Odd shape of the evolving Service Module (SM) for Orion CEV

[gunsandrockets]

<br />Key is the absense of evidence provided to sustain your claim.

 

[gunsandrockets]

[If the OMS tanks were available and if they held the required propellant quantities you have a good point about using the same tanks. This is especially true because the zero G propellant acquisition system of fine mesh screens inside the tanks have worked very well.]<br /><br />The previously linked diagram of the Orion SM shows four propellant tanks. Reusing the Shuttle OMS tanks could help explain why the SM will use four tanks instead of two tanks original to the Orion.

 

[gunsandrockets]

[Shuttle OMS is 24klb not 20klb, big difference when it comes to tanks.]<br /><br />I said the OMS tanks were "about 10 tonnes" capacity, I did not say 20klb! Once again you are mistating what I said in order to find fault where there is none present. <br /><br />[Also, there is a difference in attach fittings. And once again they are out of production are and over built.]<br /><br />And the Shuttle OMS have the virtue of a long successful service history on a manned spacecraft. Virtues not overlooked by Lockheed-Martin, or NASA who awarded LM the Orion contract over Boeing! <br /><br />

 

[jimfromnsf]

"Reusing the Shuttle OMS tanks could help explain why the SM will use four tanks instead of two tanks original to the Orion."<br /><br />Not so. There always have been 4 tanks. Four tanks are used to help maintain the CG. The changes to the tanks have been from spherical to cylindrical<br /><br />"Shuttle OMS is 24klb not 20klb, big difference when it comes to tanks."<br /><br />I wasn't quoting you. The CEV propellant requirement are only 20k and the OMS capacitiy is 24k, which is a mismatch

 

[gunsandrockets]

[...I wasn't quoting you...]<br /><br />I believe you. Now. <br /><br />Therefore I retract the accusation that you were misquoting my 10 tonne statement.<br /><br />[...There always have been 4 tanks. Four tanks are used to help maintain the CG. The changes to the tanks have been from spherical to cylindrical...The CEV propellant requirement are only 20k...]<br /><br />Very interesting...if true. Can you back up any of that with evidence? Or does that fall into the same black hole as your inability to back up your claim the Delta II engine is the current choice for the SM engine? <br />

 

[jimfromnsf]

SBU documents . DAC-1 and DAC-2

 

[MeteorWayne]

So the answer is...the same black hole. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[JonClarke]

Please desist from making statements which cannot be backed up by quoting from open literature. There are two reasons for this.<br /><br />1) If you have access to sources not publically available you probably should not refer to them any way. It saves us all from a great deal of hassle.<br /><br />2) Without access to your source people cannot judge whether you have referred to it or interpreted correctly, or whether it even exists. <br /><br />You have been repeatedly asked to support your assertions with evidence by several people. Consider this a formal instruction.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[gunsandrockets]

Stick a fork in him. He's done.

 

[jimfromnsf]

Give me a break. That is BS. I see it everywhere. You better apply this to all your posters. Especially, #1. Shuttle scheduling is not public knowledge. Do you want me to point out all the posts that don't follow those same rules? <br /><br />I don't need to be judged. Especially from outsiders or wannabes not in the business. <br /><br />I guess this site wants to remain in the dark and that why it always refers and defers to NASASpaceflight.com<br /><br /><br /><br />

 

[jimfromnsf]

GnR, keep quoting NSF.com, because some of the info comes from me

 

[gunsandrockets]

[I don't need to be judged.]<br /><br />Says the person so quick to judge others.<br /><br />I don't know you. You could be anyone. How can anyone determine if what you say is true if the best you can do is claim access to secret documentation? Can't you understand the problem with that?<br /><br />For example, what if I were to claim access to such documents and say that you are incorrect? How can anyone fairly judge such a contest? It breaks debate down into unprovable assertions and is nothing but a tremendous waste of time and energy for everyone.

 

[jimfromnsf]

Show me an SM with 2 propellant tanks. It never has had 2. The ESAS even shows 4.

 

[gunsandrockets]

"GnR, keep quoting NSF.com, because some of the info comes from me"<br /><br /><br />Yeah, sure it does.<br /><br />You didn't help your credibility when some of criticisms you made of what I wrote were flatly contradicted by available evidence. The only criticisms that still stand are the ones that rely on your secret evidence. <br /><br />

 

[jimfromnsf]

You never proved me wrong.

 

[gunsandrockets]

three false accusations<br /><br />1. That I had not read the nasaspaceflight thread I linked to, and I was wrong about the thread saying the SM changes were for weight reduction<br /><br />2. That I had advocated combining crew and cargo on Orion missions to ISS <br /><br />3. That I meant the Orion service module had it's capability reduced when I called it smaller<br /><br /><update--subject line edited />

 

[jimfromnsf]

I'll cry a tear for your hurt feelings

 

[gunsandrockets]

Projecting much? Can't ever admit error? Dude you need to scale back your emotional investment in what you post. You are only further hurting your credibility. <br /><br /><update--subject line edited />

 

[gunsandrockets]

[Show me an SM with 2 propellant tanks. It never has had 2. The ESAS even shows 4.]<br /><br />As the thread should have made obvious the SM has been furiously evolving from the original methane engined ESAS concept.<br /><br />http://www.spaceref.com/news/viewsr.html?pid=19067<br /><br />I'll restate the point I originally was making about 2 vs 4 tanks.<br /><br />I thought that the use of 4 cylindrical tanks was supporting evidence that the SM was using parts from the Shuttle OMS. It seemed to me that if original tanks were to be designed it would be simpler and more efficient to use only two tanks in the new reduced diameter SM configuration.<br /><br />You said 4 tanks were necessary to preserve CG. I was thinking of two tanks with one tank stacked atop the other as is customary with most launch vehicle rocket stages, not side by side tanks.<br /><br /><update -- subject line edited />

 

[PistolPete]

Hey, I wouldn't worry about this guy too much. He's been warned about his attitude by two separate mods on two separate threads in the past day or so (that I've seen, at least).<br /><br /><br />(borrowed from Vogon: ) <div class="Discussion_UserSignature"> <p> </p><p><em>So, again we are defeated. This victory belongs to the farmers, not us.</em></p><p><strong>-Kambei Shimada from the movie Seven Samurai</strong></p> </div>

 

[scottb50]

Give me a break. That is BS. I see it everywhere. You better apply this to all your posters. Especially, #1. Shuttle scheduling is not public knowledge. Do you want me to point out all the posts that don't follow those same rules?<br /><br />I don't need to be judged. Especially from outsiders or wannabes not in the business.... <br /><br />Twice in one night! I'm honored. Bring on the Pikes! <div class="Discussion_UserSignature"> </div>

 

[JonClarke]

Jim<br /><br /><i>Give me a break. That is BS. I see it everywhere. You better apply this to all your posters. Especially, #1. Shuttle scheduling is not public knowledge. Do you want me to point out all the posts that don't follow those same rules?</i><br /><br />We expect all our posters to supply evidence to support their statements. We do not accept them hiding behind the unprovable assertion that the information is not available to the public. <br /><br />If you find other people not supply evidence then you are entitled to ask them for it. If they do not then bring it to our attention. <br /><br />However, whether they do or do not supply the information does not excuse you from complying with requests those directed at you or ignoring moderator instructions. You have been specifically asked to supply specific information. Do so or rephrase your statment as being based on opinion rather than verifiable fact. I will not ask again<br /><br /><i>I don't need to be judged. Especially from outsiders or wannabes not in the business.</i><br /><br />Regardless of whether people are insiders or outsiders, wannabes or the real thing, on this board we expect people to adhere to standards of behaviour. People who do not find themselves suspended. I am sure you have much to offer. The choice of whether you want to be a valued part of of this community is yours.<br /><br /><i>I guess this site wants to remain in the dark and that why it always refers and defers to NASASpaceflight.com </i><br /><br />Wrong on both counts.<br /><br />Jon<br /><br /> <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[jimfromnsf]

"I was thinking of two tanks with one tank stacked atop the other as is customary with most launch vehicle rocket stages, not side by side tanks."<br /><br />It isn't a launch vehicle rocket stage. It is a spacecraft. Most spacecraft (with large amounts of propellants) don't have tandem tanks. Also the orginal SM is too squat for tandem tanks <br />

 

[steve82]

The image that instigated this discussion is a candidate architecture from one of many trade studies going on across the program. Expect to see all kinds of strange pictures at this stage of the design cycle, Nothing is cast in concrete yet and unless the specific parameters that are in play in a given trade study are known, it's hard to say what is the driver of a given representation.

 

[gunsandrockets]

[...it's hard to say what is the driver of a given representation.]<br /><br />Supposedly it was to save mass and simplify the SM.<br /><br />[...Expect to see all kinds of strange pictures at this stage of the design cycle, Nothing is cast in concrete yet...]<br /><br />Isn't it fun to watch the process and analyze the result?