiting the conflaguration relatively intact).<p>As you said, if a 'Challenger-style' leak was to occur during the launch of the CEV, it would likely have no impact on the mission, other than resulting in a first state underspeed. If the leak progressed too far, the first stage would fail and the escape tower would drag the second stage/crew module clear of the booster.</p></p></p>

 

[spacefire]

<font color="yellow">There's an escape tower. This would be essential whether the first stage was solid or liquid. </font><br /><br />The lifting body version doesn't appear to have an escape tower, the capsule does. You know by now which one I prefer...<br />Thanks for clarifying the steerable nozzle on the SRB, I was too lazy to google myself <img src="/images/icons/wink.gif" /><br /><br /> <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[nacnud]

The lifting body might have a simmialr system to the Kliper where the escape tower is at the base of the vehicle and used to increase the vehicles delta-v.

 

[spacefire]

so basically it is part of the second stage? <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[henryhallam]

<font color="yellow"><br />so basically it is part of the second stage?<br /></font><br />Not really, more of a separate mini-stage. Escape systems tend to require a sudden, large thrust and ususally use solids. So the second stage engines aren't used.