A HLLV for the masses--DIRECT:

[gunsandrockets]

"As far as the Ares I goes I'm not an aerospace engineer and I'm getting tired of hearing others who are not spouting off about how bad it is"<br /><br />It doesn't take an aerospace engineer to recognize the problems of the stick. I myself don't doubt that NASA can make it eventually work, my objection to the Ares I is it's high cost. Which leads too...<br /><br />"I don't see how emasculating the CEV down to 8.5 tons will help VSE. "<br /><br />You have to justify to me why an 8.5 tonne CEV is 'emasculated'. The whole point of building a capsule based crew system is to cut unneeded mass. If bigger was better NASA would continue to fly the Shuttle orbiter.<br /><br />You should understand that much of the gross mass of the current Orion design is propellant for the lunar mission. Since the CEV and CLV will be used for all manned missions, including those to LEO and the ISS, it doesn't make sense to specialize them for the lunar mission. The extra mass for beyond LEO missions should be carried by the unmanned cargo launcher. Anything else wastes money needlessly.<br /><br />The elephantine mass of the current Orion design is unreasonable, and directly leads into the problem of the Ares I concept. NASA's CEV was enlarged to fit the expected stick payload which is an assbackward way to define the spacecraft. It's amazingly convenient how now only the Ares I could safely launch the bloated CEV. <br /><br />I have a theory as why NASA did it. It all boils down to NASA's addiction to the HLV concept. It's as if they will do anything to satisfy that craving. The stick was chosen so that as a CLV it would subsidize the development and operational costs of the Ares V. And it seems to me the CEV was enlarged so that only the stick would work as a CLV, regardless of the official NASA rationalizations.<br /><br />

 

[tomnackid]

gunsandrockets wrote:<br /><br />"It doesn't take an aerospace engineer to recognize the problems of the stick. "<br />_______________________________________________<br /><br />Hmmmm, that's an interesting point of view considering there are engineers who spaned years learning how to spot the problems in complex machines like the Ares I. Oh well. I guess in the age of internet forum all you need to do to call yourself a rocket expert is put together a few Estes kits and launch 'em.<br /><br />NASA's mandate is to go to the moon. They aren't going to do that with an 8.5 ton capsule and a half dozen or so EELV lauches. Yes NASA is fixated on heavy lift because hevy lift is the ONLY practical way to get out of LEO. The Russians have had cheap reliable medium lift launch vehicles for decades and yet they never tried to leave LEO except for some semi-succesful unmanned tests. The moon aint gonna happen without a t least a Saturn V class HLLV or better. And Mars is right out. Zubrin pointed that out a decade ago.<br /><br />Some people are fond of quoting Hienlien by saying "LEO is half way to anywhere." I prefer to say "LEO is ONLY half way to anywhere. You don't cross a canyon by taking two small jumps."<br /><br />Another favorite saying of mine that I think is appropriate here is, "Its the stingy man who spends the most."

 

[gunsandrockets]

Just because I'm not an expert doesn't mean I can't form a valid opionion based on evidence, reason and careful and specific reference to valid information.<br /><br />Just because Zubrin says something can only work one way doesn't invalidate all the other enginneers and experts who disagree with that.<br /><br />I have no problem with HLV by itself. But that doesn't mean other imaginative architectures won't work, or that they wouldn't work less expensively than resorting to an HLV.<br /><br />And you have yet to answer my specific question of why a lighter CEV is 'emasculated'.<br /><br />

 

[josh_simonson]

You don't have to be a rocket scientist to be able to look at NASA's spending history with the shuttle and realize that NASA will be incapable of running two LVs as cheaply as one.<br /><br />That's the whole point of Direct. NASA wants to build TWO full launch systems, including separate manufacturing, pads, and processing. The Shuttle program showed that when NASA flies LVs, the entire expense goes to salaries and infrastructure costs for the 'factory' no matter how many rockets actually fly. <br /><br />A second launch vehicle only makes sense if it's full cost to launch (fixed/flightrate + incremental) is less than the cost to launch another unit of a more capable rocket - and NASA's own numbers say that will not be the case with the Aries 1. <br /><br />True the Aries 1 is slightly more safe, and appearantly NASA thinks it's okay to pay $1bln/year for a 0.05% safety improvement over the Aries V. If one were to believe their safety numbers, they'd lose 1 astronaut every 47 years on average instead of 2. That means that they'd be spending $47B per death prevented. If we took a national vote, asking wether it's worth spending $47b to save a volunteer astronaut I think the answer would be a resounding "sucks to be him..." Ask George W, and I'm sure his response would be the same. That's what's wrong with the Aries 1, and even if it worked perfectly and had no technical problems at all, it would still be a colossal waste of money.

 

[pmn1]

An extra $20 million to get that extra payload to orbit seems to be a bargain to me.<br /><br />Out of interest, could you send cargo to two separate orbits if you wanted to? <div class="Discussion_UserSignature"> </div>

 

[publiusr]

I don't see why not.<br /><br />Direct is more realistic than the more tedious EELV assembly missions and gives us a path to larger HLLVs, Team Vision style--where Direct is "Jupiter I."

 

[publiusr]

The website has been updated.

 

[tomnackid]

I think this dead horse has been beaten to a pulp. NASA is well along in there Ares development and no show stoppers have cropped up--contrary to internet rumor and the wishful thinking of spiteful low level engineers.<br /><br />Does anyone else think it is pretty ludicrous, not to mention downright insulting, that someone on this thread actually said "I don't need to be an aerospace engineer to know that the Ares I has problems" ???<br /><br />Maybe its just me. Maybe I think too little of myself. Maybe I should try and pass myself off as a launch vehicle expert. Afterall I once went to KSC. Last year I almost saw a shuttle launch (was canceled due to weather <img src="/images/icons/frown.gif" /> I've built and flow a few Estes kits.

 

[jimfromnsf]

Give it time. Don't count your chickens before they hatch. Ares I is not as far along as the X-33 was.<br /><br /><br />But you are correct, you are not launch vehicle expert, things can still change<br />

 

[tomnackid]

Jeez, you could cut the spite with a knife in here! I wish all thses passive agressive wanabes would just have it out with their bosses and not take it out on other posters.

 

[holmec]

Nice, but no.<br /><br />If there is one thing we learned from the STS, is that don't launch crew and major payload infrastructure together, launch them separate. Its safer, less complex. <br /><br />Also this quote:<br />"This architecture completely removes the costs & risks associated with developing and operating a second launcher system, saving NASA $19 Billion in development costs, and a further $16 Billion in operational costs over the next 20 years."<br /><br />1. You are still developing a new rocket. Development time would be longer than developing Ares I but probably shorter than Ares I and Ares V, granted but you ground the troops for longer time.<br />2. Two SRB's and a large core is cheaper to operate than a 5 segment SRB with a small second stage? I don't see how launching more material is cheaper to operate. <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[publiusr]

See the Direct thread at the fine: <br />http:// www.nasaspaceflight.com forum for your questions to be answered.