Stratolaunch: General Company and Development Updates and Discussions

[RanulfC]

Ok, so we'll work on that larger piece for later. I've written up a short baseline for the announcement.

http://www.nasaspaceflight.com/2011/12/stratolaunch-rutan-designed-air-launched-system-falcon-rockets/

....and strangly enough the mention of the "Crossbow" ALTO concept here got me to looking around the net which leads to THIS interesting paper:
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20070002822_2007001607.pdf

On the "Crossbow Air Launch Trade Space" which interestingly enough mentions the afore-cited "Cargo ROcket Space System BOx Wing" (CRoSSBoW) as an orginal concept floated around 2005 but having become (internally) at NASA for specific trade space studies and information gathering on pretty much ALL ALTO (Air Launch To Orbit) concepts.

I HIGHLY recomend folks read the paper as it provides a LOT of information on the various aspects of Air-Launch, benifits, economics, and various values pro-and-con that go into trade studies of various ALTO concepts.

From a quick read it's rather obvious that most of the folks in StratoLaunch either have read or have been informed of the results therein.

Randy

[iamlucky13]

If all else fails, maybe you could use it to carry submarines 

Suppose you don't want to send your sub thru the Panama Canal, or thru the Suez Canal, or around the Cape of Good Hope, or around Tiera Del Fuego. Just hook it up to Stratolaunch, and fly it wherever you want.

Gee, come to think of it, wouldn't Stratolaunch be better as a giant seaplane, like Spruce Goose? Could eliminate landing-gear weight.

Even if you off-loaded all of the Trident missles at one coast, and re-loaded them at the other coast, do you really think you can get permission to fly that nuclear reactor (or perhaps Subs have multiple reactors ??) over land ? How does that reactor get cooled during flight ?

But small conventional Diesel-electric subs is doable. As well as Deep sea Submersibles with their support equipment.

I had the impression Zed Noir was joking, but to put the idea to rest:

Submarines have a density close to that of water. A submarine light enough to fly generally already fits in a large cargo aircraft (see DSRV). A typical diesel electric submarine weighs about 10 times as much as this aircraft can lift.

IIRC the D-21 drone was deploy in such a manner off the SR71, not very successfully.

The D-21, like the Enterprise that also deployed off the back of an aircraft, didn't weigh anywhere near as much as a fully fueled rocket. You'd need a big wing to support the full weight of 225 ton rocket.

Did you guys actually watch the press conference? Like the part where Burt Rutan himself says quite specifically that a twined 747 was just plain "stupid", and that you really have to build a purpose-designed aircraft?

Also, he's apparently had this design in his back pocket since at least 1991 (!), and jumped when he heard Allen was looking for something similar. All the internal systems (electrical, actuators, landing gear, flight deck) are from the cannibalized 747s, but the structure is all new, because it has to be.

Admittedly, no I haven't had time to sit down and watch it. I was really hoping between the press release and the multiple articles I'd read that major details like this would have been clearly stated if they were discussed in the conference. Unfortunately, even Chris's article isn't clear about this, although it also does not contradict what you say like most other articles seem to:

The company announced they have already acquired two 747s to become the opening hardware for this system.

But it's refreshing to hear confirmation from Rutan of what I'd already posted a couple pages back.

[RanulfC]

As far as T-0 abort scenarios are concerned, isn't that automatically LOV whereas if you were launching from a pad you could still halt the launch and fix the problem?

On the whole this VERY much is dependent on the EXACT method and operations of the launch sequence. Which we don't REALLY know at this point so all we can do is "guess" from what we have.

Usually any Air-Launch where the rocket is released prior to firing the engines any "abort" is going to loose the booster stages. However this usually means you can "recover" the payload if there is a payload recovery system in place and this is easier overall since your already airborne.

On the other hand if the rocket engines fire prior to seperation (as some have summised) then you still have an opportunity to shut them down, dump propellant and RTB with the LV pretty much intact.

Randy

[jongoff]

On the other hand if the rocket engines fire prior to seperation (as some have summised) then you still have an opportunity to shut them down, dump propellant and RTB with the LV pretty much intact.

I should mention that I wasn't surmising that they would light the rockets prior to separation--I was more *suggesting* it as a good approach that gives a lot of reliability and performance benefits, so long as you can deal with separation dynamics challenges properly.

~Jon

[Robotbeat]

One problem I have is wondering if 1300mn are enough. From KSC they can't reach betten than 8degrees latitude...

Is the difference in payload from 8 degrees really any better than 0 degrees? Since the Earth is a sphere (not a cone with linearly increasing improvement in additional velocity as you go south), geometrically it shouldn't offer much of an advantage, certainly not as much of a difference as from, say, 36 to 28 degrees or 28 to 20 degrees.

The other thing that I've been wondering, is that once you build the aircraft, the only way to increase the payload would be to go with more efficient rocket per unit of weight (like staged combustion hydrogen). So they might eventually be interested in more "efficient" designs from SpaceX (like their proposed staged combustion light hydrocarbon engine) or somebody else.

One both accounts, I agree... They'll pay a greater premium for lower first-stage Isp than a lot of other launch concepts, since they'll be optimizing for greatest payload for a given "lift-off" mass, not allowing them to parametrize the lift-off mass. Increases in lift-off thrust for the rocket engine have less potential for performance increase than for a ground-launched rocket.

I think that once this thing is operational and if it is a big success but they're finding they need to launch larger payloads to higher energy orbits, they will probably be looking for higher Isp options, including hydrogen (though fluid transfer would be more difficult). The carrier aircraft is the biggest technical problem, not the rocket itself... It makes sense they didn't try to push the rocket's performance too much initially. They have a saying in this sort of business... Try for at most one miracle at a time.

I do wonder what Rutan would think of Jon's gamma-maneuver (or whatever you call it), which should allow a sizable increase in payload without increasing the size or mass of the rocket itself. Sounds a little scary, to be honest. Scary in a good way.

[RanulfC]

On the other hand if the rocket engines fire prior to seperation (as some have summised) then you still have an opportunity to shut them down, dump propellant and RTB with the LV pretty much intact.

I should mention that I wasn't surmising that they would light the rockets prior to separation--I was more *suggesting* it as a good approach that gives a lot of reliability and performance benefits, so long as you can deal with separation dynamics challenges properly.

~Jon

Noted and quoted thanks

Now, (not that I'm "fishing" for info here you realize) looking over the actual "Crossbow" ALTO-concept, (which I posted here to avoid running this one TOO off-topic http://forum.nasaspaceflight.com/index.php?topic=25095.msg839371#msg839371 ) I can't help but note a similarity to a concept you blogged about you and Kirk having been 'brain-storming' at one point? Care to comment on that one?

Randy

[WellingtonEast]

Interesting factoid about the F-82 Twin Mustang.

I believe it was one of the few instances where the prototype was more capable than the production versions because the US wasnt prepared to buy British Merlin engines used in the prototype.
 

[Moe Grills]

   Let's see! The Stratolaunch system will put 13,500-Ibs into LEO.

Let's assume with this system that they achieve the breakthrough of 1,000-dollars/pound to orbit.

   Throw in a healthy profit margin, let's say 16-18 million dollars to boost
a 13,500-Ib spacecraft into LEO.
Could you squeeze eight passengers into a spacecraft of an empty weight of about 11,000Ibs? OK! Let's be conservative, and more realistic, and say six passengers.
  So 18 million dollars divided by six is three million bucks per-passenger.
Not bad when you consider that the Russians send up multimillionaires,
who MUST cough up 20-30 million dollars a pop for the privilege of orbiting the earth and who MUST learn the Russian language and OBEY all the regulations and MEET all the requirements and training regimen demanded of them.

So here's the breakdown:
1) You may only have to pay 3 million, instead of 30 to orbit the earth.
2) You DON'T have to learn Russian.
3) The training and selection process won't be as byzantine nor as strict
as the Russian's.
4) And if you are not a millionaire, and if a commercial spaceport is ever
built on a Pacific island/atoll, lotteries or contests may offer you a CHANCE to go into orbit. Maybe.

 Hey! Ordinary millionaires, like pop musician, Lance Bass (remember him?), or Prince Harry, etc may finally get their chance to orbit the earth in the future with Stratolaunch. 

[Rocket Science]

Interesting factoid about the F-82 Twin Mustang.

I believe it was one of the few instances where the prototype was more capable than the production versions because the US wasnt prepared to buy British Merlin engines used in the prototype.
 

I don't want to go too OT. If you like other "Twins" that worked:

http://www.nurflugel.com/Nurflugel/n_o_d/weird_09.htm

[jongoff]

I do wonder what Rutan would think of Jon's gamma-maneuver (or whatever you call it), which should allow a sizable increase in payload without increasing the size or mass of the rocket itself. Sounds a little scary, to be honest. Scary in a good way.

I hear Kirk ran the idea by him about 5-10 years ago...the reaction was (IIRC--third hand info here) entertainingly emphatic...  Honestly, I think the only way they'd try something like that is if someone did a subscale demo first.

Another performance enhancer some have toyed with was in-flight LOX generation, ala Andrews Space.  That allows you to take off a lot lighter and gather LOX along the way.  Andrews thinks it closes, and while they're a little bit out of the box sometimes, they're also a pretty sharp company.  And with luck they may get one of the DARPA ALASA tech demonstration contracts to demo something like that. 

~Jon

[simonbp]

If all else fails, maybe you could use it to carry submarines 

I'd make one heck of a torpedo bomber; airplane drops the submarine next to the target ship, submarine torpedoes the target!

[Lee Jay]

I do wonder what Rutan would think of Jon's gamma-maneuver (or whatever you call it), which should allow a sizable increase in payload without increasing the size or mass of the rocket itself. Sounds a little scary, to be honest. Scary in a good way.

I hear Kirk ran the idea by him about 5-10 years ago...the reaction was (IIRC--third hand info here) entertainingly emphatic...  Honestly, I think the only way they'd try something like that is if someone did a subscale demo first.

What is it?

[Rocket Science]

If all else fails, maybe you could use it to carry submarines 

I'd make one heck of a torpedo bomber; airplane drops the submarine next to the target ship, submarine torpedoes the target!

Or just drop the sub on the ship

[RobLynn]

If all else fails, maybe you could use it to carry submarines 

I'd make one heck of a torpedo bomber; airplane drops the submarine next to the target ship, submarine torpedoes the target!

How about a massively increased MOAB; a 2-300 tonne bunker busting bomb.

[jongoff]

On the other hand if the rocket engines fire prior to seperation (as some have summised) then you still have an opportunity to shut them down, dump propellant and RTB with the LV pretty much intact.

I should mention that I wasn't surmising that they would light the rockets prior to separation--I was more *suggesting* it as a good approach that gives a lot of reliability and performance benefits, so long as you can deal with separation dynamics challenges properly.

~Jon

Noted and quoted thanks

Now, (not that I'm "fishing" for info here you realize) looking over the actual "Crossbow" ALTO-concept, (which I posted here to avoid running this one TOO off-topic http://forum.nasaspaceflight.com/index.php?topic=25095.msg839371#msg839371 ) I can't help but note a similarity to a concept you blogged about you and Kirk having been 'brain-storming' at one point? Care to comment on that one?

Randy

Kirk and I were looking into seeing if we could do nanosat launch using a first stage derived from Masten's Xogdor sRLV concept, with an air drop off of a UAV like a Predator C.  It looked promising, but we never got out of the really early conceptual analysis stage because the customer didn't actually have money, and it was too far out of Masten's wheelhouse at the time.  Part of why I started Altius was the thought about seeing if I could drum up customers for such a system.  We've ended up focusing more on Sticky Boom, spacecraft robotics, and trying to create markets for nanosat/microsat launchers lately, but if we had the funding opportunity to build a nanosat/microsat launch rocket to go with Sticky Boom and offer an end-to-end service, you wouldn't have to twist our arms very hard.

~Jon

[jongoff]

I do wonder what Rutan would think of Jon's gamma-maneuver (or whatever you call it), which should allow a sizable increase in payload without increasing the size or mass of the rocket itself. Sounds a little scary, to be honest. Scary in a good way.

I hear Kirk ran the idea by him about 5-10 years ago...the reaction was (IIRC--third hand info here) entertainingly emphatic...  Honestly, I think the only way they'd try something like that is if someone did a subscale demo first.

What is it?

Oh sorry, I wasn't clear.  The answer supposedly started with something like "There's no way in hell you're going to..."

Third hand info, and he may very well either have changed his mind or be open to reevaluating the view based on data and demonstrations.  At least during the press conference he mentioned the idea of putting rocket engines on the carrier plane as one option they had traded over the years.  But the idea may have somewhat of an uphill battle to convince him/others of its sanity. :-)

~Jon

[go4mars]

Expand a still from the media to your full screen and measure the ratios.  If the wingspan is 117 meters, then the rocket they show there is 5 meters diameter in my estimation. 

How about dumping the liquid oxygen if an abort is required? Liquid oxygen is one of the most environmentally friendly things to dump there is!

So is methane...

It would make for a quick and easy way to transport Falcon cores (modified to be slung under it) pretty much anywhere.

Especially if those cores get larger than 3.66 meters diameter. 

Use vacuum optimised engines with 20-30s higher ISP
Can cruise to up-range launch point to allow easier recovery of booster stages (no boost-back)
Vacuum optimised engines not as good for vertical powered landing.

Maybe if it's a 5 engine job, the middle one would be sea-level optimized for the propulsive landing ala grasshopper.

a winged F5 with flyback capability just seemed like too much complexity and too much work...It doesn't sound so crazy to me any more...

Indeed.  This would probably be the ideal system for testing out flyback side-core boosters.

Also, if only a few major airports had a capable runway, there could be two stage flights (with a middle aircraft hanging there).  "Welcome to LAX.  Passengers departing in Denver, please be sure to get on the middle part.  Passengers continuing to Chicago, please get in lines 1 or 3." 

btw.  TOO COOL!! 

[jimvela]

Oh sorry, I wasn't clear.  The answer supposedly started with something like "There's no way in hell you're going to..."

They call it conventional wisdom for a reason  . 

I keep asserting that the powered booster gamma maneuver isn't going to be well received by the folks on the airplane that have to survive launch or the folks on the ground that have to keep it in one piece.

Now if you had a fancy liquification plant on board to fill up and replenish LOX,  you might be able to save up some LN2 to inject into an after-burning jet exhaust for some extra reaction mass to do a gamma maneuver and release that way, with the booster released on an arc and lighting after the carrier aircraft has fled. 

In that case you better be darned sure the engines on that booster are going to fire up healthy and every time...

BTW, that carrier with six high bypass after-burning engines might be a better show than the booster firing up...  Though I don't know of any high bypass engines with afterburners...

[jongoff]

Oh sorry, I wasn't clear.  The answer supposedly started with something like "There's no way in hell you're going to..."

They call it conventional wisdom for a reason  . 

I keep asserting that the powered booster gamma maneuver isn't going to be well received by the folks on the airplane that have to survive launch or the folks on the ground that have to keep it in one piece.

Now if you had a fancy liquification plant on board to fill up and replenish LOX,  you might be able to save up some LN2 to inject into an after-burning jet exhaust for some extra reaction mass to do a gamma maneuver and release that way, with the booster released on an arc and lighting after the carrier aircraft has fled. 

In that case you better be darned sure the engines on that booster are going to fire up healthy and every time...

BTW, that carrier with six high bypass after-burning engines might be a better show than the booster firing up...  Though I don't know of any high bypass engines with afterburners...

At the end of the day if you're doing a reusable stage that doesn't have wings on it, gamma maneuver makes a lot of sense.  From what I've seen all of the issues look quite solvable:

1-Liquid engines are armorable as both XCOR and SpaceX have pointed out and it may even be possible to have some of the armor on the airplane so the rocket doesn't have to carry it.

2-Because rockets have a pretty known thrust level, you can design the wings and structure to take excess loads.

3-While separation dynamics and plume impingement might both be issues, there are precedents for launching missiles live off or an aircraft, so I'm pretty confident that this problem can be solved as well.

4-If the rocket is optimized for an altitude higher than the launch point (most likely) the engines will be overexpanded at launcher separation, meaning you don't have to deal with a big bushy plume.

There are details to making it work, and I know I'm bucking conventional wisdom, but quite frankly I don't have a problem with doing that.  I may be wrong, but I could probably prove the idea, one way or another, for far less than the cost of losing a single launch due to not lighting the engines before separation.  :-)

But...this may be getting off-topic.  This isn't a suggestion the Stratolaunch guys suggested, and I have no idea if they're even open to it.  If the mods want me to move further discussion elsewhere, I'd understand.

~Jon

[dbhyslop]

Oh sorry, I wasn't clear.  The answer supposedly started with something like "There's no way in hell you're going to..."

Third hand info, and he may very well either have changed his mind or be open to reevaluating the view based on data and demonstrations.  At least during the press conference he mentioned the idea of putting rocket engines on the carrier plane as one option they had traded over the years.  But the idea may have somewhat of an uphill battle to convince him/others of its sanity. :-)

~Jon

I would think the performance boost would be less of a reason than just making sure the engines lit before dropping a potentially manned booster into the sea.

Even under a scenario where Falcon is a mature and reliable launch system with dozens of launches under its belt, an occasional--if rare--pad abort is something to be fully expected, especially over the course of a hundred launches or more.  IIRC the space shuttle had several pad aborts.

Would it really be a good idea from a safety or a business standpoint to essentially be planning on dropping a couple rockets into the sea?  I would think in the "mature Falcon" scenario that several hundred ground launch flights might be made without any use of the flight abort system.  With the Stratolaunch system, assuming they drop before ignition, using the abort system is pretty much a guarantee.  On a tumbling booster, no less.

I don't post often because I'm not in the industry and have little to add, but the concept seems a little bizarre to me.  I would think some sort of "gamma maneuver" would be necessary, perhaps with the engines throttled back, or maybe only enough lit to keep the rocket in a stable attitude for an abort.  The separation dynamics would obviously be dicey, but I'm imagining the carrier releasing while near vertical while continuing to pull onto its back away from the plume, something similar to a nuke toss maneuver.