X-43 type program reemerging?

[lampblack]

Couldn't help but wonder if this is the "canceled" X-43 program reemerging into the light? Looks like more work has been happening on hypersonic flight recently than has been widely acknowledged:<br /><br />http://www.space.com/businesstechnology/060126_darpa_falcon.html <div class="Discussion_UserSignature"> <font color="#0000ff"><strong>Just tell the truth and let the chips fall...</strong></font> </div>

 

[josh_simonson]

I couldn't find anything about an x-51, but the falcon program has been around for a while. I believe that NASA cancelled the x-43 follow-on projects when DARPA picked up the ball and started running with it.<br /><br />Why should NASA pay to develop a spaceplane when the DOD is willing to?

 

[mlorrey]

Yeah, the x-51 is a program to develop a hypersonic missile with a 600+ mile range, however the engine could also be applied to manned hypersonic vehicles.<br /><br />What will really impress me is to find someone developing the GTX vehicle that NASA seems to have also dropped the ball on.

 

[scottb50]

I would like to see the cost with an all Carbon/Carbon shell.<br /><br />I don't see the use anyway,, except as a re-entry vehicle. It seems like it would be cheaper to go to an orbit then descend to a target than to go real fast and get real hot for quite a long time. Lob a 300 pound version into orbit with a Falcon I or one of the Pegasus versions using retired ICBM boosters.<br /><br />But that would be illegal.<br /><br /> <div class="Discussion_UserSignature"> </div>

 

[jschaef5]

I am happy to see that hypersonic planes are still being researched. I think scramjets could provide a great resource to getting places very fast. It just seems like we will always be combating the same issues with traveling through air (pressure and heat). The only way to avoid this is to go higher where the air is thinner, but then you lose the air breathing aspect.<br /><br />Its almost like if you could make a plane light enough to take advantage of all the technologies we have... put a turbine engine on it for takeoff, then kick in a scramjet, get up high and ignite a rocket/hybrid rocket.<br /><br />But to stay on topic, I hope they can stay on track and not get too far delayed because right now it sounds like they are planning to do a ton soon and it doesn't really sound like they have much built/tested to thoroughly yet, but i could be wrong. <div class="Discussion_UserSignature"> </div>

 

[trailrider]

"I believe that NASA cancelled the x-43 follow-on projects when DARPA picked up the ball and started running with it.<br /><br />Why should NASA pay to develop a spaceplane when the DOD is willing to?"<br /><br />There are several potential applications for such a vehicle and its derrivatives: These might include fast-response unmanned military strike/reconnaisance vehicles that can hit a target much faster than aircraft or the current crop of UAV's. Another development path could lead to a LEO-capable vehicle. NOTHING may come of this...EXCEPT knowledge! This is a basic research project to expand the envelope of technology and performance. If there can be non-military applications related to human spaceflight...ISS resupply, etc., great! <img src="/images/icons/smile.gif" /> With NASA concentrating on Constellation, and having a tight budget at that, and if DARPA and the military can do the job, outstanding! Don't forget, the X-planes were all military programs.<br /><br />Ad Luna! Ad Aries! Ad Astra!

 

[vt_hokie]

I hope that someday humanity evolves to the point where we develop new technology for peaceful, constructive purposes instead of finding new ways to kill each other.

 

[rlb2]

<font color="orange">I couldn't find anything about an x-51, but the falcon program has been around for a while.<font color="white"><br /><br />Here is a new update on the Falcon.<font color="yellow"><br /><br />Air Force Plans Flight Tests Of Hypersonic Vehicle<br /><br />A Falcon Hypersonic Test Vehicle-1 (HTV-1) is now on the books for a less than one-hour flight in September 2007. Attaining Mach 19 (19 times the speed of sound), the glided air vehicle will briefly exit the Earth’s atmosphere and reenter flying between 19 and 28 miles above the Earth’s surface. This inaugural voyage of HTV-1 would end in the Pacific Ocean.<br /><br />http://www.space.com/businesstechnology/060126_darpa_falcon.html<br /></font></font></font> <div class="Discussion_UserSignature"> Ron Bennett </div>

 

[wdobner]

Looking around I found that at least on one page which IMHO is quite dependable there seems to be some confusion over the Falcon/X-51 flights. Designation-Systems.net's database of undesignated missiles and UAVs lists the Falcon and X-51 programs, as well as the HyFly program, separately. Are these all standalone projects? I was under the impression that the X-51 was just one portion of the Falcon project. I can see the HyFly project being separate since that's more of a scramjet powered Talos type (relatively) short ranged missile rather than a vehicle optimized for high altitude, high speed, long distance flight.<br /><br />I'm pretty sure that the primary attraction of a scramjet boosted launch vehicle is the potential for a resuable launch vehicle which doesn't have to give over a lot of volume to a liquid oxygen tank. If the scramjet can get the vehicle up to Mach 20 then only a small amount of non-airbreathing rocket thrust is needed to get the vehicle into orbit. Also, so far both of the shuttle's failures have been caused while riding the stack, so the potential of an RLV using a launch method which is considerably more forgiving in its abort methods is certainly something worthy of investigation. Whether an air-dropped rocket boosted vehicle with a mere Scramjet/Rocket dual cycle engine, or a full up turbine or rocket based combined cycle engine using SSTO the promise of a reusable launch vehicle with absolutely no launch site requirements is quite exciting.<br /><br />It's very cool that DARPA and the Air Force have taken the X-43C concept and run with it. I'm looking forward to hearing about their test flights.

 

[scottb50]

I still say the only reason for that technology is for weapons, scram jet powered drones and such. Take video and crash or deliver a payload. <br /><br />I see no short-term or long term, use of Scram-jets for human access to Space.<br /><br /><br /><br /> <div class="Discussion_UserSignature"> </div>

 

[jschaef5]

How about the ability for someone to go from New York to Japan in an hour? And i believe this test plane is going to look at the ablitity to go really fast and go up. They said something like 100,000 to 150,000 feet. If they can get a scramjet to go say mach 25, I think if they then pointed it skyward they could achieve orbit. But then they would probably need a rocket to get back down <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> </div>

 

[josh_simonson]

The program envisions a re-useable hypersonic bomber in about 20 years, and specifically identifies small cargo space launches as an early application.

 

[mlorrey]

Scottb50 says: "I still say the only reason for that technology is for weapons"<br /><br />What is wrong with weapons? We need weapons... given the kvetching about a "lack of markets" for advanced launch technologies, why can't weapons be a market? It's not like Thiokol's development of the five segment SRB isn't just a jobs program to keep the country's only ICBM maker in business.

 

[wdobner]

As others have mentioned there are a variety of uses for Scramjets outside their potential uses for spaceflight. However I'm fairly certain that those uses are of little consequence so far as this board's topic is concerned. <br /><br />The potential for scramjet usage in spaceflight applications is it's capability to get an RLV up very high and very fast such that the LOX load is kept to a minimum. The possibility of mid-air refueling or air launch combined with the extremely high ISP of an airbreathing rocket makes this a potentially important route in the development of CATS. Of course I'd imagine the military would enjoy the almost total lack of launch infrastructure for a HOTOL RLV. I'm sure eventually the higher capacity and low operational costs will overcome the high development costs such that it becomes a foundation of our commercial space program. Just because it can't get you out of the earth's atmosphere doesn't mean it's useless, it just gets you above 90% of the atmosphere so you're not wasting LOX pushing through sea level air.

 

[scottb50]

Not to be pretentious, but that's just stupid. <div class="Discussion_UserSignature"> </div>

 

[scottb50]

I don't see any other use for it. I suppose we could have six or seven stages to orbit, if you want, or any other configuration, but, for the life of me I see no reason for hypersonic engines, except for weapons. I almost said WMD's, but you could probably do it conventionaly. <div class="Discussion_UserSignature"> </div>

 

[josh_simonson]

FALCON Small Launch Vehicle<br />As a step toward implementing the hypersonic cruise vehicle concept, DARPA and the Air Force propose developing, by 2010, a global strike capability that would launch common aero vehicles on a low-cost, mission-responsive small launch vehicle. DARPA and the Air Force are developing the small launch vehicle under a separate contract. <br /><br />The Defense Advanced Research Projects Agency (DARPA) and the U.S. Air Force have selected teams for the first phase of the Force Application and Launch from the Continental U.S. (FALCON) program. Nine contractors were selected for negotiations for Task 1 (Small Launch Vehicle) and three contractors were selected for negotiations for Task 2 (Hypersonic Weapon Systems). Subject to successful negotiations, each contractor will conduct a six-month system definition study within its respective task. At the conclusion of Phase I, DARPA and the Air Force will decide whether to proceed with Phase II, which would be a 36-month design and development effort. <br /><br />The goal of the joint DARPA/Air Force FALCON program is to develop and validate, in-flight, technologies that will enable both a near-term and far-term capability to execute time-critical, prompt global reach missions while at the same time, demonstrating affordable and responsive space lift. The fundamental underpinning of the technical approach to be taken in the FALCON program is the recognition that a common set of technologies can be matured in an evolutionary manner that will provide a near-term (circa 2010) operational capability for responsive, affordable smallsat spacelift and prompt global strike from the continental U.S. (or equivalent reach from alternative U.S. basing) while also enabling future development of a reusable Hypersonic Cruise Vehicle for the far-term (circa 2025). <br /><br />In FALCON Phase I Task 1, contractors will develop conceptual designs, performance predictions, cost objectives, and development and demonstrati

 

[mlorrey]

Well, Scott, apparently, despite my encouragement, you still have not read any of the literature on RBCC hypersonic engines. There is no need of "six or seven stages". An RBCC operates in four different modes: rocket/ejector, ramjet, scramjet, and rocket, to allow propulsion from mach 0-25. Read the sigline...

 

[no_way]

<blockquote><font class="small">In reply to:</font><hr /><p>It just seems like we will always be combating the same issues with traveling through air (pressure and heat). The only way to avoid this is to go higher where the air is thinner, but then you lose the air breathing aspect. <p><hr /></p></p></blockquote><br />i never got that. why is that air breathing so desireable in the first place when LOX costs next to nothing ? ( compared to costs of hypersonic machinery anyway )<br /><br />

 

[mlorrey]

In terms of dollars, LOX is cheap. In terms of mass, LOX is very expensive: it is why launchers have .90 mass fractions rather than .30 or less as aircraft do: aircraft breath air, not LOX. Designing for a .30 mass fraction is light years easier than designing for a .90 mass fraction, and the sole reason that there are no SSTO RLVs yet operating. As soon as we are able to produce rocket engines capable of breathing air for a significant fraction of their flight regime, then mass fractions will drop down to the .50-.70 range, payload mass will go way up, and launch costs will drop significantly to under hundreds of dollars per lb rather than thousands or tens of thousands. The larger portion of the flight regime that rockets can breath air, the lower the mass fraction gets, and both costs as well as dependence on exotic structural design drop.<br /><br />NASA's RBCC engine is one solution to this problem. It has be tested in wind tunnels up to mach 7, while extensive Navier-Stokes analysis of it has been done for the entire flight regime. NASA was preparing to flight test it on a scale test article for the GTX program when it was axed. The GTX was pretty cool, looks a lot like a Colonial Viper from Battlestar Galactica.<br /><br />As the Bush admin has deep sixed most airbreathing hypersonics programs, other than those the military wants, I doubt that this technology will be developed for use for a while unless a private entity steps forward with a pile of money. The GTX project would have been pretty affordable.

 

[nacnud]

For air breathing ideas check out the GNOM ICBM.

 

[scottb50]

I have and it makes little or no sense. If you have to use a rocket then use a rocket, to expect the same engine to operate in different modes adds systems onto systems and hardware up the kazoo. <br /><br />Why make it more complicated than it has to be? Why are four different modes better than one?<br /><br />Read the sigline...<br /><br />It's not that I don't know how to do the math, I don't want to do the math. <br /><br /> <div class="Discussion_UserSignature"> </div>

 

[wdobner]

That's very cool. I do remember reading that article somewhere along the line, but didn't think much of it until you posted it. I had generally been thinking that an air breathing launch vehicle would neccesarily be a horizontal take off airplane like vehicle. I know the US had an experiment with a solid fuel ramjet type engine, but that went nowhere. I have to wonder how a liquid fueled version of Gnom might do if it were made semi-resusable and used somewhat like the first stage of the Falcon launch vehicles. <br /><br />It still seems that a HOTOL RLV has the edge when it comes to manned launches, but perhaps a few liquid Gnom-type first stage could be clustered to provide for very heavy launch vehicles without the need for heavy LOX tanks.

 

[mlorrey]

General Dynamics and Martin Marietta had proposed rocket/ejector modules for some of their Nova booster proposals. The air intake shroud around the rocket engines boosts the Isp of the rocket and the fuel rich mixture allows air combustion and mathematically produces a larger exhaust nozzle to improve both thrust and Isp.<br /><br />Scott, if RBCC makes no sense to you, I'd advise against reaching an opinion until it does make sense. It isn't that hard to understand: you use the mode of propulsion that offers the best Isp for the particular speed range you are operating in, thus over the entire flight regime, your average effective Isp is high enough that you only need a mass fraction of between .60-.80.<br /><br />GTX was projected to have a minimum average Isp of 503 seconds over the entire flight regime. Possibly higher depending on the performance of the engine in the low speed ejector/ram transition range as well as the ram to scramjet transition range. If they worked more on using denser high Isp fuels, they could do better, but hydrogen alone is a loser fuel for high speed atmospheric propulsion.<br /><br />I generally don't see a huge advantage in scramjets over ramjets: by the time you reach the highspeed end of ramjet performance, you are dealing with major thermal issues with your materials, and so should start up your rocket engine to enhance the ramjet performance while climbing into a higher and thinner atmospheric range than one needs for scramjet propulsion. In an ideal world with better materials, scramjets will likely be better, but I'm willing to settle for ramjets and rockets. <br /><br />The GNOM ICBM was a pretty good concept, too bad it never went anywhere.

 

[wdobner]

<i>If you have to use a rocket then use a rocket, to expect the same engine to operate in different modes adds systems onto systems and hardware up the kazoo.<br /><br />Why make it more complicated than it has to be? Why are four different modes better than one? </i><br /><br />It's the hybrid electric of the aerospace world. Sure a hydraulic/electric transmission is more complicated than a standard hydraulic transmission, and all those pieces likely do increase the chances of a breakdown, but they also save you fuel. In this case the savings can be even more dramatic, as Mlorry illustrated. Instead of 10 to 20 mpg you're talking about an appreciable increase in your payload. You go with the scramjet to avoid hauling liquid oxygen up into space with you since it can easily be obtained from the air around your LV. I'm pretty sure something like the Gnom only worked as a ramjet, especially given it's Mach 5.5 top speed. Is there something wrong with developing new technology which adds complexity over an older technology? If so will you smash your computer? <br /><br />The rationale behind the scramjet spaceplane that so many agencies have on their future plans is that you use the oxygen for as long as you can, even if this means grabbing it from the slipstream at mach 20. This reduces the LOX load to the minimum and increases the payload. There are also of course the flexibility benefits which one doesn't get with a fixed vertical launcher. We can base HOTOL RLVs out of Kennedy and have access to every orbital inclination through the use of aerial refueling. <br /><br />Also, from the diagrams I've seen thusfar it seems like any scramjet, even an RBCC equipped to act as an ejector rocket for takeoffs, will only be moderately more complicated than a rocket using LOX or some other oxidizer. The scramjet pretty much just gulps air, uses a variable geometry inlet to adjust how much air it takes in, mixes it with gas, ignites it, and rides the thrust of that explo