If NASA's Ares rockets are dead, what should NASA do?

[scottb50]

Hey come on scott50, please do not post such a sarcastic statement as:

"Thank you for your support; The SDC Department of Redundant Redundancy."

We should really make an effort to keep our debates on a nicer level that that!

Besides which, being as dense as I am, I really did not understand your reference there. It would automatically be less sarcastic if you would take the time to explain.

Besides which, I am more than happy to entertain any and all suggestions. And R1 was merely pointing out other possibilities here.

I was commenting on the five identical posts not the post itself. It was supposed to be a funny comment not an attack on someone.

As far as the Jupiter proposal I would say it is not much different then the ARES and I would expect ARES is quite a bit further along in development considering it has funding available.

 

[jimglenn]

The LM used a pintle injector engine, different than other engines. It is simpler and provides some
flow advantages, and may be more reliable. I think the Falcon works this way. Some nice pictures
for hard core rocket fanatics. And history. :ugeek:

http://www.st.northropgrumman.com/capab ... perAIA.pdf

 

[frodo1008]

Looking at your site it must have been the lunar module ascent engine that was manufactured by Rocketdyne. TRW made the decent engine, and it was a very good one! After all, twelve great men both landed, and then successfully took off from the moon!

Actually, Rocketdyne was not NASA's original contractor on even the ascent engine. The original contractor was Bell. Rocketdyne had a very good engine, but Bell promised a manufacturing plant in Texas (you know, LBJ's home state, politics was even played on such a project as the Apollo!). But Bell kept dropping the ball, and dropping the ball, and dropping the ball. They may have made very good helicopters, but had absolutely zero experience in rocket engines!

It got so bad (and this may very well be just one of those aerospace myths, but it does fit the actual eventual facts) that the moon bound astronauts themselves stated that they did not wish to go to the moon, and get stuck there with an ascent engine that did not get them back off of that body!!

So NASA just had to ignore politics and give the ascent engine contract to Rocketdyne after all. And boy oh boy!!, did that result in a donnybrook of a fight between NASA, Rocketdyne and Bell! In order to save some face, NASA told RocKetdyne that we had to use at least what little that Bell had already done, after all wasting some $400 million even back then, was not something that NASA wanted to admit to. Bell very reluctantly turned over such items as the physical valves control system that they had developed, but would NOT turn over the blue prints to it!

I know all this as I got involved when the company (rocketdyne) then needed to find out just how "dirty" these valves were to operate. In fact, I was told they even had to take at least one such system apart just to get the measurements of it! I was working in the clean trailer at CTL IV at Santa Susana Field Laboratory (SantaSu for short). Manufacturing personnel brought this terribly complicated valve system in and we had to cycle it so many times and then take particle count samples of the fluids ran though it (I think it was the isoprophyl alcohol that we used for cleaning purposes). It was indeed relatively filthy, especially in comparison the the small valves on the RCS small rocket engines that we were then used to! Rocketdyne's engineers and manufacturing people then had to rework this system to even make it work well, and then the samples came out much better.

The cost of politics on even such a fantastic and worthwhile of a project as Apollo were not such a good thing!

 

[jimglenn]

What do you mean by a "dirty" valve? It has contamination? Or the tolerances are loose? What
kind of problems did you run into with handling cryo plumbing, this was the cold fuel, right?

Bell made the rocket belts I think, I wonder if they ripped that from a nasa program.

Russia had significant political problems with rocket engine bureaus. The reason the N1 moon failure rocket
had a cluster of so many small engines, was that the program manager was not on talking terms with
THE ONLY GUY IN RUSSIA THAT COULD MAKE BIG MOTORS. He had one about as big as the Saturn V first
stage unit. That cluster was nuts. The control system would shut down opposing motors if one had a problem.
The thing that got them was plume dynamics, causing roll that the system did not have the authority to correct.

 

[frodo1008]

Yes, by a "dirty" valve I did mean particulate contamination. And it was not part of my job to determine the fit, or even the type of propellants that would go through the valve system. We in the clean room were only to cycle the valves so many times, and then run the usual sample of some 100 ml of fluid through them while continuing to cycle them, and they did have a very high level of particulate contamination initially.

Later the valves were then brought back, and there was a significant improvement in the contamination. The main reason that Rocketdyne's small engines were run in very high levels of cleanliness (and one of the main reasons for my job as a particle count inspector at that time) was that the propellants of such as NTO (nitrogen tetroxied) as an oxidizer, and monomethyl hydrazine (MMH) as a fuel were hypergolic and ignited on contact with each other. This meant the the very small openings in the valves that controlled these small Reaction Control System (RCS) engines on the Apollo Command Module had to close completely, and very fast, or the engines would continue to run and mess up any maneuvers being made by the Command Module. This meant that there could be absolutely NO contamination that might hold them open!

Thus the absolutely extreme cleanliness levels that we had to maintain even out in an open test lab area, in a clean trailer! In fact, those engines stayed in the clean room for such operations as pre-test measurements (taken by yours truly), post-test measurements, and engine decontamination. for far longer than they ever stayed on the test stands themselves!

It was a very busy and interesting time in my life!

 

[jimglenn]

So those were on/off valves, or proportional? Was there a max time limit on the firing pulse in the CM RCS?

Sorry, just curious. Those are nasty fuels, when Apollo 13 blew up I wonder if there could have been
a leak, the tanks are probably well isolated.

So the valves can't use O-rings? It is not cryo, those fuels. There must be much better materials
today. But I keep hearing of problems with the hydrogen level sensors in the shuttle, hard to get to,
no one understands why they go intermittent. Something about if you run the engine dry it might go boom.

 

[frodo1008]

These RCS engines were very low thrust (about 50 lbs or even less), so a proportional and therefore controllable thrust was out of the question. To be short, these were indeed strictly on/off valves. The orifice through which each propellant flowed into the injector were only 0.100 inch or even smaller, there would have been no room for proportional valves.

As to the Apollo 13 problem. The explosion took place in a tank in the Service Module, and not the Command Module. And the entire RCS system for the Command Module was contained in that module. So it would have been impossible for the accident to have been due in any way with these engines. In fact they performed so well that the men on that flight (to an even greater extent than usual) owed their very lives to those small high performance engines!

As Rocketdyne got out of the small engine business after the almost complete shut down of the space program after Apollo, therefore I do not really know what developments have been made in that area since. So I really can not say just what improvements have been made there. Sorry about that lack of information.

The problems with the liquid hydrogen sensors are for an entirely different type of engine altogether. It is really impossible to in any way compare the non cryogenic 50 lb thrust RCS engines, to the cryogenic 500,000 lb thrust SSME's, which are the engines that use the sensors in question.

Once again, sorry, wish I could be more helpful.

 

[halman]

frodo1008,

Back about the time that we were getting ready to land people on the Moon, the whiz kids at NASA were examining the future, and thinking about sustainability. You didn't have to be a rocket scientist to know that throwing away huge rockets every flight was not going to cut it with the public. They wanted a totally reusable system, which would be as cheap as possible to operate. What they came up with was horizontal take-off, horizontal landing, two stage to-orbit system, which was supposed to carry 6- 8 passengers and a crew of 2. A flying wing-type craft was to carry the orbiter on its back to an altitude of about 50,000 feet, and then the orbiter would fly the rest of the way.

This is still the system that we need to build to get people to and from space cheaply. Launching straight up means that everything has to work perfectly, range conditions have to be ideal, and massive amounts of power have to be generated. All of these things add up to lots of money for every launch. But launching straight up is fighting the atmosphere, instead of using it to our advantage. The goal of a launch is to get the payload moving at orbital velocity, something on the order of 15,000 miles per hour. But we can't go really fast right off of the pad, because the atmosphere is so dense that it will rip our vehicle apart.

If we use an airfoil that is powered by engines, we can lift mass using the atmosphere. If our engines burn atmospheric oxygen, then that is less mass that has to be lifted initially. A wing built of composite materials, powered by large turbofan engines, accelerated beyond stall speed by a catapult, would be able to lift payloads far beyond what we think possible. Why? Because all of our experience with aircraft is with aircraft that must be able to accelerate to take-off speeds in the space of a mile or two, be able to support their entire weight on retractable landing gear, and be able to carry cargo inside the vehicle.

By changing the equation, providing a supporting carriage that stays on the ground, a catapult that can accelerate the vehicle over a distance of several miles, and an airframe designed purely for lift, we can achieve take-off weights on the order of 3 million pounds, and probably higher. This would allow a space plane weighing at least 1.5 million pounds to be carried to 50,000 feet altitude. At that height, you are already above the majority of the atmosphere, so the velocity of maximum aerodynamic pressure (max-Q) is around 2500 miles per hour.

A space plane igniting its engines and separating from the carrier wing will only be traveling at about 500 miles per hour. But it would be able to accelerate very rapidly, which would result in the vehicle gaining altitude as the planet curves away beneath it. By the time that the Solid Rocket Boosters separate from the shuttle, the External Tank is nearly half empty, yet the vehicle is only traveling a little over 1 mile per second. It must reach 5 miles per second to achieve orbit, but it can do that with only half the fuel the E.T. carries. Because that fuel is burned to create speed, not to fight the force of gravity!

By using aerodynamic lift instead of rocket power to climb through the thickest part of the atmosphere, we can drastically reduce the size of the rocket plane. We also can step back from using the most powerful fuel there is, with all of its attendant problems. By using kerosene instead of liquid hydrogen, we can avoid the issues involved in working with materials a few degrees above absolute zero, such as evaporation, icing, metal fatigue, etcetera. Especially as the flight to take-off altitude will last at least an hour.

The carrier wing will be able to land on its own undercarriage, returning to the take-off site. There, it can be refueled, serviced, and ready for another launch in a matter of hours, if need be. Launches could occur in less than ideal weather, including fog, and rain storms. The launch site would probably be near sea level, to provide the densest atmosphere possible for lift. The catapult will have to be miles in length, to allow for aborts.

This is the kind of system which would provide sustainable access to space. Building it should be the highest priority of the National Aeronautics and Space Administration, because every nation involved in space exploration will be a customer. Until it is ready, we should keep the shuttles operational, even if they require updating.

Our long term survival depends upon our learning how to live and work in space, because we won't be able to go on doing what we have been here on Earth. Using resources from outside our ecosystem, processing those resources with energy from outside our ecosystem, in factories outside our ecosystem, this is the only way that we can maintain our technology in the long run.

 

[frodo1008]

WOW! Halman, as usual you have put forth a truly great post! And if you look at my OP post starting this thread, you see that we are in total sync with each other!!

The only sad part of this is that we both seem to be almost totally OUT of sync with the current leaders of NASA! Perhaps this new committee chaired by Norman Augustine might just change that, hopefully anyway!

There is hope however, as it would seem that at least one of the alt.space primary guru's in Burt Rutan would easily agree with out ideas over those of the current management of NASA! His details such as the catapult launch system you describe might be somewhat different (the devil is always there in the details anyways), but I am certain that he would agree with both of us on the basic principles that we are putting forth!

Either going back to the moon, or going on to Mars by the chemical rocket powered direct route, is dangerous, unreliable, and very very expensive! The FIRST thing to give humanity a real chance at a true self sustaining space faring civilization is to make the ability to get up to a high LEO orbit in a much more reliable and relatively INEXPENSIVE methodology, THE most important activity that NASA could be doing right now, bar none!!

It IS the key to not only having far more footprints on the moon and eventually the sands of Mars, but eventually having truck tire imprints also with heavy duty mining operations first on the moon and then eventually throughout the solar system. And then using the almost limitless materials and energies of the solar system to eventually go on to the stars themselves!

I too have lots of books on the plans of the better people at NASA to go to a truly two stage to orbit launch system. Which while being somewhat more expensive to begin with, would have been far less expensive in the long run than the kluge that the infinitely wise (to themselves at least) Congress forced NASA into with its stupidly short sighted funding.

However,even with its faults, If we drop the shuttle into retirement at this time, is Russia going to remain friendly enough to continue to give us inexpensive rides to the ISS?

Heck, no they are not! At best, they are going to stiff us for just as much capital as they can, and at worse just cut us off entirely because they no longer wish to remain friendly with us anyway!!!

Are BOTH NASA and Congress really so stupid? Good Heavens, I hope not!

At any rate, thank you again for your truly excellent support, and do Have A Truly Great Day!!!

PS: Keep an eye out for my next foray into the great realm of future space activities, with a thread on the real way we should be going back to the moon!

 

[halman]

Yeah! Someone who agrees with me! Alright!

Okay, so we have gotten the technical fantasies out of the way. How are we going to pay for developing all of this new hardware? What justification can we use to chisel more money out of the government? Because what we are spending on manned space exploration is just not enough. How do we get the public behind building a new launch system? Because space nuts like you and me are a tiny minority, surrounded by people who don't realize that the Sun is a star, seen close up. Somehow, we have got to open their minds to the riches that await us out there.

Like a lot in this community, I got interested in space exploration because I was fascinated with technology, I wanted adventure in my life, and going fast was fun. But my belief in the reasons why we need to get off of this planet have evolved, until protecting this planet from ourselves is my major concern. I believe that we can enjoy the benefits of our technology without destroying the only home that we have in the process of creating those benefits. Because the place to do our smelting and refining is out in space, where the resources are, and where the energy is free.

Green is good, because green is the reason we need to go out into space. To keep the Earth green. It is not about Mars, or the stars, it is about protecting the only place in all that we can see where we can live as children and old people. You can't change a baby or an elder who is in a space suit. Getting people to understand that spending on space exploration is not going to be funding the fantasies of those who want to live somewhere else, but instead will be to make it possible to turn the Earth into a park is key to their support. Without that support, manned space exploration by the United States is in danger of coming to an end.

 

[halman]

At what point will NASA admit that its pet project isn't going anywhere? Is there a bureaucrat in the country capable of standing up before Congress and saying "We are shutting down this project because we don't have enough money to do it right, and screwing up means killing people.'? I have to wonder how much money will be thrown at a dead horse. Because there is no Plan B. That would be too expensive.

If it turns out that the Areas I can't turn with a payload sitting on top of it, or some other failure which is inherent in solid motor rockets, Congress is likely to throw in the towel. How much would it cost NASA to put together a design team to study a concept like what I described? Just to get a handle on some numbers, using highly specialized vehicles for the study, such as a true 'flying wing' carrier aircraft. A few million, maybe a hundred over several years? Wind tunnel testing, engine testing using off-the-shelf engines, these things can be done without committing to a design while at the same time informing the designers.

Also, there is more than one company which makes carbon composite aircraft right now, while I believe that there is only one company which makes the solid rocket booster segments that the Ares I is designed around. So, expertise in fabrication already exists, which means that we aren't faced with learning how to make a material before we can learn how to use it. (TPS tiles.)

Given adequate funding, I believe that the United States could be ready to test a new two stage-to-orbit system in less than five years. There are no great unknowns to conquer, because the space shuttle has already done the hard learning. If some engine testing and wind tunnel studies were completed now, then I would say that the time to testing could be cut by a year, maybe a little more. Fairly cheap insurance,

 

[jimglenn]

All very good ideas, but nasa has NIH, not invented here. If they don't think of it, they won't do it.
Also it is mostly for jobs, the people paying don't seem to care too much what they do with the money.

If we had the power to fire managers and the leader of nasa if they do stupid things, we might get somewhere!

How about a hybrid ship? The first stage would have the wings and air breathing engines, the second stage would
be space capable with rocket engines, stacked on top like the old days, not side by side. Somewhere around
50,000 feet it would separate. Not quite as good as your concept with the carriage that stays on the ground,
would need landing gear on the first stage, but it might be able to take off from normal airport runways, if not
too big. Perhaps modify a 777 or C17, break off the nose section and fuselage back to the wing, and bolt on
the second stage. With explosive bolts! Of course when the second stage goes away you don't have a nose
section anymore. Have to figure that out later.

 

[halman]

jimglenn,

Because the combined launch package is going to weigh on the order of 3 to 4 million pounds, launching from a regular runway is out of the question. Building the carrier wing to support that kind of load on its own undercarriage would invoke a huge penalty in weight, which is part of the reason that I believe that the catapult would incorporate a cradle that the wing would lie in. I advocate a catapult because turbofan engines are not very efficient at low speeds, and building the carrier with enough engine power to accelerate itself to lift off velocity would only result in engines being shut down after lift off.

Just as a catapult on an aircraft carrier does not throw the aircraft into the sky, this launch catapult would have one purpose only; to accelerate the launch package to a speed well in excess of lift off speed. Clamps would hold the package onto the cradle until the weight on the cradle had gone negative by several tons, which would mean that the package would immediately begin climbing once it was released.

In my opinion, there is nothing to be gained by trying to modify existing airframes to handle the carrier wing job. No existing airframe would be able to lift off with a payload of the size that is needed. We need an airframe which is designed for this one job, to maximize its performance. It may well be that the carrier wing will be about 100 meters from tip to tip, and its undercarriage will have to be extremely wide to prevent catching a wing tip, so a normal runway is not going to be wide enough.

 

[scottb50]

jimglenn,

Because the combined launch package is going to weigh on the order of 3 to 4 million pounds, launching from a regular runway is out of the question. Building the carrier wing to support that kind of load on its own undercarriage would invoke a huge penalty in weight, which is part of the reason that I believe that the catapult would incorporate a cradle that the wing would lie in. I advocate a catapult because turbofan engines are not very efficient at low speeds, and building the carrier with enough engine power to accelerate itself to lift off velocity would only result in engines being shut down after lift off.

Just as a catapult on an aircraft carrier does not throw the aircraft into the sky, this launch catapult would have one purpose only; to accelerate the launch package to a speed well in excess of lift off speed. Clamps would hold the package onto the cradle until the weight on the cradle had gone negative by several tons, which would mean that the package would immediately begin climbing once it was released.

In my opinion, there is nothing to be gained by trying to modify existing airframes to handle the carrier wing job. No existing airframe would be able to lift off with a payload of the size that is needed. We need an airframe which is designed for this one job, to maximize its performance. It may well be that the carrier wing will be about 100 meters from tip to tip, and its undercarriage will have to be extremely wide to prevent catching a wing tip, so a normal runway is not going to be wide enough.

Like I pointed out in the other forum I think something like this would be overly complex and have no advantage over a rocket. A 777 or C-17 wouldn't come close to launching a reasonable payload and a catapult provide an insignificant amount of energy to a vehicle, it still has to reach orbital velocity.

 

[halman]

scottb50,

What purpose does the first stage of a rocket serve? It does not appreciably impart velocity, at least considering the amount of fuel that it burns. No, the first stage is just to get the rest of the rocket high enough to where it CAN go fast. The solid rocket boosters do not do much to help the shuttle reach orbital velocity, they just lift the external tank until the space shuttle main engines have burned enough of the fuel in it that they can start to lift it themselves. When the SRB's separate, the shuttle is still moving at less than a mile per second, even though nearly half of the contents of the ET have been burned.

You have to get above the majority of the atmosphere before you can start to really go fast, no matter what kind of vehicle you have. If we built a catapult that would impart 3 miles per second of velocity to a launch vehicle, the vehicle would disintegrate before it left the catapult. Therefore, we must lift our space vehicle up somehow before it can effectively use its engines. Either we stick it on top of a rocket, or we use an airfoil to generate lift.

Take a look at either of the White Knight aircraft. Have you ever seen anything like them? I doubt it, because they were designed with a single purpose in mind, a purpose unique in the history of aviation. Take a look at Space Ship One, and ask yourself how that puny little thing is supposed to reach 100 kilometers. It can't, unless it is lifted to an altitude where the engine can be run full bore, with no throttling back. Additionally, do you think that any regular airframe could lift Space Ship One to 50,000 feet using only two small turbofan engines from an executive jet?

You say that this system would be too complex, without being specific. To my mind, the complexity of launching a rocket is not likely to be surpassed for a long time. Because everything has to be just right before the go-ahead is given. The smallest deficiency is grounds for an abort, because no one knows what kind of problems might crop up after launch. The system that I purpose is actually quite simple. The catapult gets the launch package going about 300 to 350 miles per hour, which guarantees that the wing will have enough lift to clear the cradle. Then, it is just sit back and watch the scenery for an hour or so, while the wing climbs. (By the way. That ridiculously underpowered White Knight 1 was able to climb to 50,000 feet hauling Space Ship One in about an hour. I have always thought that a rate of climb of 1000 feet per minute was pretty darn good for something which is not using afterburners.)

Once the launch altitude is reached, the wing turns toward the east, and the crew on the spaceplane begin their countdown. Running the motors at full power for a few seconds before separating from the wing gives assurance that the motors will function properly, while at the same time allowing the wing to maintain a steep nose-up attitude. At separation, the wing pushes over into a dive, and the spaceplane goes on its way. Altitude is not lost by dropping the spaceplane from underneath the wing, instead, the spaceplane simply flies off of the back of the wing. Massively powerful motors are not needed for this kind of mission profile, so reusing them should be far easier than reusing the shuttle main engines. A thrust to weight ratio of even 1.5 to 1 would ensure that the spaceplane can accelerate while maintaining altitude, and the acceleration will quickly cause the altitude to increase, simply by flying fairly straight and level while the Earth curves away.

This launch system would never be spectacular, like the step-rockets and shuttles have been. But, we are not out to put on a show, we are trying to achieve something. The show would come after the spaceplane achieved orbital insertion.

 

[R1]

Here is a recent report on the Direct vs Nasa's Ares situation.

http://www.nasaspaceflight.com/2009/05/direct-rebuttal-nasa-analysis-jupiter-launch-vehicle/


If I understood it correctly, Nasa critisized the Direct [Jupiter] system, but only now I
see that a 100+ page report from Direct explains why Nasa's critisisms are flawed.
The link to the 100+ page report is provided within the article.