Houston (SPX) Sep 30, 2005
IN his Op-Ed "Here We Go Again" in Space News: (Monday 9/26/05), Rick Tumlinson makes some good observations on Dr. Griffin�s approved version of the Space Exploration Vision Architecture. I generally agree with Rick's position but a few clarifications do need to be made.
Overall, I am saddened by the lack of a truly integrated, efficient program design; no true space transportation system synthesis is apparent, such as one with clearly defined goals driving the design. Instead, what Griffin seems to have accepted from the 60 day study are components seemingly designed for a temporary program, like an Apollo 2.
Of course, we should not be doing anything like Apollo 2, since it will seem to be just a repeat of what we did almost 50 years ago. There also seems to be no attempt to hold operating costs down for the long haul so that the program is financially sustainable.
Griffin is the perfect man for the job and he really believes in the importance of eventual human space settlement. He has had the integrity and guts to just say what should have been said decades ago: "The Shuttle and Space Station are mistakes as built and orbited".
It is incredibly hard for me to criticize him right after he made this epochal and true statement, but, then, why did he also say recently: "Of course, the lunar lander is expendable"!
He certainly must understand that expendable architectures cannot in the long run sustain a permanent space exploration and development program. What is the point of developing fuel sources on the Moon if the vehicles to be re-fueled are expendable?
The answers may be multiple. One reason could be that he lacks the sense of urgency for the space Vision that many of us feel. If a space civilization is not achieved within some reasonable time frame, natural or human-caused catastrophes could do to the human race what will happen eventually to any one-planet or one-island species we will become extinct.
Economic, social and political forces could also so long delay our effective emergence into space that we could become unwittingly trapped into being a one-planet species, just as the people of Easter Island trapped themselves when they cut down the last tree on their island.
We also may not know what kind of political pressures that Griffin is under. It is a sheer wonder that so many of the petty bureaucrats have already been removed. He must be performing a very delicate balancing act here and part of the bargain may be to "feed" the aerospace giants.
In addition, (in my opinion), the engineers who did the 60 day study (and the earlier studies it drew on which were done during 2004 and early 2005), were honest, competent and fair, (as shown by their pragmatic support of the unpopular large HLV path), but they had to follow the rules as their bosses laid them out. They could not consider options which they were not told to include. If Griffin had been able to get in place just 1 year earlier, I suspect the projected architecture would be quite different. Maybe he could suggest to the next phase contractors that they try to extend the architecture as far as practical in the direction of re-useability.
Here is my assessment of the current plan. First, I consider Griffin a hero for championing the Big booster pathway over the objections of so many critics. We need a Big rocket to deliver large, integral, ready-to-use payloads.
The problem for the long run is not that the rockets are big, but that all of them are going to be built by NASA, when (at least for the Heavy Lift Vehicle (HLV) itself), there is plenty of time before it is needed for it to be built by entrepreneurial industry.
If it is not needed until at least 2015, we would have a full 10 years to develop a privately owned HLV under fair competition, once some assurance is given that a set minimum number of launches will actually be paid for within a set period.
I strongly back the use of big HLV's over the smaller EELV's for support of Lunar missions, and have full confidence in his proposed designs, but would prefer to see a practical path (actually enunciated by Griffin as official NASA policy), to replace the NASA HLV with private HLV's at some point. This may happen once the required launch rates to support a lunar program are proved, or probably when people finally realize how much you can really do with a real HLV.
Another problem is that much of the proposed HLV itself is not recoverable. Something very similar to the ET-derived 125 ton mega-booster could use flyback or otherwise recoverable strap-on stages instead of the very expensively refurbishable solid boosters.
There are many described ways to recover large first stages that have not ever been attempted by any company. The DCX method worked fine for 9 tries, with no redundancy at all. Pretty soon, more of those ways will be demonstrated.
I also disagree with Griffins position that we cannot rely on private industry alone for transport needs, but we definitely do need more than just one means of access to space.
The HLV problem is as much about what is it will be used to launch, as who builds it. Just because it is NASA-built does not automatically make it of "limited use", except by the "limited" minds of the bureaucracy, and of course very strongly depending on the actual operational and launch costs. There is such a wealth of very useful things you can do with a really big HLV that I do not need to spell them out here.
In this regard, I was actually far more worried about the lack of re-usability for the in-space vehicles than in the boosters, and my biggest fear has come true: they are going to build the "giant expendable LEMS" that I presented as a bogeyman / worst case in my article in the forthcoming S.F.F. sponsored book "Return to the Moon".
Well, the bogeyman is now alive and waving his arms. 50 years after the original LEM (Lunar Excursion Module) was flown during Apollo, couldn't they at least build a re-usable one? I just do not think we will be able to afford to use "giant expendable LEMs" to do very many lunar missions before Congress decides that it is pointless and un-affordable. Just how many of them can we afford to build before they shut down the assembly line forever and terminate the program?
With the big HLV available, the design for a lunar cargo lander could be evolved into one for a fully re-usable lunar ferry. If it carried a smaller payload, it could use the heavy lunar oxygen and a little of the light earth-supplied hydrogen to set up a successful fuel supply cycle.
Of course, this entire fueling system would be installed only at bases which we wanted to occupy for a long time. This phase of course could also not be done until production-size In-Situ Resource Utilization (ISRU) equipment is available and running on the lunar surface, not just pilot-sized units. This need for fuel reinforces the importance of funding the development of ISRU equipment in parallel with the vehicles. Without it , the program is just another Apollo 2. However, this is one area where the plan seems to be on course.
It is also noteworthy that the lunar crew vehicle has in-flight abort capacity as long as it does not leave the landing stage behind. As soon as it does so, it has no additional abort capacity. In at least that respect, a re-usable lander is safer than an expendable one. After takeoff from the lunar surface, the "crew module" (comparable to the LEM ascent module) would then have the option of aborting to lunar orbit if the main lander module (comparable to the LEM descent module) malfunctioned at any point. By simply replacing the crew module with a cargo object or cargo canister, you also get a re-usable cargo lander.
Of course, this says nothing about how dangerous it will be to use a brand-new - untested lander on every mission. I fully realize that the problem of using valuable crew time in space to service the re-usable landers would be a major issue.
However, surely the second time one is used, it must be safer than the first time, when, acting as test pilots, the crew finds out if the thing has any hidden flaws. Such vehicles would probably have a limited service life of 5 or 10 missions, since no substantial servicing could be done in space as can be done on Earth. We also have a full decade to develop ever-more efficient and reliable self-testing and inspection systems for the deep-space vehicles.
A study would need to create a mission reliability curve to determine the appropriate service life, based on overall failure rates of ground-tested components. When the projected reliability per mission returns or drops to the level of the first use of each vehicle, then it should be retired but kept protected on site as a source of spare parts. Even using each lander just twice would save almost 50% of the lander production run costs.
When you have a re-usable vehicle, you need a depot or garage to store, protect and re-fuel it. just like a train or truck on the ground. There seems to be absolutely no consideration given to using such depots as critical components of an at least semi-permanent lunar transport system.
Thanks to the HLV, integral, complete and ready-to-use depots could be easily launched into LEO, GEO and near-lunar locations. Such depots could also serve as crew refuges in an emergency. They should also have the capacity to wrap a lander in a thermal blanket to protect it from thermal extremes and micro-meteorites. A similar simple tent shelter capacity for the lander should also be provided on the lunar surface.
AS far as the mission profiles go, I strongly urge us to push for a policy that puts a habitat module/refuge on the surface first at each manned landing point. No manned mission should ever set down without a refuge/hab already present at the site. (This thinking parallels Bob Zubrin�s Mars Direct concept).
Missions to early outposts (even those that will not be re-visited), should all test some kind of ISRU equipment. This means that BOTH the hab unit and any prototype ISRU units will need to be developed in parallel with the human lunar transportation system, or it would prove that NASA is only interested in "Flags and footprints" again.
For these reasons, I support this schedule for items landed at a lunar site (others have proposed similar lists).
I am similarly distressed that every time a CEV will be used, it will depend on a untested, brand new service module. Why could they not design a system that would preserve the service module for further use? The CEV (crew module) should in fact separate from the service module only in an emergency. Currently, all we will be getting back intact after a mission is like Apollo: just the crew module, nothing else.
This whole situation is the same as a tendency I described in an article almost 20 years ago. The danger is that the managers of any new exploration program (once declared and approved) would have the tendency to rush to build the hardware to get the program underway, and result in the building of expendable deep-space hardware.
It is indeed a paradox that we are (again) rushing to develop expendable boosters and space vehicles when there is in fact no need to rush. The risk of doing it this way is that (of course) the funds to run the assembly line(s) can be cut off eventually. Right now the Media are howling to cut off the "Moon" program to fund Gulf Coast reconstruction and the politicians listen to the Media. We better show them clearly and soon that we are not just repeating Apollo.
One additional benefit of re-usable vehicles is that you can put names on them, (politicians find it harder to throw away a vehicle with a name) and you do not have to run the production line all the time.
If we could spend just a couple more years (and we have the time) to design re-usable deep-space craft, it would be much easier and cheaper per year to maintain a lunar program. If we could then start launching the CEV on a re-usable commercial booster, the only expendable component would be the stage that sends the entire lunar stack towards the moon, and even it could be re-designed into a re-usable trans-lunar vehicle.
There are possible ways out of this problem. Since work on most of the lunar architecture will not start until 2010 or later, there will be several years where it may be possible for the space community to jawbone Griffin and persuade him to either approve a re-usable lunar lander with a lifetime of at least 5 missions, or commission a study to prove why or not re-usable spacecraft are a bad idea.
We need to find out how much each expendable service module and each expendable crew or cargo lander is actually going to cost. We need some kind of estimate for the cost of a single lunar mission (all components specified).
This would give us the approximate annual cost for lunar missions assuming that at least two are flown each year. If the costs came out high enough, some company might even propose a plan for using re-usable vehicles itself!
We should now all work to see that any real space exploration and development program actually goes somewhere, actually does something, and does just not come home again and stop when it is finished, but instead continues on to the next stage (such as Mars exploration), of building the fiscally self-supporting and expanding space-faring civilization we really need for long term human survival.
John K. Strickland Jr. is a Analyst/Programmer for the State of Texas and is an Advocate with the Space Frontier Foundation.
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Doom And Gloom Won't Sell Space
Honolulu HI (SPX) Jul 13, 2005
Teaser: Today's pro-space activists are failing to gain political traction because they are locked into gloomy worldviews that are 30 years out of date and incomprehensible to the average 21st-century voter.
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