The wrong stuff.

[frodo1008]

Sure, all government spending isn't a conspiracy or evil, sometimes it is very good indeed. Support manned space and NASA.<br /><br />Finanlly, these issues are not short sound bite issues!<br /><br />Good enough?

 

[starfhury]

First I don't think anything planned in VSA is really going to make it to Mars. Let's see. The CEV is going to be how big? I think it's going to be good enough for the Moon, but have no real purpose out to Mars. Why? Well, I don't imagine the astronauts are going to be happy camped out in such a tiny space for months on end. If they will not be staying in the CEV for the mission out to Mars, then why bring the CEV along? You're hardly going to need it at Mars because you'd need only the mothership and a lander. The only place the CEV might have a purpose on a Mars trip is the return to Earth after the trip from Mars. And why bring it all the way to Mars and back? VSE/CEV is a cheap filler program that does not accomplishes much. It's rehashing what was done with Apollo, and it's not pushing any technological here in doing so. It's going to use the most inefficient part of the Shuttle technology, the SRBs. It's going to use parachutes and ablative shielding, same as Apollo did. About the only advances are in materials and avionics to save weight. In the mean time we're going to loose the capacity to put more than four people into space at a time. We are going loose just about all down mass capability. We are going to have a minimum of two launches to do anything. So while each individual mission might be cheaper, the two or more required might push the cost well beyond what we are already paying. Tell me, how is this a better way forward? So we get to put four people on the moon for two weeks once maybe twice per year. How is that not an exclusive business for the most limited customer base? <br /><br /> I view it as uninspired and "the wrong stuff." Apollo accomplished greatness because it was fresh and supremely challenging. To steal a line right out of Star Trek, "Apollo dared to go where no man had gone before." If this vision was to go directly to Mars, I might be more impressed and inspired by it. But if we are not going to do inspiring an <div class="Discussion_UserSignature"> </div>

 

[darkenfast]

We seem to be going through the same issues again because people aren't bothering to actually read or understand the ESAS report. <br /><br />The Mars effort is down the line quite a bit, so the team did not get too specific about it because the main thing was to get started on building up a realistic and affordable foundation for missions past LEO.<br /><br />Items that will be essential for the Mars mission include the 6-man CEV, which will be well established by then. It will carry the crew to the Mars vehicle, being launched on a CLV (also well established by then). The Mars vehicle will have been launched on CaLV's (another well-established launcher by then). The CEV will go along for the ride, but will NOT be "camped out" in for months at a time. This has been repeated over and over again, yet keeps coming up as yet another reason to bash the ESAS report. The CEV will go along so that it can be used to re-enter and land back at Earth at the end of the mission. Slowing the whole spaceraft down into earth orbit to be met by a second CEV (thus avoiding carrying the first one there and back), was not seen as viable, especially in various abort scenarios. <br /><br />So, out of what we've seen proposed for the Lunar missions, the LSAM is the only article which at this time appears to not be useful for the Mars mission directly, although the experience in building and operating it will help in the long run. That there will be changes and evolution in the various components (such as LOX/Methane) goes without saying.<br /><br />The people who developed this do appear to actually have some brains, even if they are not as appealing to the Space Cadet crowd. This is a viable program that will be useful for decades, and has already come closer to fruition than anything else to come along in a long time.

 

[spacefire]

if a cheap capsule delivery is privately developed to shuttle people to and from orbit, an option now endorsed by NASA, then logicaly the CEV is going to be used ONLY for lunar missions. Assuming the private firms are succesful, there won't be a need for another capsule.<br />the CEV should become a spacebased ferry, basically a space station-like module with extended life support and maneuvering capabilities. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[no_way]

>>I can not see NASA flying their astronauts commercially to the ISS. Why not ? if the service is available at low enough price and otherwise acceptable parameters, what would justify flying on more expensive vehicle ? NASA doesnt run its own airline to get people here and there, why would they do so with LEO transportation if commercial service is available ?

 

[spacefire]

actually they did have their own airline for a while and there was a big scandal <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[no_way]

you are talking "astronauts" while is was saying "people". people like scientists. i assume mainly scientists will be the ones working on ISS once its complete, no ? i thought thats the main purpose of the ISS. i dont see why scientists would have to pilot their own vehicles ?

 

[frodo1008]

For once I have to (with one major reservation) agree with the pure private industry types. IF (and that is the reservation) companies such as spacex can develop an inexpensive (I don't like the connotations of the word "cheap", as it sounds like a compromise to safety and reliability, which for spacecraft are all important) capsule type of system for getting into LEO, then not only NASA, but the other partners that don't have NASA's funding would almost certainly use it for trips to at least the ISS! The operative word here being "IF". After all, NASA is not going to want to be the only access to the ISS, as NASA will not wish to continue to be the main source of funding for the ISS, for its entire future.<br /><br />However, the development of the CEV is still very vital to going beyond LEO, and if the pure private interests should fail (just look at the problems that spacex has had getting a Falcon I launch off the pad) which is a possibility, then NASA with the CEV becomes the insurance policy, now don't they? While NASA may very well not be the least expensive option, we KNOW that they will develop a viable vehicle. NASA has the experience, and the ability, and the very necessary funding, to do this. <br /><br />Coming back from either the moon or Mars is going to require a vehicle that can enter the Earth's atmosphere at a far higher velocity that just coming back from LEO. As darkenfest says in his excellent post, even the LSAS will have to be used as a model for the development of a similar Mars Lander. Such a vehicle is going to be needed to get to and from a Mars orbit to the surface of the planet. I am not totally certain here (I have his excellent books in my possetion, but haven't read them for some time now) but I believe that even Dr. Zubrin's Mars Direct plans called for such a vehicle.<br /><br />It is my own hope that both the pure private efforts and NASA’s are fully successful. After all even Elon Musk wants NASA to fund his companies “Dragon

 

[frodo1008]

While I still believe that NASA should develop the CEV as originally planned, as we KNOW the NASA can do this, and the pure private interests are a relatively unknown quantity at this time. <br /><br />However, your idea for a pure space transport vehicle for travel between the moon and the Earth (and even such travel between Mars and the Earth in the long run) indeed has great merit. <br /><br />Such a vehicle would have great advantages over a vehicle that would have to land on either the Earth or the moon. It doesn't have to be streamlined in any way, as it will not be going through any atmosphere. Heck, it would be best for it to be the most efficient shape, such as a sphere (shades of "2001"). It wouldn't need very powerful engines, so it could be powered by very fuel efficient plasma gas types of engines. There would be many such advantages to such a craft.<br /><br />See, you can indeed make truly useful additions and posts to these discussions! Now, if you would only lose the sarcasm, which is more appropriate for free space than M&L. Please do that and I will be happy to sing your praises!<br /><br />So this time I really mean it, Have A Great Day!<br />

 

[vt_hokie]

Well said, starfhury!

 

[spacefire]

<font color="yellow">See, you can indeed make truly useful additions and posts to these discussions! Now, if you would only lose the sarcasm, which is more appropriate for free space than M&L. Please do that and I will be happy to sing your praises! <br /><br />So this time I really mean it, Have A Great Day! </font><br /><br />just for you, I will admit that my sarcastic attitude comes in part from personal career frustrations. At the same time, I am rather unhappy with the CEV approach and will continue to criticize that. I think NASA is somewhat redeeming itself by attempting to fund private efforts and commercial launch services. <br />We shall wait and see if these startups are allowed enough autonomy to conceive great designs that will lower the cost of space access.<br /> <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[frodo1008]

I too, would like to see a lifting body type of design. However, at this time (and for development cost considerations) I can see why NASA is going with the capsule design instead. Please note that both of the leading companies: spacex of Elon Musk, and t-space of Burt Rutan are also going with the less expensive capsule types of designs.<br /><br />Perhaps in the more distant future will see true lifting body designs for travel to LEO. Heck, I am such an extremist that I would actually like to see large horizontal take-off and landing craft like the original NASP design. It would power up on conventional jet engines, and with a brief boost of its rocket engines get to the staarting velocity for its built in scramjets. Then it would either become a sub orbital vehicle capable of getting to anyplace on the Earth in less than two hours, or igniting its rocket engines (the linear aerospike engines would even fit the shape of such a craft far better than conventional nozzles). rocket into LEO! How's that for radical?<br /><br />I really think that Burt Rutan and company are going to pursue this route eventually. This is because while a capsule system is needed now, it is purly a utilitarian, and inexpensive solution. However, true space tourism is going to require a far more comfortable vehicle. A much lower gravity profile vehicle (I would say less then 2 g's) and windows! This is becuase the first such relatively ordinary (and rich) passengers will demand such comfort, or they won't go!<br /><br />However, a whole lot of research is needed to make this happen. I see where the military has become very interested in hypersonic flight. Good! they have the necessary funding to make it happen. Then someone like Burt Rutan can run with it!<br /><br />However, in the meantime the capsule designs of NASA and possibly the private concerns will do just fine!<br /><br />Thanks, you are far more effective without the sacasim! Don't let your private feelings interfere with you

 

[spacefire]

The problem with the CEV is that it is not pushing the cutting edge enough to make a difference.<br />it's lunar/deep space capabilities are too modest to justify a new program.<br />however, the expenditure in terms of access to LEO using the CEV is rather high, and right now we're not even talking about the HLV.<br />I see the wisdom of NASA developing its own system AND asking the alt.space companies to do it also. <br />Yet in this non-competition, NASAs design should at least be radically different such that the two emerging spacecraft can complement eachother. <br />Should the CEV retain LEO delivery/return capabilities, it should at least feature either a HL capability or be capable to carry astronauts to Mars-which would require, indeed, a big heavy capsule, but since NASA is at the same time developing the HLV, why not? That was the plan initially.<br />NASA is &%$#@!footing right now and the ESAS strongly smells like make-work.<br /> <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[starfhury]

Frodo1008:<br />"I really think that Burt Rutan and company are going to pursue this route eventually. This is because while a capsule system is needed now, it is purly a utilitarian, and inexpensive solution. However, true space tourism is going to require a far more comfortable vehicle. A much lower gravity profile vehicle (I would say less then 2 g's) and windows! This is becuase the first such relatively ordinary (and rich) passengers will demand such comfort, or they won't go!"<br /><br />I agree on that score. The thing is, space is too exclusive. And ESAS and CEV are going to continue that trend. I don't need to read ESAS in fine detail to understand their over arching goal. My view is simply this: "We must make more powerful and efficient propulsion systems." If we could some how consolidate the power of three SSME's into one, this would represent a greater leap forward than anything the ESAS program presents right now. In fact, I think if we had that right now, ESAS would fly forward at greater speeds. Aside from Falcon's Merlin which could fly later this year, there has not been any serious development in better flyable engine technology for decades. The linear aerospike failed and so did Beal Aerospace in creating their near Saturn class motor. They never got of the ground. My arguments are not so much against the capsule design in and of itself but what it represents to have to resort to using the capsule. We are using it to avoid doing the real necessary work of building better propulsion systems which will truly enable us to perform LEO, Lunar, and Mars missions without trying to cut every other corner known to man. I think the country or company who manages to develop the next generation propulsion system and employ it to good effect will eventually reap an unprecedented windfall. <div class="Discussion_UserSignature"> </div>

 

[no_way]

<blockquote><font class="small">In reply to:</font><hr /><p>NASA developing its own system AND asking the alt.space companies to do it also. Yet in this non-competition, NASAs design should at least be radically different such that the two emerging spacecraft can complement eachother. <p><hr /></p></p></blockquote> I have two hypotheses to offer. First, NASA is absolutely sure that nobody but them can pull of a manned space transport ( the last time they did was decades ago ) so they dont think that private industry will actually step up and provide the manned LEO capability. In this case i think they will be honestly surprised. Second possibility, they have no intention to follow through on COTS program and will pull the plug sometime in next few years like they did with Alternate Access to Station program once before. But this time there are a couple of serious players involved from industry that can probably finish their projects on their own money ( IF following NASA guidelines does not break the bank before ) and still start offering the service in a few years. IOW, what NASA is doing is largely irrelevant to getting private manned LEO launch capability online. They could speed it up and support a bit, which i hope they will. this means that CEV as envisioned will be very likely partly redundant. Which in itself is not a bad thing, having as much diversity in space launch capability as possible is good, except in CEV s case it will probably be hard to justify the comparative expense for LEO launches.

 

[spacefire]

if NASA develops a more advanced CEV, they will still have that for LEO access in case the private industry fails.<br />It will just cost more to fly, but we won't be left without a spaceship.<br />Personally I'm confident that the private industry will succeed in developing a low-cost LEO ship. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[frodo1008]

I think that you have been misinformed on a couple of points. One, the linear aerospike did have some problems, but these were worked out by Rocketdyne and the last test series exceeded expectations! I know this as I was still employed at Rocketdyne at the time.<br /><br />A new liquid hydrogen/liquid oxygen engine whose development was driven by cost was also completed before I retired in the year 2000. This was the highly successful RS68 which develops some 665 k of thrust.<br /><br />By the way, the X33 was cancelled not because of the linear aerospike, but because of problems with the propellant tanks.<br /><br />As the SRB's have shown themselves to be very reliable since the fixes to them after the Challenger, and they are a known relatively low cost item, then it makes very good sense for NASA to continue to use them on the CEV. It is going to take very little extra development and testing to go from the four segment SRB to the five segment SRB (which, from what I have seen has already been tested at least once). <br /><br />Originally, the upper second stage of the single stick CEV (which is to be developed first) was to be powered by the equally reliable SSME, but it would have taken extensive re development and testing to make these engines (which are certified to be started once on the launch pad) to be able to be started in flight as a second stage engine. So now NASA is going to use two of the equally reliable J2S engines which were developed and tested from the original J2 engines, five of which powered the second stage of the Saturn V. These engines are already available for at least the first few flights, and will be relatively easy for Rocketdyne to restart manufacturing on.<br /><br />So, between the very reliable RS27A engines used on the Delta II which has , and will continue to launch most of NASA's robotic probes. The newer, but equally robust RS68 engines used on the Delta IV, the Russian designed (and equally robust engines) engines used by LM

 

[nacnud]

Quick note: I think the CLV or Ares I will use one J-2S rather than 2.

 

[edkyle98]

"So, between the very reliable RS27A engines used on the Delta II which has , and will continue to launch most of NASA's robotic probes. The newer, but equally robust RS68 engines used on the Delta IV, the Russian designed (and equally robust engines) engines used by LM on the Atlas V, the engines used on the highly successful Zenit rockets used by SeaLaunch, The great SSME's (still the most advanced rocket engines for performance in the world) which will finish up their great careers on the remaining shuttle flights, and then go on to being one of the major power sources for the new HLLV's for going back to the moon, and finally the now very reliable SRB's, what more could we want at this time? "<br /><br />The up-thrusted RS-68 is a terrific idea, but there <br />may not be a rocket for it to fly on.<br /><br />With the end of Delta II not necessarily in sight but <br />at least dimly approaching, with the rumors about <br />Boeing dropping Delta IV, and with SSME being bypassed <br />for CLV and only proposed for use on a big launcher that<br />might get built, someday, if funding becomes available and<br />if the next President doesn't decide to cancel the whole <br />deal, it seems to me that the U.S. is in danger of losing all <br />of its remaining high-thrust liquid booster rocket engine <br />capability.<br /><br /> - Ed Kyle

 

[frodo1008]

I read where Burt Rutan has stated that Virgin Galactic and his company will not be able to actually start tourist travel to even sub orbital flight until 2008. This seems to me to be a reasonable estimate. However, in order to even get the funding (from purely private funding sources) to go on to building and testing any kind of vehicle to go to LEO, they are going to have to establish a very good reliability record, and just as importantly show that sub orbital flight itself can make good profits. This will mean perfect flights and very satisfied customers until at least 2010. <br /><br />I am certain that some relatively inexpensive paper studies for LEO vehicles could be done in the meantime. However, any actual manufacture and testing of real vehicles is going to take a considerable amount of funding, either through NASA or private sources. If NASA funding they may even be able to get something together about the same time as the CEV is ready. The difference is that the CEV is a known quantity, and other systems are not. So what NASA actually is doing (besides the CEV being the vehicle for going back to the moon) is to act as an insurance policy in case these relatively unknown vehicles don't materialize. <br /><br />Just to illustrate this, notice how much Elon Musk and spacex are learning about the difficulties of even launching a small rocket into space. Despite what some on these boards (many that have never been in the business itself) may say, this is a very difficult business to get into. Not because of some government conspiracy, but because of the nature of the physics involved! <br /><br />For instance, I have also sometimes questioned the large amount of paperwork involved in building large thrust rocket engines. As far back as my work on the small engines for the Apollo Capsules back in the 1960's, we used to joke that they could just pile the paperwork up and have the astronauts climb to the moon! However, when working on large engines I sa

 

[vt_hokie]

<i>Just to illustrate this, notice how much Elon Musk and spacex are learning about the difficulties of even launching a small rocket into space. Despite what some on these boards (many that have never been in the business itself) may say, this is a very difficult business to get into. Not because of some government conspiracy, but because of the nature of the physics involved!</i><br /><br />I never had a problem launching my cardboard and balsa wood Estes rockets! What's so hard about it? <img src="/images/icons/wink.gif" /> <img src="/images/icons/smile.gif" />

 

[strandedonearth]

"I never had a problem launching my cardboard and balsa wood Estes rockets! What's so hard about it? "<br /><br />Try that in the days before Estes developed their compact pre-fabbed solid model rocket motors, when would-be rocketeers were blowing themselves up in their basements and backyards <img src="/images/icons/wink.gif" />

 

[starfhury]

That was plenty information. Some of it I already knew. I think the X-33 site existed even before SDC. So I've been following this stuff for a while. As a veteran who worked within the field and directly on some of these vehicles and engines, I'm sure you have better insight into the difficulties involved building rocket technology. But I'm sure because of this you would agree that our biggest limitation in going to space starts and ends with those rocket motors. I will speculate that if it were possible for us to build an engine delivering three times the thrust of an SSME for the same prop flow rate and engine dimensions, then that would be more valuable than going back to the moon by 2018 using CEV technology. The RS-68 motor does not deliver those kind of specs, neither does the Linear Aerospike. I don't believe it's impossible to build such a motor. It would be very difficult. It might be akin to the invention of the FanJet for commericial aviation, but that kind of performace would be a great enabler. <br /><br />Where in ESAS are funds allocated for building better motors? They have already cancelled the proposed methane motor. They have already dropped using the SSME for the CEV SM stage. Am I to believe using the J2s from the Saturn is the best we can do? The money and talent that's being directed into CEV/shuttle complex should be directed towards building better motors even if it'd cost us five to ten years of manned space flight. <br /> <div class="Discussion_UserSignature"> </div>

 

[frodo1008]

There are physical limitations to doing what you suggest in increasing the thrust of an SSME. There are only two ways of even attempting to do this. One would be to increase the chamber and turbopumps pressures to a far greater value that they now have. Temperatures and pressures that are already on the very edge of what even computer dynamics say that we can possibly do here. And the limitations of the physical parts themselves are not even going to come close to allowing this kind of increased performance, at ANY cost!<br /><br />In fact the Block II engines actually lowered the pressures (still keeping the same thrust) by doing the opposite of what you stated here. The pressures were lowered to increase the safety margins of the engines themselves by a considerable margin. However, this was mainly done by increasing the throat diameter (the smallest diameter of the exit flow of the engine) by some 0.500 inches. I know this doesn't look like much in a throat diameter of some 18 inches, but believe me it does make a great difference in the chamber and turbopumps pressures, and hence in the safety margins of the engines! <br /><br />The only other method of improving performance is to use a fuel and oxidizer combination with a higher ISP (specific impulse, which is sort of a rocket engines “miles per gallon” so to speak). The only combination that is higher than the SSME's liquid hydrogen / liquid oxygen combination would substitute liquid fluorine for the liquid hydrogen. This was tried back in the 1960's by Rocketdyne in some test engines that were fired up at Santa Susana test labs. The problems with this combination were in the liquid fluorine part. Liquid fluorine is not only fantastically toxic, but it is also very, very sensitive. Just ordinary light can set off a horrendous explosion! Also every line that comes in contact with such a corrosive and toxic material must be very thoroughly passivated first. Passivation being a process that uses a sma

 

[no_way]

the physics of getting to space is hard ? so is getting to air .. if you live in year 1900 or so<br />i will make a repost of someones brilliant text in sci.space.policy:<br />http://groups.google.com/group/sci.space.policy/msg/42b31f8698839238<br /><br /> /> There is an enormous gap between building a plane, something two<br /> /> brothers could do by themselves with some materials<br /> /> from a bycicle shop in 1905, and building a spaceship, something<br /> /> nobody has done in a garage.<br /><br />It's a far different world now from 1905, with many things much easier<br />now and some things harder. There is far more information available<br />now, but also a lot more public scrutiny and criticism.<br /><br />If the Wright brothers had posted their 1903 plans on the internet:<br /><br />6 posters would criticise their front mounted elevator as unstable and<br />dangerous,<br />8 more would consider the chain driven propellors as heavy and<br />unreliable,<br />3 human factors engineers would rate the hip operated controls as<br />impossible to learn,<br />1 of them would decry hip wiggling as lewd and immoral, and likely to<br />bring down the wrath of the Almighty,<br />18 engineers would show that aircraft needed large amounts of energy<br />merely to stay aloft, while balloons needed none,<br />29 historians would point out that balloons have been used successfully<br />for over a century, but that no one had ever flown an airplane. A<br />debate would arise as to whetger this was due to the laws of physics or<br />a plot by the balloon industry.<br />16 balloonists would note that a ten foot altitude was only 0.05<br />percent of 20 thousand feet, so even a sucessful flight would be<br />meaningless,<br />17 fanboys would claim that the Wrights were the greatest visionaries<br />since Leonardo da Vinci, and predict transcontinental flights within<br />five years,<br />3 environmentalists would point out that gasoline is polluting while<br />hydrogen is environmentally wonderful.<br />