Posted on 04/04/2006 5:43:58 PM PDT by KevinDavis
COLORADO SPRINGS, Colorado – A rapid-turnaround launch system capable of hurling satellites or special purpose payloads into Earth orbit in as little as 48 hours is being touted by a major aerospace firm—Northrop Grumman Corporation.
The new concept is being competed in a U.S. Air Force effort to develop quick launch of space hardware.
Northrop Grumman’s idea is dubbed the Hybrid Launch Vehicle (HLV), dedicated to reducing launch costs by approximately two-thirds compared to the cost of using a medium evolved expendable launch vehicle.
In a statement released today here at the National Space Symposium, Northrop Grumman officials said the idea combines a reusable, airplane-like first stage with throw-away upper stages. Launched vertically, the vehicle’s winged first stage boosts the upper stages to speeds approaching seven times the speed of sound (Mach 7) before releasing them at an altitude of approximately 150,000 feet.
(Excerpt) Read more at space.com ...
There was a much better concept from a couple of Air Force pilots several years ago. Basically they build a British Vulcan Bomber look-alike with a rocket in the tail. It takes off on the runway with turbojets, cruises to the range, tanks with a KC-135 to get fuel they could never get off the ground with, the does the first stage trick like this thing.
You save the effort of ground handling manhours where you hoist it into place vertically and hook up all kinds of launch crap. And you use turbojets for the "first stage", making the second stage the rocket which doesn't need to be nearly as powerful or carry as much fuel/oxidizer.
I think that would be a far more cost effective booster and still pretty simple. But it wouldn't give any state pork spending for launch facilities like this would, so I guess they won't do it.
> Where's the scramjets?
Left on the drawing board, abandoned in the first round of trade studies. No such thing as a scramjet that makes space travel better or cheaper. Great for missiles, sucks for launch.
> There was a much better concept from a couple of Air Force pilots several years ago.
You're thinking of Black Horse/Pioneer Rocketplane.
No offense to Jack Northrop, but I wonder what Kelly Johnson's "Skunk Works" is up to.
Where winged horizontal systems outshine vertical launches is in their horizontal recovery on runways for quick refueling and relaunch. The whole procedure of taking this thing into a thru-flight inspection, ground transport to launch facility, then hoisting on vertical launcher just cost you anything you've gained in reduced development costs.
The key to cheap launches is quick turns, measured in hours, not days. (I need to check my facts here) but I think airbreathing vehicles are considerably more fuel efficient as well (you use outside air as mass for thrust, rather than totally self contained mass).
Check out the recent stories on the "BlackStar". Yeah, it's orbital hoist weight is apparently low, but it should theoretically be able to turn flights pretty fast. A wee bit larger system should be able to hoist people and cargo to orbit, saving throw-away boosters. I'm convinced this is the way to do space flight. Like Southwest Airlines, rather than throwaway hardware and 1930's style launch pads.
It might take dramatically larger development costs, but those should amortize themselves quickly. The biggest downside is this eliminates the national monopoly on space flight, and eliminates opportunities for pork spending. I suspect a significant amount of dis-information on what is "possible", with the only "good" solution being large throw away boosters is actually protectionism for existing business and national interests.
Some how I smell Buzz Aldrin's handiwork behind this. He has been pushing this concept for at least 10 years. I like Buzz, but the verticle launch flyback booster concept is unlikely to be cost effective. The hybrid upper stage is a good idea though.
> The whole procedure of taking this thing into a thru-flight inspection, ground transport to launch facility, then hoisting on vertical launcher just cost you anything you've gained in reduced development costs.
Ahhh.... no.
A: There no reason why a VTOHL launcher can land on a runway right next to the launch pad.
B: Tilting up to vertical Just Ain't That Hard
C: Horizontal launch and lifting accelerating trajectories are Really Hard on the vehicle structures
There is a reason why horizontal takeoff has not been commonly used for space launch. And that reason is *not* that aerospace engineers are a bunch of dolts who have somehow overlooked the obvious all these years.
> airbreathing vehicles are considerably more fuel efficient as well
Yes, but with *substantial* other penalties. Do the trade studfies. The "blindingly obvious" becomes less obvious, then doubtful, and then just plain wrong as you actually work through the numbers.
sounds good, but... let me know when it flies.
How long does it take to hoist the Shuttle and mount it on it's launcher. Then roll the launcher to the pad? Even with the optimistic predictions of 15 years ago, they were still talking about weeks, even when landing in Fla. A runway launched vehicle should drastically reduce that time, and more, can air-cruise to a favorable launch location such as the equator.
C: Horizontal launch and lifting accelerating trajectories are Really Hard on the vehicle structures
And carrying less weight reduces stress, and gives a smaller vehicle, as does air-refueling prior to acceleration.
There is a reason why horizontal takeoff has not been commonly used for space launch. And that reason is *not* that aerospace engineers are a bunch of dolts who have somehow overlooked the obvious all these years.
Never said they were dolts. They just know where their money comes from, and it doesn't come from paying passengers shopping for bargains in a capitalist enterprise. It comes from government, which likes the pork spending of large launch facilities in certain congressional districts. And it likes keeping it's monopolies (space launch) intact. A horizontal system I'm convinced would 1) break the monopoly, because it would be drastically cheaper, and 2) eliminate the pork opportunities, and 3) risk national security because more countries could afford launch technology.
My tin-foil-hat suspicion is that governments are doing everything in their power to keep the "secret" of cheap launch away from the public domain. Which includes disinformation on what works, and what doesn't.
> How long does it take to hoist the Shuttle and mount it on it's launcher.
That's your mistake right there. Do not assume that Shuttle is the right way to do *anything*. But even so... the cost of those operations are *miniscule* compared to overall Shuttle costs. What costs, what takes time and effort, is *not* tilting it up, but tearing it apart after each flight and examinign *everything*. A vehicle that had the misfortune of having to launch horizontally and plow through the air running hypersonic airbreathing engines would have all the maitenance nightmares of the Shuttle and more.
> And carrying less weight reduces stress, and gives a smaller vehicle,
Sometimes. Not always. As was seen with previous hypseronci airbreathing launch vehicle designs, yes, the gross weight is down... but the actual *size* is up, and the volumetric efficiency is *terrible,* menaing that *dry* weight goes way up. And your cost is driven far more by your dry weight than your gross. Rocket propellants are cheap.
> They just know where their money comes from, and it doesn't come from paying passengers shopping for bargains in a capitalist enterprise.
Paying customers looking to go to orbit are looking to go to orbit on basically conventional launch vehicles and capsules. There are, so far as I know, no serious winged tourist launch vehicles planned, and *certainly* no scramjet vehicles.
> My tin-foil-hat suspicion is that governments are doing everything in their power to keep the "secret" of cheap launch away from the public domain.
There is no "secret." Build lots of vehicles and fly often. Configuration does not matter so much; advanced technologies should be spurned for operational use.
You'd expect to see that sort of thing entering the open literature at some point.
There are a *lot* of problems with the supposed "Blackstar" concept. Not least of which is the total absence of any hard data.
Oh, I know that -- heck, if AvWeek has been right about this thing actually existing, the fact that it's being mothballed is enough to tell you that.
Still, if it really existed, you'd expect to see some of it coming into the real world in one form or another.
The "boron-based propellant paste" is somewhat interesting, though one would have to think there'd be difficulties using it.
> "boron-based propellant paste" is somewhat interesting, though one would have to think there'd be difficulties using it.
Indeed. Metal-fuel gelled propellants have all kinds of wonderful tactical uses - high density like a solid but with higher performance and throttling capability - but the stuff is a pain to work with, it tends to coke in the *worst* possible ways, and it produces a smoky exhaust that not only shows up wonderfully both visually and on radar, but which also happens to be classified as a chemical weapon of impressive lethality (which would annoy the base fire-fighters to no end).
As to: "you'd expect to see some of it coming into the real world in one form or another," the conventional Tinfoil Hat explanation it that that is *exactly* what the X-33 program was all about. Of the three X-33 competitors, 2 made all kinds of sense (Rockwell's looked just like the Northrop flyback booster in this very thread, and McDonnell-Douglas' was an evolved Delta Clipper), while the third was the design that made virtually *no* sense. *That* Lockheed design was the one that was chosen. Used by necessity advanced materials and construction techniques along with the linear aerospike engines.
The Tinfoil Hatter's would have you believe that this design was chosen as a means to take advanced tech out of the black world and put it into the white, without having to explain things. But what the Tinfoil Hatters forget is that the X-33 was chosen with the assistance of the Clinton administration. Who needs devilishly clever conspiracies when you have incompetance to explain something?
I've watched Southwest Airlines turn a 737 in 30 minutes with a full load and a tire change. How long does hoisting, moving to launch pad, hooking up umbilicals, everything, take, even if you ignore inspections? Imagine we can do it in a day, that's 40+ times longer than SWA. I'm not imagining that an orbital vehicle can be turned that fast, but just making the point that if you can fly much more often just because you don't have to hoist it vertical, maintain the tower, hook up umbilicals. That's a significant savings. Runways we've got, and they take virtually zero maintenance compared with launch facilities.
A vehicle that had the misfortune of having to launch horizontally and plow through the air running hypersonic airbreathing engines would have all the maitenance nightmares of the Shuttle and more.
Why? The worst part of the shuttle is the rough running SRBs and huge pressure spikes associated with them. Where's the comparable nastyness with horizontal launch? Hypersonic flight is hot, but without the harsh conditions of the SRBs. Also, hypersonic scramjets are supidly simple compared to the rockets, making overhauls a snap. While rocket upper stages would be small, and easy to overhaul.
[airbreathing] volumetric efficiency is *terrible,* menaing that *dry* weight goes way up. And your cost is driven far more by your dry weight than your gross.
Costs are driven by turn around times which require spending on man hours and ground facilities and lost vehicle amortization opportunities.
Rocket propellants are cheap.
But man hours spent in ground handling and lost flight time are expensive.
There are, so far as I know, no serious winged tourist launch vehicles planned, and *certainly* no scramjet vehicles.
No one wants to be first with a huge development cost. Which is why its such a tragedy that the one entity that *could* develop such a thing (government) has so many motivations to not do it. Motivations like space-culture inertia, national security paranoia, and overwhelming desire to keep the bureaucratic monopoly intact.
After the BlackStar was revealed last month (and I don't doubt that it's existence was known about in some circles for years), I suspect that there are quiet plans to build such things privately. Otherwise the seemingly serious plans to build "hotels in space" etc. just don't make sense with throw away rockets, no matter how much you automate their assembly process.
Comparing the shuttle and any type of airbreathing launcher is actually apples and oranges. I don't doubt that a launcher capable of lifting shuttle loads would be impractical because of size. But manned launchers shouldn't be used to hoist such loads. There needs to be two classes of launchers, one (or more) big dumb unmanned rockets for large loads, and another for crews and re-supply only. Once large facilities are in orbit, why send up any more large vehicles? They should be re-supplied with smaller manned flights flown on a much higher turn rate than anything we've seen up to now. The goal should be a docking every day, and the only way to do that is winged air breathing vehicles with ZERO throw away parts. Only refueling and simple thru-flight inspections should be required. That's it. No hoisting to vertical. Even mating two stages horizontally on a runway seems more complicated than optimal.
> How long does hoisting, moving to launch pad, hooking up umbilicals, everything, take, even if you ignore inspections?
Minutes.
> The worst part of the shuttle is the rough running SRBs and huge pressure spikes associated with them.
Nope. The worst part is re-entry. And a hypersonic airbreathign acceleration launch profiel is *vastly* worse that re-entry.
> Also, hypersonic scramjets are supidly simple compared to the rockets
Say that again when somebody, *anybody* has flown a reusable scramjet for at least ten minutes straight. And then refurbished it.
> BlackStar was revealed last month
No, it wasn't.
> I don't doubt that it's existence was known about in some circles for years
Hardly surprising, given that the same author has been writing about the same aircraft program since the early 1990's.
> The goal should be a docking every day, and the only way to do that is winged air breathing vehicles with ZERO throw away parts.
Sigh. So, how many aerospace vehicle trade studies have you been involved with?
Re-entry is merely hot, at perhaps 2G, without vehicle stresses and vibration from running engines (which could cease operation violently). So how is this the "worst part"? As long as the protection system is in place, it would seem to be a no-brainer. The only issues I'm aware of during re-entry were caused by the violent rocket launch, not re-entry itself.
And a hypersonic airbreathign acceleration launch profiel is *vastly* worse that re-entry.
Why? Acceleration in the atmosphere before a zoom climb into space would only be to around mach 10, rather than mach 25 re-entry speed. Perhaps a lower altitude generates more heat? Fine. Depart at mach 8 or provide thicker tiles.
[Also, hypersonic scramjets are supidly simple compared to the rockets] Say that again when somebody, *anybody* has flown a reusable scramjet for at least ten minutes straight. And then refurbished it.
That's easy to say. There are just so few moving parts in a scramjet. External hot parts could easily be designed to erode away and replaced on each flight. They're consumables, like fuel.
So, how many aerospace vehicle trade studies have you been involved with?
The "cheap" answer for a question of how to get 10 payloads into space is build a bigger or smaller version of what you already know about. Rockets. That's not the same answer if the question is how to get 365 payloads into space a year.
A 747 is dramatically more complicated, and took decades of research between Kitty Hawk and its first trans-atlantic flight, than your generic sailing ship. But which is actually cheaper? When the goal is transporting x number of humans across the Atlantic, the 747 is cheaper because it can make perhaps a hundred trips to the sailing ships one. And add to that the cost of time to the passengers who don't have to support themselves financially for the month or more of passage.
If you'd have measured efficiency in development and construction costs, the sailing ship would win. If you'd have measured efficiency in fuel burn, the sail boat wins. If you'd measure load carried per flight, the sail boat wins. And most importantly, if you'd measure the cost based on 1900 technology vs. the projection that a 747 might be possible, then the sail boat is the only contender.
But it's now obvious that the 747 is the only financially responsible way to cross the atlantic. Same with space travel.
When the cost of launch comes down dramatically, then the cost of space hardware comes down as well, because if a (non-human) piece of hardware fails, we can just send up another, so ultra-high quality and expense for spacecraft is not necessary. When the cost comes down, more flights will be made with the same hardware, amortizing costs faster.
I'm sure you know all this stuff. The bottom line is that we're caught on the wrong side of the cost curve, and we need to cross to the other side. There's no better time to do it than now, but because of the motivations I've stated before, I'm afraid it won't happen unless some visionary people start selling the idea like the way Vaun Braun sold the idea of Space Travel to Americans in the late 50's.
That's why I love what Rutan is doing, even though technically it's 40 year old technology. Because it motivates other people to progress forward. And I don't like your position on this, because it puts water on the fire of innovation, when it's innovation we need.
You could be totally correct on your "vehicle trade studies", when looking at the tool box we have at our disposal. I'm just campaigning that we need a little vision and energy here, so we can cross the technological divide between sailing ships and Boeing airliners.
> Re-entry is merely hot, at perhaps 2G, without vehicle stresses and vibration from running engines
Re-entry is *very* hot, with vehicle stresses and vibration that rival launch but far surpas launch in danger due to structural weakening due to thermal issues.
> Acceleration in the atmosphere before a zoom climb into space would only be to around mach 10, rather than mach 25 re-entry speed. Perhaps a lower altitude generates more heat? Fine. Depart at mach 8 or provide thicker tiles.
Just that simple, huh? OK, so now your booster either doesn't go as fast (meaning your upper stage fails to amke orbit ), or it weighs more (meaning your upper stage fails to make orbit).
> There are just so few moving parts in a scramjet.
*Really.*
> External hot parts could easily be designed to erode away and replaced on each flight.
*Really.*
>>So, how many aerospace vehicle trade studies have you been involved with?
> The "cheap" answer for a question
I noticed you didn't actually answer the question.
> Rockets. That's not the same answer if the question is how to get 365 payloads into space a year.
A position you continually repeat but fail to back up.
> And I don't like your position on this, because it puts water on the fire of innovation, when it's innovation we need.
What we *need* is innovation in operations, not technology. You would have us wait until we invent warp drive before we attempt to conquer the solar system.
We have the technology *now* to produce cheap and reliable space transport. Hel's belles, we've had that tech since the '60's. But NASA, like yourself, has not been interested in cheap space transport *now*, but in spending billions to develop technologies that *might* be helpful *someday.*
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