Orion vehicle

[nuaetius]

"I don't think it is so much Mars' atmosphere versus Earth's atmosphere as it is the fact that the Mars orbiters use delicate solar panels and very thin arms to the solar panel for their drag. With some more aggressive heat shielding you could cut the time quite a bit."<br /><br />http://www.universetoday.com/2007/07/17/the-mars-landing-approach-getting-large-payloads-to-the-surface-of-the-red-planet/<br /><br />The atmosphere and gravity on Mars is a huge issues. <br /><br />According to Universe Today and JPL the atmosphere is too thin to make Aerobraking easy over a few tons. Unlike on Earth where large items can Aerobrake to a point that parachute can be deployed, on Mars you are still going supersonic after Aerobraking. Not healthy to deploy a chute while going at supersonic speeds. Aerobraking alone will not work like there<br /><br />Also Mars has 1/3 earth norm gravity so if you use rockets to land like we do on the moon it is going to take a lot of fuel to land with.<br /><br />Read the article it explains it way better than I can.<br />

 

[JonClarke]

So did Viking and Huygens. <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>

 

[jimfromnsf]

""It's the wrong shape"???What is the wrong shape in space? "<br /><br />The shuttle is not "a space ship" It is an aerodynamic vehicle that flies in space. The shuttle's cockpit shape is driven by aerodynamic requirements for landing. Therefore the shape is wrong for any other launch vehicle/capsule. you are right that shape doesn't matter in space, but the "cockpit" would have to go throught the atmosphere before getting into space. Let's say the cockpit gets into space somehow on a different vehicle. It is still a bad shape . It is inefficient and the layout is wrong for other vehicles. Capsules don't need a flight deck, aft flight deck and middeck arraignment.<br />Because of this, it never will be incorporated into another vehicle. <br /><br />

 

[usn_skwerl]

aye. i agree with the above post completely, not to mention the fact that even for a large aircraft, the shuttle's forward section (cabin)-with or without the TPS- is ridiculously heavy. things have changed significantly in aircraft/spacecraft over the last 25 years, which brings me to another point. the space shuttle, in short, is little more than an aircraft designed to go to space and function as a crew cab pick-up truck. a Dodge Ram to the stars, if you will. <br /><br />the problem with the shuttle, like any aircraft, is that after a few years of cycled use-pressurizing and depressurizing, along with the fact that its materials are in constant effort to return to their lowest energy state, i.e. aluminum dust, aircraft fatigue is a major issue. shes an old bird, sadly, as much as some of us love the shuttle. even if "Shuttle Cabin v2.0" was reengineered, redesigned, lightened, strengthened, etc etc blah blah, its still an inefficient way to continue on with the VSE. <br /><br />also, bbrence, most of us here agree, i think, that less money should be sent to fund this war, and redirected towards space science and education. <div class="Discussion_UserSignature"> </div>

 

[holmec]

<blockquote><font class="small">In reply to:</font><hr /><p>Right now, however, NASA wants a direct abort to Earth capability, so aerobraking isn't even on the table for the manned flights. <p><hr /></p></p></blockquote><br /><br />I hear you, that's why I suggested direct reentry for the manned capsule and aerobraking for the unmanned tug. <br /><br />By the way, a scheme like this may be more suitable for private enterprise rather than NASA. What I think it demonstrates is that you can build on what NASA has done with Apollo and start creating an infrastructure in space. <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[j05h]

<i>> What I think it demonstrates is that you can build on what NASA has done with Apollo and start creating an infrastructure in space.</i><br /><br />Any infrastructure is better than none. Even storing partly used upper stages could "save the day" in an emergency. It makes the most sense with ISRU online and fuel depots. One thing that makes a lot of sense is the "long duration packages" that have been discussed for Centaur. The next step is to make the Centaurs capable of docking and propellant transfer. These are simple, stepwise improvements of existing product. The other option is tankage as a dedicated payload. For building larger tank-farms it would make sense to reuse upper stages and fly the "plumbing" and truss hardware as payloads. <br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[JonClarke]

<i>Right now, however, NASA wants a direct abort to Earth capability, so aerobraking isn't even on the table for the manned flights.</i><br /><br />This is not something I have seen. Do you have a source for this?<br /><br />Thanks<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>

 

[jimfromnsf]

It is in the ESAS

 

[dragon04]

I think this whole Orion thing lacks vision, and admits that the Apollo Program should have just been continued as opposed to ditching it for the STS program.<br /><br />The Orion/Ares concept is every bit as ugly as Soyuz.<br /><br />The notable difference is that the Russians had the foresight to scrap their shuttle program prior to ungodly expenditures simply because common sense said to do so.<br /><br />The general public (who pays NASA'S bills) has to see this as a step "backwards" and has to be scratching their heads as to how and why we're taking a step forwards as opposed to one backwards.<br /><br />To me personally, the Orion/Ares project is simply an affirmation that we wasted a hundred billion dollars on the STS Program.<br /><br />The end result is that an ugly tin can is more practical than a sleek, sexy space plane. It took 3 decades to figure that out?<br /><br />NASA has caused me to become disenfranchised in regards to manned space flight as we know it, and insist on continuing it.<br /><br />Orion is an admission of defeat. It's a statement of impractical goals that would have better not been undertaken when the Apollo Program was trashed.<br /><br /> <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>

 

[radarredux]

> <i><font color="yellow">To me personally, the Orion/Ares project is simply an affirmation that we wasted a hundred billion dollars on the STS Program.</font>/i><br /><br />While I generally agree with your view, it is important to put yourself in the shoes of the people at the time -- the political pressures they were under, the results they were expecting, the knowledge that they had, etc.<br /><br />By the late 1960s and early 1970s, people saw this giant rocket go up and only this tiny capsule come down, and even that tiny capsule couldn't be reused. The expendable launch vehicle was seen as an incredible wasteful approach.<br /><br />Also, much of the political motivation for the manned space program evaporated when Russia effectively gave up on their effort to put men on the moon. Whether we like it or not, the Apollo program was largely a product of the cold war, and that part of the war was over by 1970. Add in the cost of the Vietnam war, a president that wasn't enthusiastic about the space program (especially one associated with a rival), the huge cost of Apollo, and it was very hard to justify the cost of Apollo.<br /><br />The shuttle was about low-cost, frequent trips of a reusable vehicle to low earth orbit (eventually to visit large space stations) -- not the high-cost, infrequent trips of a brand new expendable launch vehicle for each trip.<br /><br />A laudable goal. It just didn't work out as they had hoped it would.</i>

 

[wubblie]

Hopefully the new system "will" appear ugly to the general population. Our aesthetic sense evolved on the savana in Africa in response to the imperatives of survival in that environment. It did not evolve to spot the most successful design for space vehicles. The only criterion that we can apply is "form meets function." The Soyuz is an incredibly successful vehicle by that measure. If a design seems unappealing or ugly, it usually means that the engineers stopped caring about making a vehicle that will look great on posters, and instead made one that will get the job done as efficiently as possible. The STS, Concord, Lamborghini look awesome and would appear to be "steps forward" to the average person. However, I'll take the Orion, 747, A-12 Warthog, b-52, Toyota Prius, and other "homely" designs any day (especially if I'm a taxpayer). They tend to be more successful and work much better. I think it's good that NASA has realized this (though it did take a while). It's a step in the right direction. If the constellation program leads to a permanent manned presence on the moon, then I think it will be a major success. Who knows, some day we may be <br />launching spacecraft from the moon, and have a space elevator there (which could be made with existing materials). In that case, the ends will justify the means. Could we be on mars right now if the STS had never existed- I think its probable. But if Rome hadn't fallen, it would be the year 4000 and people would probably be on extrasolar planets. The point being, the past is the past, if NASA makes the right decisions now, we still have a lot of exciting moments ahead in manned exploration.

 

[JonClarke]

Thanks Jim, I missed that when I read it. Do you have any sugegsts as to where it is? ESAS is a large document. Aerocapture is specifically mentioned for cargo elements.<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>

 

[holmec]

<blockquote><font class="small">In reply to:</font><hr /><p>The next step is to make the Centaurs capable of docking and propellant transfer. These are simple, stepwise improvements of existing product.<p><hr /></p></p></blockquote><br /><br />That is interesting. Though I don't think those steps are simple. The reason I proposed a robotic arm to do docking is that it seems the best versatile system that is you can pause. And you will probably be able to control the arm from the ground. <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[j05h]

<i>>> centaur prop-storage...<br /> />That is interesting. Though I don't think those steps are simple. The reason I proposed a robotic arm to do docking is that it seems the best versatile system that is you can pause. And you will probably be able to control the arm from the ground.</i><br /><br />The steps to making Centaur/etc into a propellant "depot" is easier than a lot of other proposed space infrastructure. Most importantly, it exists and is in production. The manufacturer has expressed interest in making an endurance package, etc. Both the NASA and alt.space suggestions usually start with "build a new rocket" which I consider a non-starter. Building a dedicated tankage system seems to make less sense than making an existing product multi-role. Docking/berthing Centaurs together is a lot easier than still having to deal with approach/rendezvous issues After Reinventing the Wheel.<br /><br />Berthing using a robotic arm greatly simplifies tankfarm operations. I have no issues with it, it definitely increases overall flexibility. Berthing also has the advantage if you need to use one of those stages as an actual transfer stage - the arm plucks it out of the tankfarm array and makes it available for integration with an arriving craft. <br /><br />For something like Centaur, this would allow upper stages to be reused on-orbit for Moon and Mars missions (where they would again form the core of tankfarms).<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[jimfromnsf]

"The reason I proposed a robotic arm to do docking is that it seems the best versatile system that is you can pause."<br /><br />It actually reduces reliability and increases complexity. It isn't needed for docking

 

[jimfromnsf]

.3. . Anytime Return<br />It is recommended that the architecture provide the capability to return to Earth in 5 days or<br />less for sortie missions at any site on the lunar globe. The requirement to return anytime from<br />the surface of the Moon to Earth was the design driver of the SM propulsion system.

 

[gunsandrockets]

<It is in the ESAS><br /><br />Jon was asking about a Mars mission not a lunar one.

 

[thereiwas]

<blockquote><font class="small">In reply to:</font><hr /><p>It actually reduces reliability and increases complexity. <p><hr /></p></p></blockquote> That is counterintuitive. What are the details to back this up?<br /><br />Musk said the grapple docking for Dragon was in response to a NASA wish to reduce thruster firing close to ISS.

 

[jimfromnsf]

ISS is manned. An arm on an unmanned vehicle is more complex

 

[j05h]

<i>>That is counterintuitive. What are the details to back this up?</i><br /><br />Progress-type or Orbital Express-type docking is a simple approach, match vector and final approach. It can be as simple as a positive-force mechanism or as complex as LIDS. The mechanical docking adapters are very reliable. Robotic arms, esp tele-operated, are more prone to failure and have unknowns WRT maintenance. For building a tankfarm, I described an arm for moving stages around. Even then it might be simpler to just hard-dock and eject putative Centaur stages as needed. With a truss/plumbing adapter, 4 Centaur would plug together truss-in and engine-out, axially. Sets of 4 would plug together in a long "bristle" of tankage. Berthing is gentler but potentially less reliable. <br /><br /> />Musk said the grapple docking for Dragon was in response to a NASA wish to reduce thruster firing close to ISS.<br /><br />NASA is worried about polluting the solar panels (and maybe the optical nadir observation port). This is somewhat different than prop-depot issues. Soyuz and Progress dock at the other end of the station. Excepting Shuttle, every planned docking with the US segment is via grapple, IIRC - HTV, Dragon and any other proposal all berth via RMS.<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[holmec]

<blockquote><font class="small">In reply to:</font><hr /><p>It actually reduces reliability and increases complexity. It isn't needed for docking<p><hr /></p></p></blockquote><br /><br />I doubt that. It would increase reliability since on the docking system you only need a grappling point and not several other stuff to do regular docking. <br /><br />It keeps the complexity on the tug and increases reliability since this function does not change and the variables do not change. With regular docking you have a large set of variables change with each new module. <br /><br />Manufacturing cost of a new module is reduced since you don't have to add extra stuff for docking.<br /><br />Also NASA chose this type of system to have dock the COTS space ships to the ISS. Why? Well I think its obvious. ISS had an arm, and SpaceX and Kistler don't have to create a nav docking system, just a dock port.<br /><br />Look what ESA went through to get their ATV to docking system up and running! Its a big cost. <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[holmec]

A "depot" ?<br /><br />Why would you want a depot? Why not just launch the fuel in tanks as you need them? The reason why I say that is to minimize fuel boiling off and leakage.<br /><br />Really in my opinion, the main reason to have a fuel depot is to temporarily store fuel made from places other than Earth. <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[holmec]

click here<br /><blockquote><font class="small">In reply to:</font><hr /><p>13.1.6 Anytime Return<br />It is recommended that the architecture provide the capability to return to Earth in 5 days or<br />less for sortie missions at any site on the lunar globe. The requirement to return anytime from<br />the surface of the Moon to Earth was the design driver of the SM propulsion system. The<br />lunar mission requires a total of 1,450 m/s of delta-V, combining a 900-m/s TEI maneuver,<br />a worst-case 90-deg nodal plane change, and Earth entry azimuth control. This capabil-<br />ity enables “anytime return†if the lander is able to perform a coplanar ascent to the CEV.<br />For sortie duration missions of 7 days or less, the CEV’s orbital inclination and node will be<br />chosen to enable a coplanar ascent. Outpost missions will also have anytime return capability<br />if the outpost is located at a polar or equatorial site. For other sites, loitering on the surface at<br />the outpost may be required to enable ascent to the orbiting CEV.<br /><p><hr /></p></p></blockquote> <br /><br />CALLI: Edited for better thread display. <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[jimfromnsf]

"1. I doubt that. It would increase reliability since on the docking system you only need a grappling point and not several other stuff to do regular docking.<br /><br />2. It keeps the complexity on the tug and increases reliability since this function does not change and the variables do not change. With regular docking you have a large set of variables change with each new module.<br /><br />3. Manufacturing cost of a new module is reduced since you don't have to add extra stuff for docking. <br /><br />4. Also NASA chose this type of system to have dock the COTS space ships to the ISS. Why? Well I think its obvious. ISS had an arm, and SpaceX and Kistler don't have to create a nav docking system, just a dock port." <br /><br />1. Wrong. It still needs a berthing system, which is just as complex as a docking system and there still is the arm.<br /><br />2. Not so, still need the berthing and rendezvous hardware <br /><br />3. Same as above<br /><br />4. NASA didn't choose. It was up to the COTS contractors. Since the only Docking interfaces were Russian, the contractors chose not to go thru them. Also the CBM allows for larger pieces of logistics to pass thru, which was a requirement. It has nothing to that ah arm is better<br /><br />

 

[MeteorWayne]

holmec, please shorten that link!! <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>