Air Launched Sortie Vehicle from the early 1980s

[Blackstar]

Here is something about an early 1980s USAF proposal for an "Air Launched Sortie Vehicle" that was supposed to be capable of quick response and reusability.  I think they chose the name to deliberately avoid the word "spaceplane."

[meiza]

The long conditioning time of the SSME motivated the change to an RL-10 cluster... This paper is from the P&W guys anyway.

I think some similar launchers have been proposed many times in many different papers, complete with the 747 thrust augmentation...

[Blackstar]

I'd be interested in seeing any other papers on this.

I can see a number of dubious aspects of this proposal.  Separation of the spacecraft from the 747 looks really dicey.  Also, look how the spaceplane is mounted.  That would require a lot of structure inside the tank to hold it up.  Would make the tank heavy.  And a rocket on the back of a 747?  But perhaps the thing that is most weird/unconventional is the idea of pumping the fuel into the tank from the 747 while in flight.

Everything I've been able to gather is that this was a study proposal by one laboratory in the USAF.  It did not stem from a requirement for this capability.

[yinzer]

Pumping the fuel into the tank during flight makes perfect sense - it really reduces the boiloff during flight and the amount of insulation required.  There might also be an effect of reducing the loads that the tank and mounting equipment have to tolerate.

The picture makes the separation look worse than it is; it would happen while in a negative g pushover.  Shouldn't be any worse than the early Shuttle tests.

I'm a bit shocked that they are claiming to be able to increase the thrust-to-weight of the RL10 by nearly a factor of two with minimal modifications.  Granted they cut the area ratio way down by expanding the throat, but still.  A factor of TWO?

[Generic Username]

Everything I've been able to gather is that this was a study proposal by one laboratory in the USAF. 

That particular design was the Boeing response to the USAF Space Sortie requirement. General Dynamics and Rockwell also tendered responses. How serious the USAF was about the concept... shrug.

Many more illustrations of the Space Sortie and related vehicles:
http://www.secretprojects.co.uk/forum/index.php/topic,2913.0/highlight,space+sortie.html

[Blackstar]

Pumping the fuel into the tank during flight makes perfect sense - it really reduces the boiloff during flight and the amount of insulation required.  There might also be an effect of reducing the loads that the tank and mounting equipment have to tolerate.

It completely alters the CG of the aircraft while in flight.  And it requires the pumping of cryogenics, while in flight and inside an airplane.

[meiza]

There are countless proposals pretty similar to this.

[yinzer]

Pumping the fuel into the tank during flight makes perfect sense - it really reduces the boiloff during flight and the amount of insulation required.  There might also be an effect of reducing the loads that the tank and mounting equipment have to tolerate.

It completely alters the CG of the aircraft while in flight.  And it requires the pumping of cryogenics, while in flight and inside an airplane.

If the tank in the fuselage is directly underneath the tank in the spacecraft, the CG will not move longitudinally. Thich is no doubt how they'd arrange it.

As for pumping cryogenics, yeah? They have cryogenic tanker trucks so the pumps have to be sort of portable. A 747 is big. Getting the purges right may be tricky, but doesn't seem insoluble.

Pioneer rocketplane was planning to do pretty much the same thing, and appear to have run aground on gross economic issues, not technical ones.   

[Blackstar]

Pioneer rocketplane was planning to do pretty much the same thing, and appear to have run aground on gross economic issues, not technical ones.   

That's not exactly an existence proof.

[Generic Username]

Pioneer rocketplane was planning to do pretty much the same thing, and appear to have run aground on gross economic issues, not technical ones.   

That's not exactly an existence proof.

The Space Shuttle, on the other hand, kinda is. LOX and LH2 are pumped *essentially* from one vehicle (the ET) to another (the Orbiter) while in flight, and the connection is then severed and doors close over the ports. Not exactly the same, of course, but in many ways more difficult.

[meiza]

Couldn't it be pressure pumped? The tank in the plane can be pretty sturdy.

It's a bit surprising how difficult some people see this, as if it would somehow be an important issue?

[Gene DiGennaro]

I think I remember seeing this in either Avweek or Popular Mechanics in the immediate post Challenger years.

[Blackstar]

Here's two more.  One is a General Dynamics paper on the ALSV.  The other is an Air Force description of an "Air Force Sortie Space System" from 1980.  I'm not sure if the latter is a USAF description of the work that was underway by contractors, or if it was what initiated the work.  I still haven't sorted all of this out.

[Blackout]

Maybe instead of on top of a 747 we put it underneath.  Then instead of a 747 lets use a Mach 3 capable carrier that can reach 70,000ft.

Oh wait a sec...
 

[Blackstar]

Maybe instead of on top of a 747 we put it underneath.  Then instead of a 747 lets use a Mach 3 capable carrier that can reach 70,000ft.

Oh wait a sec...
 

I'm thinking that ALSV may have been more real.

By the way, the author of the Aviation Week cover story on Blackstar did this interview 2.5 years ago:

http://www.kurzweilai.net/meme/frame.html?main=/articles/art0702.html

It dates from April 2007.  In it Scott states:

"Ref. the Blackstar system: I now have several photos of the XOV spaceplane sitting on a Lockheed Martin flightline ramp, so the vehicle definitely exists. Based on 15+ years of sighting reports, inside sources, etc., I determined that Blackstar's SR-3 carrier aircraft and several versions of the XOV were built and flown."

So that was over two years ago.  He hasn't released these photos anywhere.

[vt_hokie]

If it exists, it seems insane that we have this technology hidden while NASA struggles to develop a capsule and we're looking at a significant gap in US human spaceflight.  Strange times...

[Blackstar]

You can say the same thing about UFOs, or top secret aircraft in general.  Simply put: "Where are they?"

In the 1990s there was a lot of speculation about all kinds of top secret aircraft being tested out in Area 51.  Some pretty incredible claims.  You would think that if these things were successful, by now--12+ years later--they would be incorporated into the Air Force and would be in operational use.  (Like the Blackbird and later the F-117.)  In other words, we would know about them.  But they haven't appeared.  This leads to a few tentative conclusions: a) these claims were almost all wildly speculative and exaggerated, and b) much of what has been tested is not necessarily in the form of new aircraft, but in the form of things like electronics and missiles that have since entered operational use.

Back to the ALSV: this appears to be a marginal technological solution in search of a problem.  What exactly was the requirement?  Quick reaction launch of relatively small payloads was apparently not a high demand back then.  And there were (are) better ways of achieving it.

[Namechange User]

You can say the same thing about UFOs, or top secret aircraft in general.  Simply put: "Where are they?"

In the 1990s there was a lot of speculation about all kinds of top secret aircraft being tested out in Area 51.  Some pretty incredible claims.  You would think that if these things were successful, by now--12+ years later--they would be incorporated into the Air Force and would be in operational use.  (Like the Blackbird and later the F-117.)  In other words, we would know about them.  But they haven't appeared.  This leads to a few tentative conclusions: a) these claims were almost all wildly speculative and exaggerated, and b) much of what has been tested is not necessarily in the form of new aircraft, but in the form of things like electronics and missiles that have since entered operational use.

Back to the ALSV: this appears to be a marginal technological solution in search of a problem.  What exactly was the requirement?  Quick reaction launch of relatively small payloads was apparently not a high demand back then.  And there were (are) better ways of achieving it.

Or they want to keep it a secret still for other reasons.  For example, the rumors about the TR-3B, if true, are a sea change in technology and capabilities. 

[Blackstar]

Or they want to keep it a secret still for other reasons.  For example, the rumors about the TR-3B, if true, are a sea change in technology and capabilities. 

It seems highly unlikely that a secret aircraft could enter extensive operational use and remain totally unknown/unseen.  Once it starts flying regularly, and is based somewhere closer to the target, it will be seen.  One or two, yes.  A bunch?  No.

Certainly there were other secret aircraft developed there that remain secret.  But they were most likely prototypes.  And it is hard to believe that there were a lot of prototypes.  Why build a lot of secret prototypes and then never put them into production?

[Matt32]

TR-3B?

Of course it exists:
http://en.wikipedia.org/wiki/Triumph_TR3B

[Namechange User]

Or they want to keep it a secret still for other reasons.  For example, the rumors about the TR-3B, if true, are a sea change in technology and capabilities. 

It seems highly unlikely that a secret aircraft could enter extensive operational use and remain totally unknown/unseen.  Once it starts flying regularly, and is based somewhere closer to the target, it will be seen.  One or two, yes.  A bunch?  No.

Certainly there were other secret aircraft developed there that remain secret.  But they were most likely prototypes.  And it is hard to believe that there were a lot of prototypes.  Why build a lot of secret prototypes and then never put them into production?

I don't know, the F-117 was operational for 5 years before it was disclosed.  It was disclosed because the government chose to do it.  Certainly if they wanted to keep something a secret, it's possible.  If and when it is sighted, strange sonic booms are detected, or pulse-detonation contrails are spotted, all that has to be done is claim no knowledge of anything or say nothing. 

[Blackout]

I was just poking fun.  I would like for the Blackstar to be real, but I have some serious doubts. 

[Blackstar]

I don't know, the F-117 was operational for 5 years before it was disclosed.  It was disclosed because the government chose to do it.   

They were training with it for 5 years before it was disclosed.  It was public when it flew its first operational mission (Panama).  They disclosed it because they calculated that they could not use it for the purpose that it was designed (bombing) without it becoming public.

[Namechange User]

I don't know, the F-117 was operational for 5 years before it was disclosed.  It was disclosed because the government chose to do it.   

They were training with it for 5 years before it was disclosed.  It was public when it flew its first operational mission (Panama).  They disclosed it because they calculated that they could not use it for the purpose that it was designed (bombing) without it becoming public.

Two different things.  It went operational in '81-'82 timeframe.  In Panama, that was the first time is was used for the reason it was built...that you are aware of anyway.  The F-22 has not been used in combat yet.  Is it not operational?

[kevin-rf]

Do not forget the tempo of the training and the training accidents that put additional pressure for it to be made public.

As for Blackstar, best way to cover up a failure. Classify the crap out it. That way, no one can ask where all the money went. If it worked, we may have heard about it. If it flubbed... No one wants to brag about a failure.

So that leaves us:

1. It's the best kept secret since pinky swears.
2. It failed an no one wants to own up.
3. It never existed.

[Blackstar]

So that leaves us:

1. It's the best kept secret since pinky swears.
2. It failed an no one wants to own up.
3. It never existed.

Multiply by ten times.

As noted, there was all kinds of wild speculation in the early to mid-1990s that all kinds of great spooky things were happening.  But we've had several wars since then and the spooky planes don't seem to have made a showing.

[Namechange User]

So that leaves us:

1. It's the best kept secret since pinky swears.
2. It failed an no one wants to own up.
3. It never existed.

Multiply by ten times.

As noted, there was all kinds of wild speculation in the early to mid-1990s that all kinds of great spooky things were happening.  But we've had several wars since then and the spooky planes don't seem to have made a showing.

Again, I reference the F-22.  It has not shown up in Afghanistan or Iraq, therefore it most not exist. 

[vt_hokie]

Again, I reference the F-22.  It has not shown up in Afghanistan or Iraq, therefore it most not exist. 

Seems odd that when production was facing termination, the AF wasn't eager to prove the F-22's worth.  Wasn't it given a ground attack role and re-designated F/A-22?

[Blackstar]

Again, I reference the F-22.  It has not shown up in Afghanistan or Iraq, therefore it most not exist. 

Your logic is rather faulty, and getting silly.

The F-22 in fact can be used to argue the opposite--why isn't it a classified aircraft?  The reason is because it has to conduct an operational mission (air superiority) and in order to do this, it has to operate at times and in places that expose it to the public.  Therefore, it is unclassified.

My argument re spooky black aircraft at Area 51/Groom Lake is that you really _cannot_ use a covert aircraft operationally--certainly not in large numbers.  The reason is that doing so risks exposure.  Ipso facto, it is nearly impossible to believe that lots of classified aircraft have been built and tested there that have actually entered operational service.  It is much easier to believe that few things have been built/tested there, they have been almost entirely prototypes or proof-of-concept vehicles, and that they never became operational.

But we're off topic and I'll bring us back on in the next post.

[Blackstar]

Here is a bibliography posted to another list of ALSV articles:

1. Interavia Aerospace Review, 1982, v.37, II, N 2, p.117.
5. Plight International, 1984, v.125, 14/1, N 3897, p.72.
8. Air Force Magazine, 1984, v.67, N 4, p.25-26.
10.Aerospace America, 1985, v.23, II, N 2, p.50-53.
11. Journal of Spacecraft, 1986, v.23, XI-XII, N 6, p.612-619.
12. International Defense Review, 1982, v.15, N 8, p.1113.
13. Popular Mechanics, 1982, XII, p.120.
14. Space World, 1983, N T-1-229, p.33.
15. Plight International, 1982, v.122, 4/XII, N 3839, p.1637.
18. Smith B.A. Study shows space sortie concept viable by 1990. Aviation Week and Space Technology, 1982, v.117, 1/XI, N 18, p.69-70.
19. Aviation Week and Space Technology, 1982, v.117, 20/XII, N 25, p.63.
20. Aviation Week and Space Technology, 1982, v.116, 14/VI, N 24, p.28.
22. Aviation Week and Space Technology, 1982, v.117, 9/III, N 6, p.49.
23. Air Force Magazine, 1983, v.66, N 11, p.111.
30. Spaceflight, 1984, v.26, III, К 3, p.123-128.
32. Spaceflight, 1985, v.27, I, N 1, p.3.
33. Spaceflight, 1987, v.29, III, N 3, p.90-91.
34. Interavia Air Letter, 1986, 20/V, N 11001, p.6.
35. Air et Cosmos, 1986, 6/IX, N 1107, p.46.
36. Plight International, 1986, v.130, 30/VIII, N 4026, p.60.
37. Plight International Show Daily, 1986, 2/IX, N 3, p.36.
38. Air et Cosmos, 1986, 20/XII, N 1122, p.31-32.

[Namechange User]

Again, I reference the F-22.  It has not shown up in Afghanistan or Iraq, therefore it most not exist. 

Your logic is rather faulty, and getting silly.

Oh, I'm sorry you think that.  Lets review the evidence....

I simply said it is possible to keep a secret if one chooses to do that.  The reasons for doing so can range accordingly.  There is speculative evidence that something exists, what and for what purpose, I don't know.  However, accountable deniability has a role here if one chooses to do that.  Seems pretty logical so far. 

Next you implied that F-117 was not operational until Panama.  Not true.  The government chose to disclose it at that time for most likely a multitude of reasons.  Yet it was still an operational airframe operating in secret for approximately a 1/2 decade.  Not flawed so far.

The F-22.  It has not seen combat yet.  It is an operational airframe nonetheless.  While there are a couple of wars ongoing, that does not mean we have to use everything in our arsenal for those wars, F-22 included.  Yet, they still exist.  The F-22 is highly classified, just not its entire existence because, after all, it is just supposed to be a 5th generation fighter with the purpose of air superiority.  Doesn't seem silly or faulty yet....

So the entire point was that something can exist just because there is no direct evidence that conclusively points to it.  I have no idea if it does or not.  Something can be operational without having seen combat, if it is even meant for that, without knowing about the entire airframe (F-117) or components of it (B-2, F-22, F-35, UAV's, etc).  Clearly not flawed. 

[Thorny]

Seems odd that when production was facing termination, the AF wasn't eager to prove the F-22's worth.  Wasn't it given a ground attack role and re-designated F/A-22?

Briefly. They went back to plain F-22 so as not to be a rival to the F-35 (which has a much better justification for being an F/A designation). There was work to put Small Diameter Bomb on F-22, but I'm not sure how far that went.

[Blackstar]

Oh, I'm sorry you think that.  Lets review the evidence....

Yeah, whatever.  I'm back on the ALSV subject.  You got anything on that?

[Namechange User]

Oh, I'm sorry you think that.  Lets review the evidence....

Yeah, whatever.  I'm back on the ALSV subject.  You got anything on that?

Nope.  Sorry to put things in perspective for you (and for you to get defensive for some reason).  Enjoy your topic.

[Blackstar]

A mid-1980s paper on different options for "on demand" launch vehicles.  Think of this as an earlier iteration of the current Operationally Responsive Space approach.  The ALSV was one approach.

[Blackstar]

The first of a several-part article about the ALSV will appear in The Space Review on Monday.  Parts 2 and 3 will have some neat artwork.

I'm using these articles as drafts, hoping to get some people to send me additional information.

[Blackstar]

http://www.thespacereview.com/article/1569/1

Fire in the sky: the Air Launched Sortie Vehicle of the early 1980s (part 1)
by Dwayne Day
Monday, February 22, 2010
 
Moonraker is usually near the top when film critics list the worst James Bond movies. But for space enthusiasts, the film had some pretty cool hardware and a great opening sequence when a space shuttle ignites its engines atop a 747, blasting the giant jumbo jet into a fireball as it sails away. Of course, it’s all fiction: the shuttle doesn’t carry its own fuel for its main engines. But it looked good. Three decades later, Superman Returns featured a small space shuttle blasting off the back of a 777, which also fell from the sky and had to be rescued by the Man of Steel.

While these were fictional accounts, air-launching a small spaceplane from the back of a jumbo jet is an idea that was considered by both superpowers during the Cold War. The Soviet Union seems to have studied the concept more than the United States, even going so far as to build a mockup of its spaceplane. But although both sides studied it, neither ultimately developed it.

[Blackstar]

Here is a 1983 JBIS article on the ALSV.  You really won't learn much from it, because it is based only on open sources (something that was common for a lot of this author's work--his research skills consisted of owning a library card).

Since I ran that article in TSR I've been contacted by a couple of people, including someone who was in charge of the Boeing ALSV study, which is apparently the study that went the furthest (other contractors don't seem to have done as much, but that could be because they were not as public--I don't know).

He has already provided some information and says he will provide more.  He said that the Boeing study lasted about 9 months and that the Air Force lost interest in the ALSV once they found out how much the external tank would cost.  That was the one expendable piece of equipment, and the one real expense.  Probably too much for only about 3500 pounds of payload. 

He also said that Boeing programmed the flight profile into their 747 trainer to demonstrate that it could work (a 60 degree climb under rocket power!).  And he said that it turned out that because the 747 was pressurized, the aft bulkhead in the plane could take a lot of force, so pushing on it with a rocket engine was not a problem.

I'll be following up on this article sometime in the near future (although not this coming week).

[Blackstar]

http://www.thespacereview.com/article/1580/1

Fire in the sky: the Air Launched Sortie Vehicle of the early 1980s (part 2)
by Dwayne Day
Monday, March 8, 2010

"On December 11, 1980, only ten days after Hart’s description of the Air Force Space Sortie System, William J. Ketchum of General Dynamics’ Convair Division produced a memo that he sent to his superiors. Because Hart had referred to the spacecraft using tanks similar to the Atlas rocket, which Convair manufactured, it was only natural that the company would take notice.

Ketchum’s memo stated that they had sought to explore the “initial conditions provided by the 747 carrier, lifting ascent trajectory modeling and performance determination, and drop tank weight estimating based on Atlas hardware.”"

[Blackstar]

Here's one that I did not know about, dating from the late 1980s:

http://www.xcor.com/products/vehicles/frequent_flyer_and_teledyne_brown_spaceplane.html

[Blackstar]

http://www.thespacereview.com/article/1591/1

Fire in the sky: the Air Launched Sortie Vehicle of the early 1980s (part 3)
by Dwayne Day
Monday, March 22, 2010

"A few years ago a company by the name of AirLaunch had a novel idea for a rocket—put it in a C-17 cargo plane and then slide it out the back at high altitude. The rocket would rotate until it was vertical and then fire, heading into orbit. You can watch video of the drop tests.

Now imagine that instead of a relatively small rocket, there was a much larger rocket, with a pilot sitting in the nose, watching as he was pulled out of the back of a massive C-5 Galaxy cargo aircraft. And imagine that pilot falling backward, hundreds of feet, before a powerful Space Shuttle Main Engine ignited to push him into orbit. In the late 1980s Rockwell International, which built the Space Shuttle, proposed just such a system to the Air Force. According to Carl Ehrlich, an engineer for the company at the time, they had been inspired by footage of a 1974 test which involved dropping a Minuteman ICBM out the back of a C-5 and launching it. That test had proven successful, although the Air Force did not adopt the mobile ICBM concept. Ehrlich and other Rockwell engineers believed that there were certain advantages to air-launching a rocket, including rapid response and the ability to launch from virtually any location to any orbit."

[mike robel]

Again, I reference the F-22.  It has not shown up in Afghanistan or Iraq, therefore it most not exist. 

Seems odd that when production was facing termination, the AF wasn't eager to prove the F-22's worth.  Wasn't it given a ground attack role and re-designated F/A-22?

There is no need to use the F-22 in Afghanistan.  Existing aircraft are doing fine and we don't need to risk it being brought down and sent to people we don't want to have its secrets.

I wouldn't use the B-2 either.  Just the BUFF and the BONE

[Blackstar]

http://www.thespacereview.com/article/1608/1

Fire in the sky: the Air Launched Sortie Vehicle of the early 1980s (part 4)
by Dwayne Day
Monday, April 19, 2010

"With its curved upper fuselage, the 747 is certainly the most distinctive airliner currently flying. It might even be called graceful, like a whale. What nobody would call it is maneuverable. It can’t be, not with a wingspan of over 58 meters (190 feet) and a length of over 70 meters (230 feet).

But now imagine a 747 in a 60 degree climb, with a cluster of rocket engines in its tail, passing through 11,300 meters (37,000 feet) and then pushing over into a shallow dive as a rocketplane and its large external tank separated from its back. And imagine that 747 then diving for thousands of feet before its pilots pulled it out of the dive. It’s the kind of maneuver that would give your average 747 driver chills, even if they could only try it on a simulator. And according to Dana Andrews, who worked as Boeing’s principal investigator for their study of the Air Launched Sortie Vehicle concept, for years 747 pilots could hop into one of Boeing’s simulators in Seattle which had been programmed for just such a mission. For the pilots who tried it the maneuver was a fun perk, but a fantasy, because the Air Force had never pursued the mission that required it."

[Blackstar]

I've revisited this subject. Nothing new since my big article in 2021, but my new Space Review article includes some new images.

[Blackstar]

[leovinus]

I think we discussed this earlier but the artwork at this link looks similar to the Boeing stuff in your "part 4".
https://web.archive.org/web/20131103125517/http://www.pmview.com/spaceodysseytwo/spacelvs/sld053.htm

Am still waiting for more TAV materials via FOIAs :/

[Blackstar]

I think we discussed this earlier but the artwork at this link looks similar to the Boeing stuff in your "part 4".
https://web.archive.org/web/20131103125517/http://www.pmview.com/spaceodysseytwo/spacelvs/sld053.htm

Am still waiting for more TAV materials via FOIAs :/

It's much the same artwork. In some cases I found color versions of black and white art. I think that in one case there has been only black and white art circulating on the internet for a long time, and then NASA suddenly put up a decent color scan of the art. That is one of the things that prompted me to revisit this topic.

Unfortunately, for much of the color artwork that has been around awhile, we only have lower resolution scans. It's okay for the internet, but I'd really like to have the best quality scans that we could get. Nobody is bandwidth-limited anymore, and so we don't need 100k jpegs.

[Blackstar]

I think we discussed this earlier but the artwork at this link looks similar to the Boeing stuff in your "part 4".
https://web.archive.org/web/20131103125517/http://www.pmview.com/spaceodysseytwo/spacelvs/sld053.htm

I'll note that the website is captured from 2013 and was produced before then (look at the style!). It refers to the ALSV. What I discovered in my research is that ALSV and TAV overlapped, but that the terms may have been somewhat sloppily used. One document I have refers to ALSV as a subset of TAV. In other words, several TAV concepts were under consideration, and ALSV was one of them. It would have been the least expensive in terms of development because it would have used the 747 as a launch platform rather than requiring an all-new launch platform. That said, I suspect that the modifications to the 747 would have been pricey.

Also, while TAV was a general overall category, there were several companies with their own concepts of how to make that happen. From what I gathered, I think that the companies were told or encouraged to look at similar concepts, which is why there were several companies that had their own ALSV designs.

Alas, we don't have the actual contractor reports on these studies, and probably never will. There are various topics where I try to push the subject forward every few years by digging up new material. But that's not easy to do without spending a lot of dedicated time and money doing it.

[Blackhorse]

I'll note that the website is captured from 2013 and was produced before then (look at the style!).

It was created in the 1990's and last updated in 2001. The author is Markus Lindroos, a finnish aerospace engineer.

[Blackstar]

https://thespacereview.com/article/5100/1

Blue wings into space: the Air Launched Sortie Vehicle
by Dwayne A. Day
Monday, November 10, 2025

Recently, NASA and Sierra Space announced that the Dream Chaser spacecraft would not be used to resupply the International Space Station but would instead fly on a standalone mission, blurring its path to commercial viability. Small winged spacecraft do not have a storied record—the European Space Agency’s Hermes spaceplane and the US Air Force’s Dyna-Soar were both canceled during development. Some small experimental spaceplanes such as the Soviet Bor and the Air Force’s PRIME had limited test flights.
Hydrogen would also be pumped into afterburners on the 747’s large turbofan engines, providing up to 400 percent thrust augmentation. As jumbo jets go, it would have been a real hot rod.

The concept still lives. China has flown a small spaceplane three times. More recently, Dassault Aviation has unveiled the sexy VORTEX spaceplane, short for Véhicule Orbital Réutilisable de Transport et d’Exploration (Reusable Orbital Transport and Exploration Vehicle). But after three quarters of a century of spaceflight, the only real success for small spaceplanes has been the US Space Force’s secretive Boeing X-37, which has flown eight times in 15 years.

Besides the Dyna-Soar and the X-37, the Air Force has considered other winged space vehicles, most seriously in the 1980s. Early in that decade, the United States Air Force sponsored studies of what was initially designated a Space Sortie Vehicle, then renamed the Air Launched Sortie Vehicle, or ALSV. The ALSV would have launched into space off the back of a 747. In one early concept, the 747 would have been equipped with multiple rocket engines in its tail to boost it to launch altitude. Boeing conducted several studies of “Trans-Atmospheric Vehicles” in 1983, including a revised variant of the ALSV. This Sortie Vehicle would have fired its own rocket engines while on top of the 747 and pushed both vehicles higher before separating the spacecraft to head into orbit.

[leovinus]

I think we discussed this earlier but the artwork at this link looks similar to the Boeing stuff in your "part 4".
https://web.archive.org/web/20131103125517/http://www.pmview.com/spaceodysseytwo/spacelvs/sld053.htm

Am still waiting for more TAV materials via FOIAs :/

It's much the same artwork. In some cases I found color versions of black and white art. I think that in one case there has been only black and white art circulating on the internet for a long time, and then NASA suddenly put up a decent color scan of the art. That is one of the things that prompted me to revisit this topic.

Unfortunately, for much of the color artwork that has been around awhile, we only have lower resolution scans. It's okay for the internet, but I'd really like to have the best quality scans that we could get. Nobody is bandwidth-limited anymore, and so we don't need 100k jpegs.

It seems that in this case, the Boeing artwork is at NARA. Searching at the US Air University (AU) library led to a higher resolution. The search was on "Boeing transatmospheric vehicle" and shows several artwork links. The AU page is here and the downloaded picture is 3000x 1979 pixels attached.

Actually, I was trying to figure out whether there are Boeing TAV documents there. As I talked a bit with AU University in past, they seemed quite open to a FOIA request (unlike DTIC). Lots of stuff on Rockwell studies as well. Some example docs are

(a) Innovative strategic aircraft design study, phase I.
June 1978. ; Boeing Company.
https://aul.primo.exlibrisgroup.com/permalink/01AUL_INST/h7jfer/alma992903733406836
Available , Documents ; M-U 29111-7 no.180-24636-1
265 p. : ill.
Distribution of this document is limited to U.S. Government agencies only.

(b)Innovative strategic aircraft design study, phase II.
June 1979. ; Boeing Company.
Available , Documents ; M-U 29111-7 no.180-25245-1
287 p. : ill. 28 cm.
https://aul.primo.exlibrisgroup.com/permalink/01AUL_INST/h7jfer/alma992903683406836

(c) Innovative Strategic Aircraft Design Study (ISADS) Phase 1
1978; Raymer, D ; Robinson, M ; Panageas, G ; Hill, W ; Mairs, R
Open Access At DTIC
https://apps.dtic.mil/sti/citations/ADC016293

[Blackstar]

It seems that in this case, the Boeing artwork is at NARA.

Yes, I was aware of that. TSR downgrades imagery a lot. It's a shame because in the past I've included some really great originals and they look rather blah on the site.

[JAFO]

Dwayne is bringing back a lot of fond memories of growing up wondering What was next?

Bill Sweetman was convinced the YF-23 was a black project hiding inside a white project.

I don't know, the F-117 was operational for 5 years before it was disclosed.  It was disclosed because the government chose to do it. 

Not to mention that AvLeak went out to the desert and looked up. https://aviationweek.com/defense/archives-unveiling-stealth-fighter

[Blackstar]

The difference is that the ALSV was never secret. They were mostly industry studies and to some respects they were proprietary. But they were not classified.

F-117 came out of a clear set of requirements. ALSV was more of a "what can we do with the new technology?" study.

[Blackstar]

This was one of the documents I used for the article. It provides a lot of information on the several vehicles.

[Blackstar]

https://thespacereview.com/article/5100/1

There are now a few interesting comments below the article.

[leovinus]

https://thespacereview.com/article/5100/1

There are now a few interesting comments below the article.

Fascinating