Post central for information on CEV 2 - ...continue here.

Josh Cryer · 2004-08-26 19:41:43

Oops, last thread got a bit big, thansk for pointing it out Rxke (normally you guys already start a new thread though, so yeah). Feel free to quote your last few posts in the last thread to continue discussion.

GCNRevenger · 2004-08-26 20:15:44

The original modules of the ISS have been up there for a while now, its older isn't going to have too much life left in it if we get around to adding more and larger pieces to the "complete" form. Particularly not without regular heavy payload delivery from Shuttle to keep it running. It was designed to last 30 years with Shuttle flights, not sitting up there by itself.

Ah but changing the center of gravity isn't an option... ISS is not strong enough structuraly most likly to survive being a "parasite" on a larger, heavier space station. If you try to maneuver, the bending strain on the modules' seals or truss bolts will be a signifigant problem... they may simply break. Inertia still applies in space you know.

And like many space vehicles (Shuttle imparticularly), if they are extremely complex and filled with outdated hardware, it quickly becomes more expensive to modify and update and re-use than it would be to replace. ISS is one such vehicle...

A space station of equal volume built in a similar fasion to TransHab could be launched in only one or two medium HLLV flights... three for the logistical section... and would be a much more capable station for a lower cost surely than jerry-rigging ISS.

comstar03 · 2004-08-26 20:23:53

I think that we are not moving in the right way to bring commercialisation of space to reality, we need to work with the existing hardware and expand of it , we need a total reusable launch vehicle platform and have a master plan for LEO, Moon, Mars and beyond and we haven't because we would have been their by now, instead we are going over and over the same turf. example skylab, Mir and now ISS haven't we got it yet. there is 500B$ spent uselessly for humanity.

All the launches to the moon were an ego trip for one people over humanity, not a constructive action to permanently move humanity into space, and I think the development of CEV will be the same. We haven't got mechanism to move large volume of cargo to and from earth for space development and exploration. We haven't got transfer vehicles ( unmanned or manned ) that are workhorses for this activity. With these issues solved then we could work on supplying the moonbase and mars exploration more effectively.

GCNRevenger · 2004-08-26 20:47:49

I think you discount the Apollo project much too readily as a stunt only... was it the most efficent method? No, but NASA was already thinking about turning the LEM into a multi-week base and cargo lander. Why would they have included automated landing if they didn't intend to do more than land people? ...Future versions of Saturn, equipped with large SRBs most likly in addition to the J-2 TLI stage, would have been able to land many tons on the Moon in theory in a single throw, a Lunar base in a box. Alot more than you need for flags & footprints.

As for Skylab, it was built from old pieces and spare rockets... it was not that expensive. As for Mir vs ISS, which was originally SS Freedom with Mir-II parts glued on and some donated Soyuz rockets, yes alot of money was wasted... though I don't think it fair to say it was because Russia and America didn't cooperate. They are seperate countries after all.

"we need to work with the existing hardware and expand of it" Well i'm sorry but you can't, not for any reasonable sum of money with a reasonable level of risk. If anything, history has shown that the expendable route is quite sucessful with a limited number of flights... As for lunar transfer vehicles and depots and all that, thats going to cost a great deal of money. Where will it all come from?

comstar03 · 2004-08-26 23:56:13

GCNRevenger,

We are wasting money right now, we need to have a long term development approach not the expendable this and expendable that approach. The development of space is a long term cost therefore cost factors should be based on the long term approach, we need automated transfer vehicle not for 10+ mission or 100+ missions , but for 1000+ missions for earth - moon activities. Ground to LEO should be looked at the same way. Again the initial costs are large I grant that but, the long term running costs are reduced thus providing savings, most of the equipment, launch vehicles, and modules used today in space are short term, wrong perception to look from!!!!!!!!!!!.

Grypd · 2004-08-27 05:19:26

The problem with the ISS is it is falling apart. GCNRevenger is right in this. Even now occasionly large screeches similar to tortured metal has been heard to the crews aboard the station. The plans for the ISS have been changed and changed and each time cost went up. The ISS wont be up forever we will be lucky to get 5 years of use out of it left. We cant expand on the ISS as its frame will not take the stress given and it becomes dificult to move the ISS when altitude changes need to be done.

SpaceNut · 2004-08-27 06:52:16

Structural engineering would probably run an I-beam or truss the length of the modules and to tie each module to it to give it a more ridget support system rather than putting stress on the node inter connection points. But how would one get a continuous piece up to the station since no vehicle could bring up one of the appropiate length. All the more reason to do more than science at the station.

Commodore · 2004-08-27 08:26:24

There are other ways around the structural stress problem.

The problem is that the Soyuz/Shuttle is based at the very center of the of the station, with large truss peices sticking out like wings. The solution therefore, is to not just push at the ceter of the station. Place small thrusters at the end of the truss segments, and have them go off at the same time and appropreate rate to move them with the center part of the station instead of having them get dragged up.

A set of ion engines could probably keep the whole thing up permenantly without any outside help, other then refueling.

GCNRevenger · 2004-08-27 08:33:15

...we need to have a long term development approach not the expendable this and expendable that approach. The development of space is a long term cost therefore cost factors should be based on the long term approach, we need automated transfer vehicle not for 10+ mission or 100+ missions , but for 1000+ missions for earth - moon activities. Ground to LEO should be looked at the same way. Again the initial costs are large...

Making specific system-level decisions about very long term projects is a very dubious proposition, if you try and make a pitch for a project where all the systems needed will cost as much or more than ISS and take more than a decade or so to accomplish, then your plans will wind up like Bush-I's exploration initiative... $400Bn pricetag and taking too many years, and Congress just laughed. The lesson is, if you make your plans too ambitious and too long-term, then the project will never get support.

At to moment, when we are dealing with payload masses in the tens of tons and only occasionally in the hundreds of tons, and none of them very often, expendable launchers hold a large advantage because they are readily available. Building a real Space Shuttle would cost in the region of $20-25Bn dollars, where you could buy 20-30+ large HLLV flights with reasonable development or maybe >100 EELV rockets for that kind of money, plenty to build and operate a good sized base on the Moon or in LEO for a dozen people for a long time. There isn't any good reason to build a completly reuseable vehicle at the moment.

And in general, its sounding like your vision is too aggressive... vehicles good for >100 flights, major Lunar bases of dozens of people, huge >500MT space stations... there simply isn't a good reason for it at the moment. You might pull it off, and build such vehicles, but where will you get the money for payloads to put in them?

I would give the ISS about ten years from now, provided we get Shuttle back up and running soon and do serious maintenance with a crew of three, before it becomes a worthless deathtrap like Mir was. Major high-mass additions to the station's end nodes are a non-starter, there is no easy way to reinforce the stations' structure, which relies on the clamps between modules. Putting thrusters on the ends will also be difficult and would require periodic refueling, and I think would drive up the cost signifigantly. And if the thruster fails? Oh, no biggie, the piece will just break off...

Ion engines of practical size are too weak, the ISS weighs in at nearly 200-250MT... giant ones would consume too much electricity and introduce too much static charge to the station to easily compensate for.

SpaceNut · 2004-08-27 08:48:00

Speaking of adding more modules to the station, the Russian do plan on just that.

Russia to add new module to ISS in 2007
http://www.itar-tass.com/eng/level2.htm … &PageNum=0

GCNRevenger · 2004-08-27 08:54:48

One smallish module attached to the bottom of one of the nodes is not a big deal as far as dynamics are concerned, but adding very large hotel modules, associated logistics, big fuel depot tanks, spacecraft assembly trusses... doubtful.

It also seems there is now an answer to the lack of the US hab module.

SpaceNut · 2004-08-27 10:25:12

Would it be worth starting to lay any new modules in parallel to the existing station linking them together at the mid point and continuing to do so as each is added along the full length of the station. In addition bring up more gyro's to handle the additional loading weight of those new modules.

Commodore · 2004-08-27 10:49:03

It would be silly to trash the ISS untill a new station was up and running. Building them very close together would enable construction crews to work from and use some of the assets from the ISS to speed up construction.

SpaceNut · 2004-08-27 11:19:18

You are right in trying to get something for free in the reuse of the ISS. Though it it still be a long way off before any privately own corporation can send anybody to it.

GCNRevenger · 2004-08-27 12:22:13

Plus the ISS is at an unfavorable orbital inclination. Any new station ought to be placed in an equitorial orbit to minimize the payload penalty. The Russians are building a Soyuz pad in French Guiana, which I imagine could be converted to launch manned vehicles as well.

Commodore · 2004-08-27 13:15:17

Plus the ISS is at an unfavorable orbital inclination. Any new station ought to be placed in an equitorial orbit to minimize the payload penalty. The Russians are building a Soyuz pad in French Guiana, which I imagine could be converted to launch manned vehicles as well.

Was there a reason it was placed in the orbits its in?

John Creighton · 2004-08-27 15:10:10

All this talk about the demise of ISS and a disposable space program has me a little disheartened. I would of never recommended building the ISS but now that it is built I would like to see some good come out of it. I wonder if GCNRevenger is right that the ISS couldn’t be strengthened by a truss. Anyway, If the ISS is thrown away, and a new one is built lets discuss how to build it right. (Maybe in another thread though)

Clearly bigger modules are the starting point. Clearly inflatable are another obvious inclusion. Solar cells vs nuclear power can be debated. Solar cells are flimsily and take up a lot of space well nuclear power presents a radiation and a heat dissipation problem. I would like to see a space station that was structurally strong enough so that it could travel between earth and the moon. I am not sure how much more it would have to weigh, how much mass the engines would take and how much mass the fuel would take. A higher orbit would be nice but it would mean more of a mass penalty for re supply missions. Oh well at least by putting the station in an equatorial orbit some tradeoffs could be done.

GCNRevenger · 2004-08-27 15:37:56

The ISS was placed in its 51.6 degree orbit to accomdate the Russians, since their launch site is at a high inclination compared to Cape Canaveral. Russia either could not or would not improve their rockets so their Proton and Soyuz rockets could lift Mir-II and Progress payloads could reach equitorial orbit, so instead NASA came to their orbit by modifying the Shuttle external tank by lightening it to increase payload capacity.

Larger modules are obviously Item #1 on the list, at the very least, you could possibly get away with a station built predominantly from small 25MT launches if inflatable modules were used extensively, but bigger 40MT+ pieces ought to be the standard. Somthing akin to TransHab, but even wider at about 12m wide, and taller by using a partially colapseable core structure, and you could launch a great deal of volume for only one or two flights.

The logistics section would probobly be best built from aluminum coverd with heavy anti-meteroid shielding, and station OMS engines powerd by Peroxide/Kerosene rather than corrosive Hypergolics or unstable Cryogenics. The choice between solar power and nuclear power depend on what you intend to do with the station... The ISS has the huge truss it has so that the gimbaled solar arrays can turn to face the Sun without having to rotate the entire station.

This is important because if you have sensitive experiments, with crystals or bubbles or whatnot suspended in mid-air or mid-liquid and the station moves... the sensitive crystals will not, and will be ruined when they whack the sides of the container. This is one of the drawbacks of the Option-C station I linked to in the other thread, that it would have to move to aim its solar arrays... This is where the nuclear reactor would come in, so you don't have to fool with orientation at all, and it can supply a great deal of energy, but there is the radiation and disposal issue.

There isn't really much of a good reason to put the station into a high orbit, and it will weigh far too much to efficently place it on a Translunar trajectory.

Euler · 2004-08-27 19:09:29

Russia either could not or would not improve their rockets so their Proton and Soyuz rockets could lift Mir-II and Progress payloads could reach equitorial orbit, so instead NASA came to their orbit by modifying the Shuttle external tank by lightening it to increase payload capacity.

It is a lot more difficult to launch from a high inclination launch site to an equatorial orbit than it is to go from an equatorial launch to a high inclination orbit. It just isn't practical to try and launch to an equatorial orbit from Russia.

comstar03 · 2004-08-27 20:44:12

SpaceNut,

Interesting article, It also shows that all is not happy in the ISS partner Camp !!. I can see that the development of a long term crew exploration vehicles, lunar development and mars development could have major issues because of the issues with governments not getting along.

Single countries will also have issues in building a space program unless they look at cheaper alternatives, and then might get somewhere. Governments that build effective Enterprise Programs will develop successfully into space building a win-win alliance.

SpaceNut · 2004-08-27 21:10:32

As you noted with space, cost which must be lower in order to get industry to start investing. They also must have a place to call theirs to use as well in the mean time. Even if it is just an empty can with only the bare essentials to survive in it.

comstar03 · 2004-08-28 01:55:20

We need, 20+ Personnel transporter from earth to LEO; We need one way cargo vehicles from earth to LEO; and We need cargo transporters from LEO to Lunar surface go to surface then unpack based equipment and supplies and return to LEO platform for resupply, just to start with.

We design the one way vehicle to be modular for recycling when they are in orbit and be reused into space platforms, transfer vehicles. One of the first long term platforms in orbit will be a supply base to manage surplus engines and other modules from all one-way crafts.

Just think about those things

Grypd · 2004-08-28 03:23:57

We need, 20+ Personnel transporter from earth to LEO; We need one way cargo vehicles from earth to LEO; and We need cargo transporters from LEO to Lunar surface go to surface then unpack based equipment and supplies and return to LEO platform for resupply, just to start with.
We design the one way vehicle to be modular for recycling when they are in orbit and be reused into space platforms, transfer vehicles. One of the first long term platforms in orbit will be a supply base to manage surplus engines and other modules from all one-way crafts.

Just think about those things

All these where to be introduced as part of the original space station freedom. But as costs overun and Nasa's budget got slashed. The original plan was to have the Spacedock and Lunar transfer vehicles plus orbital tugs and construction pods. All this was dropped after review after review. When international partners came on board the designs where changed again and again. But the most cutting was done when it was only NASA planning to build it. It was NASA that got rid of the Tug, the Lunar transfer vehicle, the construction pod and the spaceport function.

The ISS as it is now is in the wrong orbit and does not have the design and capacity space to provide what is needed for a spaceport. It is doubtful that the ISS can actually handle all the stress we are putting on it now as some worried NASA engineers can tell you. It is putting out the signals of becoming another MIR with multiple fixes having to be done by the crew just to keep it working. Oh and there is that rather ominous noise that comes occasionly hinting at some other real trouble, Metal fatique maybe?

comstar03 · 2004-08-28 08:28:24

Gryd,

Yes, I know that the original design was a bit more expansive than the current ISS platform, the spacedock would be a bit larger than the existing space station or more. The most important objective should be long term LEO personnel, that means a gravity generated platform, to lower the return of personnel to earth and new crews launched.

A storage facility for unused modules like fuel tanks, engines, and other control modules. This storage facility will hold these components until they can be reused for short range vehicles or sent to the moon for use in other developed vehicles.

GCNRevenger · 2004-08-28 08:50:13

We need, 20+ Personnel transporter from earth to LEO; We need one way cargo vehicles from earth to LEO; and We need cargo transporters from LEO to Lunar surface go to surface then unpack based equipment and supplies and return to LEO platform for resupply, just to start with. And why do you want to put people into LEO for extended periods? Even with artifical gravity, the mind can only tollerate that for so long.
We design the one way vehicle to be modular for recycling when they are in orbit and be reused into space platforms, transfer vehicles. One of the first long term platforms in orbit will be a supply base to manage surplus engines and other modules from all one-way crafts.

Just think about those things

Much too ambitious... the question begs, why do you need to put 20 people into orbit per-flight? Ultimatly, no, we need reuseable Earth/LEO vehicles if we intend to do more than science, but those days have yet to come. At the moment, expendable rockets are the clear choice.

A fully reuseable LEO/Luna cargo shuttle will also require a great deal of fuel, even cryogenic fuel, to deliver modest masses. A good way to minimize the fuel bill would be to deliver payloads into Lunar orbit by a Solar/Ion tug fueled by Krypton or Cesium or perhaps a NTR nuclear tug fueled by Hydrogen. Base reuseable landers in Lunar orbit, initially fueled from Earth but later by Lunar fuel, to shuttle cargo or people to and from the surface.

We are far, far, far away from making "recyclable rockets" that can be converted to anything useful in space, so I would get that idea out of my head right away. And, for the time being, its looking like the best route to deliver payloads to the Moon is with a more traditional fully expendable lander, built to minimize cost and dry mass per mission.

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