Ariane 5 and the shrinking CEV

[tohaki]

Late last year we discussed a news item about a possible European involvement in the CEV. Here is the thread:<br /><br />http://uplink.space.com/showflat.php?Cat=&Board=missions&Number=403343<br /><br />One of the points raised against it was that the CEV was likely to be too heavy for the Ariane 5. Around two weeks ago a news article here explained that the CEV had been reduced in size:<br /><br />http://www.space.com/news/060120_cev_overhaul.html<br /><br />I assume this means that the Ariane 5 (ES ATV) would now be quite adequate?<br /><br />It is fun to imagine that the decrease in size has come about because ESA and NASA has agreed to cooperate, but I admit it is rather unlikely.

 

[nacnud]

Well the size might have come down, but I don't think the mass has. If anything a fully fueled CEV + SM possibaly masses more than before the redesign.

 

[tohaki]

To quote the article:<br /><br /><i>"Other newly approved changes to the CEV, according to sources familiar with the details, include reducing the diameter of the vehicle from 18 feet (5.5 meters) to 16.4 feet (5 meters) <b>for additional weight savings</b>..."</i><br /><br />http://www.space.com/news/060120_cev_overhaul.html

 

[tohaki]

I have looked at the thread again and another point against was that the CEV was too wide for the Ariane 5. That atleast is certainly not a problem now.

 

[tohaki]

<blockquote><font class="small">In reply to:</font><hr /><p>Probably to offset weight gains elsewhere. Almost all programs gain more weight than originally planned.<p><hr /></p></p></blockquote>Well, it is refered to as <b>additional</b> weight savings. That seems to suggest that weight has also been cut elsewhere.

 

[nacnud]

The switch from CH4/LOX increased the mass of the SM, so the CM had to loose some.

 

[tohaki]

<blockquote><font class="small">In reply to:</font><hr /><p>The switch from CH4/LOX increased the mass of the SM, so the CM had to loose some.<p><hr /></p></p></blockquote>The article doesn't say that they have decided against using a liquid oxygen/methane engine, but rather that it is no longer a requirement.

 

[krrr]

A partially fueled CEV could easily be lifted by an Ariane to the ISS, even bringing some additional cargo. After all, delta-v required for an ISS mission is less than 300 m/s, while the CEV is designed for 1700 m/s or so.<br /><br />However, it's really a moot point to discuss. The CEV won't ride a non-US launcher because it won't.

 

[nacnud]

Yeah probably, but it's fun to speculate <img src="/images/icons/smile.gif" /><br /><br />Personaly I'd love to see what could be done with the ATV + ARD or for an even wilder ride how about Vega + a Gemini sized capsule!

 

[tohaki]

<blockquote><font class="small">In reply to:</font><hr /><p>Yeah probably, but it's fun to speculate <img src="/images/icons/smile.gif" /><p><hr /></p></p></blockquote>Absolutely!<br /><br /><blockquote><font class="small">In reply to:</font><hr /><p>Personaly I'd love to see what could be done with the ATV + ARD.<p><hr /></p></p></blockquote>Yes, that is my wet dream.

 

[nacnud]

You'd like this British contempory to hermies then. The Multi-Role Recovery Capsule

 

[nacnud]

There was also a related European space station.

 

[tohaki]

I hadn't seen these two concepts before. Perhaps if we had gone for a more modest capsule design instead of Hermes we would have had an operational spacecraft today.

 

[nacnud]

Yep, especialy as it could use the Ariane 4.

 

[krrr]

<font color="yellow">Personaly I'd love to see what could be done with the ATV + ARD.<br /><br />Yes, that is my wet dream.</font><br /><br />Do you mean something like that?<img src="/images/icons/smile.gif" /> In my wet dream, the ARD-derived capsule is "hanging on the ceiling" of the the ATV's pressurised section (supported by removable struts during launch).

 

[cuddlyrocket]

"The CEV won't ride a non-US launcher because it won't."<br /><br />Although I agree that the US won't launch the CEV on a non-US launcher, they might consider licensing the design for launch on an Ariane, or even sell one or two off the production line. It would be good business after all, and it's not as if the technology is particularly sensitive.

 

[tohaki]

I was thinking more along the lines of attaching a larger crewed version of the ARD to the ATV service module.<br /><br />Your idea sounds a lot like PARES (PAyload REtrieval System);<br /><br />http://en.wikipedia.org/wiki/Automated_Transfer_Vehicle#ATV_Evolution<br /><br />...which I guess means that it has a better chance of happening than "my" idea.

 

[john_316]

You never know! When the contracts start going out to build the CEV abd before building it you will see DOD look over core technologies to ensure that certain things do not go on the internet.<br /><br />To be honest with you even though I see tons of books on the shuttle is the actual tech manuals on the internet? I mean everything, technical drawings, blueprints? everything?<br /><br /><img src="/images/icons/smile.gif" /><br />