Will there be orbital "space planes" in the near future?

[najab]

><i>The Shuttle orbiter is bettter than a brick, but not by much... </i><p>This was brought home by a comment shuttle_guy made: passing over Orlando International (about 25 miles from KSC) the Orbiter is over 80,000 feet high!</p>

 

[odysseus145]

I found the STS-3 landing video here. That is scary. <div class="Discussion_UserSignature"> </div>

 

[strandedonearth]

Ah, glide ratio, right, thanks SG. I had the right idea, just the wrong term for it.

 

[frodo1008]

I can indeed see why NASA will be going back to capsules at this time. If nothing else it will be far less expensive while still allowing for safety and reliability.<br />I have absolutely no problem with this.<br /><br />However, for placing large numbers of tourists into space things are going to have to change! Burt Rutan is now working on creating a vehicle for launching large numbers of paying passengers into a sub orbital flight. Such a vehicle is not going to be even a semi stir able capsule. It is going to be a TSTO winged vehicle carried by a larger version of the White Knight. The main reason for this, and the greatest advantage of a lifting body/winged vehicle is that there are literally thousands of airports already designed for aircraft throughout the world! However, there are not too many places for vertically launching large rockets. After all, the initial assembly and testing point for such a system is going to be the Mojave airport, until now not one of the best known spacecraft launching sites! <br /><br />Another major consideration that the capsule type of launching vehicle does not address for ordinary space passengers is simply comfort. I guess you could consider such requirements to indeed be style. And if that is the case then for launching relatively ordinary people into space style is indeed going to be very, very important. The average space tourist of the future IS NOT going to be an astronaut! In this case I stand solidly behind the pure commercial space interests. For one thing how do you place windows large enough to really enjoy the view from space (sub orbital at first but at least a full 62 miles altitude) in a capsule. I really don't see how. It IS these types of considerations that are going to sell relatively expensive tickets to space for tourists. <br /><br />I fully realize that the next step to orbital flight for tourism is going to be a vast jump. I have elaborated the many reasons for this on other posts, and I r

 

[thermionic]

<br />Wow, those space shuttles are cool. I didn't spot the PIO in that video, although it looked like the right wheel touched down first? That commentary was startling. "5... 4... 3... 3... What the bleep? 2... 1..." Best of luck to the shuttle team next week!

 

[halman]

frodo1008,<br /><br />For as long as I can remember, (all the way back to a puppet show about space rangers or some such in the late 1950's,) the two stage to orbit, with flyback booster and aerodynamic orbiter, has been the ideal configuration. This optimizes the characteristics of the two mediums that are crossed in going into space, the dense, lower atmospehere, and the near vacum of the upper atmosphere, as well as space.<br /><br />These vehicles invariably launch horizontaly from a rail, which usually assists in the take off. The carrier wing then hauls the orbiter up to 50 or 60,000 feet, er, excuse me, 20,000 meters, where the orbiter fires up its engines, and flys off the back of the carrier wing. When the orbiter returns, it lands on the same runway the carrier wing does, and starts turnaround. One carrier can service several orbiters, and a fleet of each would allow incredible flight rates measured in flights per day, not flights of a given vehicle per year, or whatever. Having several orbiters was the key to the flight rates which NASA pitched the shuttle with, not individual shuttles flying that often. Congress refused to pay for seven orbiters, and, well, you know the rest. <div class="Discussion_UserSignature"> The secret to peace of mind is a short attention span. </div>

 

[vt_hokie]

<font color="yellow">"Such a craft would have to have some form of conventional to hypersonic engines. Conventional for ordinary take off from reasonably conventional airports, and hypersonic to get up about mach 15."</font><br /><br />This is one reason I wish they would declassify the so called "Aurora" if it really does exist. It is likely a hypersonic vehicle powered by ramjets or perhaps the rumored pulse detonation engines. That technology will not be available for the "rest of us" as long as the program remains black. <br /><br />Also, has maglev-assisted launch been studied much? That might be a good way to get some initial velocity while saving on fuel!<br /><br />This article mentions the possibility of using maglev technology for spacecraft launches, as well as aircraft carrier takeoffs in lieu of catapults:<br /><br />http://www.spectrum.ieee.org/WEBONLY/publicfeature/aug03/mag.html

 

[spacefire]

stranded, please remember there are two issues here:<br />L/D=horizontal glide/vertical fall is an aerodynamic characteristic of the aircraft and thus can only be changed by chaning the aricfat's configuration.<br />thye weight is what determines the landing speed. So something can have the aerodynamic characteristics of a brick, but if it's light enough it will be pretty easy to land as long as you take into account the low L/D! <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[frodo1008]

The only part of Griffen’s plan that I have a worry about is that he seems to be leaning toward using the SRB’s for launching the CEV. Like Wherner Von Braun I really do not like using solids for launching human beings into space. Von Braun knew that you can’t really test solids. If you use a solid to test it, that very solid itself becomes history. You have to depend on your manufacturing methods totally to make sure that your actual flight rockets are EXACTLY the same as your test rockets. Now don’t get me wrong here, the solid engine industry does a truly magnificent job of doing this! And it is always possible for a liquid engine to also fail. However, as you can (and Rocketdyne does) test the ACTUAL engine that you are going to use for your flight vehicle, liquid engines are inherently more reliable and safe. Just as an example look at the Saturn V, which had the added safety feature of 5 engines on both the first and second stages, You could shut down one engine and even continue the mission, and I think this was actually done on one launch and it worked just fine. The only solid on the Saturn 5 was the Launch Escape Tower, and it was certainly hoped that it never had to used!<br /><br />This is why I would personally prefer the use of either the Delta IV or the Atlas V Heavy launch vehicles, but Griffen is going to be under the gun for cost considerations from congress as usual. It was such considerations (we were at war in Viet Nahm at the time just like we are at war in Iraq now, this is why I generally oppose wars, they take funding away from far more important things) that gave us the kluge that is the STS system. A magnificent kluge, but still a kluge. If you study the history of the STS system design it soon becomes readily apparent that the current design was FAR from NASA’s first choice. And as usual, the engineers and scientist were far more intelligent than the politicians. If we had taken more funding in the beginning of the program and do

 

[vt_hokie]

<font color="yellow">"What is needed is a true horizontal booster ship with is own landing gear (no launch pad needed, just a relatively long runway). Such a ship would also have to have its own liquid engines to boost its velocity up to a reasonable level. The orbiter would need some redesign as it would have to carry enough of its own fuel and oxidizer to reach orbit, and even some left over for de-orbital maneuvering. Such a vehicle could be launched in days (or possibly as Halman says in even less time, but I would rather be conservative here) with a relatively small launch crew."</font><br /><br />Do you think it's even remotely possible that such a system already exists? This was something I came across when looking for the latest "Aurora" rumors:<br /><br />http://www.abovetopsecret.com/forum/thread60762/pg1<br /><br /><i>"There is growing evidence that a mini-shuttle was developed shortly after the space shuttle Challenger disaster on January 28, 1986 and that the trials began in 1992."</i><br /><br />I personally doubt that they have an orbital vehicle. I think it's more likely that they developed something that flies in the Mach 5 - Mach 8 range. But who knows! Wouldn't it be ridiculous if NASA spent billions on an antiquated system for sending crews into orbit if we already had something far superior!

 

[frodo1008]

There have been many such less than optimal things done in the name of national security. However, I would rather see both govermental and commercial civilian interests funded because the black programs are going to continue regardless of what is done in the civilian sector. For all we know the military really is already dealing with alien technology capable of intersteller transport let alone interplanetary. Of course, as our current enemies the terrorists are using such crude devices as bombs straped to their bodies, what use is such advanced technology to the military?<br /><br />No, as I don't think the military is not going to be a help anyway (to me at least in the case of the space shuttle they were really nothing but a hinderance) then both NASA and the commercial interests should continue on and just ignore the military. <br /><br />Just as an example of the type of hinderance to true progress that this type of national security thinking can cause. When I was working on the original B1A bomber back in the 1970's I and everyone else in my group had to have a secret clearance. They hired a fantastic engineer who had done outstanding work on aircraft flight controls. As I worked in systems engineering we had to have excellent engineers in all aircraft properties.<br />At any rate, he did not yet have his clearance (it took months to get this Holy Grail of security). In the meantime he needed to see some of the data that he had generated in some of his earlier work. However, as this work had become classified in the meantime, he wasn't anle to take this short cut (he couldn't even VIEW his own wwork) and had to expensively regenerate his own data as he didn't have his clearance yet!! I know, this sounds like one of those typical aerospace myths, but I was there at the time and it was true. And then people wonder why the military buys the same hammer that you can buy at a hardware store for some $20, but they pay some $600!<br /><br />While working at Rocketd

 

[cdr6]

Indeed. the HL42 was flown in a simulator, at NASA-Langely, by a former X-15 pilot and stated that the landing characteristics were "entirely acceptable". (Llife Magazine). <br /><br />Also of note were the pilots comments of the "flying bath tub" proof of concept craft... Which lead to the successful series of lifting body X-craft....none of which landed by parachute.

 

[vt_hokie]

I found this interview with Gordon Fullerton where he mentions the STS-3 landing. <br /><br />http://www.jsc.nasa.gov/history/oral_histories/FullertonCG/FullertonCG_5-6-02.pdf<br /><br />Apparently they adjusted the control system gains as a result of that flight.

 

[halman]

frodo1008,<br /><br />I have doubts that we will be able to launch a two-stage-to-orbit composite vehicle from a runway for the simple reason of weight. Such a vehicle is likely to mass at least a million kilograms, which would demand an extremely heavy undercarriage, which would not be needed for the landing of the carrier wing by itself.<br /><br />By sacrificing the 'launch anywhere' versatility of runway launching, a rail launch system can support the combined vehicles in a cradle that they have to fly out of, insuring that sufficient airspeed has been attained to begin flight. Also, the rail can impart much of the 500 kilometers per hour velocity this huge aircraft will probably require to get airborne, thus saving the onboard fuel supply for the climb to seperation altitude. While climbing to altitude, the vehicle could move out over the ocean, so that popultion centers are not anywhere near the flight path of the orbiter. So a spaceport could be located in California, Texas, Mississippi, Alabama, or just about any of the southern tier states.<br /><br />Using such a system would mean that the spaceport does not have to be in an isolated location, because there will not be any rockets firing at the spaceport, just old fashioned aircraft operations. Also, the carrier wing does not need any fancy engines, just a whole bunch of fanjets. Because it is a very simple aircraft, turnaround means refueling, setting back on the launch rail, and mating with the orbiter, which undergoes its preperations entirely seperately. Conceivably, a carrier wing could fly two missions a day, although that is probably unlikely. Mating the carrier wing and orbiter should be a simple operation, because no umbilicals are needed between them.<br /><br />Even if such a system could only put 10,000 kilograms in orbit, flight rates would allow tremendous amounts of mass to be orbited in a short time. For anything really big, we may have to rely on an old fashioned step rocket, al a' Nova. <div class="Discussion_UserSignature"> The secret to peace of mind is a short attention span. </div>

 

[vt_hokie]

<font color="yellow">"For all we know the military really is already dealing with alien technology capable of intersteller transport let alone interplanetary."</font><br /><br />lol...uh, well, I guess! But as much as I believe that intelligent life and advanced civilations exist throughout the universe, I think that's about as likely as me getting a date with an SI swimsuit model! <img src="/images/icons/wink.gif" /><br /><br />If it were true, though, wow...what a waste our current space program efforts would be! <img src="/images/icons/smile.gif" />

 

[krrr]

<blockquote><font class="small">In reply to:</font><hr /><p>[...], I believe that a two stage system could handle some pretty large payloads. And I am certain that it would be CHEAP, compared to any other launch system, because the first stage would burn kerosene and air, and the second stage could burn kerosene and LOX, and both stages would be SIMPLE. The second stage does not benefit from fancy engines, because it will be operating only at 20,000 meters and above, and from 600 kilometers per hour up to 8 kilometers per second. Regular rocket engines operating for about 7 to 8 minutes will get the job done just fine, without having to switch powerplants part way through the climb to orbit.<br /><p><hr /></p></p></blockquote><br />What you describe is basically a 1.1-stage-to-orbit system. The "first stage" lifts the orbiter on top of the densest atmosphere and contributes a very modest forward momentum.<br /><br />I believe the orbiter would still need 8000, probably rather 8500 m/s effective delta-V capability. "Effective" taking into account G losses and residual atmospheric effects (drag and suboptimal ISP).<br /><br />Which means that for a LOX/Kerosene vehicle (ISP 350s) the empty-to-full ratio would have to be less than 9%. For LOX/LH2 (450s), this would still be less than 15%.<br /><br />Such a vehicle (with wings, TPS, landing gear, crew cabin etc.) would have to be *huge* just to lift itself without any payload into orbit. Especially the kerosene version, which I think is just not feasible.<br /><br />And as always in SSTO designs one pound growth in empty mass means one pound less payload. <br />

 

[frodo1008]

Halman:<br /><br />Almost all of the original designs for the STS were indeed TSTO. However, I think that they all showed landing gear for the boosters as well as the orbiter. Somebody must have thought that they would not be too heavy for runways. Don’t get me wrong I am not saying that your system isn’t better. Perhaps the landing gear on the booster was only meant to be exactly that, landing gear only, which with either your system or what they showed would be needed to land the fly-back boosters. The take-off mode was however, quite different, the booster and orbiter combinations were taken out to a lunch facility, either on the boosters’ landing gear, or on some kind of rail system such as the Russians use. Then the combination (I think it is called a “stack” by NASA) is tilted up on its rear end (again, like the Russians use) and launched using the boosters’ large conventional liquid rocket engines. The drawings/graphic arts pictures of the boosters’ tail showed anywhere from 8 to 12 such engines. I think most of the engines were to be of the million pound thrust category, and of course were to be like the boosters themselves completely re-usable. Now, whether or not such a system would have been better, or more properly would be better (after all, we are talking about the future not the past) than what you are proposing I really don’t know. I am admittedly not an expert on such systems. I DO know however, that the proposed systems would have been far better (except for higher initial cost) than the current STS by a very long ways. I think that it is entirely possible that both of the shuttles accidents could have been avoided with such a system. That would have saved at least the increased amount of the design over the current one. However, as that would be hindsight that no one knew at the time, I guess it really shold not be used as a jsutification over the current system.. I believe that the Sea Launch program uses a similar launching mode, an

 

[najab]

><i>However, (apologies to some on this forum) I am sorry, I just don’t believe that this is the kind of system that is going to support CATS in the long run.</i><p>No, it won't. But then, CATS isn't NASA's job!</p>

 

[frodo1008]

As usual there are three different positions about NASA and CATS. The two extremes (like thee liberals and conservatives over on FS) and somewhat in the middle (like myself a moderate over on FS).<br /><br />The first position is what you are saying, that CATS has nothing to do with NASA. I would have to agree with you that due to the usual budgetary constraints NASA is quite probably not going to be able to do the job anymore correctly this time around then when the current shuttle system was built. As a matter of fact it now looks like the new replacement for the shuttle is still going to use a lot of the current systems hardware. And using a capsule design is going back even further. I do sinscerely hope that it works better this time around, but while I continue to support NASA, I do realize that they just don't have the best track record in this area!!<br /><br />The other exreme, and while I personally lean in this direction, I really think that this is the least likely scenario of all. That is that NASA should concentrate on CATS to further enable all the other things that NASA should be doing. You know, it really would not take that much of an increase in NASA's budget to allow for this scenario. But, like in the 1960's I am a dreamer. The increase that I am talkin about is only an increase of some 10% per year of NASA's current budget for about the next 10 years, but it just isn't going to happen. Even with this increase NASA's share of the federal budget would still be miniscule when compared to the other big ticket items in the federal budget, and as I consider NASA to be an INVESTMENT in the future and NOT an EXPENSE it would seem at least resoneble to me. However, as usual the big ticket items such as the military (war), deficits, etc, etc, etc, will doom this sccenario. So the other exteme is what is going to happen. Whether or not this proves out to be best in the long run is up to history.<br /><br />Then there is the moderate viewpoint. Here

 

[halman]

frodo1008,<br /><br />Thank you for your detailed reply. And what a change to have a thread that we don't have to hijack!<br /><br />What I am proposing is a way to get the rocket to a high enough altitude that it can point the nose at the horizon and go to 100 percent throttle. The current shuttle derives only 1 mile per second and about 120,000 feet from the two Solid Rocket Boosters and nearly half the contents of the External Tank. That is because the vehicle has to climb slowly out of the densest part of the atmosphere, all the while fighting losses to gravity.<br /><br />One of the basic facts that must be kept in mind while examining this proposal is that THERE IS NO KNOWN LIMIT TO THE SIZE OF AN AIRFOIL. As long as sufficient thrust can be generated to overcome drag, there is no principle which prevents building a wing of any size. And what I am proposing is a wing, like the Flying Wing, B-49, B-2, etcetera. There is no need for a fuselage, and one would only add drag and weight.<br /><br />Another basic fact applying to this problem is that HIGH VELOCITIES ARE IMPOSSIBLE CLOSE TO THE GROUND. Any object traveling at orbital velocities within the atmosphere will burn up. So a vehicle must be above the majority of the atmosphere before it can begin to accelerate continuously at hypersonic speeds. If a vehicle can accelerate at 4 times the force of gravity, the engines will have to kept throttled back until the vehicle is at least 50,000 feet in the air.<br /><br />Another matter which affects this concept is that ORBIT IS ACHEIVED BY GOING FASTER, NOT BY CLIMBING. Rockets take off straight up so that they can climb out of the atmosphere as quickly as possible, not only to avoid air resistance, but because rockets work better in a vacum. A rocket pointed at the horizon 50,000 feet in the air will climb in altitude as its velocity increases relative to the planet, without having any major attitude of climb.<br /><br />I stress these concepts because they are the <div class="Discussion_UserSignature"> The secret to peace of mind is a short attention span. </div>

 

[frodo1008]

Thanks for the clarification. It sounds quite reasonable to me. The ideas that you heve expressed certainly deserve at least detailed testing with perhaps smaller test versions of the whole system. <br /><br />If NASA can't find the funding then perhaps the private commercial tourist industry can when it had at least shown sub orbital flights to be safe, reliable, and above all enjoyable to large numbers of people!

 

[vt_hokie]

<font color="yellow">"If NASA can't find the funding then perhaps the private commercial tourist industry can when it had at least shown sub orbital flights to be safe, reliable, and above all enjoyable to large numbers of people!"</font><br /><br />On the other hand, I hope the inevitable fatalities don't cripple the fledgling industry and put a stop to progress. I don't want to see anybody get hurt or killed, but let's be realistic - it will happen. And the fatality rate will likely be greater than it is for flying in an aircraft or even driving an automobile, at least until the technology matures. <br /><br />Also, how many people will be able to spend $200k on a joyride aboard Branson's "Virgin Galactic" vehicles? As an aerospace engineer, I sure as hell don't have that kind of spare cash! <img src="/images/icons/wink.gif" /> Guess maybe I'm in the wrong line of work! Darn, I knew I should've become an investment banker! <img src="/images/icons/smile.gif" />

 

[frodo1008]

I saw an article the other day (I think it was on real estate in the LA Times) where it was noted that there are now more millionairs in the US and western indutrialized countries than ever before in history. It pointed out that there are several million in the US alone. Of course, the middle class (where most aerospace people are employed) has declined, so you are quite probably correct, I was. and you evidently are in the wrong business. However, job satisfaction amoung the rich is strangely enough, very low. You might get richer being an investement analyst, but you would also probably be bored into an early grave!! Well, you can't necessarily have everything you know!!<br /><br />I don't know the exact numbers (perhaps going to their web site, somebody could find out), but I think the Virgin Galactic already has more orders than it could handle in many years.

 

[vt_hokie]

Well, I certainly can't see myself working for Loral for the rest of my life! The only ones getting rich off of Loral are Bernie Schwartz and his cronies...certainly not the employees or shareholders!<br /><br />I guess it's time for me to do what I should have done years ago, and return to grad school full time. I don't necessarily want to be rich, and quality of life means more to me than money. Of course, it takes a lot of money to afford even a modest home these days, but money means nothing to me if I have to work 80 hours a week and I have no life outside of work. It's a shame that the middle class is being squeezed, while the disparity between rich and poor grows, but that's a topic for another discussion! <br /><br />As for "space tourism", I think there is indeed a lot of demand. I'm surprised that so many people have signed up for Branson's flights, though, given not only the cost but also the risk. And honestly, aside from bragging rights, do you really get much out of the flight? I mean, yes, you can see the earth from 330,000 feet for a few seconds, but I think you'd get more bang for the buck seeing the planet from 80,000 feet for a sustained period of time. I know that the Russians were advertising Mig 25 flights for like $20,000 not too long ago....don't know if that's still the case.

 

[syndroma]

> <i>As long as sufficient thrust can be generated to overcome drag, there is no principle which prevents building a wing of any size. </i><br /><br />Then why don't we see planes with 1000 tons of weight?<br />I think structural strength is the issue.