NASASpaceFlight.com Forum

Commercial and US Government Launch Vehicles => Commercial Space Flight General => Topic started by: apace on 12/13/2011 05:09 PM

Title: Stratolaunch Announcement, Updates and Discussion
Post by: apace on 12/13/2011 05:09 PM
Launch everyday from everywhere: stratolaunch.com! The new project by Mr. Allen.

Http://www.stratolaunch.com
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: 2552 on 12/13/2011 05:12 PM
Tweet from Paul Allen:

Quote from: Paul Allen
https://twitter.com/#!/PaulGAllen/status/146648676700389376 (https://twitter.com/#!/PaulGAllen/status/146648676700389376):
I have an exciting space related announcement shortly. Get sneak peek http://ow.ly/7Y8kO & watch live here in 1 hour: http://ow.ly/7Y8FD

Looks like a bigger version of WhiteKnightTwo air-launching a two-stage Falcon 5-looking booster.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: baldusi on 12/13/2011 05:24 PM
URL
Quote
STRATOLAUNCH SYSTEMS : COMPANY NEWS
Press Conference:
Paul G. Allen Announces Revolution in Space Transportation Stratolaunch System to bring safer, less expensive, missions

Click Here to Watch video of the Stratolaunch Press Conference (http://bcove.me/of1k3hy5) | Dowload this Press Release as a PDF (http://stratolaunchsystems.com/presskit/Stratolaunch_PressRelease.pdf)

SEATTLE, WA, Dec 13, 2011 – Entrepreneur and philanthropist Paul G. Allen announced today that he and aerospace pioneer Burt Rutan have reunited to develop the next generation of space travel. Allen and Rutan, whose SpaceShipOne was the first privately-funded, manned rocket ship to fly beyond earth’s atmosphere, are developing a revolutionary approach to space transportation: an air-launch system to provide orbital access to space with greater safety, cost-effectiveness and flexibility.

The space flight revolution Allen and Rutan pioneered in 2004 with SpaceShipOne now enters a new era. Only months after the last shuttle flight closed an important chapter in spaceflight, Allen is stepping in with an ambitious effort to continue America’s drive for space.

“I have long dreamed about taking the next big step in private space flight after the success of SpaceShipOne – to offer a flexible, orbital space delivery system,” Allen said. “We are at the dawn of radical change in the space launch industry. Stratolaunch Systems is pioneering an innovative solution that will revolutionize space travel.”

Allen’s new company, Stratolaunch Systems, will build a mobile launch system with three primary components:

    A carrier aircraft, developed by Scaled Composites, the aircraft manufacturer and assembler founded by Rutan. It will be the largest aircraft ever flown.
    A multi-stage booster, manufactured by Elon Musk’s Space Exploration Technologies;
    A state-of-the-art mating and integration system allowing the carrier aircraft to safely carry a booster weighing up to 490,000 pounds. It will be built by Dynetics, a leader in the field of aerospace engineering.

Stratolaunch Systems will bring airport-like operations to the launch of commercial and government payloads and, eventually, human missions. Plans call for a first flight within five years. The air-launch-to-orbit system will mean lower costs, greater safety, and more flexibility and responsiveness than is possible today with ground-based systems. Stratolaunch’s quick turnaround between launches will enable new orbital missions as well as break the logjam of missions queued up for launch facilities and a chance at space. Rutan, who has joined Stratolaunch Systems as a board member, said he was thrilled to be back working with Allen. “Paul and I pioneered private space travel with SpaceShipOne, which led to Virgin Galactic’s commercial suborbital SpaceShipTwo Program. Now, we will have the opportunity to extend that capability to orbit and beyond. Paul has proven himself a visionary with the will, commitment and courage to continue pushing the boundaries of space technology. We are well aware of the challenges ahead, but we have put together an incredible research team that will draw inspiration from Paul’s vision.”

To lead the Stratolaunch Systems team, Allen picked a veteran NASA official with years of experience in engineering, management and human spaceflight. Stratolaunch Systems CEO and President Gary Wentz, a former chief engineer at NASA, said the system’s design will revolutionize space travel.

Former NASA Administrator Mike Griffin, also a Stratolaunch board member, joined Allen and Rutan at a press conference in Seattle to announce the project. “We believe this technology has the potential to someday make spaceflight routine by removing many of the constraints associated with ground launched rockets,” Griffin said. “Our system will also provide the flexibility to launch from a large variety of locations.”

The Stratolaunch system will eventually have the capability of launching people into low earth orbit. But the company is taking a building block approach in development of the launch aircraft and booster, with initial efforts focused on unmanned payloads. Human flights will follow, after safety, reliability and operability are demonstrated.

The carrier aircraft will operate from a large airport/spaceport, such as Kennedy Space Center, and will be able to fly up to 1,300 nautical miles to the payload’s launch point.

It will use six 747 engines, have a gross weight of more than 1.2 million pounds and a wingspan of more than 380 feet. For takeoff and landing, it will require a runway 12,000 feet long. Systems onboard the launch aircraft will conduct the countdown and firing of the booster and will monitor the health of the orbital payload.

The plane will be built in a Stratolaunch hangar which will soon be under construction at the Mojave Air and Space Port. It will be near where Scaled Composites built SpaceShipOne which won Allen and Scaled Composites the $10-million Ansari X Prize in 2004 after three successful sub-orbital flights. Scaled Composites is a wholly owned subsidiary of Northrop Grumman.

“Scaled is all about achieving milestones and pursuing breakthroughs, and this project offers both – building the largest airplane in the world, and achieving the manufacturing breakthroughs that will enable Scaled to accomplish it. We are thrilled to be a part of this development program,” said Scaled Composites President Doug Shane. “We anticipate significant hiring of engineering, manufacturing, and support staff in the near and medium term.”

The multi-stage booster will be manufactured by California-based Space Exploration Technologies, one of the world’s pre-eminent space transportation companies. “Paul Allen and Burt Rutan helped generate enormous interest in space with White Knight and SpaceShipOne,” said SpaceX President Gwynne Shotwell. “There was no way we weren’t going to be involved in their next great endeavor. We are very excited.”

Dynetics will provide the mating and integration system and the systems engineering, integration, test and operations support for the entire air-launch system. The mating and integration system will be manufactured in Huntsville, Alabama in Dynetics’ new 226,500 square foot prototyping facility. Dynetics has been a leader in aerospace engineering since 1974. “We are excited to play such a major role on this system. This is an ambitious project unlike any that has been undertaken and I am confident the Stratolaunch team has the experience and capabilities to accomplish the mission,” said Dynetics Executive Vice President and Stratolaunch Board Member David King.

Stratolaunch Systems’ corporate headquarters is located in Huntsville, Alabama. Today’s announcement was the first public word that Allen and Rutan were back in the space business. But space has long been on Allen’s mind. In the close of his memoir, Idea Man, published earlier this year, he hinted at his plans, writing that he was “considering a new initiative with that magical contraption I never wearied of sketching as a boy: the rocket ship.”
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: apace on 12/13/2011 05:24 PM

I see the advantage to launch everyday, everytime and from everywhere to every inclination, but I cannot see a logistics or price advantage to launch from the biggest every build aircraft then from a simple fixed launch pad.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: corrodedNut on 12/13/2011 05:25 PM
http://www.youtube.com/watch?v=sh29Pm1Rrc0&feature=youtu.be

It's a Falcon?Dragon? airlaunch? WTF?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Space Pete on 12/13/2011 05:26 PM
Basically it's an air launched Falcon 9, for both payloads and eventually crewed Dragon.

Very cool! :)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jabe on 12/13/2011 05:27 PM
that plane is HUGE!!! logistics just to build it will be fun to see :)
I wonder what its L/D ratio is? It just looks odd..but that may be me....
stresses on the "F-5" are different..looks like it could snap in half.  the side wall strength must be SO different then  a vertical F5. press conference will be interesting...
jb
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Finn on 12/13/2011 05:28 PM
Press kit, 11 pages, http://www.stratolaunch.com/presskit/Download_PressKit.pdf
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: corrodedNut on 12/13/2011 05:29 PM
Elon to Rutan: "You got my chocolate in your peanut butter!"
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: baldusi on 12/13/2011 05:29 PM
That's a 115m wingspan, gross weight of 545tonnes, needs a 3650m landing strip, and will carry an 223tonnes Falcon 9. Uses the Mojave Air and Space Port. And I still can't believe they have Mike Griffin on the board!
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Hootz on 12/13/2011 05:30 PM
Another launcher?? How utterly unexciting. I was expecting something a lot more interesting. :( Damn.....
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: HammerD on 12/13/2011 05:30 PM
That's a 115m wingspan, gross weight of 545tonnes, needs a 3650m landing strip, and will carry an 223tonnes Falcon 9. Uses the Mojave Air and Space Port. And I still can't believe they have Mike Griffin on the board!

Seems like an ambitious project, I wish them good luck, but I wonder if it is really better than a ground launch.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: baldusi on 12/13/2011 05:33 PM
the picture depicts a Falcon 5!!!
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Owen on 12/13/2011 05:35 PM
Yup, five engines.
http://www.youtube.com/watch?v=sh29Pm1Rrc0
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: M_Puckett on 12/13/2011 05:35 PM
Thy should not need all 9 engines for an airlaunch.  The carrier plane does help some you know.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Space Pete on 12/13/2011 05:35 PM
An observation from the released images:

Falcon 9 has only 5 engines (likely due to higher release altitude, requiring less fuel/thrust), and Falcon 9 also has a wing (likely for aerodymanic stabilisation during release, but also maybe to aid in booster flyback)?

http://stratolaunchsystems.com/presskit.html
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Cherokee43v6 on 12/13/2011 05:36 PM
Cool... this even got picked up by local news outlets...

ex: http://www.wral.com/news/science/story/10495959/
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: 2552 on 12/13/2011 05:37 PM
That's a Dragon on the end, so this looks like the same 3.66m diameter tooling for the booster. At only 233 tonnes, this looks quite shortened compared to Falcon 9.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: imcub on 12/13/2011 05:37 PM
That's a 115m wingspan, gross weight of 545tonnes, needs a 3650m landing strip, and will carry an 223tonnes Falcon 9. Uses the Mojave Air and Space Port. And I still can't believe they have Mike Griffin on the board!

Seems like an ambitious project, I wish them good luck, but I wonder if it is really better than a ground launch.

Well it does get Elon his reusable first stage ...
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: ugordan on 12/13/2011 05:43 PM
It's not a Falcon 9, it's obviously got much more in common with the Falcon 5. Five engines, shorter and lighter...
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: kevin-rf on 12/13/2011 05:44 PM
6 747 engines?

Or you could say 6 787 engines, Or 6 General Electric Genx, Or 6 Rolls Royce Trent 1000 engines. Saying 747 is just trying to puff it up and make it look bigger.

So will the 5 Merlin's be Vac optimized?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: apace on 12/13/2011 05:45 PM
At the end, only a new rocket (in the delta-ii, taurus ii range) more on the market place... but good for SpaceX to get one customer more which pays for R&D.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/13/2011 05:45 PM
Weird.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: M_Puckett on 12/13/2011 05:47 PM
That's a 115m wingspan, gross weight of 545tonnes, needs a 3650m landing strip, and will carry an 223tonnes Falcon 9. Uses the Mojave Air and Space Port. And I still can't believe they have Mike Griffin on the board!

Seems like an ambitious project, I wish them good luck, but I wonder if it is really better than a ground launch.

Well it does get Elon his reusable first stage ...

I am not sure, those are stubby wings.  Reminds me of the OS Taurus.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/13/2011 05:49 PM
What imcub meant is that the AIRPLANE is sort of a "first stage." ;)

I don't want to jinx it, but I thought "Spruce Goose" when I first saw it!

This plays to some of SpaceX's strengths... They know a lot about rocket manufacture, very little experience with launch operations (and they seem to want to get away from gov't launch sites).
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jason1701 on 12/13/2011 05:49 PM
Is there still a press conference at 11 PST?

I don't see any schedules on their site.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: DaveS on 12/13/2011 05:51 PM
I am not sure, those are stubby wings.  Reminds me of the OS Taurus.
Don't you mean Pegasus? Taurus and Minotaur are ground-launched while Pegasus is airlaunched by a L-1011 Tristar.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: david1971 on 12/13/2011 05:52 PM
Two interesting notes from the FAQ:
Q. When do you see the maiden flight of new launch aircraft taking place?
A. We are still in the planning stages but we expect to conduct flight testing beginning in 2016. The first flight will occur once
we are satisfied the system is ready.

and

Q. How many jobs will this program create?
A. There are already over 100 people assigned to this effort and we will see a significant ramp-up as we move deeper into the
engineering phase then start manufacturing and eventually operations. These jobs will first be located in Alabama, California and
Florida. We are proud that the headquarters for this effort are located in the Rocket City – Huntsville, Alabama.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: stockman on 12/13/2011 05:52 PM
looks like a pegasus on steroids... not terribly revolutionary but I guess its a potential step in the right direction... baby step - certainly not anything ground breaking or far reaching... sigh...
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: corrodedNut on 12/13/2011 05:53 PM
Yeah, doesn't Scaled make those for Orbital?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Zed_Noir on 12/13/2011 05:53 PM
Wonder what flavor of Merlin is on the Stratolaunch rocket. An uprated Merlin 1-D with more powerful turbo-pump and bigger exhaust nozzle perhaps.  Anyone care to estimate the thrust  and ISP for this Merlin variant. Really don't think the ground launched Merlin engine is optimized for air-launch at 30k feet.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Space Junkie on 12/13/2011 05:53 PM
I have to admit I'm slightly disappointed. It's a neat concept, but I had hoped the announcement would involve a new payload. We don't need more launch systems. We need more customers for our current launchers.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: M_Puckett on 12/13/2011 05:54 PM
I am not sure, those are stubby wings.  Reminds me of the OS Taurus.
Don't you mean Pegasus? Taurus and Minotaur are ground-launched while Pegasus is airlaunched by a L-1011 Tristar.

You are right, that is what I meant.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: mrhuggy on 12/13/2011 05:54 PM
Is there still a press conference at 11 PST?

I don't see any schedules on their site.

Yes they are playing rocket man.

It seems spaceX has found a solution to there 3rd launch site and the avaian (aviation) mass transport.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jabe on 12/13/2011 05:54 PM
merge this with the other thread in live section?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: DaveS on 12/13/2011 05:55 PM
Yeah, doesn't Scaled make those for Orbital?
No.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: M_Puckett on 12/13/2011 05:56 PM
What imcub meant is that the AIRPLANE is sort of a "first stage." ;)

I don't want to jinx it, but I thought "Spruce Goose" when I first saw it!

This plays to some of SpaceX's strengths... They know a lot about rocket manufacture, very little experience with launch operations (and they seem to want to get away from gov't launch sites).

More like the fabled Spruce Moose that can carry passengers from the Belgian Congo to Idlewilde in a mere 17 minutes!
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: kirghizstan on 12/13/2011 05:56 PM
looks like 2 spruce geese(?) attached to each other
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Lurker Steve on 12/13/2011 05:56 PM
6 747 engines?

Or you could say 6 787 engines, Or 6 General Electric Genx, Or 6 Rolls Royce Trent 1000 engines. Saying 747 is just trying to puff it up and make it look bigger.

So will the 5 Merlin's be Vac optimized?

Maybe they are going to the find a few retired 747s in the desert, and salvage the engines.

Does this thing only launch a Dragon or a fairing that happens to be the same diameter as the core stage ? Kind of restricts the number of available payloads, right ?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: mr. mark on 12/13/2011 05:59 PM
A competitor with SKYLON except jet "first stage" launch platform does not need to go orbital only the payload. A great idea and the fact that the jet does not need to have a reentry profile is a big plus.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/13/2011 06:00 PM
Yeah, doesn't Scaled make those for Orbital?
No.

Scaled makes the Pegasus wings
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: kevin-rf on 12/13/2011 06:00 PM
Does this thing only launch a Dragon or a fairing that happens to be the same diameter as the core stage ? Kind of restricts the number of available payloads, right ?

Not only that, but how do you load the crew into the dragon? What happens  to the crew in event of an accident during takeoff? 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: ugordan on 12/13/2011 06:01 PM
We need more customers for our current launchers.

You could argue SpaceX gets some of that through this. At least component production-wise.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/13/2011 06:02 PM
(and they seem to want to get away from gov't launch sites).

How many airports have 12,000 ft runways?
Not many... But still a lot easier to take-off from an airport than launch from a launch site, private or not. One of the strengths of airlaunch.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jason1701 on 12/13/2011 06:02 PM
What's your take on this, Jim? Is it a good and economical concept? Will it have payloads?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: DaveS on 12/13/2011 06:02 PM
Yeah, doesn't Scaled make those for Orbital?
No.

Scaled makes the Pegasus wings
I'm corrected then.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: hop on 12/13/2011 06:04 PM
Reminiscent of the last item here: http://buran.ru/htm/molniya7.htm

I find this whole thing a bit puzzling, but it will be interesting to see where it goes.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/13/2011 06:04 PM
(and they seem to want to get away from gov't launch sites).

How many airports have 12,000 ft runways?
Not many... But still a lot easier to take-off from an airport than launch from a launch site, private or not. One of the strengths of airlaunch.

How many airports can support spacecraft processing and propellant loading?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: mmeijeri on 12/13/2011 06:04 PM
We need more customers for our current launchers.

Maybe, but it's Paul Allen's money and he gets to decide what to spend it on...
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Hootz on 12/13/2011 06:05 PM
Allen said in a press release. "We are at the dawn of radical change in the space launch industry. Stratolaunch Systems is pioneering an innovative solution that will revolutionize space travel."

My question is....where are they going to travel TO??

We have no shortage of launchers, a handful of spacecraft are coming online.....

But where is everyone going to go?? I just don't get it I guess....
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Chris Bergin on 12/13/2011 06:08 PM
Merged the two threads we had going on this.

Webcast is here:
http://link.brightcove.com/services/player/bcpid1316857262001?bckey=AQ~~,AAABMklbUZE~,U0IycbIeqecfyrhclca62HAXd4vQ6H28&bctid=1318582131001
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: kevin-rf on 12/13/2011 06:10 PM
How many airports can support spacecraft processing and propellant loading?

Isn't a better question how many payloads can handle rolling down a runway horizontally while fully fueled?

Jim I think between the lines you appear to be seeing holes you can fly two 747's through here ;)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: mr. mark on 12/13/2011 06:11 PM
I'm hoping that this takes off from Spaceport America. What a great idea that would be and would get them into hosting orbital operations. If this can be modified for a manned Dragon then I see Virgin Galactic jumping aboard SpaceX Dragon operations. Too soon to tell. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/13/2011 06:12 PM
(and they seem to want to get away from gov't launch sites).

How many airports have 12,000 ft runways?
Not many... But still a lot easier to take-off from an airport than launch from a launch site, private or not. One of the strengths of airlaunch.

How many airports can support spacecraft processing and propellant loading?
Not many. :) One wonders, though, if spacecraft integration could be done at Vandenberg and then flown (empty) to another airport before finally taking off, like Pegasus does. Of course, the last airport needs to load the fuel and oxidizer (especially oxidizer).
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/13/2011 06:13 PM
How many airports can support spacecraft processing and propellant loading?

Look at it this way, would this be able to operate out of LAX, which is right next to Boeing and Northrup Grumman or DEN for LM? 

The infrastructure is going to be the same as a pad and launch site.  Will need LOX and RP-1 tanks/spheres next to the runway, there will need to be a "hot pad" so that the launch vehicle can be loaded with the propellants away from other areas and structures.  This same area can be used for spacecraft to launch vehicle mate. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: M_Puckett on 12/13/2011 06:13 PM
(and they seem to want to get away from gov't launch sites).

How many airports have 12,000 ft runways?
Not many... But still a lot easier to take-off from an airport than launch from a launch site, private or not. One of the strengths of airlaunch.

How many airports can support spacecraft processing and propellant loading?

KSC and Vandenberg come to mind.  Not much else.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: baldusi on 12/13/2011 06:13 PM
I see that they spoke about using the aircraft for cargo, too. It's bigger than the an-225, can carry the same payload, but has 25m extra of wingspan (i.e. not good), needs 150m extra of runway, and it's not based of any known design. I still wonder if they could have looked for a better way to tap into the heavy and oversized cargo market of the an-124/225.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: savuporo on 12/13/2011 06:14 PM
Isn't a better question how many payloads can handle rolling down a runway horizontally while fully fueled?
Perhaps a completely new kind of payloads - i.e. don't think satellites of today. Just a guess.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/13/2011 06:15 PM
I'm hoping that this takes off from Spaceport America. What a great idea that would be and would get them into hosting orbital operations. If this can be modified for a manned Dragon then I see Virgin Galactic jumping aboard SpaceX Dragon operations. Too soon to tell. 

I hope KSC and VAFB.  no need add more duplicate facilities.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Chris-A on 12/13/2011 06:16 PM
Here is a second question, How can this work over land? Crash landing in a desert? Probably only over the ocean.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jabe on 12/13/2011 06:18 PM
curious,
boil off issues while getting to launch altitude?
jb
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Chris Bergin on 12/13/2011 06:18 PM
Paul Allen mentions he watched Columbia on STS-1 :)

Mentions CxP cancellation. Mentions no US access to space.

Cargo and crew missions via air launch. End of the decade for debut.

Nothing on destinations etc.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/13/2011 06:21 PM
Jim, is this a viable concept?

Do you mean technically or financially?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/13/2011 06:21 PM
(and they seem to want to get away from gov't launch sites).

How many airports have 12,000 ft runways?
Not many... But still a lot easier to take-off from an airport than launch from a launch site, private or not. One of the strengths of airlaunch.

How many airports can support spacecraft processing and propellant loading?

KSC and Vandenberg come to mind.  Not much else.
That would make sense... Pegasus is based out of Vandenberg and does integration there; SpaceX's headquarters are quite nearby. They'll need one on the west coast, since the orbital mission range is 1300 nautical miles (i.e. when the rocket is fueled).
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: strangequark on 12/13/2011 06:21 PM
curious,
boil off issues while getting to launch altitude?
jb

Shouldn't be a big problem. Just LOX, no LH2.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/13/2011 06:21 PM
curious,
boil off issues while getting to launch altitude?
jb

Replenishment from carrier aircraft like X-15 did.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jason1701 on 12/13/2011 06:22 PM
Jim, is this a viable concept?

Do you mean technically or financially?

Both. Does the business have a bright future? Will it get payloads?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: edkyle99 on 12/13/2011 06:23 PM
Launch everyday from everywhere: stratolaunch.com! The new project by Mr. Allen.

Http://www.stratolaunch.com

Flying with a cryo bomb, first of all, gives me pause.  Will they have to dump propellant to land in case of abort?  There will be aborts.   

The cost seems dicey.  SpaceX will have to build and prep a two stage rocket nearly as costly as a full-up Falcon 9, but then will only be able to get 60% of a Falcon 9 payload to orbit. 

Maybe someone sees other needs for a supergiant aircraft.  How else could this pay off?

 - Ed Kyle
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Chris Bergin on 12/13/2011 06:24 PM
Heh, Burt doesn't like the video as it doesn't show the perspective of the size of the plane.

Talks about the history of the plane.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Guy on 12/13/2011 06:24 PM
This notion of "anytime, any orbit, any place" is ridiculous. This is no different from any other rocket here. They will not be launching this thing over land in the US, and they still can't go polar from the east coast or east from the west coast. And as Jim said, facilities.

What happens with this thing if the engine doesn't ignite? And I'll be curious about how they fuel, top off, pressurize etc.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: edkyle99 on 12/13/2011 06:27 PM
This notion of "anytime, any orbit, any place" is ridiculous. This is no different from any other rocket here. They will not be launching this thing over land in the US, and they still can't go polar from the east coast or east from the west coast. And as Jim said, facilities.

Shouldn't this be able to do polar after taking off from the Cape?  It can go very long range before drop-launch, so should be able to line it up mid-ocean aiming for the Arctic.

 - Ed Kyle
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: M_Puckett on 12/13/2011 06:28 PM
Better hope it can make orbit on 4 engines or at least abort gracefully.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Chris Bergin on 12/13/2011 06:28 PM
Mike Griffin is there! :o I missed him on the wide shot! ;D

Burt comes across as a very likable chap.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/13/2011 06:30 PM
curious,
boil off issues while getting to launch altitude?
jb

Shouldn't be a big problem. Just LOX, no LH2.
Sure, but LH2 will give it a much larger payload to orbit while keeping within the carrier aircraft's capabilities. Many orbital airlaunch concepts assume hydrogen for this reason.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Space Junkie on 12/13/2011 06:30 PM
If nothing else, Burt gets to build a huge airplane...
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: deltaV on 12/13/2011 06:33 PM
6 747 engines?

Or you could say 6 787 engines, Or 6 General Electric Genx, Or 6 Rolls Royce Trent 1000 engines. Saying 747 is just trying to puff it up and make it look bigger.

The 747 is far better known than the 787, GE Genx, or Rolls Trent 1000. The way they described it is therefore a much clearer way to communicate with laymen then the alternatives you proposed.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/13/2011 06:34 PM
curious,
boil off issues while getting to launch altitude?
jb

Shouldn't be a big problem. Just LOX, no LH2.

One potential solution I wrote about on Selenian Boondocks: http://selenianboondocks.com/2011/11/tooting-someone-elses-horn-quest-product-development-corps-advanced-mli-technologies/

These guys are developing two products (LR-MLI and LV-MLI) that could do the trick.

~Jon
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Chris Bergin on 12/13/2011 06:35 PM
Here he is.

Notes the dominance of gov involvement with commercial space. Makes a dig at that, over efficiency.

Hopes this will all be before the end of the decade.

Notes that 30 percent of the first 10 flights of a new rocket fails historically. Chancey business.

That was short.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Guy on 12/13/2011 06:36 PM

Shouldn't this be able to do polar after taking off from the Cape?  It can go very long range before drop-launch, so should be able to line it up mid-ocean aiming for the Arctic.

 - Ed Kyle

I guess that is true. Seems like a "why would they go 1,300 miles out into the Atlantic" where it is riskier, when you can go right off California as they do.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Chris Bergin on 12/13/2011 06:37 PM
Lots of people in the audience from the company, which explains all the applause going on.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: savuporo on 12/13/2011 06:37 PM
If nothing else, Burt gets to build a huge airplane...
Didnt he retire ??
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Space Junkie on 12/13/2011 06:39 PM
If nothing else, Burt gets to build a huge airplane...
Didnt he retire ??

He's doing this one for fun in his home hobby shop.  ;D
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/13/2011 06:40 PM
It's good to see that Paul understands the order of magnitude of investment he's going to need to put into this to make it work.

~Jon
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Namechange User on 12/13/2011 06:40 PM
LOL, I bet some peoples heads are exploding at this moment because all their assumptions about everything have been turned on their head to some degree....
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jason1701 on 12/13/2011 06:41 PM
I'd love to hear OV's prediction as well. Will they get customers and turn a profit?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: rcoppola on 12/13/2011 06:43 PM
Interesting but a bit perplexing and a bit disappointing. (not that I have a right to be, it's their show)

As for Space X, do they really need another effort? Crewed dragon (including propulsive landing variant), M1D, F9H, possibly Red Dragon and a 3rd alternate launch port seems like quite a bit over the next few years.





Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jason1701 on 12/13/2011 06:44 PM
Allen noting that the partner companies are not investing any of their own money.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Confusador on 12/13/2011 06:45 PM
Good to see Griffith honest about the drawbacks of the airplane .  Advantages are on the operational side.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/13/2011 06:45 PM
Interesting that SpaceX (and Scaled and Dynetics) will be subcontractors, not investors... Helps with revenue streams. (SpaceX already has a lot on their plate, so another investment would be difficult for them.)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Chris Bergin on 12/13/2011 06:48 PM
A fair amount of shuttle references and ex shuttle involvement - which is refreshing compared to the snubs by Branson's crews.

Some questions.

Still in discussions on actual launch site.

Not going to give numbers on the business model.

Mike doesn't know if this is a "better" way to launch humans. Notes some advantages/limitations. (+Weather -Growth).

Burt - air launch is big for suborbit. For orbital it's 5-10 percent better than ground launch.

Paul Allen is head, rest are all subcontractors. They think they have a lot of customers potentially. Notes the Russians are charging $63m a seat.

Don't want to give competition any numbers or technical information.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: reesekw on 12/13/2011 06:50 PM
This was a great idea when it was called Pegasus.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Lee Jay on 12/13/2011 06:51 PM
Not only that, but how do you load the crew into the dragon?

Not sure, but I'm sure a broom-stick will be involved.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/13/2011 06:54 PM
Looks like they're trading 4 or 5 Merlin engines, trading various methods to do the turn into the right flight path angle, and currently not baselining first stage reusability (though open to the possibility if it looks good in the trades).

~Jon
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/13/2011 06:56 PM
I like the reference to payloads made with unskilled labor at home...

~Jon
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/13/2011 06:56 PM
Burt: "There's a number of payloads that are easily built with unskilled labor at home." :D
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/13/2011 06:58 PM
It's also interesting to see that they're using this to go after the Delta II market that OSC's Antares vehicle was also going after...
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Chris Bergin on 12/13/2011 07:01 PM
Mike: It's well known I've been critical of some aspects of commercial space, where funding is given ahead of achievements (or close to that - was standard Mr Griffin :))

Thinks Paul Allen has demostrated the quality of being able to continue through the failures they will have.


--


Booster will be a Falcon 4 or 5.

Not yet at the PDR stage.

It exists in 100s of detailed drawings. Need a building big enough to build it. Have acquired two 747s.

Initial test flights for aircraft 2015. Initial launch 2016.

Not sure of main customer yet. Mike notes comm sats. Thinks they compare to Delta II performance as a gap in the market (what about Antares??). Burt says home made sats?

Initially this will be unmanned cargo, not to the ISS. NASA have strict Visiting Vehicle requirements.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Lee Jay on 12/13/2011 07:03 PM
I'm hoping that this takes off from Spaceport America. What a great idea that would be and would get them into hosting orbital operations. If this can be modified for a manned Dragon then I see Virgin Galactic jumping aboard SpaceX Dragon operations. Too soon to tell. 

I hope KSC and VAFB.  no need add more duplicate facilities.

Do you think Vandenburg's runway is wide enough for this thing?  The wingspan is over twice the runway width.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: corrodedNut on 12/13/2011 07:04 PM
I vote for Burt Rutan and Mike Griffin as the new "Odd Couple".
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: mr. mark on 12/13/2011 07:04 PM
Interesting, I'm assuming they will be using a Dragon spacecraft to ISS. What would be the difference? Not sure what Mike is on about?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/13/2011 07:05 PM
Burt says home made sats?

Home made *payloads*, not sats... Think self-loading cargo...

~Jon
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: david1971 on 12/13/2011 07:06 PM
Initially this will be unmanned cargo, not to the ISS. NASA have strict Visiting Vehicle requirements.

What's the definition of cargo here?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/13/2011 07:06 PM
I'm hoping that this takes off from Spaceport America. What a great idea that would be and would get them into hosting orbital operations. If this can be modified for a manned Dragon then I see Virgin Galactic jumping aboard SpaceX Dragon operations. Too soon to tell. 

I hope KSC and VAFB.  no need add more duplicate facilities.

Do you think Vandenburg's runway is wide enough for this thing?  The wingspan is over twice the runway width.

Same as KSC
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: The_Ronin on 12/13/2011 07:09 PM
Well, if anyone can build a bird like that, it would be Rutan.

I am a bit puzzled on the WHY even as Allen makes his case.  I'm not even sure VAFB could handle this bird.  KSC has the runway to make the first case, but then where?  New Mexico?

Seems like a lot of risk for such little payoff.

I was really hoping to hear something about Bigelow... one day soon (hopefully).

I'm starting to believe we will never see a BA330 or BA2100 in orbit.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Chris Bergin on 12/13/2011 07:09 PM
Burt troubled by it becoming more expensive to put people into orbit than in early days.

Pulling the safety card out on Shuttle.

Paul Allen pauses about flying on one of his own vehicles! Opps. Wants to do cargo before talking about crew.

Burt tries to convience him.

Wants a large number of flights before he goes on one. "I'm a very conservative guy".

Don't think that was in Branson's PR playbook.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Nathan on 12/13/2011 07:11 PM
Launch everyday from everywhere: stratolaunch.com! The new project by Mr. Allen.

Http://www.stratolaunch.com

Flying with a cryo bomb, first of all, gives me pause.  Will they have to dump propellant to land in case of abort?  There will be aborts.   

The cost seems dicey.  SpaceX will have to build and prep a two stage rocket nearly as costly as a full-up Falcon 9, but then will only be able to get 60% of a Falcon 9 payload to orbit. 

Maybe someone sees other needs for a supergiant aircraft.  How else could this pay off?

 - Ed Kyle
Using five engines instead of nine has to work out cheaper. Video though said 13500 pounds to orbit which is 6.1kg. Can't figure out if this is payload within the dragon capsule or includes the capsule itself. If latter then dragon not that useful.


Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Ronsmytheiii on 12/13/2011 07:13 PM
Well one thing is for sure, this wont be for DoD payloads (Payload will be horizontal, DoD needs them vertical)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Chris Bergin on 12/13/2011 07:14 PM
Make a big deal about flexibility of payload, launch site and orbit in the closing comments.

Gets a bit crazy at the end as the company people start clapping and he doesn't get to end his statement :D

And that's over. Can't help thinking it's a massive Pegasus, basically.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: hyper_snyper on 12/13/2011 07:19 PM
What does air launch buy you again?  A little bit of performance?  But most of the delta v needed to get to orbit is horizontal so it doesn't help that much.  You still need the same amount of ground support complexity plus now you have a huge airplane to maintain. 

I don't get it at all. This is just like one more launch site for F9. But launch sites already exists for Falcon 9.  I'll read more into it when I get home.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/13/2011 07:22 PM
Can't use Spacex's holddown before launch PR spin
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: KEdward5 on 12/13/2011 07:23 PM
Thanks for the notes Chris. Excited about this?

Can we maybe have a poll?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: mr. mark on 12/13/2011 07:23 PM
I'm curious about payload performance. Can a standard Dragon capsule be launched using this system or will it have to be modified. Some of Griffin's comments seemed a bit brief when it came to discussing payload to ISS. If they plan on using a Dragon for cargo to ISS i'm not sure what the requirement differences would be on the Dragon?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: hyper_snyper on 12/13/2011 07:24 PM
Can't use Spacex's holddown before launch PR spin

HAHA now that's a funny image.  ;D  Would be a heck of a ride before the wings snap off.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Chris Bergin on 12/13/2011 07:24 PM
Thanks for the notes Chris. Excited about this?

Can we maybe have a poll?

All rockets are exciting ;D

Poll on if it's exciting?? Err, maybe later. It's only just been announced.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Space Junkie on 12/13/2011 07:24 PM
Well, if anyone can build a bird like that, it would be Rutan.

I am a bit puzzled on the WHY even as Allen makes his case.

Maybe you answered your own question. Allen is interested in space travel. His friend Burt builds vehicles with wings.

If you're holding a hammer...
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Ronsmytheiii on 12/13/2011 07:26 PM
I cant say that I am getting excited for the project in that I dont really forsee it going through.  Even Orbital is getting away from air launch, and going with Taurus/Minotaur that use Pegasus stages and a zero stage rocket instead of the L-1011.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: mtakala24 on 12/13/2011 07:27 PM
It will get somewhat exciting when they have some hardware to show. And popcorn-time will come with flight tests. For now, it only causes some tingly feelings. :P
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: strangequark on 12/13/2011 07:30 PM
Like Chris said, all rockets are exciting. That said, I was really hoping, given the location, that this was going to involve Blue Origin, and funding for a two-stage fully reusable.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Zed_Noir on 12/13/2011 07:31 PM
I'm hoping that this takes off from Spaceport America. What a great idea that would be and would get them into hosting orbital operations. If this can be modified for a manned Dragon then I see Virgin Galactic jumping aboard SpaceX Dragon operations. Too soon to tell. 

I hope KSC and VAFB.  no need add more duplicate facilities.

Do you think Vandenburg's runway is wide enough for this thing?  The wingspan is over twice the runway width.

Same as KSC

As long as the total width of the landing gears fits on the runway, it should work. It's like an A3 Sky Warrior or an A5 Vigilante catapulting off a carrier.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Lee Jay on 12/13/2011 07:31 PM
I'm hoping that this takes off from Spaceport America. What a great idea that would be and would get them into hosting orbital operations. If this can be modified for a manned Dragon then I see Virgin Galactic jumping aboard SpaceX Dragon operations. Too soon to tell. 

I hope KSC and VAFB.  no need add more duplicate facilities.

Do you think Vandenburg's runway is wide enough for this thing?  The wingspan is over twice the runway width.

Same as KSC

The SLF is twice as wide.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Lee Jay on 12/13/2011 07:32 PM
As long as the total width of the landing gears fits on the runway, it should work. It's like an A3 Sky Warrior or an A5 Vigilante catapulting off a carrier.

You do need margin for steering and landing inaccuracies, and you have to make sure there aren't things off the runway to clip.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Hauerg on 12/13/2011 07:41 PM
Looks like a tanker to me. And a lot like the cvx proposal by t/space before ESAS study showed us the way to the past. But using available parts wherever possible like dragon, merlins, falcon 9 machining etc.
Without recovery of first stage i just cannot understand what the business case does look like. The F5 stage simply cannot be not cheap enough.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: wolfpack on 12/13/2011 07:45 PM
As long as the total width of the landing gears fits on the runway, it should work. It's like an A3 Sky Warrior or an A5 Vigilante catapulting off a carrier.

You do need margin for steering and landing inaccuracies, and you have to make sure there aren't things off the runway to clip.

Runways are cheap compared to aircraft, launch vehicles and spacecraft. Especially out west, where geology has just about built them for you! How many takeoff/landing site would it need?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: HammerD on 12/13/2011 07:51 PM
As long as the total width of the landing gears fits on the runway, it should work. It's like an A3 Sky Warrior or an A5 Vigilante catapulting off a carrier.

You do need margin for steering and landing inaccuracies, and you have to make sure there aren't things off the runway to clip.

Runways are cheap compared to aircraft, launch vehicles and spacecraft. Especially out west, where geology has just about built them for you! How many takeoff/landing site would it need?

Sure but you are going to need FAA clearance to launch this over land.  Are they going to get that when they are essentially carrying a huge bomb?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: SpacexULA on 12/13/2011 07:52 PM
Can't use Spacex's holddown before launch PR spin

Could they fire all 5 engines before the vehcile is released?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Lars_J on 12/13/2011 07:55 PM
Falcon 5 lives! ;-) (in PowerPoint at least)

I like the concept of air launch, but the fuzzy details make me a bit skeptical. But I'm hoping for the best. Nice for SpaceX to have another revenue stream, even if it might not be significant initially.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jeff Lerner on 12/13/2011 07:55 PM
...only thing missing was having Mike Griffin call this "Pegasus on Steroids".....:)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Tcommon on 12/13/2011 07:58 PM
can't download the press kit yet and didn't see the webcase but my take from the video on youtube ...

-more complicated than an F9 launch, probably more expensive
-evolution towards reusable components
-ability to launch at different latitudes, but carrier only doesn't have that great a range or speed.

I don't see many advantages for this yet.

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: savuporo on 12/13/2011 07:58 PM
Even as the concept is fairly "meh" as it looks like right now ( but we dont know what their intended market is ) at least it is another major investment in new type of launch capability, maybe it will help attract mode angel type funding to the area.

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: BeanEstimator on 12/13/2011 08:02 PM
what the hey?

because we have such a large market for commercial sats to orbit we need another option?

because we have such a long list of rich folks waiting for rides into space? (how many has spaceshipone carried thus far?)

because launching from a pad is bad practice?

maybe it's just me...but i don't understand where this is going, or what they expect their business to do.  then again, they have all the money, and i'm just a working stiff...what do i know.

Quote
Do you mean technically or financially?

i would assume that the latter would be important...since we have available options today to technically accomplish what they propose (payload to leo)

Quote
LOL, I bet some peoples heads are exploding at this moment because all their assumptions about everything have been turned on their head to some degree...

the only thing my head is doing is shaking from left to right, repeatedly

Quote
Plans call for a first flight within five years.

riiightttt....i assume that's first test flight.  how many people/tourists/etc have we launched collectively thus far mr. rutan, mr. musk, and mr. branson?

Quote
The air-launch-to-orbit system will mean lower costs, greater safety, and more flexibility and responsiveness than is possible today with ground-based systems.

will be interested to hear how this is backed up and supported by evidence with analysis.  i don't dispute we are ineffective today.  i do find it hard to reconcile a completely new air to launch system, with lower costs.

Quote
Stratolaunch’s quick turnaround between launches will enable new orbital missions as well as break the logjam of missions queued up for launch facilities and a chance at space.

we have a logjam of payloads just sitting around?  who knew?


sorry to be a sour puss.  i just don't get it.  don't get me wrong, i love innovation.  think outside the box.  do it differently.  but at this point, i'm not a buyer.  one thing i will say, is hopefully the continued announcements from commercial (f9h, red dragon, osc @ wallops, this, etc.) will get people re-interested in space.  good luck to them, and here's to hoping the market appears like they have forecasted.  maybe my future kids and grandkids will get to ride on one. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/13/2011 08:04 PM

Runways are cheap compared to aircraft, launch vehicles and spacecraft. Especially out west, where geology has just about built them for you! How many takeoff/landing site would it need?

Not true, see this link

http://forum.nasaspaceflight.com/index.php?topic=27520.msg838854#msg838854
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: iamlucky13 on 12/13/2011 08:06 PM
Wow...I would never have guessed this would be the announcement.

A few comments, some in reference to past posts, others just my thoughts:

 - Ed Kyle had an astute point about fuel and landing in case of a post-takeoff abort. Maximum landing weights are typically substantially less than maximum takeoff weights.

 - An-225 has about a 2500 mile range with a 550,000 pound payload. A 1300 mile radius in a twin fuselage aircraft with additional equipment for fuel topoff and drop sounds ambitious.

 - 1.2 million pounds is less than the max takeoff weight of either the An-225 or the A380, although the 385 foot wingspan is 65 feet longer than the next widest span ever built - the Spruce Goose.

 - The nose of the aircraft is visually similar to a 747. Since the rest of the fuselage has nothing in common with a 747 (most importantly the high-mounted wing), I can think of no practical reason for this. The 747's hump was created to accommodate the nose door on the freighter version.

 - The current Falcon does not have to deal with horizontal gravity loads while fueled. Significant structural modification would be expected.

 - You can build a Vandenberg pad plus a lot of Falcon 9's for the billions of dollars this plane will cost to build. I'm really puzzled by this architecture.

 - You only save a couple percent on energy due to the altitude and speed of a carrier aircraft.

 - You potentially gain a few percent in ISP by starting at a higher altitude with optimized nozzles.

 - It would be impossible to say for sure right now they're planning on using the current 747 engine option (GEnx or Trent 1000). It could just as easily be the more cheaply available CF-6 series. They have similar thrust ratings, and I doubt the fuel efficiency gains would cover the added cost for a low flight rate aircraft like this.

- Video cites 9200 mile "alternate cargo range." I've seen pictures of the An-225 being loaded with cargo that barely fits and requires custom handling equipment. A centerline cargo pod might find them some specialty business like that. Consider that you have rockets with 5 meter fairings, but if you move payloads by aircraft, the largest has a 4.4 meter high load height, including the transport container.

- 13,500 pounds to LEO. Unsurprisingly a fair amount lower than the Falcon 9 or EELV.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: ugordan on 12/13/2011 08:06 PM
Quote
Plans call for a first flight within five years.

riiightttt....i assume that's first test flight.  how many people/tourists/etc have we launched collectively thus far mr. rutan, mr. musk, and mr. branson?

And just what do space tourists have to do with this?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: JMS on 12/13/2011 08:08 PM
What a shame Rutan, Griffin, Musk and Allen didn't consult with the members of this forum first before embarrassing themselves with this proposal.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: mmeijeri on 12/13/2011 08:08 PM
And just what do space tourists have to do with this?

They are the countless payloads made at home with unskilled labour.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: ugordan on 12/13/2011 08:09 PM
What a shame Rutan, Griffin, Musk and Allen didn't consult with the members of this forum first before embarrassing themselves with this proposal.

LOL.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: sdsds on 12/13/2011 08:11 PM
Did they explicitly say the systems integration role falls to Stratolaunch?  Who does Stratolaunch employ with credentials for that?  Somebody with a long background handling big projects at e.g. LM or Boeing?  Unless they want things done "the NASA way" it doesn't seem like a long career as a NASA bureaucrat counts!

Did they say anything about contingencies on the runway, during initial climb out, during carrier flight, or at rocket separation/ignition?

Dynetics is privately held but presumably Griffin knows the principals there well (given the Huntsville connection).  The Dynetics prototyping facility is less than a year old, if it is even complete yet:
Dynetics breaks ground on 226,500-square-foot prototyping facility
Published: Monday, November 15, 2010

http://blog.al.com/huntsville-times-business/2010/11/dynetics_breaks_ground_on_2265.html

Has Dynetics been involved in projects like this attach/disconnect system in the past?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jkew on 12/13/2011 08:13 PM
can't download the press kit yet and didn't see the webcase but my take from the video on youtube ...

-more complicated than an F9 launch, probably more expensive
-evolution towards reusable components
-ability to launch at different latitudes, but carrier only doesn't have that great a range or speed.

I don't see many advantages for this yet.



I would add to advantages
   - launch under more diverse weather conditions
   - ability to fly out towards a more unpopulated area or the ocean for the launch
   - results in a carrier plane for other large rockets ( may help resolve the problem of getting falcon 9s to the cape )
   - fewer engines to lose to the sea
   - appears to be an evolutionary change from the SS2 ( SS3? )

The little wings on the falcon 4/5 also make me think of a fly-back booster, but that's grossly speculative.

Disadvantages:
   - much more complicated
   - rocket needs to held horizontally, fully fueled during flight; significant change to the structure
   - possible fairing size issues
   - possible payload integration issues
   - as Jim mentioned no hold-back
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/13/2011 08:14 PM
So is Griffin going to get them to put an SRB on it?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: wolfpack on 12/13/2011 08:16 PM

Runways are cheap compared to aircraft, launch vehicles and spacecraft. Especially out west, where geology has just about built them for you! How many takeoff/landing site would it need?

Not true, see this link

http://forum.nasaspaceflight.com/index.php?topic=27520.msg838854#msg838854

I said runways. I agree ground support facilities are NOT cheap. A runway is a giant concrete rectangle. Or a dry lake bed with some paint on it.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: space_dreamer on 12/13/2011 08:17 PM
I am excited about this, it could be a great system for manned space flight in the 2020s. 

However the bottom line is we are still at least 5 years away from private manned space flight and its badly needed now. This 5 year wait just makes money for Russia and could kill off the Bigelow space station. Then by the end of the decade there will be over capacity with several space ships and no where for them to go. (apart from two flights per year to the ISS)

IMHO A better investment would have been to fast track the SpaceX manned dragon and the Bigelow BA330 space station.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: BeanEstimator on 12/13/2011 08:18 PM
Quote
Plans call for a first flight within five years.

riiightttt....i assume that's first test flight.  how many people/tourists/etc have we launched collectively thus far mr. rutan, mr. musk, and mr. branson?

And just what do space tourists have to do with this?

i prefer the other posters humorous response...but allow me to expand.

this is, as they seem to be portraying it, a natural evolution of spaceshipone and spaceshiptwo.  both of those have a distinctly "space tourist" angle to them, do they not? 

this is in their statement: 

Quote
The Stratolaunch system will eventually have the capability of launching people into low earth orbit. But the company is taking a building block approach in development of the launch aircraft and booster, with initial efforts focused on unmanned payloads. Human flights will follow, after safety, reliability and operability are demonstrated.

people, whether they be "astronauts" or "space tourists" seem to be part of their equation. 

if space tourists, people, spam, garage built payloads (though i would propose bedroom built payloads as more proper term) are not part of their business then cool.  my bad. 

that means commercial payloads are their business.  and by extension government payloads

i didn't know we had a glut of commercial and gov payloads hanging out waiting for rides.  afaik, we have payloads on schedule, way out in the future.  you do have que issues, competition, etc.  perhaps i am drawing too distinct a line between "logjam" and "future planning".

hey its their money.  if they want to spend it on this, or something else, i'm all for it.  and as i said, at least it promotes space and keeps it in the publics eye.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: strangequark on 12/13/2011 08:18 PM
So is Griffin going to get them to put an SRB on it?

Of course, to make it safe. It should be a simple thing to do, too, so we can expect it to happen soon.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: BeanEstimator on 12/13/2011 08:18 PM
So is Griffin going to get them to put an SRB on it?

only if it's a five segment  ;)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Space OurSoul on 12/13/2011 08:21 PM
Some other things occur to me:

There's another hidden cost with crew launch: given that the booster's initial ground track would be over ocean, there would have to be a rescue ship pre-placed should the booster fail to light, since that Dragon's gonna make a splash-down not so very far away. (But maybe the Dragon can propulsively land on the ship's heli-pad :-) )


The flexibility of inclination and phase would position this system well to be the LON for many a customer. Might be a possible revenue stream.


Interesting times.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: iamlucky13 on 12/13/2011 08:21 PM
As long as the total width of the landing gears fits on the runway, it should work. It's like an A3 Sky Warrior or an A5 Vigilante catapulting off a carrier.

You do need margin for steering and landing inaccuracies, and you have to make sure there aren't things off the runway to clip.

Wing clearance isn't a major issue. There's several hundred feet of clear space on either side of a runway to any major obstacles like buildings. Smaller obstacles can theoretically be rebuilt.

However, in general engines aren't allowed to overhang off pavement because of FOD concerns.

Can't use Spacex's holddown before launch PR spin

Could they fire all 5 engines before the vehcile is released?

You'd be adding another half million pounds of thrust to an aircraft designed to take 2/3 that. That would also exert a very large torque about a single point on the wings, risk the aircraft taking debris from any engine failures, and have to deal with the plume.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: ugordan on 12/13/2011 08:22 PM
So is Griffin going to get them to put an SRB on it?

One could always claim the booster will need some ullage rockets to settle the propellants before ignition  ::)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Tim S on 12/13/2011 08:24 PM
Hard to judge with so little info.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: ugordan on 12/13/2011 08:26 PM
i prefer the other posters humorous response...but allow me to expand.

this is, as they seem to be portraying it, a natural evolution of spaceshipone and spaceshiptwo.  both of those have a distinctly "space tourist" angle to them, do they not? 

Not really, the press conference was mainly about payloads of the Delta II class and any human launch would be more in the future.

this is in their statement: 

Quote
The Stratolaunch system will eventually have the capability of launching people into low earth orbit. But the company is taking a building block approach in development of the launch aircraft and booster, with initial efforts focused on unmanned payloads. Human flights will follow, after safety, reliability and operability are demonstrated.

people, whether they be "astronauts" or "space tourists" seem to be part of their equation. 

So you have a problem with none of them actually having flown any humans to space to date, despite the obvious "eventually" part above?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Chris Bergin on 12/13/2011 08:27 PM
Another previous concept bumped on L2 Historical:

"Air Launch (Crossbow) carrier - Delta IV"
(L2 Members: http://forum.nasaspaceflight.com/index.php?topic=2011.0 )
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: deltaV on 12/13/2011 08:28 PM
What does air launch buy you again?  A little bit of performance?  But most of the delta v needed to get to orbit is horizontal so it doesn't help that much.  You still need the same amount of ground support complexity plus now you have a huge airplane to maintain. 

I don't get it at all. This is just like one more launch site for F9. But launch sites already exists for Falcon 9.  I'll read more into it when I get home.
Technically it seems unlikely that air launch would help enough to be worth the trouble, but air launch hasn't been explored sufficiently for anyone to say for sure.  If it were my money I would spend it on other projects, but Paul Allen is the billionaire.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: ugordan on 12/13/2011 08:29 PM
If it were my money I would spend it on other projects, but Paul Allen is the billionaire.

Well put.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: AnalogMan on 12/13/2011 08:29 PM
Did they explicitly say the systems integration role falls to Stratolaunch?  Who does Stratolaunch employ with credentials for that?  Somebody with a long background handling big projects at e.g. LM or Boeing?  Unless they want things done "the NASA way" it doesn't seem like a long career as a NASA bureaucrat counts!

Did they say anything about contingencies on the runway, during initial climb out, during carrier flight, or at rocket separation/ignition?

Dynetics is privately held but presumably Griffin knows the principals there well (given the Huntsville connection).  The Dynetics prototyping facility is less than a year old, if it is even complete yet:
Dynetics breaks ground on 226,500-square-foot prototyping facility
Published: Monday, November 15, 2010

http://blog.al.com/huntsville-times-business/2010/11/dynetics_breaks_ground_on_2265.html (http://blog.al.com/huntsville-times-business/2010/11/dynetics_breaks_ground_on_2265.html)

Has Dynetics been involved in projects like this attach/disconnect system in the past?

From the press kit:

"SpaceX will provide the booster and space launch mission design and mission integration services; Dynetics will provide program management and systems engineering and integration, as well as test and operations support to Stratolaunch; Dynetics will also build the mating and integration system hardware."
...

Dynetics
Founded in 1974 in Huntsville, Alabama, Dynetics provides engineering, research, and development products and services to both government and commercial customers. Dynetics enjoys a growing presence in five strategic business areas: intelligence, missiles, aviation, cyber, and space. It has extensive experience in large air-dropped payloads, including leading the development, integration, and flight of the world’s largest precision-guided air dropped systems, the Massive Ordnance Air Blast (MOAB), and providing support to the follow-on program, the Boeing Massive Ordnance Penetrator (MOP).

Dynetics has extensive aerospace systems integration and analysis experience from programs such as FASTSAT, our commercial satellite; the Multi Purpose Nano Missile System (MNMS), a small launch system for the U.S. Army Space and Missile Defense Command; and numerous complex missile and aviation defense integration projects.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: 93143 on 12/13/2011 08:29 PM
...so SpaceShipThree is actually Dragon?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: wolfpack on 12/13/2011 08:30 PM

However, in general engines aren't allowed to overhang off pavement because of FOD concerns.


Yes. I almost saw an L-1011 ingest a bunny rabbit while looking out the window. I called the flight attendant over but they didn't seem too worried. I guess Bugs would have registered somewhere on the flight deck if he decided to inspect the turbofan!
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: sdsds on 12/13/2011 08:33 PM
given that the booster's initial ground track would be over ocean, there would have to be a rescue ship pre-placed should the booster fail to light, since that Dragon's gonna make a splash-down not so very far away.

I don't see that as an absolute.  This could be one of those Dragon's that has considerable abort propellant it can use for soft touchdowns on land.

If the carrier flight path is from the U.S. southwest out over the Pacific, then the impact point of the rocket would likely trace a path over e.g. Guatemala before crossing the Caribbean.  Conceivably there is an abort opportunity leading to a soft landing there.

Of course the whole picture would look better if the spacecraft on the nose of the rocket looked more like a Dreamchaser!  ;)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: BeanEstimator on 12/13/2011 08:37 PM
i prefer the other posters humorous response...but allow me to expand.

this is, as they seem to be portraying it, a natural evolution of spaceshipone and spaceshiptwo.  both of those have a distinctly "space tourist" angle to them, do they not? 

Not really, the press conference was mainly about payloads of the Delta II class and any human launch would be more in the future.

this is in their statement: 

Quote
The Stratolaunch system will eventually have the capability of launching people into low earth orbit. But the company is taking a building block approach in development of the launch aircraft and booster, with initial efforts focused on unmanned payloads. Human flights will follow, after safety, reliability and operability are demonstrated.

people, whether they be "astronauts" or "space tourists" seem to be part of their equation. 

So you have a problem with none of them actually having flown any humans to space to date, despite the obvious "eventually" part above?

Perhaps I read a different statement then...

Quote
Rutan, who has joined Stratolaunch Systems as a board member, said he was thrilled to be back working with Allen. “Paul and I pioneered private space travel with SpaceShipOne, which led to Virgin Galactic’s commercial suborbital SpaceShipTwo Program. Now, we will have the opportunity to extend that capability to orbit and beyond.

I don't have any "problems".  I have "concerns"   :D

Chief among them being:  assuming that a market exists today, and/or that a market will materialize in the future for what they are proposing.  Secondary being: this is somehow more cost effective, and/or cheaper (admittedly the jury will be out on that for quite some time)

You may disagree, fine.  You may think this has nothing to do with people and/or space tourists, fine.  You may think this has nothing to do with SS1 or SS2, fine.  That's not how I read their statement, nor how I perceived their presser.

I propose we go back to naming and describing the "numerous payloads built by unskilled labor" in our garages and bedrooms.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: ugordan on 12/13/2011 08:39 PM
Of course the whole picture would look better if the spacecraft on the nose of the rocket looked more like a Dreamchaser!  ;)

Or, dragging all this back toward slightly more realistic scenarios... a normal fairing on top of the booster, see artwork http://stratolaunch.com/

You all are getting way ahead of something that's already way out there.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Nascent Ascent on 12/13/2011 08:42 PM
Hey Paul Allen!  We really could have used a lunar lander...

Just saying..   :D
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: sdsds on 12/13/2011 08:48 PM
From the press kit:

"[...] Dynetics will provide program management and systems engineering and integration, as well as test and operations support to Stratolaunch; Dynetics will also build the mating and integration system hardware."

Ah, my apologies for not reading more closely.  Looking deeper, it seems the talented staff at Dynetics includes Steve Cook, former Ares Launch Vehicle program manager.  http://stratolaunch.com/readmore_dynetics.html
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Space OurSoul on 12/13/2011 08:51 PM
I hadn't noticed this part before:

"At the end of the press conference, Mr. Griffin held up a poster of his alternative design, stating that use of existing components, only slightly modified, would provide a more reliable system sooner."

I've attached a snipped from a screen capture of the webcast.

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Chris Bergin on 12/13/2011 08:55 PM
I hadn't noticed this part before:

"At the end of the press conference, Mr. Griffin held up a poster of his alternative design, stating that use of existing components, only slightly modified, would provide a more reliable system sooner."

I've attached a snipped from a screen capture of the webcast.



Eh? I watched the webcast all the way through to it going black and this was not shown. And that doesn't even look like a screen capture. What gives??
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: BeanEstimator on 12/13/2011 08:56 PM
I hadn't noticed this part before:

"At the end of the press conference, Mr. Griffin held up a poster of his alternative design, stating that use of existing components, only slightly modified, would provide a more reliable system sooner."

I've attached a snipped from a screen capture of the webcast.



That's mean...I just spit coffee on my keyboard.  Now I have to clean that stuff up. 

edit to add:  hey chris...it's sarcasm :)

(http://fc05.deviantart.net/fs71/f/2010/077/c/3/The_Sarcasm_Misunderstanding_by_ThePlotThinnens.jpg)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: tigerade on 12/13/2011 08:56 PM
This proposal is either insane or brilliant.  I'm betting on insane, but hey I'm not going to tell Paul Allen how to invest his money.  My hope here is that, if this isn't successful, that new technologies are developed that make spaceflight cheaper and more reliable.  It would be a step towards reusability.  This is all going to be pure wait-and-see for the next 5 years.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: kirghizstan on 12/13/2011 08:59 PM
too bad there isn't a like button for this post

I hadn't noticed this part before:

"At the end of the press conference, Mr. Griffin held up a poster of his alternative design, stating that use of existing components, only slightly modified, would provide a more reliable system sooner."

I've attached a snipped from a screen capture of the webcast.


Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Chris Bergin on 12/13/2011 08:59 PM

hey chris...it's sarcasm :)

(http://fc05.deviantart.net/fs71/f/2010/077/c/3/The_Sarcasm_Misunderstanding_by_ThePlotThinnens.jpg)

Bazinga!!

Damn! ;)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: deltaV on 12/13/2011 09:02 PM
- Ed Kyle had an astute point about fuel and landing in case of a post-takeoff abort. Maximum landing weights are typically substantially less than maximum takeoff weights.

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!

Quote
- An-225 has about a 2500 mile range with a 550,000 pound payload. A 1300 mile radius in a twin fuselage aircraft with additional equipment for fuel topoff and drop sounds ambitious.

Boeing's 747-100 had a range of 5300 nm in the 1960s. Burt Rutan has successfully designed and built two different three-fuselage aircraft with 26,000 mile range: http://en.wikipedia.org/wiki/Rutan_Voyager and http://en.wikipedia.org/wiki/Virgin_Atlantic_GlobalFlyer .  I don't understand why you expect a measly range of 2600 miles to challenge Rutan.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: simonbp on 12/13/2011 09:04 PM
...only thing missing was having Mike Griffin call this "Pegasus on Steroids".....:)

Wildthing wins the thread.

KSC does seem the most logical, what with the SLF, payload integration facilities, and existing SpaceX support facilities. And, just because they takeoff from KSC doesn't mean they actually launch in the Atlantic Test Range (i.e. just go off in into international waters), alleviating the range constraints that SpaceX has complained about.

Of course, another option is Korou, which has similar advantages to KSC, but closer to the equator. Or, why not LAX, going out to sea a good bit before launching.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/13/2011 09:09 PM
Ah, a side step to my Flyback Falcon concept… hmmm  ;)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: krytek on 12/13/2011 09:09 PM
So what do you think about the none space launch applications of the plane itself?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: deltaV on 12/13/2011 09:15 PM
"When Rutan replied that it would never fly, Griffin held up the following other poster"
The 747-8F has a max payload of 0.3 million pounds. The shuttle stack masses about 4.5 million pounds, or about 15 747's worth. Your extremely humorous proposal would require on the order of 60 engines.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Space Junkie on 12/13/2011 09:16 PM
This proposal is either insane or brilliant.

I just decided I don't care if it's a good concept or not. I want to see that plane fly!
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Tcommon on 12/13/2011 09:18 PM
Still don't get it, what am I missing ...

This system has less capability and is more complicated than an F9, and probably more expensive. The advantages are relatively minor.

Maybe Allen wants to launch payload and SpaceX is the cheapest supplier of stages?

Maybe the system is the beginning on a evolutionary design working towards reusability?

Maybe SpaceX is happy for more F5 work, especially with the upgraded merlins, and this is a good way for someone else to pay for it?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/13/2011 09:19 PM
So what do you think about the none space launch applications of the plane itself?
I think the a/c as a multi use platform is interesting for both R&D test flights and possibly for a multi-mission military purposes.   
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Lee Jay on 12/13/2011 09:23 PM
As long as the total width of the landing gears fits on the runway, it should work. It's like an A3 Sky Warrior or an A5 Vigilante catapulting off a carrier.

You do need margin for steering and landing inaccuracies, and you have to make sure there aren't things off the runway to clip.

Runways are cheap compared to aircraft, launch vehicles and spacecraft. Especially out west, where geology has just about built them for you! How many takeoff/landing site would it need?

DIA's international runway was $166 million.  It's roughly the size of the difference between the SLF and the runway at VAFB.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jimvela on 12/13/2011 09:24 PM
So what do you think about the none space launch applications of the plane itself?

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

Note I didn't say cheap.

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RobLynn on 12/13/2011 09:28 PM
Advantages:
1/ Pick your orbital inclination.
2/ Save 4-500m/s deltaV
3/ Use vacuum optimised engines with 20-30s higher ISP
4/ Can cruise to up-range launch point to allow easier recovery of booster stages (no boost-back)
5/ Fewer issues with range safety, noise and NIMBYs

Downsides:
1/ lateral fully fuelled g-loading will probably require heavier LV structure.
2/ Big expensive plane to develop and maintain.
3/ Vacuum optimised engines not as good for vertical powered landing.
4/ Potentially huge torsional loads on center wing without a secondary bridging connection at the tail.

Guesses:
1/ Launch LV empty and fuel in-flight to improve safety and reduce lateral stresses on LV and other components as well as perhaps reducing need for LV tank insulation.
2/ Start rockets before release for safety checkout and then while continuing to refuel, use rocket power to enable swoop upwards and acceleration up to near Mach 1 at maximum atltiude
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: hop on 12/13/2011 09:30 PM
Maybe SpaceX is happy for more F5 work, especially with the upgraded merlins, and this is a good way for someone else to pay for it?
There's an interesting question here. The statement in the press conference was that this wouldn't compete with F9, because it was a smaller payload class. Much was made of capturing the Delta II class market. Now, if SpaceX thought there was a big market there, they could just build Falcon 5. So the answer seems to be they didn't think it was worth doing on their own dime, or don't have the cash to try.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Prober on 12/13/2011 09:30 PM
So is Griffin going to get them to put an SRB on it?

You wish them to carry a "Liberty" Jim?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Astromark on 12/13/2011 09:32 PM
Cool... this even got picked up by local news outlets...

ex: http://www.wral.com/news/science/story/10495959/

But oddly, not by nasaspaceflight.com. Yet.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: hop on 12/13/2011 09:34 PM
3/ Vacuum optimised engines not as good for vertical powered landing.
Wild thought: if you have wings on the first stage anyway, maybe you land it on a runway ?  ;D OK, probably won't work given the very different flight regimes, but if there is a tricky way to make work, Rutan would be the guy to do it.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: alk3997 on 12/13/2011 09:37 PM
I've got a few operational questions...

1) How does the payload / crew get into the Dragon?  If it's payload I guess it gets loaded in the hanger.  But, for people that would mean the crew is loaded before the booster is fueled, since propellant loading would have to take place outside the hanger.  So how is this done?

2) How do you dump prop without affecting the flying capabilities of the turbofans?  Nothing like dumping a bunch of liquid oxygen to change the mixture ratio.  I'll have to go back and look at how Pegasus does this.

Andy
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: DaveS on 12/13/2011 09:40 PM
2) How do you dump prop without affecting the flying capabilities of the turbofans?  Nothing like dumping a bunch of liquid oxygen to change the mixture ratio.  I'll have to go back and look at how Pegasus does this.

Andy
Pegasus is all-solid, there's nothing to dump in the event of a scrub.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/13/2011 09:40 PM
As long as the total width of the landing gears fits on the runway, it should work. It's like an A3 Sky Warrior or an A5 Vigilante catapulting off a carrier.

You do need margin for steering and landing inaccuracies, and you have to make sure there aren't things off the runway to clip.

Runways are cheap compared to aircraft, launch vehicles and spacecraft. Especially out west, where geology has just about built them for you! How many takeoff/landing site would it need?

Sure but you are going to need FAA clearance to launch this over land.  Are they going to get that when they are essentially carrying a huge bomb?

Quite possibly, because there are plenty of ways of mitigating those risks...remember people have been studying this general concept for decades.  It's not like you're the first one to think of most of these concerns.

~Jon
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jimvela on 12/13/2011 09:41 PM
Maybe SpaceX is happy for more F5 work, especially with the upgraded merlins, and this is a good way for someone else to pay for it?
There's an interesting question here. The statement in the press conference was that this wouldn't compete with F9, because it was a smaller payload class. Much was made of capturing the Delta II class market. Now, if SpaceX thought there was a big market there, they could just build Falcon 5. So the answer seems to be they didn't think it was worth doing on their own dime, or don't have the cash to try.

Once upon a time, I had the insane idea that an interesting F9 configuration would be to strap on a couple of F5 sized boosters using the  9-engine thrust structure and use them as boosters.  It almost made sense if the boosters could fly back.

I discounted it in part because a winged F5 with flyback capability just seemed like too much complexity and too much work.  I was also pretty sure that with all the other things SpaceX was doing, there wasn't any money around to fund such a crazy idea.

It doesn't sound so crazy to me any more... So aside from building a F5 booster, I can see where SpaceX could benefit from the development activities associated with this activity.

I'm not at all convinced this stratolaunch concept is a practical thing, but I for one would sure like to see one fly someday.

Edit: Plus, if SpaceX ever wanted to license one of Rutan's novel swivel-wing recovery methods for a booster (hint, hint)- this would be a good way to end up with such a license...
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/13/2011 09:43 PM
What a shame Rutan, Griffin, Musk and Allen didn't consult with the members of this forum first before embarrassing themselves with this proposal.

:-)

You beat me to the punch.

~Jon
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: MP99 on 12/13/2011 09:48 PM
- The nose of the aircraft is visually similar to a 747. Since the rest of the fuselage has nothing in common with a 747 (most importantly the high-mounted wing), I can think of no practical reason for this. The 747's hump was created to accommodate the nose door on the freighter version.

 - The current Falcon does not have to deal with horizontal gravity loads while fueled. Significant structural modification would be expected.


Could that hump be there because the two fuselages contain large fuel tanks? I'm wondering if the Falcon is empty (bu pressurised) when it takes off, then is fuelled up at altitude.

I'm assuming that loads on the Falcon would be greatest at takeoff, and that would reduce stresses? Sounds pretty hairy, though.



This whole thing does seem rather weird to me. A group of people are going to get into a Dragon, then spend a nervous couple of hours strapped on their backs while the plane takes off and manoeuvres towards launch?

As Jim says, those Merlins had better light first time.

It seems to trade four Merlins for a reduced payload and having to maintain a big plane, and Falcon doesn't seem to have the recovery hardware that I'd have expected. Perhaps because it's too heavy. Max payload of the plane is less than half that of F9 (about the same in pounds instead of kg).

But, with recovery hardware, it would seem to be a candidate for Jon Goff's http://selenianboondocks.com/2008/09/orbital-access-methodologies-part-vi-air-launched-glideforward-tsto/ (http://selenianboondocks.com/2008/09/orbital-access-methodologies-part-vi-air-launched-glideforward-tsto/).

cheers, Martin

Edit: and I'm sure Glynn Shotwell said that they'd looked at an F5 with M1D (nearly same thrust as 9x M1C) but it had some controllability issues.

Edit 2: Looks like RobLynn beat me to most of this.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/13/2011 09:48 PM
You'd be adding another half million pounds of thrust to an aircraft designed to take 2/3 that. That would also exert a very large torque about a single point on the wings, risk the aircraft taking debris from any engine failures, and have to deal with the plume.

And all of those are ones that can be mitigated easily if designed in from the start.  As a bonus, doing such a rocket assisted zoom climb (or gamma maneuver) saves you a lot of delta-V in gravity losses, eliminates the need for the Pegasus wing, and reduces the bending moments on the rocket stages allowing you to have lighter structures.

Plus the whole making sure you don't drop a fully-loaded rocket till you know its engines are working properly.

There *are* definitely engineering considerations, but Kirk Sorensen sold me years ago on this approach making a lot of sense.  Compared to a wingless drop-and-light approach you're talking about as much as a 500m/s reduction in delta-V to orbit.

~Jon
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/13/2011 09:52 PM
I’m sorry if I can’t get too excited by all this. Unless a system becomes simple and fully reusable, I just can’t grasp the point of the concept yet. I need more time to think on it a bit…
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jimvela on 12/13/2011 09:57 PM
And all of those are ones that can be mitigated easily if designed in from the start. 

The pilot would need some serious stones to be willing to have a burning F5 go zinging by the cockpit at close range and high airspeed. 

Way big stones.

Kelly Johnson and company had nightmares with separating (from above) a smaller vehicle from a larger one at supersonic speeds. 

I'd imagine similar problems with that in a rocket-powered zoom climb configuration of this thing.

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: iamlucky13 on 12/13/2011 09:59 PM
This proposal is either insane or brilliant.  I'm betting on insane, but hey I'm not going to tell Paul Allen how to invest his money.

Yes, it's his right to decide how to spend the money, but that doesn't mean the rest of us have to forfeit our opinions on how best to spend it. I've got plenty of opinions myself, but for now I'm just a little awestruck at the ambition he's displaying (perhaps naively).

I just decided I don't care if it's a good concept or not. I want to see that plane fly!

I have to agree with your sentiments there. I'd be thrilled to see it fly, even if I don't think he can make money with it.

- Ed Kyle had an astute point about fuel and landing in case of a post-takeoff abort. Maximum landing weights are typically substantially less than maximum takeoff weights.

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!

That is potentially feasible, although dumping only one fuel screws with your center of gravity. Landing weight is a complication, not a showstopper.

Quote
Quote
- An-225 has about a 2500 mile range with a 550,000 pound payload. A 1300 mile radius in a twin fuselage aircraft with additional equipment for fuel topoff and drop sounds ambitious.

Boeing's 747-100 had a range of 5300 nm in the 1960s. Burt Rutan has successfully designed and built two different three-fuselage aircraft with 26,000 mile range: http://en.wikipedia.org/wiki/Rutan_Voyager and http://en.wikipedia.org/wiki/Virgin_Atlantic_GlobalFlyer .  I don't understand why you expect a measly range of 2600 miles to challenge Rutan.

Global Flyer was only 17% airplane and payload by weight, and the payload was almost nothing. The rest was fuel. It was very structurally efficient, but not very versatile.

Aircraft often trade payload for fuel. It's not terribly uncommon for airliners flying longer routes to have to bump passengers when a headwind is expected (or divert if one comes up unexpectedly).

Stratolauncher doesn't have that luxury. They have a more or less fixed half-million pound payload.

If the carrier aircraft comes in overweight as design progresses, they have little recourse but to reduce the range.

If you assume Scaled can achieve an empty weight comparable to the An-225, add on the weight of the rocket, then a 1.2 million pound MTOW leaves you 82,000 pounds for fuel - about 1/4 what the 747-100 could carry.

Flying half the distance on 1/4 the fuel in a much larger plane with 50% more engines sounds questionable. It seems almost certain they plan to build a lighter plane than the An-225.

That's where my skepticism comes in. Scaled is great at building light aircraft, and this one is helped by not needing most of the fuselage volume pressurized, but they have two fuselages to carry, a bigger wing with a very beefy center section, and a collection of launch support equipment. They also don't have hundreds of planes to amortize development cost over to make lots of weight optimizing feasible.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/13/2011 10:00 PM
Advantages:
1/ Pick your orbital inclination.
2/ Save 4-500m/s deltaV
3/ Use vacuum optimised engines with 20-30s higher ISP
4/ Can cruise to up-range launch point to allow easier recovery of booster stages (no boost-back)
5/ Fewer issues with range safety, noise and NIMBYs

Glad you saw #4.  Here's a few more:

1-You can actually save as much as 1000m/s of losses by air-launching so long as you release in a good flight path angle (zoom climb or rocket-assisted zoom climb)
2-For manned launches, launch escape is easier, especially if you have one of the propellants (probably the Kero) stored on the airplane until a few minutes before the launch.  Max Q is tons lower, and the "pad abort" type scenario is also easier.
3-Much easier to do first-orbit rendezvous for space facilities, which matters a lot for manned flight and higher ops tempos.
4-Makes it easier to ferry a rocket from the factory to the launch site...no need for trains, trucks, or barges.

Quote
Downsides:
1/ lateral fully fuelled g-loading will probably require heavier LV structure.
2/ Big expensive plane to develop and maintain.
3/ Vacuum optimised engines not as good for vertical powered landing.
4/ Potentially huge torsional loads on center wing without a secondary bridging connection at the tail.

Guesses:
1/ Launch LV empty and fuel in-flight to improve safety and reduce lateral stresses on LV and other components as well as perhaps reducing need for LV tank insulation.
2/ Start rockets before release for safety checkout and then while continuing to refuel, use rocket power to enable swoop upwards and acceleration up to near Mach 1 at maximum atltiude

While they didn't appear to be baselining either of those options, I agree that rocket assisted zoom climb to get a good flight path angle (and check out the engines) is a great idea, and having at least one of the propellants stored on the airplane and transferred right before launch is also a good idea. 

~Jon
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Dappa on 12/13/2011 10:01 PM
- The nose of the aircraft is visually similar to a 747. Since the rest of the fuselage has nothing in common with a 747 (most importantly the high-mounted wing), I can think of no practical reason for this. The 747's hump was created to accommodate the nose door on the freighter version.
Could that hump be there because the two fuselages contain large fuel tanks? I'm wondering if the Falcon is empty (bu pressurized) when it takes off, then is fueled up at altitude.

Or could it be because you don't want to have the rocket next to the cockpit? I can imagine that a pilot wants to look over the payload fairing, not have his view blocked by it.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/13/2011 10:03 PM
And all of those are ones that can be mitigated easily if designed in from the start. 

The pilot would need some serious stones to be willing to have a burning F5 go zinging by the cockpit at close range and high airspeed. 

Way big stones.

Kelly Johnson and company had nightmares with separating (from above) a smaller vehicle from a larger one at supersonic speeds. 

I'd imagine similar problems with that in a rocket-powered zoom climb configuration of this thing.

You wouldn't separate at supersonic speeds.  You're just using the airplane's wings to bend the velocity vector upwards before separation.  This is something you could totally prove-out thoroughly in subscale.

The idea of mid-air refueling of aircraft used to be considered scary too.

:-)

~Jon
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Namechange User on 12/13/2011 10:08 PM
I'm slightly annoyed by some of the comments on this thread.

So many yesterday (on the thread that has disappeared) were going on and on, basically SpaceX-gushing, about how great today would be and my comments on that thread were seemingly on point.

Now, with this thread, too many are dismissing it without knowning anything about it in reality (nor likely qualified to speak about it).  You want commercial?  This is commercial, not a dime to be taken from the government, but instead someone trying to do something with private capital.  That is outstanding news but instead it is meeting with grumbling. 

Also, here is Paul Allen, Burt Rutan, Mike Griffin, etc standing shoulder-to-shoulder discussing a very unique concept, which invalidates the arm-wavers running around always spewing Griffin-Hate.  It's stupid and childish (and the same goes for that other website) and personally, I believe, why the "space community" is not taken seriously. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Chris Bergin on 12/13/2011 10:11 PM
Cool... this even got picked up by local news outlets...

ex: http://www.wral.com/news/science/story/10495959/

But oddly, not by nasaspaceflight.com. Yet.

1) The local news didn't pick it up. They just selected what AP articles they'd paste into their site. It even says AP in the byline.

2) We technically already did with this thread. No interest in rehashing the press release, available in this thread. And hopefully we'll have a more interesting article via Isaac soon, per arrangement.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: lorahpj on 12/13/2011 10:11 PM
Advantages:
1/ Pick your orbital inclination.
2/ Save 4-500m/s deltaV
3/ Use vacuum optimised engines with 20-30s higher ISP
4/ Can cruise to up-range launch point to allow easier recovery of booster stages (no boost-back)
5/ Fewer issues with range safety, noise and NIMBYs

Downsides:
1/ lateral fully fuelled g-loading will probably require heavier LV structure.
2/ Big expensive plane to develop and maintain.
3/ Vacuum optimised engines not as good for vertical powered landing.
4/ Potentially huge torsional loads on center wing without a secondary bridging connection at the tail.

Guesses:
1/ Launch LV empty and fuel in-flight to improve safety and reduce lateral stresses on LV and other components as well as perhaps reducing need for LV tank insulation.
2/ Start rockets before release for safety checkout and then while continuing to refuel, use rocket power to enable swoop upwards and acceleration up to near Mach 1 at maximum atltiude

I wonder if the advantages are enough.

I have always thought a Gryphon style launch concept (similar to some of the 70's Shuttle proposals) would be a huge breakthrough and a more natural follow-on to SpaceShipTwo - the 1st stage aircraft would take a SpaceShipOne/Two style flight trajectory (fully reusable and quickly turned around) and would loft a 2nd stage rocket with payload.

A Gryphon style carrier could also be used for dedicated suborbital flights - a variant without payload carrying capability could haul a lot of passengers (space tourists) on suborbital ballistic flights cheaply.  Now whether there is enough demand, is a completely separate question.
http://www.andrews-space.com/content-main.php?subsection=MTA4
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: HammerD on 12/13/2011 10:13 PM
This proposal is either insane or brilliant.  I'm betting on insane, but hey I'm not going to tell Paul Allen how to invest his money.  My hope here is that, if this isn't successful, that new technologies are developed that make spaceflight cheaper and more reliable.  It would be a step towards reusability.  This is all going to be pure wait-and-see for the next 5 years.

I applaud the efforts but if I had the cash I would have spent it on developing a lander or a spacecraft like the Nautilus X or some other craft to get us beyond LEO, or they could have announced a program to return to the moon using Falcon 9 or Falcon 9 Heavy.

I think there are enough commercial satellite launchers either already available or in development.

I also think this is will turn out to be very expensive way of launching (more expensive than a Falcon 9 with less capability)....just IMHO.

Wish them the best but disappointed in what was announced.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/13/2011 10:18 PM
Why does everybody talk about recovery?  They explicitly say they are not doing it.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/13/2011 10:18 PM
I'm slightly annoyed by some of the comments on this thread.

So many yesterday (on the thread that has disappeared) were going on and on, basically SpaceX-gushing, about how great today would be and my comments on that thread were seemingly on point.

Now, with this thread, too many are dismissing it without knowning anything about it in reality (nor likely qualified to speak about it).  You want commercial?  This is commercial, not a dime to be taken from the government, but instead someone trying to do something with private capital.  That is outstanding news but instead it is meeting with grumbling. 

Also, here is Paul Allen, Burt Rutan, Mike Griffin, etc standing shoulder-to-shoulder discussing a very unique concept, which invalidates the arm-wavers running around always spewing Griffin-Hate.  It's stupid and childish (and the same goes for that other website) and personally, I believe, why the "space community" is not taken seriously. 

Yeah, I have to agree that it's always impressive as hell to see someone like Mr Allen with the balls to put several hundred $M on the line for something that people are so ready to nay-say.  I think they've got a technical approach that while not identical to what I've been looking at over the years, is still perfectly workable (and definitely lower development risk).  I think they've got a good shot to make a real difference here, and am looking forward to seeing more details coming out.

I'm also looking forward to seeing posts 5-7yrs from now by people currently nay-saying the idea claiming that they always knew it would work.

~Jon
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: apace on 12/13/2011 10:22 PM
Why does everybody talk about recovery?  They explicitly say they are not doing it.

Looking into it later they told, but not start with it. So the question will be, why they think, their concept of a 3 stage launch system is cheaper than a 2 stage rocket. Hope it works, but I cannot belive it.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: mr. mark on 12/13/2011 10:23 PM
Is the SpaceX rocket and Dragon capsule subcontracted for Stratolaunch or licenced for use in this system? I was wondering if Spacex retains ownership of their portion of the vehicle such as the Dragon spacecraft.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/13/2011 10:24 PM
I think they've got a good shot to make a real difference here, and am looking forward to seeing more details coming out.


that is the real question.  It is technical feasibly but economic.

Also, it is all on Allen; Rutan and Musk have no skin in the game.  As far as they are concerned, why not? they have nothing to lose.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/13/2011 10:24 PM
Is the SpaceX rocket and Dragon capsule subcontracted for Stratolaunch

Read the documents
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Prober on 12/13/2011 10:28 PM
Compare with this design
Svitiaz

http://www.yuzhnoye.com/index.php?id=30&path=Aerospace Technology/Launch Vehicles/Svitiaz/Svitiaz_e&lang=en

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/13/2011 10:28 PM
Why does everybody talk about recovery?  They explicitly say they are not doing it.

Well, they said that they hadn't ruled it out of the trades, but weren't currently planning on it.  I think air-launch actually makes recovery/reuse a *ton* easier (see the link MP99 provided above to my article on the idea from several years ago), but I agree that at this juncture they're not pitching this as a reusable system at all.  I hope they change their mind, but would understand if they didn't.

~Jon
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/13/2011 10:31 PM
I think they've got a good shot to make a real difference here, and am looking forward to seeing more details coming out.


that is the real question.  It is technical feasibly but economic.

Also, it is all on Allen; Rutan and Musk have no skin in the game.  As far as they are concerned, why not? they have nothing to lose.

While I think Allen expects to make a profit on this, he also may be willing to take a much higher risk than other investors.  That's the one nicest things about a philantrocapital setup--is that you're not facing the same economics that other capitalist ventures typically face.  The personal, non-economic interests of the philantrocapitalist matter a lot.  If Allen were say, willing to write-off the startup costs as "sunk costs", I'm just about positive he could make a good profit from there.  The bigger challenge will be making sure it's a profit without him mentally writing off the initial investment.

That make any sense?

~Jon
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: iamlucky13 on 12/13/2011 10:38 PM
You'd be adding another half million pounds of thrust to an aircraft designed to take 2/3 that. That would also exert a very large torque about a single point on the wings, risk the aircraft taking debris from any engine failures, and have to deal with the plume.

And all of those are ones that can be mitigated easily if designed in from the start.  As a bonus, doing such a rocket assisted zoom climb (or gamma maneuver) saves you a lot of delta-V in gravity losses, eliminates the need for the Pegasus wing, and reduces the bending moments on the rocket stages allowing you to have lighter structures.

Plus the whole making sure you don't drop a fully-loaded rocket till you know its engines are working properly.

Well, yes, they can be mitigated, but building the wing to take that kind of torque doesn't help with keeping aircraft mass down, and I'm not sure you can ever really be confident you won't have an uncontained engine failure.

As for delta-V, you'd lose about 9.8 m/s for each second between release and ignition, right?

I'm not sure you gain reduced bending moments. I assume that little wing doesn't generate anywhere near 1 G of lift, but the rocket has to take over 1 G in lateral loads while being carried.

I'm also not sure about mitigating plume affects. We're talking about 1000+ pounds per second of a 3000 m/s exhaust stream at several thousand degrees potentially impinging on an aluminum and composite airframe.

I also didn't previously consider acoustic effects.

I understand your arguments, but to me it looks like it's risking a few hundred million dollars in payload versus risking the aircrew and a one-off aircraft that is likely worth more than most payloads, plus leaves your business dead in the water for a couple years while you build a replacement.

As far as bending the velocity vector upwards, the video animation shows a pitch up maneuver before release. That should be possible simply using the aircraft's momentum.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: simonbp on 12/13/2011 10:42 PM
Well, they said that they hadn't ruled it out of the trades, but weren't currently planning on it.

And, for what it's worth, vertical landing the much shorter/lighter Falcon 4/5 would be a heck of lot easier than the very long Falcon 9 first stage. So, even if it's not used operationally, Stratolaunch could be a good test platform for SpaceX's recovery development (a kind of Grasshopper 2).
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jason1701 on 12/13/2011 10:50 PM
Did they say if the plane will be aluminum or composite?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/13/2011 10:52 PM
Ian,

It's more complicated than that. 

Just do a quick thought experiment.

You drop the vehicle and light the engine 3 seconds later.  That means the engine has just under 30m/s of downward velocity at ignition.

Say your rocket stage has a T/W ratio of 1.4:1 (which is actually really high for a liquid rocket).  That means that your net upward acceleraiton is 4m/s^2.  Which means you end up taking 7.5s to null out the initial downward velocity.  But in that time, you've taken about 75s of gravity losses in addition to your 30m/s of downward velocity drop.

There are papers going into the physics of all this, but the short answer is that you need your velocity vector at the point the rocket leaves the aircraft under powered flight to be pointed at a fairly steep angle to get the most out of an air launch.  Otherwise you end up losing back most of the delta-V benefit from the air launch.

The small pull-up they showed in the video will help a little, but not as much as a full-up zoom climb.


That said, you don't *need* to do things this way, and I doubt that it makes sense for Stratolaunch to take that much development risk on.  I was just pointing out that if you wanted to use the rocket-assisted zoom-climb (and there are some real benefits), these problems can be solved, and in fact several groups have previously investigated the concept and felt it was workable. 

~Jon

You'd be adding another half million pounds of thrust to an aircraft designed to take 2/3 that. That would also exert a very large torque about a single point on the wings, risk the aircraft taking debris from any engine failures, and have to deal with the plume.

And all of those are ones that can be mitigated easily if designed in from the start.  As a bonus, doing such a rocket assisted zoom climb (or gamma maneuver) saves you a lot of delta-V in gravity losses, eliminates the need for the Pegasus wing, and reduces the bending moments on the rocket stages allowing you to have lighter structures.

Plus the whole making sure you don't drop a fully-loaded rocket till you know its engines are working properly.

Well, yes, they can be mitigated, but building the wing to take that kind of torque doesn't help with keeping aircraft mass down, and I'm not sure you can ever really be confident you won't have an uncontained engine failure.

As for delta-V, you'd lose about 9.8 m/s for each second between release and ignition, right?

I'm not sure you gain reduced bending moments. I assume that little wing doesn't generate anywhere near 1 G of lift, but the rocket has to take over 1 G in lateral loads while being carried.

I'm also not sure about mitigating plume affects. We're talking about 1000+ pounds per second of a 3000 m/s exhaust stream at several thousand degrees potentially impinging on an aluminum and composite airframe.

I also didn't previously consider acoustic effects.

I understand your arguments, but to me it looks like it's risking a few hundred million dollars in payload versus risking the aircrew and a one-off aircraft that is likely worth more than most payloads, plus leaves your business dead in the water for a couple years while you build a replacement.

As far as bending the velocity vector upwards, the video animation shows a pitch up maneuver before release. That should be possible simply using the aircraft's momentum.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/13/2011 10:52 PM
Did they say if the plane will be aluminum or composite?

I can't remember if they explicitly said it, but come on, this is Scaled *Composites* we're talking about.  :-)

~Jon
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: iamlucky13 on 12/13/2011 10:52 PM
Yeah, I have to agree that it's always impressive as hell to see someone like Mr Allen with the balls to put several hundred $M on the line for something that people are so ready to nay-say. 

Because my posts have probably come across as critical, I want to clarify that I don't intend to be a naysayer.

I suppose part of my nature as an engineer is to naturally think about the technical challenges of a project like this.

So even though I agree this project is technically feasible, and I'm in fact quite excited by the prospect of seeing this system fly, I'm most interested in talking about the things that make this endeavor difficult, (and in comparing different ideas about how best to approach this, like our discussion about pre-release ignition).

On the flip side, those difficult aspects are also the things that will earn Allen and his team huge amounts of respect if they succeed.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/13/2011 10:53 PM
Did they say if the plane will be aluminum or composite?
Does Rutan ever bend metal? ;D
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/13/2011 11:01 PM
As far as real concerns, mine is ex MSFC and the Huntsville area involvement in this project.  They don't and wont understand the Scaled and Spacex culture and I see a clash in the future
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jason1701 on 12/13/2011 11:01 PM
Did they say if the plane will be aluminum or composite?
Does Rutan ever bend metal? ;D

They did say they were acquiring some 747s. Perhaps the fuselages will be aluminum and the wings will be composite.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: AS-503 on 12/13/2011 11:11 PM
Most of my thinking has already been elaborated by others on this forum, but....

Jim actually cracked a joke (a good one too), about Griffin putting an SRB on it.

It is a good day......

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/13/2011 11:18 PM
As far as real concerns, mine is ex MSFC and the Huntsville area involvement in this project.  They don't and wont understand the Scaled and Spacex culture and I see a clash in the future

Well, one thing to remember is that the part of Dynetics most likely involved in this is going to be the old Orion Propulsion guys.  While Dynetics is run by a lot of the old Ares-I people, the former Orion group is led by Tim Pickens--who helped with the SS1 propulsion system, and also built his daughter a hybrid rocket powered bike...I think at least that part of Dynetics isn't goint to have any problem interfacing with the SpaceX/Scaled people... :-)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/13/2011 11:20 PM
Did they say if the plane will be aluminum or composite?
Does Rutan ever bend metal? ;D

They did say they were acquiring some 747s. Perhaps the fuselages will be aluminum and the wings will be composite.
I could see by the pics and video the forward fuselage and cockpit, engines, gear and other mechanical systems. It would be a departure for him to do other than composite… But hey, its early days!
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: iamlucky13 on 12/13/2011 11:22 PM

Say your rocket stage has a T/W ratio of 1.4:1 (which is actually really high for a liquid rocket).  That means that your net upward acceleraiton is 4m/s^2.  Which means you end up taking 7.5s to null out the initial downward velocity.  But in that time, you've taken about 75s of gravity losses in addition to your 30m/s of downward velocity drop.

There are papers going into the physics of all this, but the short answer is that you need your velocity vector at the point the rocket leaves the aircraft under powered flight to be pointed at a fairly steep angle to get the most out of an air launch.  Otherwise you end up losing back most of the delta-V benefit from the air launch.

Good point, and in fact 3 seconds is probably even being conservative, especially when you add in the time it takes to throttle up. I want to make three additional points, and then I think we've covered the pros and cons of igniting before release pretty well.

1.) You're definitely losing a non-trivial amount of delta-V, but not actually most of it. You start out with about 200 m/s of horizontal velocity and an elevation advantage equivalent to another 400-450 m/s. As a very rough ballpark, I'd say a nozzle sized for the launch altitude might gain you another couple hundred m/s.

2.) With your rocket attached to your plane, the thrust/weight ratio drops significantly. That doesn't eliminate the benefit you describe, but it does reduce it.

3.) As I understand it, starting delta-V isn't really the biggest benefit of air launch anyways. Rather, it's the ability to chose your launch location to best suit your orbit and safety constraints, and to avoid some of the weather-related factors.

I might add in relation to the launch location benefit, they probably aren't staring at costs to achieve that radically different from what Sea Launch faced, so I'd be remiss in not recognizing another venture that had been successful in doing something radically different from the norm with a launch vehicle even bigger than what Stratolaunch is attempting.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Zed_Noir on 12/13/2011 11:37 PM
Wonder if the Stratolaunch carrier aircraft is capable of ferrying  something like a empty 10m diameter  FXX core stage? If it does, than SpaceX will probably pay for the service. Guess the 6m diameter FX core shouldn't be a problem as a ferry payload.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: kevin-rf on 12/13/2011 11:39 PM
The idea of mid-air refueling of aircraft used to be considered scary too.
~Jon
It still is, notice only some military's do it. It does not always go well... planes and sadly crews are sometimes lost.

To me, remembering SpaceX's several launch aborts, lighting an air drop turbo pumped liquid engine is scary. If they switched to pressure fed...

Honestly, the story is they are building a plane that can air drop a large rocket. To me the Falcon V is a place holder. What about a Falcon V first stage, a X-37 shape that is mostly a fuel tank, and a couple of seats as the second stage. See where I am going?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Namechange User on 12/13/2011 11:52 PM
Honestly, the story is they are building a plane that can air drop a large rocket. To me the Falcon V is a place holder. What about a Falcon V first stage, a X-37 shape that is mostly a fuel tank, and a couple of seats as the second stage. See where I am going?

Essentially correct.  However, currently, SpaceX is a subcontractor/partner to Stratolaunch.

Could other rockets do it theoretically in place of the SpaceX booster? Sure.  However, there are a slew of system engineering issues and integrated vehicle performance issues to address first. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Namechange User on 12/13/2011 11:54 PM
Wonder if the Stratolaunch carrier aircraft is capable of ferrying  something like a empty 10m diameter  FXX core stage? If it does, than SpaceX will probably pay for the service. Guess the 6m diameter FX core shouldn't be a problem as a ferry payload.


There is no FX or FXX.  There is not even an FH at this point in time. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/13/2011 11:56 PM
The idea of mid-air refueling of aircraft used to be considered scary too.
~Jon
It still is, notice only some military's do it. It does not always go well... planes and sadly crews are sometimes lost.

To me, remembering SpaceX's several launch aborts, lighting an air drop turbo pumped liquid engine is scary. If they switched to pressure fed...

Honestly, the story is they are building a plane that can air drop a large rocket. To me the Falcon V is a place holder. What about a Falcon V first stage, a X-37 shape that is mostly a fuel tank, and a couple of seats as the second stage. See where I am going?
Look right here... ;D

http://forum.nasaspaceflight.com/index.php?topic=27477.15
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/13/2011 11:57 PM
Like Chris said, all rockets are exciting. That said, I was really hoping, given the location, that this was going to involve Blue Origin, and funding for a two-stage fully reusable.
I keep getting the feeling that this idea was in the process for quite a while and that they were just looking for a cheap enough and realistic enough rocket.

It does seem relatively logical to me that they may tank it up only once they're airborne for structural (and safety) reasons. Can you imagine a full abort stop on the runway with a fueled rocket?

If they do the "zoom" maneuver that Jon was talking about (I doubt it, but you never know), this should be a very big boost (1km/s total) to orbit. If it were hydrolox, it could be even more powerful. On the other hand, they could use the extra performance for making a reusable version.

I get the feeling they aren't married to SpaceX as much as you might think. It will be a while before they get airborne.

And yeah, it is too bad the big announcement wasn't about a bunch of payloads.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/13/2011 11:58 PM

Well, one thing to remember is that the part of Dynetics most likely involved in this is going to be the old Orion Propulsion guys.  While Dynetics is run by a lot of the old Ares-I people, the former Orion group is led by Tim Pickens--who helped with the SS1 propulsion system, and also built his daughter a hybrid rocket powered bike...I think at least that part of Dynetics isn't goint to have any problem interfacing with the SpaceX/Scaled people... :-)

Really?  This isn't a propulsion task for them but an system engineering task and that is what the people listed in the PR documents are supposed to be "good" at.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: grr on 12/13/2011 11:58 PM
Its cool, but the question becomes, to where and how often?
It seems to me that the smart thing for Allen and other billionaires would be to invest into Bigelow or IDC Dover and get a private space station up there along with ONE human launch company. And that needs to be ASAP.

once you have at least one private space station up there along with a human launcher, then you will have loads of competition to drop the prices. Without it, then all of the various launchers are chasing the same dollars and it will not be enough.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: simonbp on 12/13/2011 11:59 PM
What about a Falcon V first stage, a X-37 shape that is mostly a fuel tank, and a couple of seats as the second stage. See where I am going?

Makes sense, and could be made into a fully reusable system with a recoverable Falcon (e.g if you took off from California, launched out in the Pacific, and recovered again in California).

Developing the spacecraft would be quite expensive though, similar in cost to the entire Stratolaunch vehicle. Best to get that working first.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Namechange User on 12/14/2011 12:01 AM
Yeah, Dynetics is doing the SE&I of the overall system.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Namechange User on 12/14/2011 12:04 AM
Its cool, but the question becomes, to where and how often?
It seems to me that the smart thing for Allen and other billionaires would be to invest into Bigelow or IDC Dover and get a private space station up there along with ONE human launch company. And that needs to be ASAP.

once you have at least one private space station up there along with a human launcher, then you will have loads of competition to drop the prices. Without it, then all of the various launchers are chasing the same dollars and it will not be enough.

What the hell?  Why do so many refuse to address this question with government-funded "commercial" but then when someone decides to spend their own money, for something truly commercial, then everyone decides to find religion?  And then people say instead how they should spend *their* money.

It is as simple as this.  A business case has been assessed for this concept.  ROM numbers have been created to show what the ROI is (under "normal" assumptions and then "worse-case" and "best-case" assumptions) versus the investment required to bring it to fruition.  The investor, Paul Allen (and maybe others), has determined this to be worth their time. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: M_Puckett on 12/14/2011 12:09 AM
Wonder if the Stratolaunch carrier aircraft is capable of ferrying  something like a empty 10m diameter  FXX core stage? If it does, than SpaceX will probably pay for the service. Guess the 6m diameter FX core shouldn't be a problem as a ferry payload.


As long as it doesn't drag the runway with its belly it might work.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: yinzer on 12/14/2011 12:13 AM
It's hard to see how this makes sense on what's been released so far.  The mid-sized Delta-2-ish launch market is pretty small, as can be seen by the Delta 2 being withdrawn for lack of customers.  That airplane is not going to be cheap even if you get Scaled Composites to build it, nor are the modifications to existing Falcon launch vehicles.  With the comparatively small market, paying back the development costs is going to be tricky.

Of course, it was also hard to see how you could make money mining manganese nodules from the sea floor...
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: grr on 12/14/2011 12:18 AM
Its cool, but the question becomes, to where and how often?
It seems to me that the smart thing for Allen and other billionaires would be to invest into Bigelow or IDC Dover and get a private space station up there along with ONE human launch company. And that needs to be ASAP.

once you have at least one private space station up there along with a human launcher, then you will have loads of competition to drop the prices. Without it, then all of the various launchers are chasing the same dollars and it will not be enough.

What the hell?  Why do so many refuse to address this question with government-funded "commercial" but then when someone decides to spend their own money, for something truly commercial, then everyone decides to find religion?  And then people say instead how they should spend *their* money.

It is as simple as this.  A business case has been assessed for this concept.  ROM numbers have been created to show what the ROI is (under "normal" assumptions and then "worse-case" and "best-case" assumptions) versus the investment required to bring it to fruition.  The investor, Paul Allen (and maybe others), has determined this to be worth their time. 


As to checking ROIs etc, you obviously have not tuned into Allen's previous work.  He was the person predominately responsible for pushing cable into the internet (think allen's original backing of SC's SS1 or Musk's creation of Tesla and the impact on electric cars). Allen backed it by creating Charter to expand this.  He is obviously doing the same thing here. 

My earlier posting was hazarding a SWAG that he will be spending more down the road on destinations. It was not meant as criticism.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: simonbp on 12/14/2011 12:24 AM
The mid-sized Delta-2-ish launch market is pretty small, as can be seen by the Delta 2 being withdrawn for lack of customers.

Delta II was not withdrawn for lack of customers, it was withdrawn because ULA wanted to focus on EELVs, which are more profitable. There were plenty of government payloads for the mass range. Whether the market can support both Stratolaunch and Antares, I don't know.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: NotGncDude on 12/14/2011 12:27 AM
Excellent. The more companies working on space launch with NASA out of equation the better!
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: edkyle99 on 12/14/2011 12:29 AM
Honestly, the story is they are building a plane that can air drop a large rocket. To me the Falcon V is a place holder. What about a Falcon V first stage, a X-37 shape that is mostly a fuel tank, and a couple of seats as the second stage. See where I am going?

I did notice that the launch vehicle mass just about matches the liftoff weight of a Delta IV CBC.  With a more efficient engine (J-2X?), a CBC-sized stage drop-launched in this manner might be able to lift itself into orbit, or nearly so, with a 10-ish tonne payload, eliminating the staging. 

I'll have to figure out what 232 tonnes of solid motor rocket might be able to do air-launched.  It would have to be multi-stage of course.  A first guess would be 4 tonnes, as a straight scale-up estimate of Pegasus XL.

 - Ed Kyle
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: lorahpj on 12/14/2011 12:33 AM
I'm glad to see it (Paul Allen spending his money on this project) - it is good to see different approaches being pursued and Allen definitely has the resources to go the distance on any project he chooses.  I wish he had gone with a more ambitious approach.  I don't see how a subsonic carrier plane dropping a rocket at 30,000 feet is going to give any kind of order of magnitude cost reduction - we haven't seen that Orbital's Pegasus has had a breakthrough on costs from what I know, so why would a scaled up Pegasus (with a fully custom carrier plane) have a breakthrough? I guess the risk is lower but it seems like the rewards are too.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: docmordrid on 12/14/2011 12:34 AM
Aviation Week article.... (http://www.aviationweek.com/aw/generic/story_channel.jsp?channel=space&id=news/awx/2011/12/13/awx_12_13_2011_p0-405946.xml&headline=Stratolaunch%20Aims%20to%20Break%20Affordability%20Barrier)

13.5 MT
747-400 engines, flight deck, landing gear & systems.
Falcon 5/6
Falcon will use a feathered flight profile (!?!)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/14/2011 12:36 AM
Excellent. The more companies working on space launch with NASA out of equation the better!
Except what are they going to launch? We have Delta IV (possibly also remnants of Delta II), Atlas V, Falcon 9, Taurus II Antares, and now Stratalaunch plus other people seriously vying for a medium-to-heavy launch service including Blue Origin and ATK (not just Liberty). Those are just the domestic folks. You also have Soyuz, Proton, Ariane 5, Indian, and Chinese launch vehicles. It's getting pretty crowded, here!

I think it's a really cool concept, but what the heck are these going to all launch? The EELVs were already having a hard time finding payloads just by themselves...

Everyone loves to make a big sexy rocket, and wings are icing on the cake! :)

They are clearly pushing for new or greatly expanded markets with this. I'm not going to bet against them.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Namechange User on 12/14/2011 12:38 AM
Its cool, but the question becomes, to where and how often?
It seems to me that the smart thing for Allen and other billionaires would be to invest into Bigelow or IDC Dover and get a private space station up there along with ONE human launch company. And that needs to be ASAP.

once you have at least one private space station up there along with a human launcher, then you will have loads of competition to drop the prices. Without it, then all of the various launchers are chasing the same dollars and it will not be enough.

What the hell?  Why do so many refuse to address this question with government-funded "commercial" but then when someone decides to spend their own money, for something truly commercial, then everyone decides to find religion?  And then people say instead how they should spend *their* money.

It is as simple as this.  A business case has been assessed for this concept.  ROM numbers have been created to show what the ROI is (under "normal" assumptions and then "worse-case" and "best-case" assumptions) versus the investment required to bring it to fruition.  The investor, Paul Allen (and maybe others), has determined this to be worth their time. 


As to checking ROIs etc, you obviously have not tuned into Allen's previous work.  He was the person predominately responsible for pushing cable into the internet (think allen's original backing of SC's SS1 or Musk's creation of Tesla and the impact on electric cars). Allen backed it by creating Charter to expand this.  He is obviously doing the same thing here. 

My earlier posting was hazarding a SWAG that he will be spending more down the road on destinations. It was not meant as criticism.

His previous work is irrelevant.  He believes in this concept and has been satisfied to the extent that he needs to be that there is an ROI and a reason to do this.  Cased closed.  It is his money.

History is littered with investors who put money into things.  Some worked out and some did not.  However, that is what pushes things along.  Government cannot nor should it do it all.

I still just find it astounding that so many think we should just "go commercial" as if it exists (partially based on the perpetuated internet myth and ill-formed bloggers) but government should pay for it all and then when something truly commercial happens, it met with skepticism and arm-chair quaterbacking, when none of those questions were asked (either out of ignorance, a reluctance to want to know the truth or both) for government-funded "commercial". 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Namechange User on 12/14/2011 12:39 AM
Excellent. The more companies working on space launch with NASA out of equation the better!

This is the only one.  Also, let's not be so myopic that this could not benefit NASA just as it could benefit others.  NASA is not an enemy, which is the opposite extreme viewpoint, and also not where reality exists. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/14/2011 12:45 AM

Delta II was not withdrawn for lack of customers, it was withdrawn because ULA wanted to focus on EELVs, which are more profitable. There were plenty of government payloads for the mass range.

Wrong, it was lack of customers willing to pay for the actual costs of Delta II once the USAF no longer was supporting it.  ULA offered it to NASA and no payloads were willing to pay for the true costs.

It had nothing to do with profitability.  ULA is not the bad guy here, NASA got used to a subsidized vehicle.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: yinzer on 12/14/2011 12:49 AM
The mid-sized Delta-2-ish launch market is pretty small, as can be seen by the Delta 2 being withdrawn for lack of customers.

Delta II was not withdrawn for lack of customers, it was withdrawn because ULA wanted to focus on EELVs, which are more profitable. There were plenty of government payloads for the mass range. Whether the market can support both Stratolaunch and Antares, I don't know.

I think it was withdrawn because of a lack of enough customers, and specifically lack of a customer (the USAF GPS program) who was willing to pay to keep the launch system available for a T-30 day launch and thus absorb a lot of the fixed costs.  The payloads left weren't able to keep it out of the procurement death spiral...
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Chris Bergin on 12/14/2011 01:24 AM
Falcon 5/6


Falcon 4 or 5, isn't it!?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Seattle Dave on 12/14/2011 01:33 AM
Falcon 5/6


Falcon 4 or 5, isn't it!?

Yes. Aviation Week made a mistake there.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Prober on 12/14/2011 01:34 AM
I find this all very weird, nothing about Stratolaunch on the SpaceX web site.

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: kkattula on 12/14/2011 01:35 AM
I applaud Mr Allen's willingness to invest (yet again) in space flight. We can't get enough people like him.

It may not be the architecture I'd choose, but it's still interesting and workable. Plus it's his money. :)


I wonder: is Gary Hudson involved at all?  His company AirLaunch LLC were until recently experimenting with air-dropped liquid fuel launchers, and also involved in T/Space, (with Scaled Composites), looking at a very similar concept.  If it was up to me, I'd at least hire him as a consultant on this project.

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: baldusi on 12/14/2011 01:37 AM
Aviation Week article.... (http://www.aviationweek.com/aw/generic/story_channel.jsp?channel=space&id=news/awx/2011/12/13/awx_12_13_2011_p0-405946.xml&headline=Stratolaunch%20Aims%20to%20Break%20Affordability%20Barrier)
13.5 MT
747-400 engines, flight deck, landing gear & systems.
Falcon 5/6
Falcon will use a feathered flight profile (!?!)
13,500lbs
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: robertross on 12/14/2011 01:39 AM
Well this is an interesting project!

I kind of like the Spruce Goose comment, but ithat vehicle had an application that was outdated (end of a war requiring movement of military vehicles), yet we still have that very need today.

I also like Jon's concept on his webpage on the the in-flight cryo cooling, something I was thinking of while reading about all this.

Thinking of the excellent comment on Mike Griffin & solids, when you have a launch like this, wouldn't there be an advantage of having an SRB kick stage during launch? Start the kerelox engines at minimum throttle, and with a good reading on all engines, engage the kicker stage at vehicle separation as it begins throttle up.

In the case of a launch failure/abort, the booster drops off, the US engine lights (maybe not) to separate the PLF/spacecraft and land under parachutes in the ocean with the help of inflatable bags (maybe?).

Launching from KSC & Vandenburg just make sense. You can transport the components on aircraft or by barge to the launch (take-off) sites, fly an unloaded aircraft (or maybe even an empty rocket) there, integrate, fuel, and take off.

Some questions are:
WHERE will it be built. I'm wondering about excess capacity at MAF.

How much structural strengthening might be required from some of the engineering types on here? I'm thinking the load paths on the ground and in 'carried flight' when fully fueled will be challenging, especially for the underside of the transport aircraft. Also, the outer skin of the rocket will tend to 'droop' downwards, and that added rigidity would add a fair bit of mass I assume.

Fuel pickup. The fuel tanks being the way they are will require some serious anti-slosh features, and fuel pumps will need to be rather special for low pressure pickup and higher discharge pressures.

The market issue has been thrown around, but I believe if the costs were low enough, there is an expanded business case. This might play well into the Bigelow-style module concept for orbital labs: crewed or otherwise.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Oberon_Command on 12/14/2011 01:40 AM
I wonder: is Gary Hudson involved at all?  His company AirLaunch LLC were until recently experimenting with air-dropped liquid fuel launchers, and also involved in T/Space, (with Scaled Composites), looking at a very similar concept.  If it was up to me, I'd at least hire him as a consultant on this project.

I was going to say, I wonder what the t/Space folks think of this?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/14/2011 01:43 AM
I applaud Mr Allen's willingness to invest (yet again) in space flight. We can't get enough people like him.

It may not be the architecture I'd choose, but it's still interesting and workable. Plus it's his money. :)


I wonder: is Gary Hudson involved at all?  His company AirLaunch LLC were until recently experimenting with air-dropped liquid fuel launchers, and also involved in T/Space, (with Scaled Composites), looking at a very similar concept.  If it was up to me, I'd at least hire him as a consultant on this project.


I wish I could get him to fund the R&D for my Flyback Falcon concept. ;D

http://forum.nasaspaceflight.com/index.php?topic=27477.15
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/14/2011 01:47 AM
I wonder: is Gary Hudson involved at all?  His company AirLaunch LLC were until recently experimenting with air-dropped liquid fuel launchers, and also involved in T/Space, (with Scaled Composites), looking at a very similar concept.  If it was up to me, I'd at least hire him as a consultant on this project.

I was going to say, I wonder what the t/Space folks think of this?
HMXHMX?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: 360-180 on 12/14/2011 01:49 AM
Compare with this design
Hercules
(http://www.buran.ru/images/gif/model81.gif)
http://www.buran.ru/htm/aviager.htm
(http://www.buran.ru/images/jpg/her4.jpg)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: baldusi on 12/14/2011 01:50 AM
I'm still wondering about the Aircraft. I understand, from comments in this forums, that the Pegasus ended up being too expensive because of the cost of the plane, that has to be kept exclusively for this launcher.
I also remember that theres plenty of demand for An-124, and they even tried to finish the second An-225 airframe, but couldn't finance the extra 300M they needed to finish it. Since this was extra demand for the current An-124/225 operators, a possible competitor would have more incentives to enter the market. For those that are not savy in economic theory, the basic idea is that for the an-225 monopolist, adding a second unit will bring some extra revenue, but it might have to lower it prices a bit to get enough business. So he (hopefully) will earn more profits, but not twice as much. A new entrant, instead, will not care to go with lower prices, since whatever they do over costs is profit. Given that Anatov and it's partners seriously tried for a second An-225, it's quite probable that there's a very good business opportunity for an equivalent cargo lifter.
This is my conundrum. Why haven't they designed a plane that can also compete with the an-225? You can get so much extra performance on the LV market to capture the extra profit of competing with the Ukrainian monster? From a business perspective an airplane that can cover both roles would be great at earning a steady revenue.
On the other hand, my wild assumption is that they are going to the route of cheaper DDE&T, which quite probably is the dominating cost/risk here. I've also theorized if they could fit a sort of lifting body cargo carrier in the middle, maybe with some extra fuel compartment. On advantage is that it ca be developed as a separate project, if the plane is a technical success, without making too many compromises. May be even if the RP-1 tank is compatible with JP-1, use that for extra ferry distance. With that option they could cover almost both markets.
The ferry cost would be higher and the an-225 appears to be compatible with more runways. But being able to compete on some routes is better than having development costs so high that you don't do the project, right.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RocketJack on 12/14/2011 01:54 AM
Excellent. The more companies working on space launch with NASA out of equation the better!
Except what are they going to launch? We have Delta IV (possibly also remnants of Delta II), Atlas V, Falcon 9, Taurus II Antares, and now Stratalaunch plus other people seriously vying for a medium-to-heavy launch service including Blue Origin and ATK (not just Liberty). Those are just the domestic folks. You also have Soyuz, Proton, Ariane 5, Indian, and Chinese launch vehicles. It's getting pretty crowded, here!

I think it's a really cool concept, but what the heck are these going to all launch? The EELVs were already having a hard time finding payloads just by themselves...

Everyone loves to make a big sexy rocket, and wings are icing on the cake! :)

They are clearly pushing for new or greatly expanded markets with this. I'm not going to bet against them.

Not only are there not enough payloads- there are not enough tourists. The only proof you need is that the Russians are not flying any. And don't be fooled into thinking that NASA and RSA need all the seats - I can guarantee that if a paying customer showed up who wasn't a nutcase the Russians would find a way to take their money and launch them. The problem is that they have run out of people with sufficient funds who can invest the amount of training time that is required. Think about what this means for the "tourist" launch companies - they will have to SIGNIFICANTLY reduce below Soyuz and/or not train them as much as a spaceflight participant.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Chris Bergin on 12/14/2011 02:07 AM
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/
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Bubbinski on 12/14/2011 02:13 AM
Just catching up.....WOW.  To me the plane is the bigger deal than the rocket underneath it.  The size of 2 747's.....reminds me of a concept I saw in Dennis Jenkins' book about the Space Shuttle, a shuttle carrier aircraft concept that would carry the orbiter underneath the middle wing section, a plane that had twin fuselages and was really big.

I would imagine a whole lot could be done with the plane besides launch the "big Pegasus" - perhaps fly very heavy cargoes in a pod slung underneath?  Or act as a shuttle carrier aircraft if there was a need to move one of the retired orbiters from one museum to another?  Maybe be the carrier aircraft for a suborbital successor to Concorde that could carry passengers and cargo from California to the east coast in an hour?

If that thing ever flies into Salt Lake International I guarantee you I'd try to get a glimpse and some pics of it.  And I could see myself doing a road trip to Mojave to see that thing in action.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jimvela on 12/14/2011 02:27 AM
Aviation Week article.... (http://www.aviationweek.com/aw/generic/story_channel.jsp?channel=space&id=news/awx/2011/12/13/awx_12_13_2011_p0-405946.xml&headline=Stratolaunch%20Aims%20to%20Break%20Affordability%20Barrier)

13.5 MT
747-400 engines, flight deck, landing gear & systems.
Falcon 5/6
Falcon will use a feathered flight profile (!?!)


Yeah, that seems to be one of the big potential wins for SpaceX along with having a customer for more falcons and some development money...

As I said here
http://forum.nasaspaceflight.com/index.php?topic=27520.185

Quote
Edit: Plus, if SpaceX ever wanted to license one of Rutan's novel swivel-wing recovery methods for a booster (hint, hint)-this would be a good way to end up with such a license...
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Paul Howard on 12/14/2011 02:32 AM
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/

Thanks Chris. That's a much easier read than going through this thread :)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: spectre9 on 12/14/2011 02:38 AM
I don't like it.

Building some giant plane for an uninspiring payload for a market that isn't demanding it.

What's to like?  ???
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: docmordrid on 12/14/2011 02:50 AM
Must be something because the USAF recently let a contract to LockMart for early work on a flyback system.

http://www.lockheedmartin.com/news/press_releases/2011/125_ss_reusablebooster.html

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: yg1968 on 12/14/2011 02:54 AM
Here is the archived press conference:
http://www.youtube.com/watch?v=tc6c8i9q2IE
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Andrew_W on 12/14/2011 03:59 AM
While others here are asking what the big deal is, I think the development of a large carrier aircraft is a huge step in the development of cheap access to space. This is a system with the potential to evolve to carry other upper stages, including fully reusable space planes.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: neilh on 12/14/2011 04:17 AM
I still just find it astounding that so many think we should just "go commercial" as if it exists (partially based on the perpetuated internet myth and ill-formed bloggers) but government should pay for it all and then when something truly commercial happens, it met with skepticism and arm-chair quaterbacking, when none of those questions were asked (either out of ignorance, a reluctance to want to know the truth or both) for government-funded "commercial". 

Have you been reading a different forum from the rest of us? This thread has a mix of cheerers, skeptics, and those waiting for more information, just like any other commercial announcement thread on this forum.

For the record, I'm one of the many folks excited by this announcement, and I look forward to seeing it progress.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/14/2011 04:28 AM
Yeah, Dynetics is doing the SE&I of the overall system.

Ah, I hadn't read all the details on how they were doing the team.  Yeah, I might be more concerned about culture clash between them and SpaceX/Scaled in that case. But hopefully they've already been working together on this enough behind the scenes to have reason to believe they can make the intra-team relationships work.

~Jon
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: neilh on 12/14/2011 04:29 AM
Wonder if the Stratolaunch carrier aircraft is capable of ferrying  something like a empty 10m diameter  FXX core stage? If it does, than SpaceX will probably pay for the service. Guess the 6m diameter FX core shouldn't be a problem as a ferry payload.

I was wondering the same. I was also wondering how the cost/risk of transporting an empty Falcon 9 stage on such a carrier aircraft would compare to ground transportation.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: quanthasaquality on 12/14/2011 04:34 AM
Like some others here, I am skeptical about the cost effectiveness of air launched rockets. Pegasus has been doing this for twenty years, and it is still expensive per pound. If air launch has potential, why hasn't Orbital Sciences put more effort into Pegasus' costs, instead of going after conventional liquid fuel rockets?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/14/2011 04:38 AM
Excellent. The more companies working on space launch with NASA out of equation the better!
Except what are they going to launch? We have Delta IV (possibly also remnants of Delta II), Atlas V, Falcon 9, Taurus II Antares, and now Stratalaunch plus other people seriously vying for a medium-to-heavy launch service including Blue Origin and ATK (not just Liberty). Those are just the domestic folks. You also have Soyuz, Proton, Ariane 5, Indian, and Chinese launch vehicles. It's getting pretty crowded, here!

I think it's a really cool concept, but what the heck are these going to all launch? The EELVs were already having a hard time finding payloads just by themselves...

Everyone loves to make a big sexy rocket, and wings are icing on the cake! :)

They are clearly pushing for new or greatly expanded markets with this. I'm not going to bet against them.

Not only are there not enough payloads- there are not enough tourists. The only proof you need is that the Russians are not flying any. And don't be fooled into thinking that NASA and RSA need all the seats - I can guarantee that if a paying customer showed up who wasn't a nutcase the Russians would find a way to take their money and launch them. The problem is that they have run out of people with sufficient funds who can invest the amount of training time that is required. Think about what this means for the "tourist" launch companies - they will have to SIGNIFICANTLY reduce below Soyuz and/or not train them as much as a spaceflight participant.


Well, Eric Anderson could be lying through his teeth, but if he isn't, he says that they actually have a backlog of interested customers.  The problem is also:

1-What price point?
2-How much time does it take out of a high-net-worth individual's life to train for the flight?
3-Is it out of the US or a somewhat sketchy not quite 1st world country that doesn't speak English, etc?

If you can get the price point right, you can have a massive market.  The question is can they come up with a system that can make a price point that starts getting into elastic demand ranges.

~Jon
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: neilh on 12/14/2011 04:39 AM
I applaud Mr Allen's willingness to invest (yet again) in space flight. We can't get enough people like him.

It may not be the architecture I'd choose, but it's still interesting and workable. Plus it's his money. :)


I wonder: is Gary Hudson involved at all?  His company AirLaunch LLC were until recently experimenting with air-dropped liquid fuel launchers, and also involved in T/Space, (with Scaled Composites), looking at a very similar concept.  If it was up to me, I'd at least hire him as a consultant on this project.

Right after I saw the announcement, one of my first thoughts was about how we haven't seen him around here in the past couple of months...
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: sanman on 12/14/2011 04:41 AM
Richard Branson was heard muttering, "Crap! I got last year's model!" :'(
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/14/2011 04:43 AM
Like some others here, I am skeptical about the cost effectiveness of air launched rockets. Pegasus has been doing this for twenty years, and it is still expensive per pound. If air launch has potential, why hasn't Orbital Sciences put more effort into Pegasus' costs, instead of going after conventional liquid fuel rockets?

Space launch is such an interesting field. I wonder where computers or even airplanes would be if people in those fields were as used to drawing hasty generalizations from single data points.

"Sam Langley's Aerodrome didn't work out, so that obviously shows that heavier than air flight can't work"...

~Jon
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Wyvern on 12/14/2011 04:46 AM
Honestly this concept seems so crazy that it simply must work.  Or at least be tried so that humanity can have the dignity to say that we attempted to make it fly.

Still I do agree with those who wanted payloads instead of another launcher.  After all commercial needs commercial payloads in order to take off (no pun intended) and bigelow being the only people around needing orbital access doesn't seem to be good for the market place.  What we don't need is yet another launcher, even if the launcher is really cool. 

I know that there are apparently a lot of tiny science experiments that could net a tidy sum but those seem to limited to suborbital.  I guess the launch guys are hoping that if they build it then payload will come.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: neilh on 12/14/2011 05:17 AM
I wonder: is Gary Hudson involved at all?  His company AirLaunch LLC were until recently experimenting with air-dropped liquid fuel launchers, and also involved in T/Space, (with Scaled Composites), looking at a very similar concept.  If it was up to me, I'd at least hire him as a consultant on this project.

I was going to say, I wonder what the t/Space folks think of this?

I took a quick look, and was surprised to see that (assuming I'm reading things correctly) the payload of t/Space's pre-ESAS CEV proposal is fairly similar to Stratolaunch's:

http://exploration.nasa.gov/documents/reports/cer_midterm/tSpace.pdf
http://exploration.nasa.gov/documents/reports/cer_final/tSpace.pdf

Besides the involvement of Scaled, another similarity is the involvement of Orion Propulsion (since acquired by Dynetics).
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: kkattula on 12/14/2011 05:19 AM
Like some others here, I am skeptical about the cost effectiveness of air launched rockets. Pegasus has been doing this for twenty years, and it is still expensive per pound. If air launch has potential, why hasn't Orbital Sciences put more effort into Pegasus' costs, instead of going after conventional liquid fuel rockets?

Space launch is such an interesting field. I wonder where computers or even airplanes would be if people in those fields were as used to drawing hasty generalizations from single data points.

"Sam Langley's Aerodrome didn't work out, so that obviously shows that heavier than air flight can't work"...

~Jon

LOL.

Pegasus has a pretty small payload, about 10% of this new vehicle's. I expect many of the operational costs of air launch won't scale up with payload size.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Comga on 12/14/2011 05:28 AM
Like some others here, I am skeptical about the cost effectiveness of air launched rockets. Pegasus has been doing this for twenty years, and it is still expensive per pound. If air launch has potential, why hasn't Orbital Sciences put more effort into Pegasus' costs, instead of going after conventional liquid fuel rockets?

Space launch is such an interesting field. I wonder where computers or even airplanes would be if people in those fields were as used to drawing hasty generalizations from single data points.

"Sam Langley's Aerodrome didn't work out, so that obviously shows that heavier than air flight can't work"...

~Jon

LOL.

Pegasus has a pretty small payload, about 10% of this new vehicle's. I expect many of the operational costs of air launch won't scale up with payload size.

It will probably cost way more than ten times as much to build this one-off, six engine, twin hulled behemoth than it cost to buy an old, used L-1011.

Still, one data point....
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Tcommon on 12/14/2011 05:31 AM
Honestly this concept seems so crazy that it simply must work.  Or at least be tried so that humanity can have the dignity to say that we attempted to make it fly.
It's not crazy. It does work. It has been tried (Pegasus) and is still in operation. It doesn't make sense though; reduced capacity of an F9 with more complexity and, presumably, more cost.

It just doesn't make sense unless the F5 is a placeholder, as proposed earlier in this thread.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/14/2011 05:37 AM
I'm not convinced that it'd be higher cost than a fully expendable Falcon 9. There are real operational advantages, and in the real world that translates to cost advantages. But this is a huge airplane.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Comga on 12/14/2011 05:47 AM
Not that it hasn't been said before, but the contrast with "the SpaceX way" is stark

SpaceX: Minimalist launch pad - rails, pivoting hold-down block, strong-back/umbilical tower
Stratolaunch:  Maximum launch pad - a giant six jet engine aircraft

SpaceX: Two stages, one profile - up
Stratolaunch: Three stages, three profiles - suspended, aerodynamic flight, rocket flight.

SpaceX: ten versions of one engine in two flavors, sea level & vacuum
Stratolaunch: 11 engines of 3 types- turbofan, high altitude rocket and vacuum rocket

SpaceX: Hold down ground startup - used twice so far?
Stratolaunch: Air start in a very time critical fashion

SpaceX: Reusability is supposedly key, reasonable plan to bring back first stage, single expendable engine,
Stratolaunch: Reusable zeroth stage, no reuse of the rocket, six expendable engines

SpaceX: If capacity is insufficient, add 4 more engines, lengthen tanks
Stratolaunch: If capacity is insufficient, then what?

SpaceX: SpaceX as entrepreneurial entity, build the hardware and market or disappear
Stratolaunch: SpaceX as aerospace contractor, its a job with limited upside, possibly a good way to amortize manufacturing capacity

It will be very interesting to watch.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Comga on 12/14/2011 05:58 AM
Other questions:

The engine cowls on the "Falcon 5".  Don't think they needed them "the first time".  Only the corner engines, the last 4 of 9, project beyond the tank diameter on the Falcon 9.

No solar panel pontoons on Service Module.  Just a graphic detail that was ignored?  If there is lift on the wing, there is lateral force on the pontoon.

Hard to tell, but that wing looks to be really far back.  How does that compare to Pegasus?  It almost looks to be near the C/M of an empty first stage, which would be good for the flyback they announced they weren't working on.

How would you sit in a Dragon launch couch while waiting for takeoff, and as the force vector rotates?  T/space pivoting couches?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: kkattula on 12/14/2011 05:58 AM
Not that it hasn't been said before, but the contrast with "the SpaceX way" is stark

SpaceX: Minimalist launch pad - rails, pivoting hold-down block, strong-back/umbilical tower
Stratolaunch:  Maximum launch pad - a giant six jet engine aircraft

SpaceX: Two stages, one profile - up
Stratolaunch: Three stages, three profiles - suspended, aerodynamic flight, rocket flight.

SpaceX: ten versions of one engine in two flavors, sea level & vacuum
Stratolaunch: 11 engines of 3 types- turbofan, high altitude rocket and vacuum rocket
...

The aircraft is a launch pad in one paragraph and a stage in the next?  LOL.  Perhaps the runway is the true 'Minimalist launch pad'?

If SpaceX are doing the whole rocket, US engine is likely a Merlin Vac, so just another flavour of the booster engine.

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: kkattula on 12/14/2011 06:01 AM
Other questions:

The engine cowls on the "Falcon 5".  Don't think they needed them "the first time".  Only the corner engines, the last 4 of 9, project beyond the tank diameter on the Falcon 9.


With a high altitude start, they probably want bigger nozzles for better Isp. Plus making them more aerodynamic will improve the carrier aitcraft range.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: kkattula on 12/14/2011 06:04 AM
...
Pegasus has a pretty small payload, about 10% of this new vehicle's. I expect many of the operational costs of air launch won't scale up with payload size.

It will probably cost way more than ten times as much to build this one-off, six engine, twin hulled behemoth than it cost to buy an old, used L-1011.

Still, one data point....

Building it is not an operational cost.

Apparently they've already bought two old used 747.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Comga on 12/14/2011 06:12 AM
SpaceX: Minimalist launch pad - rails, pivoting hold-down block, strong-back/umbilical tower
Stratolaunch:  Maximum launch pad - a giant six jet engine aircraft

SpaceX: Two stages, one profile - up
Stratolaunch: Three stages, three profiles - suspended, aerodynamic flight, rocket flight.

SpaceX: ten versions of one engine in two flavors, sea level & vacuum
Stratolaunch: 11 engines of 3 types- turbofan, high altitude rocket and vacuum rocket
...

The aircraft is a launch pad in one paragraph and a stage in the next?  LOL.  Perhaps the runway is the true 'Minimalist launch pad'?

You are apparently very easy to make laugh.  That's good.
OK Leave out the word "stage" from the second.  The point remains.  Jet engines and wings are more complex than a rail car and strongback. The point about three profiles also remains.

kkatula: Good point on the larger engine bells.  That would pretty much demand that they space the engines far apart, requiring the cowlings.

As for buying two old 747s to canabalize and stitch together, I find that hard to believe.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: yinzer on 12/14/2011 06:34 AM
Like some others here, I am skeptical about the cost effectiveness of air launched rockets. Pegasus has been doing this for twenty years, and it is still expensive per pound. If air launch has potential, why hasn't Orbital Sciences put more effort into Pegasus' costs, instead of going after conventional liquid fuel rockets?

Space launch is such an interesting field. I wonder where computers or even airplanes would be if people in those fields were as used to drawing hasty generalizations from single data points.

"Sam Langley's Aerodrome didn't work out, so that obviously shows that heavier than air flight can't work"...

When checking out an idea costs $100M or more, data points are very hard to come by.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Archibald on 12/14/2011 06:45 AM
Wow, just caught this one. Nice video, but many concerns.
I can understand where this one is going - they hope to make the mammoth carrier aircraft less expensive / risky by scaling up the White Knight II.
They based the rest of the system on two metrics - Falcon and Dragon standards.
The equation seems to be kind of
Virgin Galactic + Scaled + SpaceX = a winning combination.
Ok, I'm glad to see those innovative companies working together on an orbital system.
But seriously - they can do much better than that bizarre hybrid.
Developing such a giganormous machine just to launch a miserable 13 500 pounds to orbit ? Color me skeptical.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: manboy on 12/14/2011 07:18 AM
Launch everyday from everywhere: stratolaunch.com! The new project by Mr. Allen.

Http://www.stratolaunch.com
Pretty disappointed by this, I thought it might be something else.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: geza on 12/14/2011 07:40 AM
Like many of you, I do not believe that the slight operational advantage worth the effort. On the other hand, it is difficult to believe that Allen, Rutan & Musk & Griffin do this without serious analysis. Who to be trusted in this field, if not these gentlemen?

I think the key is that Rutan and t/Space consider vertical launch unexpectedly dangerous for non-astronaut humans. A malfunction during the early phase of flight results in falling back and the capsule has to escape from a fireball. A (contained) failure in air launch is much more benign: shut the engines down and separate the capsule for landing.

Burt believes that he figured out the safe (horizontal!) way to suborbital and wish to extend it for orbital flight to make human spaceflight routine. Sure, it does not make sense without full reusability. The first rocket stage we saw in the move is a fly-back one: As somebody has pointed out already, the position of the pretty small wing corresponds to the CG of an empty booster. One can dream about the resusability of the second stage also, as SpaceX does, even if it is not clear whether the mass budget is calculated accordingly.

So, I think the real dream here is the cheap and safe orbital human spaceflight. However, as Allen consider himself a conservative men, he announced the first step now, without the fanfares and the dreams. He probably knows that he will not be rich in this step more than on SETI research. Next time, with tourism.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: MP99 on 12/14/2011 08:11 AM
Stratalaunch

That makes it sound like it's burrowing down rather than launching upwards! ;)

Cheers, Martin
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: AlexCam on 12/14/2011 08:39 AM
This is a technically viable concept. We know that from Pegasus and Orbital. I just cannot see its financial viability. Cost per lb to orbit will likely go up with this approach, not down. And the flexibility that an airlaunch provides in terms of inclination will not make up for the higher costs.

Sometimes I do not understand people like Paul Allen. He is a very smart guy and he is really enthusiastic about space flight. Projects that he should be doing should be high risk technically (in terms of project success) in order to push the boundaries, while in case of success they are game changes. Instead he is backing a project that has low to medium risk technically, but very high risk financially to succeed.

Paul, if you want to make the world happy, try your luck with the continuation of something like VentureStar. You have the money and it was a viable concept. If you succeed, you may have just changed how spaceflight is done.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: thomson on 12/14/2011 08:45 AM
I find this very exciting. Regardless of Stratolaunch success or failure, that is another revenue stream for SpaceX, which increases SpaceX chances of succeeding. IMHO Musk has the most ambitious plans regarding space AFAIK and anything that helps achive his vision is a good thing.

Did they mention maximum altitude this plane can reach? What about launch altitude?

I'm a bit sceptical about flight within 5 years. Although I'm complete layman, I never heard of any aerospace project that was completed sooner than planned. I think 5 years is really a lower bound estimate. I still remember Rutan saying something about routine flights within 2 years. I think it was back in 2005 or 2006.

Anyway, it would be amazing to see this beast in the air. I wish them all the best.

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Eerie on 12/14/2011 09:01 AM
It seems like Burt Rutan and Elon Musk are there because, being contractors, they have nothing to lose. They will be paid to do what they like to do (building planes and rockets) and gain PR and experience regardless of the success of the whole enterprise.

What's in it for Paul Allen I don't know.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: AlexCam on 12/14/2011 09:08 AM
I find this very exciting. Regardless of Stratolaunch success or failure, that is another revenue stream for SpaceX, which increases SpaceX chances of succeeding. IMHO Musk has the most ambitious plans regarding space AFAIK and anything that helps achive his vision is a good thing.

In the next few years it won't be any help for SpaceX. We can assume some manpower will have to go on this project, so it will be more of a drain than a resource.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Garrett on 12/14/2011 09:22 AM
Ok, from what I gather this is a long-term project, right? I mean, Allen mentioned a first test of the carrier craft in 2015 and maybe first flights of the launch system around the end of the decade. Most of us here can translate that as first tests of the carrier aircraft by the end of the decade and first flights of the launch system around the middle of the 2020's.

Using those dates to put things into perspective, issues such as potential customers and no need for new launch vehicles just don't seem relevant for the time being. This is a concept. It's validity and ultimate goals probably won't be known, by us or Allen, for another 10 years. This project depends a lot on the progress of space travel over the next decade. To me, this is a launch system for 2025.

With SpaceShipOne, Allen and Rutan started talking about the idea in the mid 90's I think, but it was all kept under wraps until the final moments. That was possible because the project was relatively small. This is too big a project to keep secret, so I presume they've just decided to beat the rumours by making an advanced announcement.

I'm very excited about this idea. The equation Scaled + SpaceX + Dynetics makes a space enthusiast like me drool! The naysayers and nitpickers can drone all they like, that's their problem. I usually try to avoid inviting such people to my barbecue.

For those who think the project looks strange: so what? I actually think it's a pretty conservative evolution of existing technology.

For those who think it's just a scaled up Pegasus: I remind you that the Saturn V was just a scaled-up soda bottle launcher. Ok, maybe a scaled-up multi-stage soda bottle launcher. Absurd comparison? Definitely. Scaling up and/or modifying existing designs is part of progress. It's called standing on the shoulders of giants.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Garrett on 12/14/2011 09:34 AM
In the next few years it won't be any help for SpaceX. We can assume some manpower will have to go on this project, so it will be more of a drain than a resource.
What a silly statement. Projects like this (and Falcon Heavy, Red Dragon, etc.) allow SpaceX to keep a large R&D team employed and busy. Companies that don't invest in R&D, even on projects that later get cancelled, are doomed to failure or at the very best to only occupy a small part of the market.

SpaceX's involvement in projects such as this appears to me to be analogous to Google's Lab projects. Not all of those projects succeed (Buzz, Wave, Notebook, ...) while others become quasi-household names (Google Maps, Google Scholar). Somehow I think the notion that those projects, and Google's other initiatives, have somehow drained Google's resources, would be met with bemusement from those at Google.
I would not be surprised if the Google research model helped inspire Musk's vision of how R&D should work.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: John Duncan on 12/14/2011 09:45 AM
I would have rather seen new payloads too.  We have enough launcher options either in service or nearly that way.

Of course the snarky comment that wants to get out is this:

With Griffin on the board, no wonder the thing is so big.

(ducks) :D :o
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: pippin on 12/14/2011 09:56 AM
I wonder where computers or even airplanes would be if people in those fields were as used to drawing hasty generalizations from single data points.

"Sam Langley's Aerodrome didn't work out, so that obviously shows that heavier than air flight can't work"...
How about
"I think there is a world market for maybe five computers", Thomas J. Watson, IBM CEO, 1943
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: corrodedNut on 12/14/2011 10:57 AM
So this Falcon will have feathers?

http://www.aviationweek.com/aw/generic/story_channel.jsp?channel=space&id=news/awx/2011/12/13/awx_12_13_2011_p0-405946.xml&headline=Stratolaunch%20Aims%20to%20Break%20Affordability%20Barrier&next=10

"Rutan said the human-rated Falcon system will fly the “feathered” low-drag re-entry profile he used for SpaceShipOne."

"What type of thermal protective system the man-rated winged Falcon will require is unclear."
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/14/2011 11:36 AM
Might make an interesting airliner project to compete with the A380…
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Ben the Space Brit on 12/14/2011 11:46 AM
I have to say that, at first blush, I'm not overly impressed with this concept.  It's high risk and really, at the current time, can only further dilute the MLV market.

That said, the really exciting thing is the introduction of a reusable air-breathing first stage into a much heavier lifter than ever before.  I think it's good to see that the pioneers and entrepeneurs are seriously looking at scaling up things like air launch in an attempt to get the cost per pound to orbit down.

Ultimately, I think it is the technology and concept that will be significant, whether or not the Stratolaunch-F5 ever actually flies.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Nomadd on 12/14/2011 11:52 AM
 Does that video make any sense? It and the AWST article says 13,500 lbs, but show the system launching a Dragon. Isn't that payload kind of light for a Dragon with any usefull payload? Even the M1c F9 at 22,000 lb can't lift one with full fuel and published payload.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: baldusi on 12/14/2011 11:57 AM
I fogot to mention that there's an international standard for airports of an 80m square box. This means that if you go past that box, there's no guarantee whatsoever that the airport will accept your aircraft. This means FOD dangers on the runway, passages between buildings, and hangar doors and such. So this aircraft has no possibility of being used as anything else than launcher and very special cargo (think an-225 sort of cargo).
There's one "limitation", of the an-225 is the 4.4m height of the payload bay. I mean, what sort of payloads are bigger than 4.4m? Very few, and a trip of the an-225 is in the 200k range. So I don't think this would be a very cheap approach to move rockets around. But they must have their motives.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Chris Bergin on 12/14/2011 12:37 PM
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/

Thanks Chris. That's a much easier read than going through this thread :)

Cheers Paul.

Surprisingly lukewarm thread at that too!
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Kaputnik on 12/14/2011 12:41 PM
So this Falcon will have feathers?

http://www.aviationweek.com/aw/generic/story_channel.jsp?channel=space&id=news/awx/2011/12/13/awx_12_13_2011_p0-405946.xml&headline=Stratolaunch%20Aims%20to%20Break%20Affordability%20Barrier&next=10

"Rutan said the human-rated Falcon system will fly the “feathered” low-drag re-entry profile he used for SpaceShipOne."

"What type of thermal protective system the man-rated winged Falcon will require is unclear."


Is everyone singing from the same hymn sheet? Is the rocket stage going to be reusable or not?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: wolfpack on 12/14/2011 12:50 PM
- Ed Kyle had an astute point about fuel and landing in case of a post-takeoff abort. Maximum landing weights are typically substantially less than maximum takeoff weights.

Aircraft are capable of landing overweight - just not repeatedly. The preference is to always burn off or dump fuel, but if you ABSOLUTELY have to get back on the ground you can do it. Yes, you'll bend metal and it'll be headed for the scrapyard but if everything's done right you won't be having any funerals.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/14/2011 12:55 PM
So this Falcon will have feathers?

http://www.aviationweek.com/aw/generic/story_channel.jsp?channel=space&id=news/awx/2011/12/13/awx_12_13_2011_p0-405946.xml&headline=Stratolaunch%20Aims%20to%20Break%20Affordability%20Barrier&next=10

"Rutan said the human-rated Falcon system will fly the “feathered” low-drag re-entry profile he used for SpaceShipOne."

"What type of thermal protective system the man-rated winged Falcon will require is unclear."


Is everyone singing from the same hymn sheet? Is the rocket stage going to be reusable or not?
If we are all asking the same questions, I guess the presser was rushed with all the facts not presented clearly.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jabe on 12/14/2011 12:55 PM
Interesting quote from WSJ artitcle (http://online.wsj.com/article/SB10001424052970203518404577097230883918426.html)

Quote
The cost of developing such a mammoth plane, Mr. Rutan added, "historically had been judged as prohibitive." But the logjam broke after engineers came up with "innovative processes to build very large structures" out of composite materials, according to the veteran designer. "Now, it's quite affordable," Mr. Rutan said, and that's one of the reasons the Stratolaunch team decided to lift the veil on the plans.

I wonder what the process was.
jb
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RanulfC on 12/14/2011 01:02 PM
How many airports can support spacecraft processing and propellant loading?

Look at it this way, would this be able to operate out of LAX, which is right next to Boeing and Northrup Grumman or DEN for LM? 

The infrastructure is going to be the same as a pad and launch site.  Will need LOX and RP-1 tanks/spheres next to the runway, there will need to be a "hot pad" so that the launch vehicle can be loaded with the propellants away from other areas and structures.  This same area can be used for spacecraft to launch vehicle mate. 
Trying to catch up on the thead but real quick:
The infrastructure actually is NOT going to be the same as needed for a fixed pad really. Number one, most major airports have a "haz-cargo" handling and loading/unloading facility attached. Number two it was admitted in the documentation and conference that there are going to be a limited number of airports this can operate from but that's a runway restriction more than anything else. Number three, they won't need LOX/RP-1 "spheres" as the rocket as well as the carrier aircraft can be filled with standard tanker trucks like any other aircraft.

Possible "sticking" points are going to be FAA sign-off on LOXing operations and carrying LOX in flight.

Randy
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: mr. mark on 12/14/2011 01:08 PM
Scale comparison
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/14/2011 01:28 PM

Trying to catch up on the thead but real quick:
The infrastructure actually is NOT going to be the same as needed for a fixed pad really. Number one, most major airports have a "haz-cargo" handling and loading/unloading facility attached. Number two it was admitted in the documentation and conference that there are going to be a limited number of airports this can operate from but that's a runway restriction more than anything else. Number three, they won't need LOX/RP-1 "spheres" as the rocket as well as the carrier aircraft can be filled with standard tanker trucks like any other aircraft.

Possible "sticking" points are going to be FAA sign-off on LOXing operations and carrying LOX in flight.

Randy

Wrong again.  It is going to be the same.  LOX spheres will be required. Same goes for GN2 and He cylinders.   There is a reason launch vehicles don't use tanker trucks.  Also, RP

Most airports don't have "haz-cargo" handling and loading/unloading facility sized for this or for processing spacecraft.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Lee Jay on 12/14/2011 01:30 PM
Interesting quote from WSJ artitcle (http://online.wsj.com/article/SB10001424052970203518404577097230883918426.html)

Quote
The cost of developing such a mammoth plane, Mr. Rutan added, "historically had been judged as prohibitive." But the logjam broke after engineers came up with "innovative processes to build very large structures" out of composite materials, according to the veteran designer. "Now, it's quite affordable," Mr. Rutan said, and that's one of the reasons the Stratolaunch team decided to lift the veil on the plans.

I wonder what the process was.
jb

Don't know, but we regularly build fiberglass composite wind turbine blades of lengths 40-65 meters each for a very low cost per pound (like $6).
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: sanman on 12/14/2011 01:46 PM
If all else fails, maybe you could use it to carry submarines  :D

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.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: hektor on 12/14/2011 01:57 PM
They can replace the launcher by a cargo pod an d carry oversized payloads ? Airbus airframes and wings ?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/14/2011 02:03 PM
If you are going to aquire 747's why not just join two 747s together with a new center section and add two more engine plyons. Why do you need the expense of designing a whole new aircraft?

Regards
Robert
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: rdale on 12/14/2011 02:11 PM
If you are going to aquire 747's why not just join two 747s together with a new center section and add two more engine plyons. Why do you need the expense of designing a whole new aircraft?

You think it would be easier to design conjoined 747's which were never intended to be joined, than going new? Hmmm... My reply is much more polite than what you would get posting on an aircraft engineering forum ;)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/14/2011 02:21 PM
I wonder where computers or even airplanes would be if people in those fields were as used to drawing hasty generalizations from single data points.

"Sam Langley's Aerodrome didn't work out, so that obviously shows that heavier than air flight can't work"...
How about
"I think there is a world market for maybe five computers", Thomas J. Watson, IBM CEO, 1943

Yeah, I mean there is a legitimate rejoinder to these anecdotes "They laughed at Columbus, but they also laughed at Bozo the Clown", but personally I think that people who haven't studied the problem in detail making handwavy dismissals based off of a single execution attempt is just plain ridiculous.

~Jon
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: kevin-rf on 12/14/2011 02:23 PM
If you are going to aquire 747's why not just join two 747s together with a new center section and add two more engine plyons. Why do you need the expense of designing a whole new aircraft?

You think it would be easier to design conjoined 747's which were never intended to be joined, than going new? Hmmm... My reply is much more polite than what you would get posting on an aircraft engineering forum ;)

Better yet, the 747 is a low wing plane, this application needs a high winged plane. Either you have some gawd awful landing gear or something equally weird.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/14/2011 02:25 PM
Interesting quote from WSJ artitcle (http://online.wsj.com/article/SB10001424052970203518404577097230883918426.html)

Quote
The cost of developing such a mammoth plane, Mr. Rutan added, "historically had been judged as prohibitive." But the logjam broke after engineers came up with "innovative processes to build very large structures" out of composite materials, according to the veteran designer. "Now, it's quite affordable," Mr. Rutan said, and that's one of the reasons the Stratolaunch team decided to lift the veil on the plans.

I wonder what the process was.
jb

Don't know, but we regularly build fiberglass composite wind turbine blades of lengths 40-65 meters each for a very low cost per pound (like $6).

Yeah, I was going to say that the wind turbine blades I was seeing in Mojave were mind-blowingly ginormous, and they were cranking those out like they were going out of style.

~Jon
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/14/2011 02:32 PM
If you are going to aquire 747's why not just join two 747s together with a new center section and add two more engine plyons. Why do you need the expense of designing a whole new aircraft?

You think it would be easier to design conjoined 747's which were never intended to be joined, than going new? Hmmm... My reply is much more polite than what you would get posting on an aircraft engineering forum ;)

Better yet, the 747 is a low wing plane, this application needs a high winged plane. Either you have some gawd awful landing gear or something equally weird.
Here is a proposal using twin C-5’s. I guess if Burt could get his hands on those…
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110015353_2011016245.pdf

P.S. On the 747 you could mount the Falcon above the center wing section and have it slide back off a rack at launch.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/14/2011 02:39 PM
Airplanes aren't Legos.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/14/2011 02:42 PM
Airplanes aren't Legos.
Nope, they are Erector Sets…  ;D
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: robertross on 12/14/2011 03:03 PM
Interesting quote from WSJ artitcle (http://online.wsj.com/article/SB10001424052970203518404577097230883918426.html)

Quote
The cost of developing such a mammoth plane, Mr. Rutan added, "historically had been judged as prohibitive." But the logjam broke after engineers came up with "innovative processes to build very large structures" out of composite materials, according to the veteran designer. "Now, it's quite affordable," Mr. Rutan said, and that's one of the reasons the Stratolaunch team decided to lift the veil on the plans.

I wonder what the process was.
jb

IIRC, the new Dreamliner doesn't require the use of an autoclave to manufacture the composite wing structures - maybe that's the reason.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: sammie on 12/14/2011 03:15 PM
Just to add about the possibility of this new aircraft carrying (WK3?) to carry outsize cargo. The An-225 is often considered too large to be easily operated at regular airports due to wingspan, WK3 would be even worse. Also if you really want to carry something bigger then the 4.4m currently available it could be carried on top of the An-225. But usually such large cargo's are shipped with truck and barge.

And of course large blimps will dominate the outsize cargo market in a decade or two.

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RanulfC on 12/14/2011 03:23 PM
Wrong again.  It is going to be the same.  LOX spheres will be required. Same goes for GN2 and He cylinders.   There is a reason launch vehicles don't use tanker trucks.  Also, RP

Most airports don't have "haz-cargo" handling and loading/unloading facility sized for this or for processing spacecraft.
Ok I'll bite; "Why?" Why do you need the "spheres" and what are the "reasons" LVs can't/don't use tankers for propellant loading?

(Also keep in mind the idea that the fuselages may carry the propellant load or part of it to altitude)

Admittidly "MY" experiance may be unusual (I've actually spent far more time on Air Force bases than international airports :) ) but I have seen the quite large Haz-processing area at LAX, and a smaller one at Little Rock both of which were processing 747s at the time.

Randy
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RanulfC on 12/14/2011 03:35 PM
Sure, but LH2 will give it a much larger payload to orbit while keeping within the carrier aircraft's capabilities. Many orbital airlaunch concepts assume hydrogen for this reason.
And many don't :) Liquid-Methane, Cryo-Propane, etc have all been suggested to aviod the majority of the boil off issues, so it's not a black-and-white choice here :)

Edit: Plus, if SpaceX ever wanted to license one of Rutan's novel swivel-wing recovery methods for a booster (hint, hint)- this would be a good way to end up with such a license...
Would the 'feather' actually work for a booster trajectory? Last I'd heard from Rutan the feather doesn't work at orbital reentry speeds but it SHOULD be good for suborbital...

Randy
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: robertross on 12/14/2011 03:47 PM
Wrong again.  It is going to be the same.  LOX spheres will be required. Same goes for GN2 and He cylinders.   There is a reason launch vehicles don't use tanker trucks.  Also, RP

Most airports don't have "haz-cargo" handling and loading/unloading facility sized for this or for processing spacecraft.
Ok I'll bite; "Why?" Why do you need the "spheres" and what are the "reasons" LVs can't/don't use tankers for propellant loading?

(Also keep in mind the idea that the fuselages may carry the propellant load or part of it to altitude)

Admittidly "MY" experiance may be unusual (I've actually spent far more time on Air Force bases than international airports :) ) but I have seen the quite large Haz-processing area at LAX, and a smaller one at Little Rock both of which were processing 747s at the time.

Randy

The amount of propellant required would be too large to fill from tankers, and the hazards too great. A single-source 'sphere' (optimum storage device in this case) can allow for pressurized filling of the vehicle from a good distance away, and if a drain-back is required (due to a leak in the piping or the vehicle), it has somewhere to go all at once.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: sprocket on 12/14/2011 03:55 PM

Yeah, I mean there is a legitimate rejoinder to these anecdotes "They laughed at Columbus, but they also laughed at Bozo the Clown", but personally I think that people who haven't studied the problem in detail making handwavy dismissals based off of a single execution attempt is just plain ridiculous.

~Jon

We suffered though endless pages here of why this is all a boondoggle. The people behind this project aren't stupid. They've disclosed only those facts that can no longer be hidden. Wouldn't our time be better spent speculating on what is really going to be be dropped from this thing?  Let's see. Meant to carry lots of people. 30,000 ft. 500,000 lbs. I, for one, look forward to Jon's next major blog entry.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: iamlucky13 on 12/14/2011 03:58 PM
Space launch is such an interesting field. I wonder where computers or even airplanes would be if people in those fields were as used to drawing hasty generalizations from single data points.

"Sam Langley's Aerodrome didn't work out, so that obviously shows that heavier than air flight can't work"...

~Jon

Oh believe me, it happens in both those other fields, too. I'd say it's actually a lot more prevalent in the aircraft industry than in the space industry.

In all these fields, the armchair engineers sat in their armchairs and watched while the Sam Langley's made excellent attempts and failed and scoffed at dedicated amateurs like the Wright Brothers even as they cracked the secrets of their field.


It will probably cost way more than ten times as much to build this one-off, six engine, twin hulled behemoth than it cost to buy an old, used L-1011.

Still, one data point....

10x for the plane sounds like the right ballpark...it might even be low. But the L1011 is probably a very small portion of Pegasus program's cost, and the conversion work probably actually cost more than the aircraft itself. Allen's aircraft will be a huge cost up front, but if his market develops like he wants, it will be only one small part of the whole operation.

I suspect he's looking at development and construction costs similar to what Sea Launch faced for converting their launch platform and tender, and that company has held together so far, albeit after struggling through a bankruptcy. Meanwhile, Allen is facing a fairly competitive environment these days.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: InvalidAttitude on 12/14/2011 03:59 PM
Its simply wont happen, a non-sense. Very small market for this, and to build this plane will be much greater undertaking than simply stitching two 747 together.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: simonbp on 12/14/2011 04:18 PM
Would the 'feather' actually work for a booster trajectory? Last I'd heard from Rutan the feather doesn't work at orbital reentry speeds but it SHOULD be good for suborbital...

Well, for the sake of the passengers of SS2, I certainly hope so!

For booster recovery in general, a lofted trajectory (climbing fast to orbital altitude and then burning out) is best, and is generally similar to the tourist suborbital trajectories. This is especially true if you have a wing to allow you to climb almost (but not quite) vertically. The second stage of the "StratoFalcon" (?) doesn't not seem to be much smaller than Falcon 9, also implying a lofted trajectory (which puts more dv load on the second stage).

I think I agree with the suggestions that the "Falcon 9 with a delta wing" shape is a placeholder showing the minimum development option. I'm sure Scaled has some different idea about how it should look. The second stage, though is probably set, thus keeping maximum commonality with F9.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: iamlucky13 on 12/14/2011 04:36 PM
Other questions:

The engine cowls on the "Falcon 5".  Don't think they needed them "the first time".  Only the corner engines, the last 4 of 9, project beyond the tank diameter on the Falcon 9.


With a high altitude start, they probably want bigger nozzles for better Isp. Plus making them more aerodynamic will improve the carrier aitcraft range.

It might also let them use a common thrust structure with the Falcon 9.


As for buying two old 747s to canabalize and stitch together, I find that hard to believe.

This one puzzles me somewhat. The rendered fuselage has only superficial similarity to the 747 around the nose.

Most importantly, the 747 is a low-winged aircraft. The entire fuselage structure around that area is designed to support the wing from that location. A high-winged aircraft would need probably about 40' of fuselage completely rebuilt.

However, the entire fuselage aft of the wing is different, too. It seems most likely to me they plan on using a lot of the systems (hydraulics, electrical, etc) if anything, but a minimal amount of the structure.

Might make an interesting airliner project to compete with the A380…

Even the A380 only fits at a few airports that had to modify their terminals to make it work. This wouldn't even come close. There's also no advantage for a twin fuselage for an airliner, unlike the need to center the cargo for Stratolaunch.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: savuporo on 12/14/2011 04:44 PM
Just an observation. I've seen about half a dozen statements like "people behind this project aren't stupid" - of course they are not, but such statements can also be seen as argumentum ad verecundiam.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: neilh on 12/14/2011 04:47 PM

Yeah, I mean there is a legitimate rejoinder to these anecdotes "They laughed at Columbus, but they also laughed at Bozo the Clown", but personally I think that people who haven't studied the problem in detail making handwavy dismissals based off of a single execution attempt is just plain ridiculous.

~Jon

We suffered though endless pages here of why this is all a boondoggle. The people behind this project aren't stupid. They've disclosed only those facts that can no longer be hidden. Wouldn't our time be better spent speculating on what is really going to be be dropped from this thing?  Let's see. Meant to carry lots of people. 30,000 ft. 500,000 lbs. I, for one, look forward to Jon's next major blog entry.

Indeed. A Falcon 9-derived stage serves as a "payload" with relatively low development risk and cost. It can also help with initial working out of systems and starts to bring in an income stream for the company, much like Falcon 1 did for SpaceX. Once the basic system is working and the development risk of the carrier aircraft is retired, they can then move onto other higher-risk launcher efforts.

Just to toss some random ideas out... Besides flyback systems, I'm particularly curious about how having access to a large carrier helps close the case for an SSTO. What about a jet-powered first stage or SSTO, as danderman described on another thread, which could also use the jets to increase the capacity of the carrier? Heck, could the case for a laser-launch system be improved if both the laser and launcher are above most of the distorting atmosphere?

It mighty be fun to create a separate thread brainstorming space-related uses for a giant carrier plane.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/14/2011 04:59 PM
Other questions:

The engine cowls on the "Falcon 5".  Don't think they needed them "the first time".  Only the corner engines, the last 4 of 9, project beyond the tank diameter on the Falcon 9.


With a high altitude start, they probably want bigger nozzles for better Isp. Plus making them more aerodynamic will improve the carrier aitcraft range.

It might also let them use a common thrust structure with the Falcon 9.


As for buying two old 747s to canabalize and stitch together, I find that hard to believe.

This one puzzles me somewhat. The rendered fuselage has only superficial similarity to the 747 around the nose.

Most importantly, the 747 is a low-winged aircraft. The entire fuselage structure around that area is designed to support the wing from that location. A high-winged aircraft would need probably about 40' of fuselage completely rebuilt.

However, the entire fuselage aft of the wing is different, too. It seems most likely to me they plan on using a lot of the systems (hydraulics, electrical, etc) if anything, but a minimal amount of the structure.

Might make an interesting airliner project to compete with the A380…

Even the A380 only fits at a few airports that had to modify their terminals to make it work. This wouldn't even come close. There's also no advantage for a twin fuselage for an airliner, unlike the need to center the cargo for Stratolaunch.
Try to figrure this...
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: iamlucky13 on 12/14/2011 05:00 PM
Interesting quote from WSJ artitcle (http://online.wsj.com/article/SB10001424052970203518404577097230883918426.html)

Quote
The cost of developing such a mammoth plane, Mr. Rutan added, "historically had been judged as prohibitive." But the logjam broke after engineers came up with "innovative processes to build very large structures" out of composite materials, according to the veteran designer. "Now, it's quite affordable," Mr. Rutan said, and that's one of the reasons the Stratolaunch team decided to lift the veil on the plans.

I wonder what the process was.
jb

I've got some ideas.

One of the biggest costs for composite manufacturing is the tooling. Tooling costs grow rapidly with size and accuracy requirements. Single use tooling is less expensive individually, but more difficult to justify the cost for high accuracy. The accuracy requirements for wind turbines, as far as I've been able to tell, are not nearly as high as for aircraft wings, which helps simplify things for the wind turbine industry.

One possibility would be smaller tooling sections that are aligned using metrology tools that were available a few years ago, like laser trackers.

IIRC, the new Dreamliner doesn't require the use of an autoclave to manufacture the composite wing structures - maybe that's the reason.

They do. Each of the major structure suppliers has their own set of autoclaves, and they are very big:

787 wing autoclave (http://www.aviationweek.com/aw/blogs/commercial_aviation/ThingsWithWings/index.jsp?plckController=Blog&plckScript=blogScript&plckElementId=blogDest&plckBlogPage=BlogViewPost&plckPostId=Blog%3A7a78f54e-b3dd-4fa6-ae6e-dff2ffd7bdbbPost%3Aad8a6d3c-276d-41e0-8b98-a79a8788d926)

But there's another big cost. Bigger structures mean bigger autoclaves,  which means more money.

There are room temperature curing resins, but they're more difficult to work with.

I have seen thermosetting resins be partially cured locally with heat lamps to make parts easier to handle. I presume they don't do this normally because of time, uniformity, and desire for high pressure compression during final cure. I wonder if Scaled has proven out full, uniform curing of large structures with small heat sources.

That doesn't address fiber compaction, but maybe for one-off production, Scaled is satisfied with being extremely meticulous about their layup process and fiddling with huge vacuum bags.

Lots of smaller composite parts are made by using clamp molds to apply pressure instead of air pressure, and electric heaters built into the molds, but those are even more expensive unless you're building really high volumes.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Thorny on 12/14/2011 05:06 PM

Try to figrure this...


Despite the caption, that is actually an F-82 Twin Mustang, not two P-51s bolted together. The F-82 was an all new aircraft that started from the P-51H design, but diverted from it radically. It was not two P-51s.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: iamlucky13 on 12/14/2011 05:08 PM
The "Stratolaunch" name goes back to at least May of this year.

The trademark was applied for May 4, 2011. From the USPTO record:

Quote
Goods and Services    IC 039. US 100 105. G & S: Freight transportation by aircraft and spacecraft; Transportation of passengers and/or goods by aircraft and spacecraft; Travel and tour information service; Travel courier and travel guide services
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/14/2011 05:11 PM

Try to figrure this...

Despite the caption, that is actually an F-82 Twin Mustang, not two P-51s bolted together. The F-82 was an all new aircraft that started from the P-51H design, but diverted from it radically. It was not two P-51s.

No, I guess I did not make my point clear as to the big "why"?
(P.S. I was being rhetorical) ;D
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: iamlucky13 on 12/14/2011 05:41 PM

Try to figrure this...

Despite the caption, that is actually an F-82 Twin Mustang, not two P-51s bolted together. The F-82 was an all new aircraft that started from the P-51H design, but diverted from it radically. It was not two P-51s.

No, I guess I did not make my point clear as to the big "why"?

I'm afraid you still haven't. You quoted my whole post, but it discussed several different topics.

Were you asking why the twin fuselage on the F-82 but not on a passenger jet?

They needed a second engine and bigger wings to lift the extra fuel for longer range, and they wanted a second pilot to reduce fatigue on long overwater flights. Basing it on the P-51 saved development cost, and the separate cockpits avoided disadvantaging one crewman with a backseat view, as he was not a systems operator, but a full co-pilot.

In some ways it was similar to the twin-boom P-38, but that plane had a central fuselage and was single-seated.

If you're carrying passengers, you need a large pressurized volume, something neither the F-82 nor the Stratolauncher aircraft require. Two fuselages is not a structurally efficient way to provide that volume.

If you were asking why I think modifying two 747's to this configuration is more difficult than building the F-82, you'll have to point out which part of what I said in my previous post you disagree with.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Lurker Steve on 12/14/2011 05:44 PM
If all else fails, maybe you could use it to carry submarines  :D

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 ?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: hop on 12/14/2011 05:45 PM
For booster recovery in general, a lofted trajectory (climbing fast to orbital altitude and then burning out) is best, and is generally similar to the tourist suborbital trajectories.
For *very* loose values of similar. Any useful first stage will be re-entering a lot faster than SS2.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/14/2011 06:13 PM
Just an observation. I've seen about half a dozen statements like "people behind this project aren't stupid" - of course they are not, but such statements can also be seen as argumentum ad verecundiam.

The problem is that a lot of us who have studied air launch for years see some of the hand-wavy concerns on here, and don't have time to go dig up the references to quote chapter and verse on why people are blowing things out of proportion.  Personally, from having looked at liquid-fueled air-launch for as long as I have, I think a lot of the nay-saying is based on simplistic logic, ignoring key details, and ignoring the work that's been done in the field.  The approach Allen at least presented yesterday is totally technically feasible.  The bigger concern is that while they may make a system that can operate in a cashflow positive manner, he's taking an approach that I think misses some of the potential of air-launch.

~Jon
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RocketmanUS on 12/14/2011 06:17 PM
I like the t/Space concept with the Airlaunch LLC Quick Reach II rocket with the trapez release. Only one engine one the first stage, simple pressure feed design, same with the second stage. Crew enters capsule after plan is in the air for added safety.

With the Falcon
Could it be for the first stage 5 Merlin vacuum engines around 90,000lb+ each with one engine out from engines start?

Could the Falcon 9 second stage be the same size as for the air launch version?

Cost wise how could this compare to a possible future Falcon 9 RLV?

The advantage to air launch is
 The ability to go above bad weather.
 Multiple launches in one day not waiting for the launch pad to be ready.
 Multiple launch areas do to plane takes the rocket to launch area in the sky.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: docmordrid on 12/14/2011 06:20 PM
An SSTO spaceplane with large internal tanks akin to Venture Star? 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Namechange User on 12/14/2011 06:25 PM
P.S. On the 747 you could mount the Falcon above the center wing section and have it slide back off a rack at launch.

Oh my.  Something goes wrong with the rack, it gets hung up on one roller, wind gust at just the right moment.  Risk is part of this game, unnecessary risk is another thing entirely. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Zed_Noir on 12/14/2011 06:30 PM
If all else fails, maybe you could use it to carry submarines  :D

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.

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/14/2011 06:30 PM

Try to figrure this...

Despite the caption, that is actually an F-82 Twin Mustang, not two P-51s bolted together. The F-82 was an all new aircraft that started from the P-51H design, but diverted from it radically. It was not two P-51s.

No, I guess I did not make my point clear as to the big "why"?

I'm afraid you still haven't. You quoted my whole post, but it discussed several different topics.

Were you asking why the twin fuselage on the F-82 but not on a passenger jet?

They needed a second engine and bigger wings to lift the extra fuel for longer range, and they wanted a second pilot to reduce fatigue on long overwater flights. Basing it on the P-51 saved development cost, and the separate cockpits avoided disadvantaging one crewman with a backseat view, as he was not a systems operator, but a full co-pilot.

In some ways it was similar to the twin-boom P-38, but that plane had a central fuselage and was single-seated.

If you're carrying passengers, you need a large pressurized volume, something neither the F-82 nor the Stratolauncher aircraft require. Two fuselages is not a structurally efficient way to provide that volume.

If you were asking why I think modifying two 747's to this configuration is more difficult than building the F-82, you'll have to point out which part of what I said in my previous post you disagree with.
I guess it’s not that I disagree with you at all. If an aircraft constructor is adamant that a certain concept is in their opinion “the best” and is well funded, then why not? It’s their money… I have total faith in Burt Rutan going right back to his early days. If he believes in this a/c, it will fly…  That doesn’t mean that there have not been alternatives throughout the years. My gut tells me that Burt really wants another record breaking aircraft and that is cool too…  8)

Regards
Robert
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Zed_Noir on 12/14/2011 06:33 PM
P.S. On the 747 you could mount the Falcon above the center wing section and have it slide back off a rack at launch.

Oh my.  Something goes wrong with the rack, it gets hung up on one roller, wind gust at just the right moment.  Risk is part of this game, unnecessary risk is another thing entirely. 

IIRC the D-21 drone was deploy in such a manner off the SR71, not very successfully.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: simonbp on 12/14/2011 06:41 PM
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.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Dalon on 12/14/2011 06:43 PM
P.S. On the 747 you could mount the Falcon above the center wing section and have it slide back off a rack at launch.

Oh my.  Something goes wrong with the rack, it gets hung up on one roller, wind gust at just the right moment.  Risk is part of this game, unnecessary risk is another thing entirely. 

There is definite risk, even with this underwing design.

They could put explosive bolts within the strongback to effect a secondary separation in the event of a faulty separation.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Dalon on 12/14/2011 06:51 PM
I won't be surprised if the carrier aircraft is designed to mid-flight refuel.

While I'm not aware of any civilian use of mid-flight refueling, the technology behind it is very mature.   Mid-flight refueling would drastically increase the available payload. 

I cannot imagine the military raising any objections against a group with these credentials.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RanulfC on 12/14/2011 07:07 PM
I won't be surprised if the carrier aircraft is designed to mid-flight refuel.

While I'm not aware of any civilian use of mid-flight refueling, the technology behind it is very mature.   Mid-flight refueling would drastically increase the available payload. 
Actually there are a couple of companies that operate "civilian" mid-air refueling business. They usualy augment military operations or for governments that don't have "in-house" long-range refuelers.

Quote
I cannot imagine the military raising any objections against a group with these credentials.
"Objections" as in not allowing them to use military assets? Currently that's not "legal" for the military to do so while they won't "object" the truth is that they would have to go to the aforementioned companies as they would not be allowed access to military equipment.

Randy
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: rdale on 12/14/2011 07:14 PM
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?

That's not how the Internet rolls ;) You read bits and pieces of a press release, don't bother to look for info yourself, and post hair brained ideas with the purpose of starting a fight with those who actually know what is going on.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Namechange User on 12/14/2011 07:29 PM
P.S. On the 747 you could mount the Falcon above the center wing section and have it slide back off a rack at launch.

Oh my.  Something goes wrong with the rack, it gets hung up on one roller, wind gust at just the right moment.  Risk is part of this game, unnecessary risk is another thing entirely. 

There is definite risk, even with this underwing design.

They could put explosive bolts within the strongback to effect a secondary separation in the event of a faulty separation.

Of course there is risk.  "Risk" in its own right should not be something that strikes fear in the hearts of everyone and keeps that job from happening.  What one does is design to minimize the risk within practical terms that have the least impact on technical, cost and schedule.

As for redundancy, what you suggested is a possibility, and is a function of the overall risk strategy, their design and ConOps. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Dalon on 12/14/2011 07:41 PM
Of course there is risk.  "Risk" in its own right should not be something that strikes fear in the hearts of everyone and keeps that job from happening.  What one does is design to minimize the risk within practical terms that have the least impact on technical, cost and schedule.

As for redundancy, what you suggested is a possibility, and is a function of the overall risk strategy, their design and ConOps. 

I've nothing against risk.  I think this is an enthralling design and I'm very happy to see more private investment attempting to lower costs to space.

I do have concerns about the tremendous complexity involved with this system.  Fueling will be complicated.  The tight timing from release to engine start could be hairy.  Safely mitigating abort scenarios could be the biggest undertaking of all.

There seem to be significant risks to the carrier aircraft.  I wouldn't want to be flying in that aircraft during the first few launches.  I even wonder if it will be remotely piloted.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Namechange User on 12/14/2011 07:47 PM
Of course there is risk.  "Risk" in its own right should not be something that strikes fear in the hearts of everyone and keeps that job from happening.  What one does is design to minimize the risk within practical terms that have the least impact on technical, cost and schedule.

As for redundancy, what you suggested is a possibility, and is a function of the overall risk strategy, their design and ConOps. 

I've nothing against risk.  I think this is an enthralling design and I'm very happy to see more private investment attempting to lower costs to space.

I do have concerns about the tremendous complexity involved with this system.  Fueling will be complicated.  The tight timing from release to engine start could be hairy.  Safely mitigating abort scenarios could be the biggest undertaking of all.

There seem to be significant risks to the carrier aircraft.  I wouldn't want to be flying in that aircraft during the first few launches.  I even wonder if it will be remotely piloted.

Your concerns are noted.  None of them are insurmountable nor do they have to be overly complicated.  Given the freedom the carrier aircraft has and it's ability to not be fixed to one location at "T-0", abort scenarios (if and when even required) may be the easiest thing of all to mitigate.

As for the carrier aircraft risks, I suggest you do not apply for the job. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/14/2011 07:54 PM
By the way, this hasn't been touched on here very much, but one thing people on the ARocket list are pointing out is that airlaunch would make first-orbit rendezvous a lot easier, meaning that if you are sending people/supplies or propellant to a space station or depot, you could launch any day (probably with multiple opportunities per day) without having to wait a couple days in a phasing orbit. This means you can make the cabin much more cramped than you otherwise would be able to get away with (think elevator versus sleeper car), and boil-off for cryogens on a tanker is a lot less of a design problem. Also, you can get time-critical supplies up there a lot faster.

This means you can offload more of the spacecraft mass to the station, getting more bang for your buck.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: baldusi on 12/14/2011 08:02 PM
One problem I have is wondering if 1300mn are enough. From KSC they can't reach betten than 8degrees latitude without launching ove Venezuelan air space. If they can launch form Puerto Rico (the longest runway is 11.500 feet, and I don't know how are they going to replenish the LOX), then they can get close to Kourou altitude. But still would be a problem to hit the Brazilian air space.
Kwajalein doesn't have a runway long enough. So they can't hit the equator from there.
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.
At last, I'm still wondering if that aircraft isn't the perfect case for the GE90-94B. Two of those would have the same thrust of three of the 747-400 (around 820kN). nd I doubt GE would be worried of it competing with the Boeing 777. Or they could go with the GE90-115B monsters and get 20% more payload.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: HMXHMX on 12/14/2011 08:20 PM
Some people have asked if I'm involved, or AirLaunch or t/Space.  The answer is no to all three.

Perhaps someday I can comment, but not today.  NDAs and confidences are involved.  Sorry.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: rjholling on 12/14/2011 08:29 PM
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?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RanulfC on 12/14/2011 08:56 PM
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
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: iamlucky13 on 12/14/2011 08:59 PM
If all else fails, maybe you could use it to carry submarines  :D

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:

Quote
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.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RanulfC on 12/14/2011 09:00 PM
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
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/14/2011 09:03 PM
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
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/14/2011 09:05 PM
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.
Quote
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. ;)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RanulfC on 12/14/2011 09:09 PM
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
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: WellingtonEast on 12/14/2011 09:23 PM
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.
 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Moe Grills on 12/14/2011 09:32 PM
   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. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/14/2011 09:34 PM
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
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/14/2011 09:41 PM
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
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: simonbp on 12/14/2011 09:43 PM
If all else fails, maybe you could use it to carry submarines  :D

I'd make one heck of a torpedo bomber; airplane drops the submarine next to the target ship, submarine torpedoes the target!
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Lee Jay on 12/14/2011 09:46 PM
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?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/14/2011 09:47 PM
If all else fails, maybe you could use it to carry submarines  :D

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 :D
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RobLynn on 12/14/2011 09:50 PM
If all else fails, maybe you could use it to carry submarines  :D

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.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/14/2011 09:50 PM
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
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/14/2011 09:56 PM
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
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/14/2011 10:11 PM
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!! 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jimvela on 12/14/2011 10:17 PM
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...
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/14/2011 10:30 PM
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
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: dbhyslop on 12/14/2011 10:33 PM

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.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/14/2011 10:37 PM
You would obviously set the "abort" parameters a lot more liberally than if you can abort without losing the rocket. Tell me: were all those pad aborts we keep hearing of really going to lead to a failed launch? A significant fraction (and, just a guess, the large majority) could probably have launched successfully just fine.

Obviously, if you can do a pad abort and just recycle the rocket in a couple hours, you're going to set the criteria for aborting (before lift-off) a lot more strictly, since your cost in case of a false alarm is a lot less.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: dbhyslop on 12/14/2011 10:42 PM
Point taken.  I remember some discussion of this during the Falcon launch where it was an issue but unfortunately I don't have the background to understand the trades that go into those abort criteria.  Nonetheless, given a choice I'd prefer to ride the one that launches from the ground.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/14/2011 10:44 PM
You would obviously set the "abort" parameters a lot more liberally than if you can abort without losing the rocket. Tell me: were all those pad aborts we keep hearing of really going to lead to a failed launch? A significant fraction (and, just a guess, the large majority) could probably have launched successfully just fine.

Obviously, if you can do a pad abort and just recycle the rocket in a couple hours, you're going to set the criteria for aborting (before lift-off) a lot more strictly, since your cost in case of a false alarm is a lot less.
An abort on the ramp or during takeoff would be interesting. I hope the carrier craft crew would have some means to escape and ejection could return you to any plume on the ground. All need to be considered…
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: zaitcev on 12/14/2011 10:45 PM
Here's an apropos quote from Elon Musk:

http://www.nasaspaceflight.com/2006/08/spacexmusk-the-rocket-business/
Quote
There is a fundamental difference in architecture between ourselves and the Pegasus. I think if you were the smartest person on earth you could not make the Pegasus cheap.

The reason I say that is because it is a five stage rocket. You’ve got an airplane, which is a dedicated Lockheed L-1011. No matter how many times you launch, you have to maintain that plane at several million dollars per year. You have to have dedicated pilots.

Your range safety is much more complex because you essentially have a man-rated system – you are interacting a rocket and a plane with people on board, and then launching it with maybe 20 or 30 feet separating the pilot and that rocket. So I think that complicates things.

Then you have three solid rocket motor stages, including a complete hypersonic airplane in the first solid rocket stage. And then you have the fifth stage, which is the liquid apogee HAPS stage. So if you were the smartest person on Earth, I don’t think you could make that system very cheap.

If you look at ours in contrast: it is a two stage rocket, no wings, no control surfaces, both stages are the cheapest propellant you can use, LOX/Kerosene.

The animation shows a manned carrier airplane and the "complete hypersonic airplane" with a triangular wing. Why such a change of mind? Because this time Elon is spending someone's else money.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/14/2011 10:47 PM
Point taken.  I remember some discussion of this during the Falcon launch where it was an issue but unfortunately I don't have the background to understand the trades that go into those abort criteria.  Nonetheless, given a choice I'd prefer to ride the one that launches from the ground.

My concern is just that "relaxing constraints" could end up getting you into trouble.  If those constraints aren't thought to increase the odds of getting a good flight, then why are they there in the first place?  If they do increase the odds of getting a good flight, then aren't you still playing risky games with relaxing them to increase the light probability?

For a VTVL powered landing, I can totally see having the landing ignition requirements be a lot looser, since the engine only has to hold together for a few seconds, and you can probably tolerate some hardware rich combustion if it gets the engine on the ground safely.  But anyway, my biases are showing.

~Jon
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Lee Jay on 12/14/2011 11:22 PM
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

I had a discussion a while back with Antonio Elias here on NSF about using what I called a "zoom launch".  The idea is to place the carrier aircraft into a shallow dive to pick up speed, and then pull up hard and release the rocket at the proper angle, thus avoiding most or all of the turning losses that the wing on Pegasus is supposed to also help to mitigate.  I've simulated this a little (don't ask) and I still don't see exactly why this wouldn't work, but I could imagine some implementation details that could be a problem.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/14/2011 11:40 PM
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. 


It isn't, it is a F9 type core
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/15/2011 12:32 AM
Some other twin conversion carrier aircraft...

http://www.pmview.com/spaceodysseytwo/spacelvs/sld039.htm
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: simonbp on 12/15/2011 12:44 AM
I had a discussion a while back with Antonio Elias here on NSF about using what I called a "zoom launch".  The idea is to place the carrier aircraft into a shallow dive to pick up speed, and then pull up hard and release the rocket at the proper angle, thus avoiding most or all of the turning losses that the wing on Pegasus is supposed to also help to mitigate.  I've simulated this a little (don't ask) and I still don't see exactly why this wouldn't work, but I could imagine some implementation details that could be a problem.

That sounds pretty cool, and doable with the design they're showing. The structural loads on the wing roots at the point you pull up might be a killer, though.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: edkyle99 on 12/15/2011 01:19 AM
Launch everyday from everywhere: stratolaunch.com! The new project by Mr. Allen.

Http://www.stratolaunch.com

Largest aircraft ever. 

The problem is, it is still not big enough.

 - Ed Kyle
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: robertross on 12/15/2011 01:26 AM
Some people have asked if I'm involved, or AirLaunch or t/Space.  The answer is no to all three.

Perhaps someday I can comment, but not today.  NDAs and confidences are involved.  Sorry.

No worries here - I totally understand. Thanks for the note.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/15/2011 01:29 AM
Launch everyday from everywhere: stratolaunch.com! The new project by Mr. Allen.

Http://www.stratolaunch.com

Largest aircraft ever. 

The problem is, it is still not big enough.

 - Ed Kyle
Aw, come on now Ed… Let’s not cloud the issue with facts… ;D

Robert
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Lee Jay on 12/15/2011 01:39 AM
I had a discussion a while back with Antonio Elias here on NSF about using what I called a "zoom launch".  The idea is to place the carrier aircraft into a shallow dive to pick up speed, and then pull up hard and release the rocket at the proper angle, thus avoiding most or all of the turning losses that the wing on Pegasus is supposed to also help to mitigate.  I've simulated this a little (don't ask) and I still don't see exactly why this wouldn't work, but I could imagine some implementation details that could be a problem.

That sounds pretty cool, and doable with the design they're showing. The structural loads on the wing roots at the point you pull up might be a killer, though.

I think the g-load could be kept under 1.5, which is equivalent to a decent turn.

If it buys you a couple hundred m/s saved, maybe it's worth beefing up the structure a bit.  Don't forget, by the time you get to this point, you've already burned off quite a bit of jet fuel.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Lee Jay on 12/15/2011 01:40 AM
Launch everyday from everywhere: stratolaunch.com! The new project by Mr. Allen.

Http://www.stratolaunch.com (http://Http://www.stratolaunch.com)

Largest aircraft ever. 

The problem is, it is still not big enough.

 - Ed Kyle

Heh!  When I envisioned this long ago, it had 6-8 GE90-115Bs.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/15/2011 02:49 AM
Here's an apropos quote from Elon Musk:

http://www.nasaspaceflight.com/2006/08/spacexmusk-the-rocket-business/
Thanks for posting that.  This was interesting too:

"We pay $1.90 per gallon of rocket propellant grade Kerosene…[laugh]…I can’t fill my car up for that…and the liquid oxygen in Texas – unfortunately in Kwajalein it ends up being a little more expensive than I’d like – but certainly in the continental United States you can actually buy liquid oxygen for about 40 cents per gallon."


Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: neilh on 12/15/2011 02:56 AM
Here's an apropos quote from Elon Musk:

http://www.nasaspaceflight.com/2006/08/spacexmusk-the-rocket-business/
Quote
There is a fundamental difference in architecture between ourselves and the Pegasus. I think if you were the smartest person on earth you could not make the Pegasus cheap.

The reason I say that is because it is a five stage rocket. You’ve got an airplane, which is a dedicated Lockheed L-1011. No matter how many times you launch, you have to maintain that plane at several million dollars per year. You have to have dedicated pilots.

Your range safety is much more complex because you essentially have a man-rated system – you are interacting a rocket and a plane with people on board, and then launching it with maybe 20 or 30 feet separating the pilot and that rocket. So I think that complicates things.

Then you have three solid rocket motor stages, including a complete hypersonic airplane in the first solid rocket stage. And then you have the fifth stage, which is the liquid apogee HAPS stage. So if you were the smartest person on Earth, I don’t think you could make that system very cheap.

If you look at ours in contrast: it is a two stage rocket, no wings, no control surfaces, both stages are the cheapest propellant you can use, LOX/Kerosene.

The animation shows a manned carrier airplane and the "complete hypersonic airplane" with a triangular wing. Why such a change of mind? Because this time Elon is spending someone's else money.

Also keep in mind that he's comparing the Pegasus and the Falcon 1 in that remark. The economics change a fair bit when you increase the payload by an order of magnitude.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: fotoguzzi on 12/15/2011 03:18 AM
396 comments!

Well, I will ask these questions and cross them out as I find them already covered in the comments as I plow through said comments:

Perhaps this plane could launch rockets into funny orbits without having to fly over cities. Are there that many funny orbits that are needed?

Does the initial altitude and speed really help all that much with cost? What are we saving? Fuel?

Is the cost per kg lower or is it just that one can get that kg exactly where it needs to be?

Is there something about an air launch that makes more parts recoverable?

Well, back to reading the thread....
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Proponent on 12/15/2011 03:27 AM
Perhaps this plane could launch rockets into funny orbits without having to fly over cities. Are there that many funny orbits that are needed?

Being able to move the launch point makes for more frequent launch windows to, for example, the ISS.  How important that is depends on how frequently you need to fly.

Quote
Does the initial altitude and speed really help all that much with cost? What are we saving? Fuel?

The speed provided by an air launch is not very significant.  What is significantly beneficial is that the lower air pressure at ignition permits a greater expansion ratio for the first-stage engines, making them more efficient.  Starting above well over half of the atmosphere reduces drag losses.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: simonbp on 12/15/2011 03:31 AM
Does the initial altitude and speed really help all that much with cost? What are we saving? Fuel?

There's a wonderful post on this forum by Antonio Elias, the original designer of Pegasus, about the advantages of the design. Effectively, it's more performance and more flexible launch operations.

The performance comes from launching in lower-pressure high-altitude air (which increases the rocket's efficiency) and from the wing providing lift to the rocket, reducing the losses due to gravity and drag. The flexibility comes from being able to launch in locations where building a launch pad is too expensive (i.e. anywhere other than established sites), and to be able to go around bad weather.

It's obviously not a smoking gun (as evidenced by the lack of any Pegasus launches this year), but it could be enough to be cheaper than Orbital's Antares (ex-Taurus II), the main competition in this range.

Speaking of which, I wonder if Allen initially offered the booster contract to Orbital; it seems much better suited to an air-launched Antares than a foreshortened Falcon 9...
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/15/2011 04:30 AM
Antares has a few of differences: Not entirely domestic, hasn't flown, solid upper stage (i.e. harder to carry around when the rocket isn't fueled up... upper stage is always fueled), and possibly higher cost compared to foreshortened Falcon 5 (whatever). There are a lot more subcontractors to deal with for the different parts of Antares since that's Orbital's style (and it has suited them well in the past) compared to SpaceX's vertically integrated approach.

I think it's interesting that both of Elon's big projects, Tesla and SpaceX, have taken the vertical integration approach and now both are selling the heart of their primary product (i.e. electric drivetrain to Toyota and others and Falcon 5 to Stratolaunch) as a contractor to what some might call competitors. A couple of reasons for that: 1) Elon is very ambitious, pushes for something really great (with a great team), they partially succeed, but he over-steps and so sells out partially to competitors... 2) Elon possibly cares more about the technology succeeding in a way that changes the landscape than that it's "his." Maybe that last one is a little too generous (Musk is incredibly cocky, and it probably hurts his ego a bit that he sells out... sometimes learning a little humility can be good for ya). Either way, I don't really care who is making electric cars or launching rockets, as long as they're cheap and work well.

I wish Stratolaunch the best of luck. It will be quite interesting to see footage of a launch from this thing...
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Andrew_W on 12/15/2011 05:09 AM
It's only a few months ago that the concept of a dedicated stratospheric lift aircraft carrying this size rocket was being rubbished by people on this forum as too revolutionary, too expensive, and requiring too much in the way of new development.

 Now that it looks like it might actually be realistic and affordable, it's being rubbished as not innovative enough!
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Zed_Noir on 12/15/2011 05:44 AM
Also, if only a few major airports had a capable runway

Actually there is a lot of redundant ex-B52 airfields available for conversion to operate the Stratolaunch carrier aircraft.

Think a runway wide enough to be able to accommodate the outrigger landing gears of a B52 should do the same for the Stratolaunch.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: kkattula on 12/15/2011 05:54 AM
I fogot to mention that there's an international standard for airports of an 80m square box. This means that if you go past that box, there's no guarantee whatsoever that the airport will accept your aircraft. This means FOD dangers on the runway, passages between buildings, and hangar doors and such. So this aircraft has no possibility of being used as anything else than launcher and very special cargo (think an-225 sort of cargo).

That easily solved. Shorten the wingspan by building the world's biggest biplane. ;)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/15/2011 10:20 AM

 Now that it looks like it might actually be realistic and affordable,

There is nothing that says it is affordable.  There is an investor who might not make any money on it just like he didn't with SS1
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/15/2011 11:59 AM
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. 

It isn't, it is a F9 type core
In the video that shows friction stir welding (I forget where that was).  They were building tanks in sections and that video gave me the impression that the diameter could be increased using the equipment they already have.  I am not sure if that impression is accurate.
If a 5 engine version can still be considered 'F9 type', even though it's plumbing and programming completely changes, if it uses big vacuum optimized engines, (maybe methane), etc.  Then it might be fair to call a slightly different tank diameter also F9 type.  Especially if their graphics imply a different size. 

Then again, the length of the rocket including dragon (and trunk presumably) looks to be just under 1/3 the wingspan of the aircraft (and about 1/2 the length of the aircraft). 
Regular F9 weighs 735 kilopounds at 1.78 hectofeet tall ;)
This rocket should only weigh 490 kilopounds.   If the wingspan is 3.85 hectofeet, then this rocket is about 1.2 hectofeet long (total).  That implies a weight of 495 kilopounds.  Toss in some assumptions about dragon and trunk overall weight ratio, and presuming RP-1, I am forced to agree with your contention that it is probably a standard "F9-type diameter". 

While a 5 meter dragon could probably fit an extra 5+ tourists, KISS suggests that you are right. 

Would it work to use the same thrust structure and plumbing as F9 but with 4 of the pipes closed and 4 engines missing?  Not exactly optimized, but cheaper than complete re-development?  Especially if multi-engine-out programming exists, and most especially if code was developed for F5 back in the day.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/15/2011 12:01 PM
Also, if only a few major airports had a capable runway

Actually there is a lot of redundant ex-B52 airfields available for conversion to operate the Stratolaunch carrier aircraft.

Think a runway wide enough to be able to accommodate the outrigger landing gears of a B52 should do the same for the Stratolaunch.
Funny you mentioned the airfields. I thought that a twin B-52 would make an interesting conversion as well for a launch aircraft. I don’t know of any in private hands though yet, it is still an active aircraft in service.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/15/2011 12:18 PM
I don't know, but suspect that Paul Allen wants these companies to do the development work at cost on this project.  No profit until maybe some type of profit-sharing arrangement in the far future. 

Easy to see how Elon would be agreeable to that (keeps guys busy and creates an ideal fly-back-booster drop test carrier).  The more rockets he launches, the more statistics and tests he has.  Plus it's just frickin' cool.  And Elon likes frickin' cool stuff.  The feathered re-entry license doesn't hurt either.

Easy to see how scaled composites would be interested in that arrangement too.  If they develop this thing, they could potentially build a bunch of the big aircraft to launch all sorts of stuff.  George Whitesides at VG for example, has been clear that orbital is the eventual goal too.  Plus there might be military customers (Ultra-Massive-Ordinance-Penetrators anyone?)

UMOP's might be an extra reason for Dynetics to be attracted to such an arrangement.  Or maybe they would be cost-plus.  Not as easy to see their benefit other than as an exceptional advertisement of their capability. 

Any way you slice it, one observation keeps hitting me:  It would be cool to have enough loot laying around that as a hobby, you could buy a couple 747's and hire a bunch of smart people to build something cool out of them (like the worlds largest aircraft that doubles as an orbital rocket launcher).

Too Cool!!   
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/15/2011 12:27 PM
Article from PM...

http://www.popularmechanics.com/science/space/rockets/new-space-company-stratolaunch-will-launch-orbital-rockets-from-twin-747s-6615736
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/15/2011 12:36 PM
I don't know, but suspect that Paul Allen wants these companies to do the development work at cost on this project.  No profit until maybe some type of profit-sharing arrangement in the far future. 

Easy to see how Elon would be agreeable to that (keeps guys busy and creates an ideal fly-back-booster drop test carrier).  The more rockets he launches, the more statistics and tests he has.  Plus it's just frickin' cool.  And Elon likes frickin' cool stuff.  The feathered re-entry license doesn't hurt either.

Easy to see how scaled composites would be interested in that arrangement too.  If they develop this thing, they could potentially build a bunch of the big aircraft to launch all sorts of stuff.  George Whitesides at VG for example, has been clear that orbital is the eventual goal too.  Plus there might be military customers (Ultra-Massive-Ordinance-Penetrators anyone?)

UMOP's might be an extra reason for Dynetics to be attracted to such an arrangement.  Or maybe they would be cost-plus.  Not as easy to see their benefit other than as an exceptional advertisement of their capability. 

Any way you slice it, one observation keeps hitting me:  It would be cool to have enough loot laying around that as a hobby, you could buy a couple 747's and hire a bunch of smart people to build something cool out of them (like the worlds largest aircraft that doubles as an orbital rocket launcher).

Too Cool!!   
Loot is not the problem… Allen has a lot which is one of the reasons that Burt can spend it all building this “Beast”. He is more excited about it than the rocket if you listen to him speak.  I still feel that the money would be better spent on a Flyback first and second stage thus fully reusable and no need to design a huge a/c with a small selection of available airfields available for it…

Regards
Robert
http://forum.nasaspaceflight.com/index.php?topic=27477.30
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: baldusi on 12/15/2011 01:31 PM
I would love to have a summary of "problems and complications". I've seen how from the moment they presented the SLS to the small details that started to appear, a lot of those "problems" were addressed (LRB ground hold down points, width, vertical welding, etc.).
I guess most of what we talk here will probably be addressed in the final design. But I love when details start trickling down and you can say "those are smart cookies". Because you'd never thought of such a solution. Or even when someone says "I knew it!".
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: muomega0 on 12/15/2011 01:53 PM
Here is a proposal using twin C-5’s. I guess if Burt could get his hands on those…
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110015353_2011016245.pdf


http://www.pmview.com/spaceodysseytwo/spacelvs/sld039.htm
Thanks for the links!

Quotes from the references

Quote
Based on the point design vehicle results, payloads up to 15,000 lbs can be obtained using a much larger two-stage system that is empty of fuel at takeoff and utilizing a tanker for in-air fueling of the carrier or the launch vehicle.


The major cost of a subsonic horizontal take-off space launch is the launch vehicle. To use these for horizontal launch, aerodynamic surfaces and other structures are added to enable separation and pull-up  maneuvers. These additions, along with the need for a carrier
aircraft, have the potential to make horizontal launch a more expensive option.  However, horizontal launch provides the potential for improved basing flexibility, covert launch, weather avoidance, and offset launch for orbital intercept and reconnaissance that may outweigh any increased cost.


and
Salkeld regarded advanced airbreathing propulsion as less cost-effective than tripropellant rocket engines. He noted that although airbreathing  LVs offer several potential advantages over rockets (=reduced takeoff noise, compatibility with existing airport facilities, convential aircraft type HTHL operations, reduced acceleration profile during ascent), hypersonic ramjet engines cannot evolve as direct outgrowths of supersonic airliner or Space Shuttle technology. The aerodynamics (e.g. interaction between engine & airframe) and thermal protection problems also would require new technologies whereas SSTO rocketplanes could be based directly on Shuttle systems such as high-pressure SSMEs, thermal protection tiles etc.. Salkeld concluded high-speed airbreathing RLVs have to be large (=sonic boom problem during climbout & acceleration), and the engines will be much heavier and probably require advanced technologies that will not be available for another 20-30 years. Ground launched SSTO generally seemed more economical than air-launched vehicles although they may offer some operational advantages (e.g. mobile platforms) for small space payloads and suborbital missions. For TSTOs, Salkeld found the GLOW is mimimized at Mach 5 separation if the booster uses jet fuel and Mach 7-8 for LH2 platforms. The hydrogen booster showed clear weight reductions compared to JP bosters. Tripropellant engines may significantly reduce the overall mass of air launched RLVs (e.g. 25-30% orbiter dry mass reduction in the super/hypersonic regime). Salkeld found that hypersonic HTHL TSTOs offer GLOW reductions of 50% compared to SSTO rockets, but the dry weight (and hence cost) is 100-300% higher. He dismissed in-flight refueling and airbreathing-rocket launch platforms since they require technologies which will not be available for 2 or 3 decades. Marginal cost/lb payload estimates (185km polar orbit): $130 for fully reusable Phase B VTHL TSTO Shuttle, $1258 for the Space Shuttle, $76 for triprop. HTHL SSTO, $135-137 for Mach 6-9 HTHL TSTOs.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Blackmorecaster on 12/15/2011 02:06 PM
I like it. It should open a lot of possibilities as to what you can carry/launch with it. A fully reusable space plane comes to mind, that would be fantastic. I think that may be the ultimate goal of this project.

Speaking of which, it can carry a 223 tonne rocket... So it means some 20-25 tonnes to LEO should be doable, am I right?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RanulfC on 12/15/2011 02:13 PM
Some people have asked if I'm involved, or AirLaunch or t/Space.  The answer is no to all three.

Perhaps someday I can comment, but not today.  NDAs and confidences are involved.  Sorry.
Thanks. Out of curiosity have you folks reviewed the paper I cited earlier?
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20070002822_2007001607.pdf

The more I'm reading the more I am seeing confirmationo of many of the background themes you/TSpace/AirLaunch have espoused over the years.

If it doesn't impinge on any of the above "issues" is the fact that this project is moving forward going to have a postivie outcome for your efforts?

Randy
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RanulfC on 12/15/2011 02:16 PM
Also, if only a few major airports had a capable runway

Actually there is a lot of redundant ex-B52 airfields available for conversion to operate the Stratolaunch carrier aircraft.

Think a runway wide enough to be able to accommodate the outrigger landing gears of a B52 should do the same for the Stratolaunch.
Funny you mentioned the airfields. I thought that a twin B-52 would make an interesting conversion as well for a launch aircraft. I don’t know of any in private hands though yet, it is still an active aircraft in service.
Probably NOT going to happen given the plan is to run the airframe out till the mid 2050s.

Randy
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: yg1968 on 12/15/2011 02:19 PM
Article from PM...

http://www.popularmechanics.com/science/space/rockets/new-space-company-stratolaunch-will-launch-orbital-rockets-from-twin-747s-6615736


Quote
Their sights are set on ferrying humans to orbit by 2020.


Thanks for the link. The 2020 objective for a manned flight wasn't very clear during the press conference. They mentionned an umnanned test flight in 2016. It seems like the project actually started in 2010.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Kaputnik on 12/15/2011 02:20 PM
Speaking of which, it can carry a 223 tonne rocket... So it means some 20-25 tonnes to LEO should be doable, am I right?

The advertised payload is just over 6 tonnes. That's 2.75% of initial mass which is about normal.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/15/2011 02:21 PM
I fogot to mention that there's an international standard for airports of an 80m square box. This means that if you go past that box, there's no guarantee whatsoever that the airport will accept your aircraft. This means FOD dangers on the runway, passages between buildings, and hangar doors and such. So this aircraft has no possibility of being used as anything else than launcher and very special cargo (think an-225 sort of cargo).

That easily solved. Shorten the wingspan by building the world's biggest biplane. ;)

I wonder if folding wings (ala some carrier airplanes) would help.  Since they're building the wing themselves, adding the wing folding capability might help.  At least for maneuvering on the ground on the way to the runway.  But I'm by no means an expert in wingy-things.

~Jon
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/15/2011 02:36 PM
I fogot to mention that there's an international standard for airports of an 80m square box. This means that if you go past that box, there's no guarantee whatsoever that the airport will accept your aircraft. This means FOD dangers on the runway, passages between buildings, and hangar doors and such. So this aircraft has no possibility of being used as anything else than launcher and very special cargo (think an-225 sort of cargo).

That easily solved. Shorten the wingspan by building the world's biggest biplane. ;)

I wonder if folding wings (ala some carrier airplanes) would help.  Since they're building the wing themselves, adding the wing folding capability might help.  At least for maneuvering on the ground on the way to the runway.  But I'm by no means an expert in wingy-things.

~Jon
Interesting idea Jon. Or at least the outer sections could swing back. It still would add weight and complexity though…

Robert
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RanulfC on 12/15/2011 02:46 PM
If all else fails, maybe you could use it to carry submarines  :D

Quoting from this document:
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20070002822_2007001607.pdf
(let me know if you think I'm spamming this too much ;P )

"The Carrier Aircraft must have a continual utilization demand that is profitable"

Simply; "suppose" that there is a demand for 50-launchers per year utilizing this ALTO-System. the carrier-aircraft is being used only a few hours every week! It's noted that the airline industry has difficulty (even prior to the current economic climate) financially whilst running aircraft multiple times daily.
(Note that this is a really, really high launch rate, coupled with this single system having the entire "launch market". Far fetched but illustrates a point)

Having other income streams is going to be important to reduce the amoritization costs associated with each rocket launch. Part of the reason Pegasus cost so much is the ONLY application for the L-1011 is as a carrier aircraft. So all mainteance, operations, and amoritized purchase and modifications costs need to be appended to each and every launch flight price.

Randy
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: kkattula on 12/15/2011 02:58 PM
I wonder if folding wings (ala some carrier airplanes) would help.  Since they're building the wing themselves, adding the wing folding capability might help.  At least for maneuvering on the ground on the way to the runway.  But I'm by no means an expert in wingy-things.

~Jon

Maybe.  The wing span is 115m so you only need the last 18m on each side to fold to fit into that 80m box.  That looks to be beyond the outboard engine mounts. More difficult if that section of the wing needs to be wet, but that's been done before too. Probably depends on what sort of cleverness Burt is designing into the wing to keep it light but strong.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: baldusi on 12/15/2011 03:20 PM
Help me here. The ISS has a period of 90 minutes, right? This means that the earth moves 1/16th or about 22.5degrees between orbits, right?
1300nm from the KSC going straight to the East are 25degrees. Would that mean that they could do daily first orbit rendezvous?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: MP99 on 12/15/2011 04:04 PM
Help me here. The ISS has a period of 90 minutes, right? This means that the earth moves 1/16th or about 22.5degrees between orbits, right?
1300nm from the KSC going straight to the East are 25degrees. Would that mean that they could do daily first orbit rendezvous?

Supplementary question - if the answer to above is yes.

If you restricted ground-launch F9 to the same payload as Stratolaunch (cut by nearly half), could you fly a dogleg from either KSC or Vandenburg to achieve the same thing as above?

cheers, Martin
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/15/2011 04:08 PM
Help me here. The ISS has a period of 90 minutes, right? This means that the earth moves 1/16th or about 22.5degrees between orbits, right?
1300nm from the KSC going straight to the East are 25degrees. Would that mean that they could do daily first orbit rendezvous?

Should be able to. It's one of the greatest advantages in this approach. Join the ARocket mailing list and read what Henry Spencer wrote about Stratolaunch.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: baldusi on 12/15/2011 04:23 PM
Should be able to. It's one of the greatest advantages in this approach. Join the ARocket mailing list and read what Henry Spencer wrote about Stratolaunch.
Could you point me out the list? Google is sort of inconsistent.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: krytek on 12/15/2011 04:27 PM
What would folding wings accomplish?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/15/2011 04:31 PM
What would folding wings accomplish?
Make it cost more? ;D
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: HMXHMX on 12/15/2011 04:34 PM
Some people have asked if I'm involved, or AirLaunch or t/Space.  The answer is no to all three.

Perhaps someday I can comment, but not today.  NDAs and confidences are involved.  Sorry.
Thanks. Out of curiosity have you folks reviewed the paper I cited earlier?
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20070002822_2007001607.pdf

The more I'm reading the more I am seeing confirmationo of many of the background themes you/TSpace/AirLaunch have espoused over the years.

If it doesn't impinge on any of the above "issues" is the fact that this project is moving forward going to have a postivie outcome for your efforts?

Randy

I've read that paper, and know Joe, and we have discussed that work and other air-launch matters while he was on sabbatical at the Naval Postgraduate School. He makes some very good points.

In response to your other question, in general, any announced project from a credible source will tend to help similar projects, even if they are competitive.  So yes, it would help if I was doing something related.  :)

As is said: "A rising tide lifts all boats."

Paul Allen has a bigger boat than I, however.

And since we are being a bit nautical here, perhaps it is time for another related turn of phrase:

Brutus:
There is a tide in the affairs of men.
Which, taken at the flood, leads on to fortune;
Omitted, all the voyage of their life
Is bound in shallows and in miseries.
On such a full sea are we now afloat,
And we must take the current when it serves,
Or lose our ventures.
Julius Caesar Act 4, scene 3
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/15/2011 04:39 PM
Should be able to. It's one of the greatest advantages in this approach. Join the ARocket mailing list and read what Henry Spencer wrote about Stratolaunch.
Could you point me out the list? Google is sort of inconsistent.
http://exrocketry.net/mailman/listinfo/arocket You have to subscribe.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: docmordrid on 12/15/2011 04:45 PM
Rutan was just on Fox via phone and said they need to buy a 3rd 747 for its landing gear & other bits.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Lee Jay on 12/15/2011 05:08 PM
I had a discussion a while back with Antonio Elias here on NSF about using what I called a "zoom launch".  The idea is to place the carrier aircraft into a shallow dive to pick up speed, and then pull up hard and release the rocket at the proper angle, thus avoiding most or all of the turning losses that the wing on Pegasus is supposed to also help to mitigate.  I've simulated this a little (don't ask) and I still don't see exactly why this wouldn't work, but I could imagine some implementation details that could be a problem.

I just got around to watching their video, and it shows them doing this maneuver without the pre-maneuver dive.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RobLynn on 12/15/2011 05:34 PM
Wonder if strut braced wings would make sense for the Stratolaunch carrier?
http://www.dept.aoe.vt.edu/~mason/Mason_f/AIAA2000-0420.pdf

Basically aerofoil struts from bottom of fuselage to a long way out on wing and also to low down on the centre rocket mounting pod.

For such a massively long wing it would reduce structural weight a lot, and might allow the wings to be thinned down to increase speed or to increase the aspect ratio even further for improved L/D.  Any of these improvements would potentially increase the payload capacity of the plane or reduce the field length requirement.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: mrmandias on 12/15/2011 07:45 PM
Quote
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. ;)

I recognize the utility of "one miracle at a time," but I think that if you want to do Jon Goff's near-vertical launch maneuver, you have to design your aircraft and connection systems for it from the beginning.  I think retrofitting would be extremely expensive.  You can probably get incremental performance increases with a redesigned rocket, but if you want to gamma, you have to gamma from the get-go.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RanulfC on 12/15/2011 08:00 PM
I recognize the utility of "one miracle at a time," but I think that if you want to do Jon Goff's near-vertical launch maneuver, you have to design your aircraft and connection systems for it from the beginning.  I think retrofitting would be extremely expensive.  You can probably get incremental performance increases with a redesigned rocket, but if you want to gamma, you have to gamma from the get-go.
And Gamma is "important" in this concept, the various loses without it seem to be a deal killer for economics on the concept.

Given the "pull-up" shown in the video I don't see how else they could pull it off without using the rockets unless they are going to invest some big bucks in advanced duct-burning turbo-fans.

Randy
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RanulfC on 12/15/2011 08:02 PM
Some people have asked if I'm involved, or AirLaunch or t/Space.  The answer is no to all three.

Perhaps someday I can comment, but not today.  NDAs and confidences are involved.  Sorry.
Thanks. Out of curiosity have you folks reviewed the paper I cited earlier?
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20070002822_2007001607.pdf

The more I'm reading the more I am seeing confirmationo of many of the background themes you/TSpace/AirLaunch have espoused over the years.

If it doesn't impinge on any of the above "issues" is the fact that this project is moving forward going to have a postivie outcome for your efforts?

Randy

I've read that paper, and know Joe, and we have discussed that work and other air-launch matters while he was on sabbatical at the Naval Postgraduate School. He makes some very good points.

In response to your other question, in general, any announced project from a credible source will tend to help similar projects, even if they are competitive.  So yes, it would help if I was doing something related.  :)

As is said: "A rising tide lifts all boats."

Paul Allen has a bigger boat than I, however.

And since we are being a bit nautical here, perhaps it is time for another related turn of phrase:

Brutus:
There is a tide in the affairs of men.
Which, taken at the flood, leads on to fortune;
Omitted, all the voyage of their life
Is bound in shallows and in miseries.
On such a full sea are we now afloat,
And we must take the current when it serves,
Or lose our ventures.
Julius Caesar Act 4, scene 3
Cryptic as (almost) always but interesting, as always also :)

Randy
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Magnus_Redin on 12/15/2011 08:21 PM
And Gamma is "important" in this concept, the various loses without it seem to be a deal killer for economics on the concept.

Given the "pull-up" shown in the video I don't see how else they could pull it off without using the rockets unless they are going to invest some big bucks in advanced duct-burning turbo-fans.

Randy

Finding the optimal engine or adding an advanced afterburner are ill suited ideas for a specialized low milege aeroplane with second hand engines. The obvious low cost way to increase performace is to add more engines, go from six to eight or even ten engines.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/15/2011 08:29 PM
I thought this Systems Engineering talk by our excellent antonioe (a member here) was pertinent:
He goes on to talk about the advantages of airlaunch, etc.
http://www.youtube.com/watch?v=-1fh3diw-DY
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RanulfC on 12/15/2011 08:33 PM
And Gamma is "important" in this concept, the various loses without it seem to be a deal killer for economics on the concept.

Given the "pull-up" shown in the video I don't see how else they could pull it off without using the rockets unless they are going to invest some big bucks in advanced duct-burning turbo-fans.

Randy

Finding the optimal engine or adding an advanced afterburner are ill suited ideas for a specialized low milege aeroplane with second hand engines. The obvious low cost way to increase performace is to add more engines, go from six to eight or even ten engines.
The "problem" is that you're just not going to get the thrust out of a turbo-fan at altitude, the thrust-to-weight isn't there and adding more engines won't help.

Randy
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RanulfC on 12/15/2011 08:42 PM
I posted this over in Advanced Concepts but for "completeness" figured I might as well post it here too:
Crossbow=Cargo ROcket Space System, BOx Wing
http://eddy.nps.edu/IDDR/techMatrixPages/3d/crossbow/crossbow.html

Randy
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/15/2011 09:08 PM
I thought this Systems Engineering talk by our excellent antonioe (a member here) was pertinent:
He goes on to talk about the advantages of airlaunch, etc.
http://www.youtube.com/watch?v=-1fh3diw-DY
In parts of the video, Antonio talks about larger, medium-lift airlaunched rockets. The first time is cut from the video soon after he mentions it, the second time when talking about trading flight path angle and flight velocity he starts talking about what Burt Rutan was doing right before he retired, then he stops himself (and the audience laughs). It sounds like Antonio was well aware that something like Stratolaunch was in the works (not that that's surprising).

Even I heard rumblings of this coming, with hints dropped by people who had talked to Rutan at space conferences and such. Of course, they didn't recognize it as such at the time, but I can see the hints in hindsight.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: starsilk on 12/15/2011 09:35 PM
And Gamma is "important" in this concept, the various loses without it seem to be a deal killer for economics on the concept.

Given the "pull-up" shown in the video I don't see how else they could pull it off without using the rockets unless they are going to invest some big bucks in advanced duct-burning turbo-fans.

Randy

Finding the optimal engine or adding an advanced afterburner are ill suited ideas for a specialized low milege aeroplane with second hand engines. The obvious low cost way to increase performace is to add more engines, go from six to eight or even ten engines.

JATO bottles?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: deltaV on 12/15/2011 10:33 PM
JATO bottles?

If you're going to propel the aircraft using rocket engines you might as well use the rocket engines you already have, i.e. the ones on the Falcon 5 like stage. That would work nicely most of the time, but when things get exciting you'd risk losing the aircraft and its pilots. Allen and Rutan have apparently decided that risk isn't worth taking.

Another option would be using low bypass afterburning F100 fighter engines instead of high bypass turbofans to improve thrust to weight. I'm guessing they rejected this option because an aircraft with around twenty F100 engines would not be cheap. The reduced fuel efficiency would also hurt range and make it harder to use the launch aircraft for cargo transport.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: starsilk on 12/15/2011 11:08 PM
JATO bottles?

If you're going to propel the aircraft using rocket engines you might as well use the rocket engines you already have, i.e. the ones on the Falcon 5 like stage. That would work nicely most of the time, but when things get exciting you'd risk losing the aircraft and its pilots. Allen and Rutan have apparently decided that risk isn't worth taking.

Another option would be using low bypass afterburning F100 fighter engines instead of high bypass turbofans to improve thrust to weight. I'm guessing they rejected this option because an aircraft with around twenty F100 engines would not be cheap. The reduced fuel efficiency would also hurt range and make it harder to use the launch aircraft for cargo transport.

JATO are solids, so you're pretty much guaranteed they'll work reliably, minimal risk of ignition failures etc... and if things do go wrong they could be dropped without losing a large, expensive rocket and its payload.

it would be a (relatively) cheap, simple way of adding 'afterburners' to the plane for the pull up maneuver.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: simonbp on 12/15/2011 11:31 PM
Paul Allen has a bigger boat than I, however.

And most countries' navies, for that matter... ;)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Nomadd on 12/16/2011 12:39 AM
JATO bottles?

If you're going to propel the aircraft using rocket engines you might as well use the rocket engines you already have, i.e. the ones on the Falcon 5 like stage. That would work nicely most of the time, but when things get exciting you'd risk losing the aircraft and its pilots. Allen and Rutan have apparently decided that risk isn't worth taking.

Another option would be using low bypass afterburning F100 fighter engines instead of high bypass turbofans to improve thrust to weight. I'm guessing they rejected this option because an aircraft with around twenty F100 engines would not be cheap. The reduced fuel efficiency would also hurt range and make it harder to use the launch aircraft for cargo transport.

JATO are solids, so you're pretty much guaranteed they'll work reliably, minimal risk of ignition failures etc... and if things do go wrong they could be dropped without losing a large, expensive rocket and its payload.

it would be a (relatively) cheap, simple way of adding 'afterburners' to the plane for the pull up maneuver.
JATO doesn't mean solid. It's a generic term that could be any type of motor. The Messerschmitt used peroxide ones. The US navy experimented with liquids for a while.
 But, I think the whole topic might be off base anyhow. Airliners only use what, 50% of their thrust at cruising altitude? I might be off, but I had the idea that thrust for airliner engines at 35,000 ft was something like half what they could do at sea level, meaning that if the Stratolauncher was crusing at 50% throttle like an airliner, they'd be at around 100,00 lb and could add another 100,000 lb of thrust just by pushing the throttles forward.
 Or, if the fuselages had O2 tanks, they could just shove two Merlins up their twin butts. That would be something to see.

 Not sure if "747 engines" means 45,000 lb or 66,000 lb. They've grown quite a bit in 40 years.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: sanman on 12/16/2011 12:43 AM
Furthermore, JATO/RATO are aircraft-related technologies, which would likely make them cheaper than pure dedicated spaceflight-specific technologies. The problems should be framed in terms of economics, and not merely physics alone.

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: ArbitraryConstant on 12/16/2011 02:13 AM
I thought this Systems Engineering talk by our excellent antonioe (a member here) was pertinent:
He goes on to talk about the advantages of airlaunch, etc.
He's an excellent speaker, he does a great job of explaining the trades. I think I understand more of the stratolaunch approach now.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: starsilk on 12/16/2011 02:31 AM
JATO bottles?

If you're going to propel the aircraft using rocket engines you might as well use the rocket engines you already have, i.e. the ones on the Falcon 5 like stage. That would work nicely most of the time, but when things get exciting you'd risk losing the aircraft and its pilots. Allen and Rutan have apparently decided that risk isn't worth taking.

Another option would be using low bypass afterburning F100 fighter engines instead of high bypass turbofans to improve thrust to weight. I'm guessing they rejected this option because an aircraft with around twenty F100 engines would not be cheap. The reduced fuel efficiency would also hurt range and make it harder to use the launch aircraft for cargo transport.

JATO are solids, so you're pretty much guaranteed they'll work reliably, minimal risk of ignition failures etc... and if things do go wrong they could be dropped without losing a large, expensive rocket and its payload.

it would be a (relatively) cheap, simple way of adding 'afterburners' to the plane for the pull up maneuver.
JATO doesn't mean solid. It's a generic term that could be any type of motor. The Messerschmitt used peroxide ones. The US navy experimented with liquids for a while.

yeah, generic term. all the 'in service' ones were solid I think though.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: 360-180 on 12/16/2011 04:58 AM
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/16/2011 05:47 AM
Here's a comparison with the largest satellites in orbit, the MENTOR (or "Advanced Orion") SIGINT GSO satellites launched by NRO (there are now about 4 or 5 of these guys up there). They are pretty big, with the main reflector being perhaps over 100m (330ft) in diameter:
http://en.wikipedia.org/wiki/Mentor_(satellite)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RanulfC on 12/16/2011 01:19 PM
JATO bottles?

JATO are solids, so you're pretty much guaranteed they'll work reliably, minimal risk of ignition failures etc... and if things do go wrong they could be dropped without losing a large, expensive rocket and its payload.

it would be a (relatively) cheap, simple way of adding 'afterburners' to the plane for the pull up maneuver.
Note here, IF you use JATO/RATO ("Jet" or "Rocket" which was/is used interchangably for this type of motor) your airframe has to be strengthened and reinforced. Both to handle the thrust loads AND transfer those loads through the whole airframe. Military aircraft (and some civilian versions there-of) are the ONLY airframes built this way and they are normally only used for certain situations.

Yes for the most part modern JETOs are solid rockets, they however are NOT cheap as they are made in limited numbers and availability is questionable. They are not "easy" ways to add extra thrust as noted the airframe will have to be substationally beefed-up to take the thrust.

Lastly, consider that you would already HAVE a set of rocket engines strapped to the airframe, and if you built it to take those loads already the fact that you can test your LV engines prior to release is a very, very big plus. (As is the ability to get to a high gamma angle)

But, I think the whole topic might be off base anyhow. Airliners only use what, 50% of their thrust at cruising altitude? I might be off, but I had the idea that thrust for airliner engines at 35,000 ft was something like half what they could do at sea level, meaning that if the Stratolauncher was crusing at 50% throttle like an airliner, they'd be at around 100,00 lb and could add another 100,000 lb of thrust just by pushing the throttles forward.
 Or, if the fuselages had O2 tanks, they could just shove two Merlins up their twin butts. That would be something to see.

 Not sure if "747 engines" means 45,000 lb or 66,000 lb. They've grown quite a bit in 40 years.

This paper does a good bit of explaining on that subject:
http://home.anadolu.edu.tr/~mcavcar/common/Jetengine.pdf

High-bypass turbofans (such as on the 747 and most modern airliners) move the majority of their air (thrust) with the fan element rather than the jet element. Since air density decreases with altitude, the available thrust of the engine decreases also. As figure 4 shows if your engine has 2000lbs of thrust available at 5000ft, at 35,000ft it would have a little under 800lbs of thrust available. Since you need to have a thrust to weight ratior of over 1.0 when performing the pitch-up manuver (to avoid stalling) you can easily see that just turbofans themselves would be unable to produce the needed thrust.

Randy
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Lee Jay on 12/16/2011 01:27 PM
Since you need to have a thrust to weight ratior of over 1.0 when performing the pitch-up manuver (to avoid stalling)...

No you don't.  You carry energy in the form of inertia.  This is why even gliders can do vertical maneuvers.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RanulfC on 12/16/2011 01:29 PM
Furthermore, JATO/RATO are aircraft-related technologies, which would likely make them cheaper than pure dedicated spaceflight-specific technologies. The problems should be framed in terms of economics, and not merely physics alone.
While it's true that problems should be framed in more than just "physics" terms there are many other terms of which economics is only one :)

JATO/RATO systems ARE "aircraft-related" technology but they ARE also "rocket/space" systems related, and fall under the economics of a "niche" market, low production rates, and operational/safety concerns.

Randy
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RanulfC on 12/16/2011 01:44 PM
Since you need to have a thrust to weight ratior of over 1.0 when performing the pitch-up manuver (to avoid stalling)...

No you don't.  You carry energy in the form of inertia.  This is why even gliders can do vertical maneuvers.
True, I just didn't want to get into that much detail :)

Vertical maneuvers bleed energy at a VERY fast rate that's why you don't see gliders performing "zoom-climb" manuevers ;)

Without a form of thrust capable of equaling the force of gravity you can't maintain the required angle for more than a few seconds before your wings stall. This is "worse" for a heavily loaded aircraft, especially at high altitude.

Ugh, now that I think of it the problem gets worse once you release the rocket! If you were using the rockets motors to both check them out and to provide the needed thrust for the "zoom" you lose that as soon as you release AND what lift you have it now pushing you to a HIGHER Angle-of-Attack!

Without the mass of the LV you should be able to use the engines an controls to "push-over" back to nose level while retaining control, but if you had an on-board high-thrust device (have to be liquid rockets as solids don't throttle well and you'd have to constantly throttle the thrust over the whole manuever) to get you through it would be much easier.

Anyway you look at it the flight is going to be 'exciting' but as noted this is all pretty much speculation because of what we don't know combined with some extrapolation from what we do know....

Still, it's fun ain't it? :)

Randy
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/16/2011 02:06 PM
What are the limiting factors for diminishing returns with (technically and unrelated to the market)? 

Could a "stratolauncher" be made to carry a million pound rocket?  3 million?  8 million? 

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Ben the Space Brit on 12/16/2011 03:33 PM
What are the limiting factors for diminishing returns with (technically and unrelated to the market)? 

Could a "stratolauncher" be made to carry a million pound rocket?  3 million?  8 million? 

Ultimately, it is the point where the carrier aircraft and related infrastructure (loading hanger, fuelling and safety facilities and also runway) become more expensive to develop and run than a VL rocket first stage, pad and infrastructure.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: neilh on 12/16/2011 04:05 PM
What are current rates like for the air transport of cargo? I'm wondering about ways for the Stratolaunch carrier to make money when not being used for launch, a little like how the Zero-G aircraft gets used for cargo flights.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: robertross on 12/16/2011 04:22 PM
What are current rates like for the air  of cargo? I'm wondering about ways for the Stratolaunch carrier to make money when not being used for launch, a little like how the Zero-G aircraft gets used for cargo flights.

http://en.wikipedia.org/wiki/Antonov_An-225

"An example of the cost of shipping cargo by An-225 was €266,000 for flying a chimney duct from Denmark to Kazakhstan in 2008.[22]"
22: http://www.steelcon.com/fileadmin/user_upload/pdf/News/Steelcon__News_GB.pdf

and (as a ref):
"In May 2011 Antonov CEO is reported to have said that the completion of a second An-225 Mriya transport aircraft with a carrying capacity of 250 tons requires at least $300 million, but if the financing is provided, its completion could be achieved in three years.[9]"
9: http://www.ukrainianjournal.com/index.php?w=article&id=12454
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/16/2011 04:52 PM
What are the limiting factors for diminishing returns with (technically and unrelated to the market)? 

Could a "stratolauncher" be made to carry a million pound rocket?  3 million?  8 million? 

Ultimately, it is the point where the carrier aircraft and related infrastructure (loading hanger, fuelling and safety facilities and also runway) become more expensive to develop and run than a VL rocket first stage, pad and infrastructure.
Agree Ben, that's why I think my Flyback Falcon makes more sense. But, hey that's just me... ;D

Robert
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Norm38 on 12/16/2011 05:52 PM
Is a "zoom" maneuver really needed?  The Crossbow paper says the main requirement for the carrier is to hit the gamma angle, and ensure the rocket remains above 10km after the drop.  The carrier will already be going Mach 0.85 and can't go any faster as the separation needs to be subsonic.  So all that is needed is extra starting altitude and a pitch up maneuver, but not any real acceleration.

The Crossbow paper also says the thrust for pitch up can come basically for "free" from the rocket itself.  If the first stage engines are started at low thrust for checkout prior to the drop (and they need to be), then the position of the rocket below the carrier's CG will cause the carrier to pitch up naturally.

The rocket then throttles up immediately after the drop and accelerates forward while the carier climbs up and banks away.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RanulfC on 12/16/2011 06:43 PM
Is a "zoom" maneuver really needed?  The Crossbow paper says the main requirement for the carrier is to hit the gamma angle, and ensure the rocket remains above 10km after the drop.  The carrier will already be going Mach 0.85 and can't go any faster as the separation needs to be subsonic.  So all that is needed is extra starting altitude and a pitch up maneuver, but not any real acceleration.

The Crossbow paper also says the thrust for pitch up can come basically for "free" from the rocket itself.  If the first stage engines are started at low thrust for checkout prior to the drop (and they need to be), then the position of the rocket below the carrier's CG will cause the carrier to pitch up naturally.

The rocket then throttles up immediately after the drop and accelerates forward while the carier climbs up and banks away.
Well you "kinda" answered your own question Norm38, as the "zoom" (pitch-up) IS required in one form or another to get the rocket to the proper gamma for release.

The rocket itself could be used, though as far as I know rockets don't start out at "low-throttle" but would have to be throttled back after they fire. Not really an overall "issue" if you design for it.

Of course at this point I need to mention that you don't HAVE to change the AoA of the carrier aircraft at all given a system like the AirLaunch trapeze-and-lanyard drop method:
http://www.airlaunchllc.com/AIAA-2008-7835-176.pdf

Other papers here:
http://www.airlaunchllc.com/TechPapers.html#

Which is why "I" personally am leaning towards StratoLaunch planning on igniting the rocket prior to seperation. Otherwise they are planning on spending a lot of money on both the aircraft and rocket without having any way to verify engine operability prior to release, and in which case Airlaunch's business plan beats the economic pants off them despite having the "worlds-biggest-aircraft"!

If Gary-et-al can come up with a way to check-fire the engines on their concept, (and I fully imagine there ARE ways) then despite the 'brain-power' and 'depth-of-money' invested in StratoLaunch I'm of the opinion that AirLaunch can and will end up eating these guys lunch...

Randy
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Nomadd on 12/16/2011 06:51 PM
What are current rates like for the air transport of cargo? I'm wondering about ways for the Stratolaunch carrier to make money when not being used for launch, a little like how the Zero-G aircraft gets used for cargo flights.
I was just thinking about that. This thing could haul a lot of payloads too large or heavy for any aircraft today. Say, they needed to transport 6 meter unfueled first stage cores. Or airliner fuselage sections. Or airlaunching anything the Air Force or NASA wants to air launch. You'd have to design it for those purposes to have cargo ground clearence to start, but they must be thinking of uses besides launching Falcon IVs for this beast.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/16/2011 07:22 PM
I have a question: is this Stratolaunch carrier craft sized for future growth of the rocket diameter-wise? It seems to me as if it is.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: baddux on 12/16/2011 07:48 PM
Would it be impossible to attach wings and landing gear + some airbus or boeing jet engines to Falcon 9 (or Falcon 4/5) first stage? You would get reusable Falcon rocket that Elon desires and air lauch at the same time. If that's possible I'd like to see Paul Allen investing his money to that rather than Stratolaunch.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/16/2011 08:09 PM
Would it be impossible to attach wings and landing gear + some airbus or boeing jet engines to Falcon 9 (or Falcon 4/5) first stage? You would get reusable Falcon rocket that Elon desires and air lauch at the same time. If that's possible I'd like to see Paul Allen investing his money to that rather than Stratolaunch.
See link here:
http://forum.nasaspaceflight.com/index.php?topic=27477.0
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/16/2011 08:11 PM
Half a million pounds would be plenty to drop a large onshore oil rig with BIG parachutes into remote locations.  The market for that would be substantial.  Maybe not enough for one oil company to develop an aircraft like this, but if the service was available, with capital costs covered elsewhere, it would definately happen.  If the rig delivery costs were less than perhaps 10 million dollars, it would find customers.  Yes it would be a one way trip for the rig, but a there are a lot of land-based rigs out there and if you had a 5 or 10 well program in a local area, then it could make sense to leave the dumb metal behind and only strip higher value items.  Or leave it out there for a follow-on drilling program in the future.  Companies find another company with an adjacent lease and make a deal.  I know this to be true of Arctic drilling in Canada (yes ice-roads are occasionally possible but that is not the point).  I suspect it would find lots of use in remote jungles and such as well. 

Helicopters would extract extra drill-pipe or smallish bulldozers after operations are complete.        Not only would it save on the cost of roads, it would be environmentally friendly as roads wouldn't carve up pristine wilderness at the exploration phase as is done currently.  (Obviously discoveries would eventually lead to infrastructure like roads and pipelines, but most wells are unsuccessful).
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: hop on 12/16/2011 08:16 PM
I have a question: is this Stratolaunch carrier craft sized for future growth of the rocket diameter-wise? It seems to me as if it is.
Doubt it. I'd expect the baseline booster to pretty much max out the payload of the aircraft. That's certainly the impression I got from the press conference. No need for a significantly bigger diameter booster unless they switch to LH2, which seems unlikely.

From the renderings, I don't really get the impression it's oversized, there's plenty of width but in the ground clearance looks fairly tight (though perhaps the attachment point on the wing could be more svelt.) In any case, it's probably not safe to assume the renderings reflect the actual design in great detail.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/16/2011 08:31 PM
I have a question: is this Stratolaunch carrier craft sized for future growth of the rocket diameter-wise? It seems to me as if it is.
Doubt it. I'd expect the baseline booster to pretty much max out the payload of the aircraft. That's certainly the impression I got from the press conference. No need for a significantly bigger diameter booster unless they switch to LH2, which seems unlikely.

From the renderings, I don't really get the impression it's oversized, there's plenty of width but in the ground clearance looks fairly tight (though perhaps the attachment point on the wing could be more svelt.) In any case, it's probably not safe to assume the renderings reflect the actual design in great detail.
I said diameter, not payload. And yes, I said that because it may allow a switch to hydrogen in the future.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: baddux on 12/16/2011 08:36 PM
Would it be impossible to attach wings and landing gear + some airbus or boeing jet engines to Falcon 9 (or Falcon 4/5) first stage? You would get reusable Falcon rocket that Elon desires and air lauch at the same time. If that's possible I'd like to see Paul Allen investing his money to that rather than Stratolaunch.
See link here:
http://forum.nasaspaceflight.com/index.php?topic=27477.0

Yeah, cool pictures.

About what I was thinking of. Still it sounds better idea than just having a huge plane to carry a non-reusable rocket.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RanulfC on 12/16/2011 08:43 PM
Would it be impossible to attach wings and landing gear + some airbus or boeing jet engines to Falcon 9 (or Falcon 4/5) first stage? You would get reusable Falcon rocket that Elon desires and air lauch at the same time. If that's possible I'd like to see Paul Allen investing his money to that rather than Stratolaunch.
Think of how much the F-9/5/4 stages would have to be re-built and beefed up to act like aircraft and how badly they'd then work as actual "rockets? You WANT a seperate carrier aircraft to "offload" all the extra equipment so you don't have to stack it on the rocket.

The jet-engines alone would probably wipe out all your "payload" and that's before you even begin to add recovery gear...

I could "wish" that Paul Allen had invested in AirLaunch but "he" thinks this is a "better" idea and it is, after all is said and done, HIS money :)

Randy
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RanulfC on 12/16/2011 08:48 PM
I have a question: is this Stratolaunch carrier craft sized for future growth of the rocket diameter-wise? It seems to me as if it is.
Doubt it. I'd expect the baseline booster to pretty much max out the payload of the aircraft. That's certainly the impression I got from the press conference. No need for a significantly bigger diameter booster unless they switch to LH2, which seems unlikely.

From the renderings, I don't really get the impression it's oversized, there's plenty of width but in the ground clearance looks fairly tight (though perhaps the attachment point on the wing could be more svelt.) In any case, it's probably not safe to assume the renderings reflect the actual design in great detail.
There is also the possibility of doing "upgrades" through the life of the airframe. Upgraded engines, say, some rebuilding of the wing-boxes for more payload mass, things like that.

Air-Launch usually "begs" for LOX/LH2 rockets since they are the most effective chemical combination, but there are other propellant choices too. LOX/Cryo-Propane would effectivly retain the same dimensions as an RP-1/LOX rocket with almost LH2/LOX isp, then there is Liquid Methane so there are a lot of possible "tweeks" to the system.

Randy
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/16/2011 08:54 PM
LOx/cryo-propane has nearly the same Isp as LOx/Methane, NOT hydrolox! :)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/16/2011 09:13 PM
Methane would be about 20% more volume than RP-1? 
I wonder if that could be enough difference to be a clue WRT the rendering length. We know dragon and trunk dimensions pretty well.  We know the likely diameter... 

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/16/2011 09:15 PM
Methane would be about 20% more volume than RP-1? 
I wonder if that could be enough difference to be a clue WRT the rendering length. We know dragon and trunk dimensions pretty well.  We know the likely diameter... 
Let's not get ahead of ourselves. We were just talking about possible FUTURE variations on this design. At the press conference and with the supporting material, we have every indication that they will be using RP-1/LOx. According to their current plans, they won't be using methane/LOx at least initially.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Norm38 on 12/16/2011 09:54 PM
Well you "kinda" answered your own question Norm38, as the "zoom" (pitch-up) IS required in one form or another to get the rocket to the proper gamma for release.

From the talk about solids and afterburners I had the impression the zoom was more about trying to gain speed than just getting the nose up.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/16/2011 10:19 PM
True.  And even if the staged combustion engine turns out to be methane, Paul Allen might like the flight history of Merlin engines by then more than a newer design.  Good baseline all around.  Paul Allen doesn't have to pay the risk or expense of a new program (new engine type, different fuel/procedure type, or rocket reusability).  Elon prefers it because as a contractor, he can supply expendables (extra cash and activity to keep assembly lines full) while he tries to build systems that out-compete this over the longer term.  A great hedge actually.  Win-win for both parties IMO. 

When Elon said 40 cores per year, 30 were for the FH.  I wonder if some of the 10 were anticipated to be for this.  I wonder how much it will cost to throw away Falcon 5's...
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Lee Jay on 12/16/2011 10:26 PM
Since you need to have a thrust to weight ratior of over 1.0 when performing the pitch-up manuver (to avoid stalling)...

No you don't.  You carry energy in the form of inertia.  This is why even gliders can do vertical maneuvers.
True, I just didn't want to get into that much detail :)

Vertical maneuvers bleed energy at a VERY fast rate that's why you don't see gliders performing "zoom-climb" manuevers ;)

Without a form of thrust capable of equaling the force of gravity you can't maintain the required angle for more than a few seconds before your wings stall. This is "worse" for a heavily loaded aircraft, especially at high altitude.

A few seconds is enough.  You release the rocket at the right point during the pitch-up.  As to time - see the Vomit Comet flight profile.

Quote
Ugh, now that I think of it the problem gets worse once you release the rocket! If you were using the rockets motors to both check them out and to provide the needed thrust for the "zoom" you lose that as soon as you release AND what lift you have it now pushing you to a HIGHER Angle-of-Attack!

I seriously doubt the idea of using the main rockets while attached to the plane.  So, when you release the rocket, things get way, way better because you keep the same thrust and lose half your mass.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jimvela on 12/16/2011 11:18 PM
So, when you release the rocket, things get way, way better because you keep the same thrust and lose half your mass.

I actually think that phase is really hairy, because when you release the rocket, you have the same lift, and loose half your mass.  Think about that for a few minutes...

The airframe is going to see significant Gs in that period, and you don't easily change the lift that the aircraft is generating very quickly- particularly since the carrier aircraft will also be taking evasive actions to get out of the thrust centerline of the now-launched rocket.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: HMXHMX on 12/16/2011 11:37 PM
So, when you release the rocket, things get way, way better because you keep the same thrust and lose half your mass.

I actually think that phase is really hairy, because when you release the rocket, you have the same lift, and loose half your mass.  Think about that for a few minutes...

The airframe is going to see significant Gs in that period, and you don't easily change the lift that the aircraft is generating very quickly- particularly since the carrier aircraft will also be taking evasive actions to get out of the thrust centerline of the now-launched rocket.

Ah, something I can actually comment upon!

In 2005 we flew belly drops from the 747, using the NASA 747 simulator at Ames.  We were dropping 209K lbm, or about the same payload to gross mass ratio of the system under debate.  The maneuver went extraordinarily smoothly, and could be flown even by low-time pilots.  Like me – I had six hours at the time. 

We also determined that clearing turns were not really required for air-launching, if you do it right.  There's a bunch of t/LAD papers out there that explain what "right" is.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: yg1968 on 12/17/2011 03:11 AM
A few promotional videos:
http://www.youtube.com/watch?v=nbd7TwYVuOA

http://www.youtube.com/watch?v=ns71qKqlhGI

See the following link for other videos:
http://www.youtube.com/user/VulcanIncVideo?feature=watch
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/17/2011 04:44 PM
I seriously doubt the idea of using the main rockets while attached to the plane.  So, when you release the rocket, things get way, way better because you keep the same thrust and lose half your mass.
So, when you release the rocket, things get way, way better because you keep the same thrust and lose half your mass.

In 2005 we flew belly drops from the 747, using the NASA 747 simulator at Ames.  We were dropping 209K lbm, or about the same payload to gross mass ratio of the system under debate.  The maneuver went extraordinarily smoothly, and could be flown even by low-time pilots.  Like me – I had six hours at the time. 

We also determined that clearing turns were not really required for air-launching, if you do it right.  There's a bunch of t/LAD papers out there that explain what "right" is.
(Aside: Cool!  Can you say what you were dropping?)

Can a 747 engine also run on RP-1? 

Would this be possible: 
1)  Fly to launch area with a fully fueled rocket, but the tank size ratio on stage 1 of the rocket is mostly oxygen, with small RP-1 tanks

2)  Mid-air-re-fuel of stratolauncher aircraft tanks with RP-1. 

3)  Fire the rocket, while pushing RP-1 into it from the stratolauncher.

4)  Let F5 loose at the highest and fastest point that stratolauncher could survive from (could it get pushed past the sound barrier without coming apart?  How high might it go?). 

5)  At the point stratolauncher lets go, there is a proper ratio of oxygen and RP-1 for the rest of its 1st stage burn, and the rocket might even shut off for a second or so while stratolauncher evades its plume. 

6)  F-5 does it's thing up to 2nd stage separation, while stratolauncher goes back to land at its base.   

This would make stratolauncher a pseudo-drop tank. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/17/2011 04:49 PM
No, the whole point is to use the plane to change the flight path angle.  Using the rocket to accelerate of the mass of the plane (beyond the flight path angle change) is counter productive.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/17/2011 05:14 PM
No, the whole point is to use the plane to change the flight path angle.
   Do you mean starting the rocket from ~a tangent to the earth?  Launch-location flexibility for getting to certain orbits more easily? 

Using the rocket to accelerate of the mass of the plane (beyond the flight path angle change) is counter productive.
  What about if oxygen was pumped in from the stratolauncher as well as RP-1 (rocket let go higher, faster, and still completely full)? 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Zed_Noir on 12/17/2011 05:23 PM
Question for folks. Is the Stratolaunch flight profile similar to the F15 ASAT launch flight profile? Or is it more similar to the F15 Streak Eagle zoom climb flight profile.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/17/2011 07:54 PM
Do you mean starting the rocket from ~a tangent to the earth?

  What about if oxygen was pumped in from the stratolauncher as well as RP-1 (rocket let go higher, faster, and still completely full)? 

No, to go from level flight to a pull up.  That is real performance benefit is.  The launch vehicle doesn't get "dropped", it is "pointed" in the proper flight path angle

no,
A. just fly the rocket free and clear of the airplane
b.  impacts the design of the aircraft (don't want to go supersonic)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/17/2011 07:55 PM
Question for folks. Is the Stratolaunch flight profile similar to the F15 ASAT launch flight profile? Or is it more similar to the F15 Streak Eagle zoom climb flight profile.

Neither, it is similar to a B-52/Pegasus profile with a pull up.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Diagoras on 12/17/2011 08:30 PM
Do we know if SpaceX is merely a subcontractor, or if it has signed on for risk-bearing development? Does its presence on the board imply the latter in any way?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: ugordan on 12/17/2011 08:31 PM
Subcontractor.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: simonbp on 12/17/2011 11:13 PM
I have a question: is this Stratolaunch carrier craft sized for future growth of the rocket diameter-wise? It seems to me as if it is.

It certainly looks so as far as horizontal (spanwise) growth; the fuselages are much further apart than they need to be otherwise. A lifting-body-style first stage would provide plenty of volume for a recoverable LH2 first stage. And, it should be said, an LH2 vehicle would needed to carry crew, as is their stated intention. I'm not sure that the aircraft could lift the mass of RP-1 need for a crew vehicle.

If Stratolaunch is a success, I have no doubt they'll push for a fully reusable system sooner rather than later. Their focus right now, though, is on getting the minimum system working, which means subcontracting the booster for the time being.

A logical plan of action for them would then be for them to get the Falcon-based system fully operational by 2017-ish. Then, using lessons learned, Scaled/Northrup Grumman could develop a reusable first stage to bring the system to Atlas V/Falcon 9 performance levels.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/18/2011 12:05 AM
I have a question: is this Stratolaunch carrier craft sized for future growth of the rocket diameter-wise? It seems to me as if it is.

It certainly looks so as far as horizontal (spanwise) growth; the fuselages are much further apart than they need to be otherwise. A lifting-body-style first stage would provide plenty of volume for a recoverable LH2 first stage. And, it should be said, an LH2 vehicle would needed to carry crew, as is their stated intention. I'm not sure that the aircraft could lift the mass of RP-1 need for a crew vehicle.

If Stratolaunch is a success, I have no doubt they'll push for a fully reusable system sooner rather than later. Their focus right now, though, is on getting the minimum system working, which means subcontracting the booster for the time being.

A logical plan of action for them would then be for them to get the Falcon-based system fully operational by 2017-ish. Then, using lessons learned, Scaled/Northrup Grumman could develop a reusable first stage to bring the system to Atlas V/Falcon 9 performance levels.
Something like this Simon?
http://forum.nasaspaceflight.com/index.php?topic=27477.0
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Dalon on 12/18/2011 12:34 AM
It certainly looks so as far as horizontal (spanwise) growth; the fuselages are much further apart than they need to be otherwise. A lifting-body-style first stage would provide plenty of volume for a recoverable LH2 first stage. And, it should be said, an LH2 vehicle would needed to carry crew, as is their stated intention. I'm not sure that the aircraft could lift the mass of RP-1 need for a crew vehicle.

It makes me suspect they have a truly massive cargo module in the works.  Something that can quickly attach to the same hard point as the rocket and fill most of the void between the dual hulls.  A container of that scale would almost certainly carry more volume than any air cargo system currently in use.

There's been a lot of comment bemoaning how few airports at which this bird could land.  In truth, the surprising fact is how many airports in the US this bird could use for cargo operations.

There are a surprising number of 2 mile long runways in the US.  Many of them are former SAC bases.  There are also a large number of civilian airports with runways designed for dual civilian / military use.   In addition, military airports can and have been used for civilian operations.  Further, some significant proportion of this oversize cargo work may in fact be for the military.

If Stratolaunch is a success, I have no doubt they'll push for a fully reusable system sooner rather than later. Their focus right now, though, is on getting the minimum system working, which means subcontracting the booster for the time being.

A logical plan of action for them would then be for them to get the Falcon-based system fully operational by 2017-ish. Then, using lessons learned, Scaled/Northrup Grumman could develop a reusable first stage to bring the system to Atlas V/Falcon 9 performance levels.

I very much doubt Stratolaunch has any plans to develop their own rocket. 

After all, why would SpaceX have involved themselves in this if they believed Stratolaunch's  eventual plan was to build their own rocket and compete directly with SpaceX?  SpaceX is so concerned with keeping their developments secret that they rarely even file patents.   They'd be hard pressed to keep secrets from a partner with such easy access to their product.

I have two possible answers.  The first is that SpaceX may have contractual assurances that no such competition will occur.  At a minimum, they probably have contractual assurances against any copying of SpaceX intellectual property.

It's also possible that SpaceX is simply confident enough in their technology that they don't believe Stratolaunch could develop a competitive rocket in any reasonable timeline.  Perhaps thinking that even if Stratolaunch eventually plans to build a rocket, it's better to take Stratolaunch's money today and use it to develop better and better rockets.  SpaceX would effectively be using Paul Allen's money to move the goal posts further and further away from Stratolaunch and the rest of SpaceX's competition.  This fact is certainly not lost on Stratolaunch.

The other reason I don't believe Stratolaunch will develop their own rocket is complexity.  As difficult and as complex it will be to develop the Stratolaunch carrier aircraft, developing an orbital rocket is harder still.  Much, harder. 

You can screw up all sorts of things while developing an aircraft, many if not most of the problems can be worked out in testing.  With orbital rockets, such test are far more limited and comprehensive testing is impossible.  Even a big problem in a prototype aircraft rarely results in a loss of vehicle, while the smallest problem with an orbital rocket can certainly result in loss of vehicle. 

There's yet another reason I don't believe Stratolaunch will develop their own rocket.  This is based on the fact that Stratolaunch won't be doing any of their own integration, they've chosen to sub it out to Dynetics. If Stratolaunch were planning to build their own rockets, I suspect they would have kept integration in house.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: quanthasaquality on 12/18/2011 01:18 AM
Airplane launch gives the rocket a higher starting speed and altitude. So do reusable (flyback?) booster rockets. Are airplane launch systems (like Stratolaunch ) worth the extra cost over bigger, reusable boosters?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/18/2011 01:49 AM

There's been a lot of comment bemoaning how few airports at which this bird could land.  In truth, the surprising fact is how many airports in the US this bird could use for cargo operations.

There are a surprising number of 2 mile long runways in the US.  Many of them are former SAC bases.  There are also a large number of civilian airports with runways designed for dual civilian / military use.   In addition, military airports can and have been used for civilian operations.  Further, some significant proportion of this oversize cargo work may in fact be for the military.


Surprising fact is that you are wrong.  The bemoaning is justified.
length is not the only constraining factor.  The wing span and turning radius are more constraining.  Anyways, 2 miles is too small for this aircraft, it needs 12k not 10k feet.
What oversize cargo work  for the military?  The military designs to existing capabilities.

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: sanman on 12/18/2011 01:56 AM
Would it need just as much runway length to land on, as to take off from?

If not, then could the JATO/RATO approach make it work with 2-mile runways?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: sanman on 12/18/2011 02:08 AM
Also - can anyone guess at what the velocity of the aircraft would be, when releasing the rocket? What initial velocity would that rocket have, as it ignites its engines? (Sorry if the answer was already posted, because I didn't see it anywhere.)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/18/2011 02:25 AM
It makes me suspect they have a truly massive cargo module in the works.  Something that can quickly attach to the same hard point as the rocket and fill most of the void between the dual hulls.  A container of that scale would almost certainly carry more volume than any air cargo system currently in use.
length is not the only constraining factor.  The wing span and turning radius are more constraining.  Anyways, 2 miles is too small for this aircraft, it needs 12k not 10k feet.
What oversize cargo work  for the military?  The military designs to existing capabilities.
Oil and gas, and mining sectors will certainly have interested customers (air-drops of equipment and rigs into remote locations).  Maybe forest fire fighting too if they make a water module.  I wouldn't be surprised if there is some sort of deal with SpaceX related to flying rocket stages around too.   I agree with Dalon that a cargo module is likely a part of this.  Multi-billionaires usually have back-up plans and synergies in mind when tossing hundreds of Megabucks into projects. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Dalon on 12/18/2011 02:43 AM
Would it need just as much runway length to land on, as to take off from?

A combination of thrust reversers and high drag aero surfaces could certainly allow for significantly shorter landings than takeoffs.  As yet, we don't have enough information to determine whether this is part of the aircraft's design.


If not, then could the JATO/RATO approach make it work with 2-mile runways?

The aircraft would have to be designed from inception to accommodate JATO, given that this is a clean sheet aircraft, it is a possibility. 

Personally, I don't think there's enough benefit in JATO to justify the cost and complexity.  This is already a formidable design challenge.

I do wonder at the lack of any mention of mid-air refueling.  While JATO could give some modest benefit, mid-air refueling could result in massive benefits.  Payload weight would increase dramatically.  I'm not even considering the wild ideas of fueling the rocket in-flight.  Simply launching the aircraft with minimum fuel then topping it off in flight should drastically increase the payload to orbit.  If both the aircraft and rocket could be fueled in-flight, payload would rise yet again.

For cargo use, mid-air refueling could work to reduce runway takeoff length.  If Stratolaunch is going to mix any other complex technology into this aircraft, I strongly suspect it will be mid-air refueling.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Dalon on 12/18/2011 02:47 AM
[Anyways, 2 miles is too small for this aircraft, it needs 12k not 10k feet.
What oversize cargo work  for the military?  The military designs to existing capabilities.


There are a surprising number of 12,500 ft runways in the US.

The list below includes roughly 30 in the US, each over 13,000 feet.  There are quite a number not on this list that meet or exceed  Stratolaunch's 12,500 requirement.

http://en.wikipedia.org/wiki/List_of_longest_runways
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: HappyMartian on 12/18/2011 05:43 AM
....

There are a surprising number of 12,500 ft runways in the US.

The list below includes roughly 30 in the US, each over 13,000 feet.  There are quite a number not on this list that meet or exceed  Stratolaunch's 12,500 requirement.

http://en.wikipedia.org/wiki/List_of_longest_runways

Wow! What a list! Who knows, maybe some other airports would be willing to increase the length of one of their runaways. Lots of farsighted nations want to be a high tech space power. Add a few thousand feet to an existing long runway, increase the runway's turning area, add a specialized preparation area and some propellant storage tanks and presto, your nation or company has the basics needed to be a 'space player'. It won't happen tomorrow, but maybe it could begin to happen around 2018.


Stratolaunch Aims to Break Affordability Barrier   Dec 13, 2011  By Michael Mecham
"Former NASA Administrator Michael Griffin, a Stratolaunch board member, says the emphasis initially will be on customers to use Stratolaunch as a self-contained system, whether for manned or unmanned flights." From: http://www.aviationweek.com/aw/generic/story_channel.jsp?channel=space&id=news/awx/2011/12/13/awx_12_13_2011_p0-405946.xml&headline=Stratolaunch%20Aims%20to%20Break%20Affordability%20Barrier


"'We believe this technology has the potential to someday make spaceflight routine by removing many of the constraints associated with ground launched rockets,' Griffin said. 'Our system will also provide the flexibility to launch from a large variety of locations.'"
From: http://www.stratolaunch.com/news.html


"'Any orbit. Any time' is the new company’s slogan."
From: Space Company Stratolaunch To Blast Rockets From Huge New Aircraft  At: http://www.popularmechanics.com/science/space/rockets/new-space-company-stratolaunch-will-launch-orbital-rockets-from-twin-747s-6615736


"I'm reminded of what Wernher Von Braun replied when someone asked him,'What's the hardest thing about going to the moon?' And Von Braun said, 'The will to do it.'" Paul G. Allen, from book Idea Man
From: http://www.stratolaunch.com/presskit.html


Stratolaunch also already has an up-to-date Wikipedia article that references "Bergin, Chris (2011-12-13). 'Stratolaunch introduce Rutan designed air-launched system for Falcon rockets'"
From: http://en.wikipedia.org/wiki/Stratolaunch_Systems


Yep. Pretty nifty. Lots of countries could eventually gain routine access to LEO. Stratolaunch could turn out to be better than ice cream on apple pie!


Cheers!

Edited.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Dalon on 12/18/2011 06:05 AM

Yep. Pretty nifty. Lots of countries could eventually gain routine access to LEO. Stratolaunch could turn out to be better than ice cream on apple pie!


Cheers!

Edited.

I'm not sure if you're a strawman's strawman, or a cynic's cynic.

Based on that post, perhaps both.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: HappyMartian on 12/18/2011 08:18 AM

Yep. Pretty nifty. Lots of countries could eventually gain routine access to LEO. Stratolaunch could turn out to be better than ice cream on apple pie!


Cheers!

Edited.

I'm not sure if you're a strawman's strawman, or a cynic's cynic.

Based on that post, perhaps both.

Well, I'm sorry if I confused you or anyone else.

I am a cynic sometimes, but I do love Stratolaunch because, besides the benefits I and many others noted above, it could also help to enable a commercial LEO dawn-dusk Sun synchronous orbit zero boil off hydrolox argon propellant depot which could enable efficient solar powered zero boil off hydrolox argon tankers and cargo spacecraft traveling from LEO to L1, L2, and Lunar orbits and thus enable efficient and affordable international Orion SLS missions to the Moon.

The Moon will eventually become a source of propellant for missions to everywhere in the Solar System.

"'Any orbit. Any time' is the new company’s slogan."
From: Space Company Stratolaunch To Blast Rockets From Huge New Aircraft  At: http://www.popularmechanics.com/science/space/rockets/new-space-company-stratolaunch-will-launch-orbital-rockets-from-twin-747s-6615736

The widely accepted and positive ongoing example provided by the International Space Station, and other NASA agreements with a large diversity of countries, seems to be the most politically wise and sustainable model for our international space exploration efforts of the Moon, asteroids, and Mars.

However, a commercial propellant depot in a LEO dawn-dusk Sun synchronous orbit would be both valuable to our planet's international space exploration efforts and lovely to see in the dawn or dusk sky. Stratolaunch could indeed turn out to be better than ice cream on a piece of apple pie! And trust me, I do love ice cream on a piece of apple pie!

Cheers!
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RobLynn on 12/18/2011 11:11 AM
If Skylon is a workable concept then a similar all-rocket vehicle could be built for Stratolaunch minus the Air breathing engines - use vacuum optimised SSME instead.

Wings on Skylon-like LV would support substantial weight and with another couple of 747 engines should allow a slightly heavier launch vehicle; eg maybe 300tonnes GTOW.  Mass ratio to orbit is about 6.5ish so should still get pretty substantial payload.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Carreidas 160 on 12/18/2011 12:36 PM
If Skylon is a workable concept then a similar all-rocket vehicle could be built for Stratolaunch minus the Air breathing engines - use vacuum optimised SSME instead.

Wings on Skylon-like LV would support substantial weight and with another couple of 747 engines should allow a slightly heavier launch vehicle; eg maybe 300tonnes GTOW.  Mass ratio to orbit is about 6.5ish so should still get pretty substantial payload.

Dunno, at 30kft there's still a lot of atmosphere to plough through before switching to on-board LOX is necessary, so why not keep the air-breathing rockets?

I do like the thought of air-dropping a Skylon derivative, IF it's possible to scale it down. Saves a lot of LOX/LH2 between 0 and 30kft and mitigates some nasty takeoff issues (such as 150m/s takeoff speed)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/18/2011 12:42 PM

Oil and gas, and mining sectors will certainly have interested customers (air-drops of equipment and rigs into remote locations).  Maybe forest fire fighting too if they make a water module.  I wouldn't be surprised if there is some sort of deal with SpaceX related to flying rocket stages around too.   I agree with Dalon that a cargo module is likely a part of this.  Multi-billionaires usually have back-up plans and synergies in mind when tossing hundreds of Megabucks into projects. 

no, big parachutes don't exist.  They don't use the existing capability now, why would they use this.  The impact loads would be too great for any hardware.

No, not firefighting, the vehicle is too big and not manuverable.  And where is it going to stage from?

No, not rocket stages.  The rocket for this aircraft is going to be structurally different from F9.  And again, where is it going to stage from?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: mmeijeri on 12/18/2011 12:45 PM
The rocket for this aircraft is going to be structurally different from F9.

Would it be more structurally similar to a future reusable F9 first stage, or just different in a different way?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/18/2011 12:47 PM
[Anyways, 2 miles is too small for this aircraft, it needs 12k not 10k feet.
What oversize cargo work  for the military?  The military designs to existing capabilities.


There are a surprising number of 12,500 ft runways in the US.

The list below includes roughly 30 in the US, each over 13,000 feet.  There are quite a number not on this list that meet or exceed  Stratolaunch's 12,500 requirement.

http://en.wikipedia.org/wiki/List_of_longest_runways

Many in the US are not usable such as JFK
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/18/2011 12:48 PM

Yep. Pretty nifty. Lots of countries could eventually gain routine access to LEO. Stratolaunch could turn out to be better than ice cream on apple pie!


Cheers!

Edited.

No, there still is ITAR
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/18/2011 12:49 PM

Yep. Pretty nifty. Lots of countries could eventually gain routine access to LEO. Stratolaunch could turn out to be better than ice cream on apple pie!


Cheers!

Edited.

I'm not sure if you're a strawman's strawman, or a cynic's cynic.

Based on that post, perhaps both.

Well, I'm sorry if I confused you or anyone else.

I am a cynic sometimes, but I do love Stratolaunch because, besides the benefits I and many others noted above, it could also help to enable a commercial LEO dawn-dusk Sun synchronous orbit zero boil off hydrolox argon propellant depot which could enable efficient solar powered zero boil off hydrolox argon tankers and cargo spacecraft traveling from LEO to L1, L2, and Lunar orbits and thus enable efficient and affordable international Orion SLS missions to the Moon.

The Moon will eventually become a source of propellant for missions to everywhere in the Solar System.

"'Any orbit. Any time' is the new company’s slogan."
From: Space Company Stratolaunch To Blast Rockets From Huge New Aircraft  At: http://www.popularmechanics.com/science/space/rockets/new-space-company-stratolaunch-will-launch-orbital-rockets-from-twin-747s-6615736

The widely accepted and positive ongoing example provided by the International Space Station, and other NASA agreements with a large diversity of countries, seems to be the most politically wise and sustainable model for our international space exploration efforts of the Moon, asteroids, and Mars.

However, a commercial propellant depot in a LEO dawn-dusk Sun synchronous orbit would be both valuable to our planet's international space exploration efforts and lovely to see in the dawn or dusk sky. Stratolaunch could indeed turn out to be better than ice cream on a piece of apple pie! And trust me, I do love ice cream on a piece of apple pie!

Cheers!
I already posted that PM link. If you read the article and saw the video, you will see/hear/read Griffin’s “wishy washy” comments about the concept.  “I don’t know that its a better way….” Why that person is on that team apart from his connections is beyond me….
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: HappyMartian on 12/18/2011 01:19 PM

Yep. Pretty nifty. Lots of countries could eventually gain routine access to LEO. Stratolaunch could turn out to be better than ice cream on apple pie!


Cheers!

Edited.

No, there still is ITAR

Eventually Jim, eventually...

Cheers!
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/18/2011 02:10 PM

Yep. Pretty nifty. Lots of countries could eventually gain routine access to LEO. Stratolaunch could turn out to be better than ice cream on apple pie!


Cheers!

Edited.

No, there still is ITAR

Eventually Jim, eventually...

Cheers!

Nope, not in your lifetime, ITAR will always be around.  The issues now days is components and satellites.  This is an integrated system that does have military applications.  It is not going to be sold to anyone.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/18/2011 03:59 PM
no, big parachutes don't exist.  They don't use the existing capability now, why would they use this.  The impact loads would be too great for any hardware.
I was unaware of the big parachute issue.  As to why it isn't done now, part of the reason is that a sufficiently large rig is too large for current capabilities.  As to the impact loads; the way rigs are overbuilt, I would find that assessment surprising, but you might be right.  Looking back, the only schemes I've heard discussed in O&G board rooms are neutral buoyancy airships much larger than anything available. 

At second glance, I think even if 3/4 of the 250 ton capability was for the rig components, and 50 tons was parachutes and an aerodynamic case, and if the rig would survive landing, that still is not enough capacity for most arctic applications. 
http://www.youtube.com/watch?v=T4ELOeh6R6M&feature=related

No, not firefighting, the vehicle is too big and not manuverable.  And where is it going to stage from?
Depending on topography, manueverable might not be a big deal.  Where to stage it from?  Somewhere with a long runway within range of the fire.  Dropping 250 tons of water on a forest fire would be a useful capability, and could save money vs. zillions of little trips by smaller aircraft.  Also, if it had a pontoon version (getting less likely I know) then any long lake might work.   

No, not rocket stages.  The rocket for this aircraft is going to be structurally different from F9.  And again, where is it going to stage from?
A sling or aerocase that can hold individual empty F9 stages.  Where would it stage from?  LAX and somewhere near McGregor, and somewhere near its launch pad.  It takes 2 weeks to drive these stages from Hawthorne to the Cape IIRC.  It might become beneficial to make that a 1-3 day process instead.   I'm not saying it certainly is the case.  But instead of stratolauncher aircraft spending most of its time just waiting around for the next F5 launch, it might as well do something useful in-between.  Also, driving stages down a bumpy interstate for 2 weeks through all kinds of traffic and weather conditions may be higher risk than flying stages around. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/18/2011 04:08 PM
http://www.youtube.com/watch?v=KrlU-vXC4BA&feature=related
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/18/2011 04:18 PM
http://www.youtube.com/watch?v=nDpDovpkEjw

There are also car crashes, rocket failures, airplane crashes, and people have walked into things.   Exceptions rather than the rule.  But the risk of building a new giant parachute system might turn off individual oil execs.  If the capability was there, and had been demonstrated to work, impact forces had been measured, I think it would get used for that purpose.   

Being able to drop 490000 pounds opens up new possibilities is all. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: sammie on 12/18/2011 04:21 PM
Using the stratolauncher aircraft for anything other then launching rockets is like a solution looking for a problem. The heavy lift market is rather small, and the even the An-225 is often too large for regular airports. The FAA refused to certify the Evergreen 747 firebomber for a long time, although it seems to flying nowadays.

Most of the time moving large parts can be done cheaper by road or barge. Only when time is really important is stuff shipped by oversize cargo plane. Anyway, blimps will probably do most of the heavy lifting in 10 15 years, that will really change things...

(edit, firebomber does fly nowadays)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/18/2011 04:22 PM
http://en.wikipedia.org/wiki/Evergreen_747_Supertanker

If 747 can be used to fight forest fires, I don't see why this couldn't.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/18/2011 04:26 PM
The FAA refused to certify the Evergreen 747 firebomber,

 "issue that impacted usage by the Forest Service was the USFS requirement for using fire retardant rather than water. When Evergreen attempted to convert the system from water dispensing to retardant, they encountered objections from the FAA. The FAA's issue related to the much greater density of fire retardant and the corresponding increased stress on the airframe thus delaying the FAA certification. "

On 5 December 2010, the Supertanker was deployed to Israel for fighting Mount Carmel forest fire. This undertaking goes side by side with crew and utilities donated by other international fire agencies.[11] On 9 June 2011, the Supertanker was also deployed to fight the Wallow Fire in Arizona

"Currently the first tanker in North America is under a CWN (call when needed) contract with Cal Fire and is stationed at McClellan Field outside of Sacramento, California.[9]"



Anyway, blimps will probably do most of the heavy lifting in 10 15 years, that will really change things...
I hope you're right, but I'm sure that's been said 10 or 15 years ago too. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/18/2011 04:31 PM
1,  There are also car crashes, rocket failures, airplane crashes, and people have walked into things.   exceptions rather than the rule.  But the risk of building a new giant parachute system might turn off individual oil execs.  If the capability was there, and had been demonstrated to work, impact forces had been measured, I think it would get used for that purpose.   

2.  Being able to drop 490000 pounds opens a new possibilities is all. 

1.  No look past the crashes and at the impact of a normal drop.  It is huge shock. (the ones were the cargo tipped over).   Shuttle SRB's hit at 60mph

2.  Huh? Get real.  No it doesn't.  We don't even parachute the max capacities of existing planes <100klbs.

geesh, do you believe every idea is going to work?  You have trouble seeing past the hype and focusing on reality.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/18/2011 04:40 PM
1.  No, look at the impact of a normal drop.  It is shock.
Have you ever walked around on an oil rig?  They aren't built dainty or minimalist.  Everything is way overbuilt.  The main reason for the excess mass is to deal with gas kicks and to control blowouts if things go wrong.  They are meant to get smacked.  Liability being what it is, they are WAAAAY overbuilt. 

We don't even parachute the max capacities of existing planes.
You don't have any existing capability big enough for dropping oil rig components. 

geesh, do you believe every idea is going to work?
I'm more of an innocent until proven guilty kind of guy.  What would you have said about the odds of an F5 launch aircraft a year or two ago? 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/18/2011 04:41 PM
Depending on topography, manueverable might not be a big deal.  Where to stage it from?  Somewhere with a long runway within range of the fire.  Dropping 250 tons of water on a forest fire would be a useful capability, and could save money vs. zillions of little trips by smaller aircraft.  Also, if it had a pontoon version (getting less likely I know) then any long lake might work.   

huh? Topography is the reason they are use.  On mountain, valley, ravines, canyons, where land vehicle can't go.  This is not areas for vehicle like Strato.  There are few runways where it can operate and .

Again, get in the real world
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/18/2011 04:42 PM
What would you have said about the odds of an F5 launch aircraft a year or two ago? 

Still hasn't happened.  And when it does, it still doesn't mean it is economically viable.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/18/2011 04:43 PM
Have you ever walked around on an oil rig?  They aren't built dainty or minimalist.  Everything is way overbuilt.  The main reason for the excess mass is to deal with gas kicks and to control blowouts if things go wrong.  They are meant to get smacked.  Liability being what it is, they are WAAAAY overbuilt. 


Not enough to survive a parachute drop.   Nor are they designed to be suspended.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/18/2011 04:46 PM
You don't have any existing capability big enough for dropping oil rig components. 
 

So what does that have to do with anything?  There is no airdrop capability for 100klbs.  No one is going to jump to 5 times that
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/18/2011 04:48 PM
A sling or aerocase that can hold individual empty F9 stages.  Where would it stage from?  LAX and somewhere near McGregor, and somewhere near its launch pad.  It takes 2 weeks to drive these stages from Hawthorne to the Cape IIRC.  It might become beneficial to make that a 1-3 day process instead.   I'm not saying it certainly is the case.  But instead of stratolauncher aircraft spending most of its time just waiting around for the next F5 launch, it might as well do something useful in-between.  Also, driving stages down a bumpy interstate for 2 weeks through all kinds of traffic and weather conditions may be higher risk than flying stages around. 

Sling?  you must be joking.  Musk could use the C-5 or AN-124 if he want to fly the F9.  They never had to drive it.

LAX can't be used, too short.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/18/2011 04:54 PM
huh? Topography is the reason they are use.  On mountain, valley, ravines, canyons, where land vehicle can't go.  This is not areas for vehicle like Strato.  There are few runways where it can operate and .
Again, get in the real world
Having grown up in Alberta, and worked in silvaculture as a teenager, I think it's likely that I have a lot more real world experience and knowledge with respect to fighting forest fires than you.  Did you know that sometimes there are places in a forest that you can't drive to because there are trees in the way?  There only needs to be one long runway near an important national park to make this idea possible.  One of the big advantages of the 747 fire-fighter is its pressurized system and overwhelming volume allows for night-time drops from higher up.  The 747 unloads 20000 gallons in controlled spray.  Stratolauncher could almost double that capacity.  It likely won't happen.  Just saying it's a possibility for future use. 

Here's the main advantage of this in fire fighting vs. 747:

747 is a dedicated aircraft.  Stratolauncher can moonlight as a firefighter if it has a module that can clip in to the attachment point. 

Fire fighting is not the main point here. 

What I am trying to say, is that stratolauncher could have other uses that just launching F5 (once it exists).  You seem to disagree with that. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/18/2011 04:57 PM
There only needs to be one long runway near an important national park to make this idea possible.   

there are none
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/18/2011 04:58 PM

What I am trying to say, is that stratolauncher could have other uses that just launching F5 (once it exists).  You seem to disagree with that. 

yep, it is a point solution.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/18/2011 04:59 PM

What I am trying to say, is that stratolauncher could have other uses that just launching F5 (once it exists).  You seem to disagree with that. 

yep, it is a point solution.
Well at least we've cleared that up. 

So you don't think the military would consider a bigger MOP once this thing exists.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/18/2011 05:10 PM
What would you have said about the odds of an F5 launch aircraft a year or two ago? 
Still hasn't happened.  And when it does, it still doesn't mean it is economically viable.
Whether something will happen or will work does not always correlate with economic viability.   But you are well aware of that. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/18/2011 05:17 PM
What would you have said about the odds of an F5 launch aircraft a year or two ago? 
Still hasn't happened.  And when it does, it still doesn't mean it is economically viable.
Whether something will happen or will work does not always correlate with economic viability.   But you are well aware of that. 

Perceived economic viability is the whole reason that it exists.

Anyways, the Stratolaunch won't have timefight fires, deliver drilling rigs or transport large containers.  If it does, it means it failed its primary task.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/18/2011 05:18 PM

So you don't think the military would consider a bigger MOP once this thing exists.

No,  It already has large aircraft (C-5, 747, C-17) that could deliver larger ones and but they don't.

This is not a battlefield aircraft, it will be a sitting duck

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: mmeijeri on 12/18/2011 05:19 PM
Theoretically, could the carrier be used to transport SLS stages?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/18/2011 05:20 PM
If it does, it means it failed its primary task.
I don't understand how you conclude that. 
Unless they are going to be launching F5's with stunning frequency, then there will be times between launches where it could be used for other purposes.  There may also be more than one created.  Why can't multi-purpose be a definition of success? 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/18/2011 05:22 PM

Unless they are going to be launching F5's with stunning frequency,

Then why build it? 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/18/2011 05:24 PM
yep, it is a point solution.

Potential for passenger travel along very limited routes?  Perhaps with a smaller craft dropping off sooner? 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/18/2011 05:25 PM
There may also be more than one created. 

Where has that been said? 

I am through with this.  You have no objectivity.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/18/2011 05:27 PM
Then why build it? 

Exactly.  They have said they will be doing expendible rockets with it.  There isn't enough demand for throwing tens of millions away every day for getting smallish things to LEO.  So unless they are actually thinking of a reusable F5, then they will need other income sources to make this more than just a rich mans hobby (specifically Paul Allen).  And even if it is just a rich mans hobby, it is nice when hobbies can at least subsidize themselves somehow.   
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/18/2011 05:28 PM
yep, it is a point solution.

Potential for passenger travel along very limited routes?  Perhaps with a smaller craft dropping off sooner? 

No, there is still debate whether the A380 is viable.  Passenger design has many more constraints. 
Drop off aircraft is inane, it buys you nothing. 

It keeps getting more inane and ludicrous.

The way to approach this is to see ways you don't need a specialized aircraft
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: mmeijeri on 12/18/2011 05:29 PM
There isn't enough demand for throwing tens of millions away every day for getting smallish things to LEO.

They've essentially said they're hoping to make this cheap enough to launch large numbers of paying customers into space and bring them back safely.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/18/2011 05:31 PM
Then why build it? 

Exactly.  They have said they will be doing expendible rockets with it.  There isn't enough demand for throwing tens of millions away every day for getting smallish things to LEO.  So unless they are actually thinking of a reusable F5, then they will need other income sources to make this more than just a rich mans hobby (specifically Paul Allen).  And even if it is just a rich mans hobby, it is nice when hobbies can at least subsidize themselves somehow.   

No, they are not thinking of other sources of income to support this concept.   this is exists because they think they can make money.  Other uses have not entered the picture.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/18/2011 05:32 PM
They've essentially said they're hoping to make this cheap enough to launch large numbers of paying customers into space and bring them back safely.
"Cheap enough" implies F5 reusability imo. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: neilh on 12/18/2011 05:32 PM
I'm pretty sure that when not being used for launches, the Stratolaunch carrier will be pretty busy rescuing spice harvesters from incoming sandworms.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/18/2011 05:34 PM
They've essentially said they're hoping to make this cheap enough to launch large numbers of paying customers into space and bring them back safely.
"Cheap enough" implies F5 reusability imo. 

nope, it doesn't
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/18/2011 05:46 PM
They've essentially said they're hoping to make this cheap enough to launch large numbers of paying customers into space and bring them back safely.
"Cheap enough" implies F5 reusability imo. 

nope, it doesn't
Any scenarios you think are likely to support a high-flight-rate expendable F5 system?  Do you think they are planning to get to a space station with it?

Even if tickets were $2 million each (requires F5 manufacture to be $10 million or so), I find it hard to imagine an extremely frequent flight-rate for people to do a few orbits in a cramped dragon with one little window.  One or two per month maybe.  I think tickets would need to come down lower than that to support a very frequent-flight market.  Maybe you can imagine expendible F5's getting a lot less expensive than $10 M each, or maybe you imagine a much larger market at several million per flight.  I think reusability is more likely required. 

Having a station might account for the need to launch to "any orbit any time". 

If there was no specific destination, then "random orbit, most times" would be good enough.     
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: mmeijeri on 12/18/2011 05:52 PM
I'm pretty sure that when not being used for launches, the Stratolaunch carrier will be pretty busy rescuing spice harvesters from incoming sandworms.

Heheh, "Harkonnen harvester deployed".
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: mmeijeri on 12/18/2011 06:05 PM
Other uses have not entered the picture.

They did say there would be other uses during the press conference, but I haven't heard any details.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: sanman on 12/18/2011 06:31 PM
Could a ground-based catapult system improve on the Stratolaunch capabilities? Or would that be a waste of time?

Carrier-launched aircraft benefit from a catapult because it allows them to take off from that shorter carrier runway. In the case of Stratolaunch, you're not constrained by runway length, but rather by take-off weight.

Turbofan engines are limited in the amount of thrust they can develop, but a ground-based catapult-launcher can in principle apply any arbitrarily high amount of delta-V to the aircraft to help it take off.

Sure, I know that this then restricts your choice of takeoff sites, but when the aircraft can then easily fly to the equator, then I don't think it matters as much.

Also, what if the aircraft were optimized to make use of ground effect for liftoff purposes? Or what if it were designed to be variable geometry (ie. swing-wing or something else)?

What changes/improvements could be made to the carrier aircraft, to enable it to fly to greater even altitudes and airspeeds? If Stratolaunch 1.0 becomes a success, then what improvements/upgrades would you recommend for Stratolaunch 2.0?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Carreidas 160 on 12/18/2011 09:22 PM
Could a ground-based catapult system improve on the Stratolaunch capabilities? Or would that be a waste of time?

Carrier-launched aircraft benefit from a catapult because it allows them to take off from that shorter carrier runway. In the case of Stratolaunch, you're not constrained by runway length, but rather by take-off weight.

Turbofan engines are limited in the amount of thrust they can develop, but a ground-based catapult-launcher can in principle apply any arbitrarily high amount of delta-V to the aircraft to help it take off.

Sure, I know that this then restricts your choice of takeoff sites, but when the aircraft can then easily fly to the equator, then I don't think it matters as much.

Also, what if the aircraft were optimized to make use of ground effect for liftoff purposes? Or what if it were designed to be variable geometry (ie. swing-wing or something else)?

What changes/improvements could be made to the carrier aircraft, to enable it to fly to greater even altitudes and airspeeds? If Stratolaunch 1.0 becomes a success, then what improvements/upgrades would you recommend for Stratolaunch 2.0?

Pulling 550 metric tons to takeoff speed will require a huge catapult infrastructure and a brand new runway (don't think you can install it on an existing one). Also you're very limited in the way you can improve on the design; you're likely to add weight in the process.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/18/2011 09:39 PM
It's a hard and fast rule of NASASpaceflight.com's forum: As soon as some hardware development is announced, users will immediately ask how to make it bigger...

(Yes, I've been guilty of this.)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/18/2011 09:55 PM
One of the many things to consider is a rejected take off or RTO at max weight with a fully fueled rocket and aircraft. That could also be a bad day…
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/18/2011 09:58 PM
One of the many things to consider is a rejected take off or RTO at max weight with a fully fueled rocket and aircraft. That could also be a bad day…
I'm sure that's what drives such a long runway. It's also why I think that most of the propellant loading may be done only once airborne (with the capability to dump propellant).
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/18/2011 10:06 PM
One of the many things to consider is a rejected take off or RTO at max weight with a fully fueled rocket and aircraft. That could also be a bad day…
I'm sure that's what drives such a long runway. It's also why I think that most of the propellant loading may be done only once airborne (with the capability to dump propellant).
I was thinking more of a brake fire and or tire explosion than runway available. If you could not safely abort during roll, you should never have been trying to take off from that runway in the first place, which I’m sure will be calculated and refined….
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: hop on 12/18/2011 10:21 PM
I was thinking more of a brake fire and or tire explosion than runway available. If you could not safely abort during roll, you should never have been trying to take off from that runway in the first place, which I’m sure will be calculated and refined….
FOD incidents (think Air France 4590) also come to mind. Having many tons of LOX on hand gives room for things to go wrong much more quickly and spectacularly than jet fuel alone.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/18/2011 10:32 PM
I was thinking more of a brake fire and or tire explosion than runway available. If you could not safely abort during roll, you should never have been trying to take off from that runway in the first place, which I’m sure will be calculated and refined….
FOD incidents (think Air France 4590) also come to mind. Having many tons of LOX on hand gives room for things to go wrong much more quickly and spectacularly than jet fuel alone.
Yup, I guess they will have to "walk" the runway for close inspection.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: kevin-rf on 12/18/2011 10:42 PM
It's a hard and fast rule of NASASpaceflight.com's forum: As soon as some hardware development is announced, users will immediately ask how to make it bigger...

(Yes, I've been guilty of this.)
And yet no one has yet proposed a heavy Stratolaunch constructed by mating three of these beasts wingtip to wingtip.

And to finally to put the whole fire thing to rest, yes there is a modified 747 and a modified DC-10, and many more smaller planes that have not been replaced by 747's and DC-10's. Why?

I am reminded of an event in 2007 when the DC-10 managed to clip some trees ( http://www.flightglobal.com/news/articles/investigation-opens-after-fire-fighting-dc-10-clips-trees-in-california-215230/ ). My point, firebombers need to accurately target the fire, this means coming in low and abusing the airframe. Accidents happen, airframes get over stressed, and lives sadly are lost. Stratolaunch is not designed to fly in the mud. It may even be to fragile to do this kind of flying. As show by the DC-10 event, even the DC-10 may be to large to safely handle the task. Stratolaunch is designed to take a very heavy payload very high. Something that is not really needed for firefighting, airdrop, or even transporting out sized equipment halfway round the globe. Why has no one  modified a U-2 for water bombing forest fires?

I secretly suspect, like certain rocket scientists who want to build the next rocket bigger than a Saturn V, Rutan is in this because it is a way to build the largest air frame ever. And yes Virginia that is cool enough in it's own right.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: yg1968 on 12/19/2011 12:44 AM
I watched the press conference again to better understand the logic of this business venture. In a nutshell, Stratolaunch believes they have a good concept because:

-They think that their launch system will be significantly cheaper than the competition. Rutan said that launching from an airplane gives you a 5% to 10% weight advantage. To the extent that a Falcon 5 is cheaper than a Falcon 9, I would imagine that their system should be very competitive pricewise.

-For manned launches, they also believe that their system is a lot safer since a lot of accidents of other rockets happen at the beginning of a launch.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: edkyle99 on 12/19/2011 01:56 AM
I watched the press conference again to better understand the logic of this business venture. In a nutshell, Stratolaunch believes they have a good concept because:

-They think that their launch system will be significantly cheaper than the competition. Rutan said that launching from an airplane gives you a 5% to 10% weight advantage. To the extent that a Falcon 5 is cheaper than a Falcon 9, I would imagine that their system should be very competitive pricewise.

The comparison shouldn't be with Falcon 9 (nearly 10 tonnes to LEO).  It should be with Antares (Taurus II), or any other rocket in the 6 tonne to LEO class (e.g. Delta II Heavy).

Quote
-For manned launches, they also believe that their system is a lot safer since a lot of accidents of other rockets happen at the beginning of a launch.

I think we have to go back to the January 30, 2007 failure of a Zenit 3SL at liftoff to find a "beginning of launch" failure.  That was 365 world-wide launches ago, a total that included 21 orbital launch vehicle failures, none of which occurred right at the "beginning".

But even the Sea Launch failure should have been survivable if a proper abort system had been used on a crewed capsule.  I'm not sure I see how a drop launch is necessarily safer in that regard.  For example, an abort system would have to shape its escape to avoid hitting the drop aircraft.

 - Ed Kyle
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: yg1968 on 12/19/2011 02:11 AM
I watched the press conference again to better understand the logic of this business venture. In a nutshell, Stratolaunch believes they have a good concept because:

-They think that their launch system will be significantly cheaper than the competition. Rutan said that launching from an airplane gives you a 5% to 10% weight advantage. To the extent that a Falcon 5 is cheaper than a Falcon 9, I would imagine that their system should be very competitive pricewise.

The comparison shouldn't be with Falcon 9 (nearly 10 tonnes to LEO).  It should be with Antares (Taurus II), or any other rocket in the 6 tonne to LEO class (e.g. Delta II Heavy).
 - Ed Kyle

Fair enough. But (based on CRS prices) an Antares flight is more expensive than a Falcon 9 flight.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/19/2011 03:15 AM
Launch flexibility is a big one, bigger than the performance improvement you get with airlaunch. They're looking to target orbital human spaceflight at relatively high launch rates. At high launch rates, it really starts making sense to try to do first-orbit rendezvous. There are considerably more opportunities for that if you have the flexibility of airlaunch.

As far as the advantages of first-orbit rendezvous with a space station, imagine if Soyuz didn't have to have the orbital module, didn't need solar arrays, and didn't need consumables for several days waiting for orbital phasing. It'd be considerably less massive (probably around 30% less mass, maybe even more).

Or, more pertinently, imagine what first-orbit rendezvous would do for Dragon... Dragon could get by without needing the trunk (just relying on Dragon's thermal mass or maybe some phase-change material for thermal control) except for structure. Also, it could well be that fitting 7 people for 2 or 3 days in a Dragon may be too crowded (and so could only do 4 or 5 or so), but if you have first-orbit rendezvous, they can withstand a few hours cramped in the Dragon capsule. Plus fewer consumables, no significant food provisions, etc, etc. And happier customers, since they get to the roomier space station with the big windows and the full toilets a lot sooner.

This all adds up to a significant reduction in mass for the spacecraft (and perhaps even along with an increase in viable crew size from 4 to 7) and better responsiveness and more reusability for the Dragon spacecraft itself (don't need to build new solar arrays or radiators each trip). That will probably end up being much more valuable than a small reduction in cost per kg to orbit compared to a Falcon 9. Remember, people are their big target market and spacecraft are generally more expensive than launch vehicles, so improving that side of the equation may well have more opportunity for improving the economics of the whole thing than just the cost-per-kg-to-LEO part.

If you can get almost twice as many people into space with the same IMLEO and a lot faster, that's a pretty big difference. Launch On Need would be an easier capability, as well, with the launch flexibility that airlaunch provides.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RanulfC on 12/19/2011 01:06 PM
LOx/cryo-propane has nearly the same Isp as LOx/Methane, NOT hydrolox! :)
Ya, ya... there you go again, sticking peanut butter facts into my dreamland chocolate ;)

(I knew that just got carried away a bit :)

Randy
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: HappyMartian on 12/19/2011 01:21 PM

Yep. Pretty nifty. Lots of countries could eventually gain routine access to LEO. Stratolaunch could turn out to be better than ice cream on apple pie!


Cheers!

Edited.

No, there still is ITAR

Eventually Jim, eventually...

Cheers!

Nope, not in your lifetime, ITAR will always be around.  The issues now days is components and satellites.  This is an integrated system that does have military applications.  It is not going to be sold to anyone.

Jim, you seem to be assuming that I think it would be sold. I do not. Most small and medium sized countries would most likely prefer the cheaper option of renting the launch service from Stratolaunch when they need it. Non ITAR spacecraft are available. Most countries wouldn't have enough space traffic to justify owning such a Stratolaunch aircraft. 

Since one of a country's airports could become a glamorous spaceport, that investment might be considered reasonable.

"For the F-X2 program, the Brazilian government have chosen the French Rafale over the Boeing F/A-18E/F Super Hornet due to concerns over technology transfer barriers and ITAR regulations, regardless that the Brazilian air force and the majority of their pilots preferred the Super Hornet over other bidders."  From: http://en.wikipedia.org/wiki/International_Traffic_in_Arms_Regulations

If ITAR issues prohibit international access to Stratolaunch services, another provider that is not subject to ITAR may eventually decide to offer a similar type of launch service.

Cheers!
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RanulfC on 12/19/2011 02:12 PM
Catching up from the weekend :)
Well you "kinda" answered your own question Norm38, as the "zoom" (pitch-up) IS required in one form or another to get the rocket to the proper gamma for release.

From the talk about solids and afterburners I had the impression the zoom was more about trying to gain speed than just getting the nose up.
It's all about the "gamma" or Angle-of-Attack from the horizon. Which is why they need to get the nose up to launch the rocket.

Any "speed" boost less than about Mach-4 isn't much help, and those kind of speeds require very expensive aircraft and engines to reach ;)

No, the whole point is to use the plane to change the flight path angle.  Using the rocket to accelerate of the mass of the plane (beyond the flight path angle change) is counter productive.
Not accelerate per-se but assist in the nose-pitch up manuever. (Well that's what "I" was talking about anyway :) )

Also - can anyone guess at what the velocity of the aircraft would be, when releasing the rocket? What initial velocity would that rocket have, as it ignites its engines? (Sorry if the answer was already posted, because I didn't see it anywhere.)
A guess, (an only a guess :) ) @30,000ft to around 40,000ft and around Mach-0.87 or so (645)

Using the stratolauncher aircraft for anything other then launching rockets is like a solution looking for a problem. The heavy lift market is rather small, and the even the An-225 is often too large for regular airports. The FAA refused to certify the Evergreen 747 firebomber for a long time, although it seems to flying nowadays.

Most of the time moving large parts can be done cheaper by road or barge. Only when time is really important is stuff shipped by oversize cargo plane. Anyway, blimps will probably do most of the heavy lifting in 10 15 years, that will really change things...

(edit, firebomber does fly nowadays)
Sammie, Jim, etc, note that they SAID at the press conference that they would be pursuing "other-uses" for the carrier aircraft. This is a sound and logical part of the business plan. It is NOT going to be launching Falcon-5s often enough and having this thing sitting in a hanger awaiting the next launch is going to COST. You want to keep the airframe in use as much as possible since it's actually going to be the less expensive to operate and maintain part of the overall system.

IF the flight rate ramps up as they expect then they can afford to cut back on "other" uses. No I don't know for sure what "other" uses they are looking at. I suspect oversize cargo delivery yes, but beyond that is iffy. We'll just have to wait and see what the folks who are actually building this bird find :)

Perceived economic viability is the whole reason that it exists.

Anyways, the Stratolaunch won't have timefight fires, deliver drilling rigs or transport large containers.  If it does, it means it failed its primary task.
Jim, the concepts "primary-purpose" is to air-launch Falcon-V/Delta-II class payloads to LEO and beyond. If it does it ONCE a year it's "achieved" it's primary task. In order to LOWER costs it has to capture a significant amount of the market share within it's catagory. So how often would it be utilized if it captures 100% of that market share? About 8 or so hours every couple of WEEKS! The rest of the time it will be sitting in the hanger awaiting the next payload/flight and costing the company money.

In order to keep that from happening the aircraft will have to be utilized for OTHER purposes. As above I've no idea WHAT those might be, but I WILL point out that you are VERY wrong on the military interest in this bird!

@2005 Boeing proposed a similar idea utilizing a single "hull" airframe and an air-launched version of the Delta-IV CCB. It was a duel pitch to the military as the Delta-IV could be replaced by a large cargo container set up for end-to-end loading similar to the C-5 Galaxy. The military WAS interested, (they have been looking to replace the C-5 and would PREFER a high-wing, roll-on/roll-off rather than a civil conversion) but wanted more work done so Boeing pitched it to NASA as an LV test program. No takers. IIRC this actually might have been the "Crossbow" mentioned in the cited paper.

In all this aircraft will be capable of carrying almost twice what the C-5 can, and a little under the maximum payload of the An-225. If they can build it for what they think they can build it for there is incentive for the military to look into testing it. Since it will be using a majority of older parts there will be room for improvements with more powerful modern engines, avionics and other gear. (Upgrading the engines alone might give it capability to take off and land at more airports)

In general there is going to be pressure on StratoLaunch to find alternate uses for the aircraft and given an aircraft with it's capabilities there is probably going to be a large combination of far-out, silly, and mundane suggestions for various uses and test programs it would allow.

Randy
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/19/2011 02:39 PM
Does the stratolauncher only need a really long runway assuming the rocket is fueled on the ground?  Phrased differently, could a lighter load use more common, shorter runways? 

What i'm thinking: Mid-air refueling of stratolauncher or F5 could impact runway requirements.
Even if no mid-air refueling, loaded stratolauncher would need the long runway.  After it shoots its rocket, it could land somewhere with a more typical runway, re-fuel, and fly to somewhere else (potentially to a more common (shorter) runway. 

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/19/2011 03:08 PM

Yep. Pretty nifty. Lots of countries could eventually gain routine access to LEO. Stratolaunch could turn out to be better than ice cream on apple pie!


Cheers!

Edited.

No, there still is ITAR

Eventually Jim, eventually...

Cheers!

Nope, not in your lifetime, ITAR will always be around.  The issues now days is components and satellites.  This is an integrated system that does have military applications.  It is not going to be sold to anyone.

Jim, you seem to be assuming that I think it would be sold. I do not. Most small and medium sized countries would most likely prefer the cheaper option of renting the launch service from Stratolaunch when they need it. Non ITAR spacecraft are available. Most countries wouldn't have enough space traffic to justify owning such a Stratolaunch aircraft. 


And the spacecraft would come to the US to be launched vs Stratolaunch going to another country's airport.  That is how to work around ITAR.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: as58 on 12/19/2011 03:17 PM
Does the stratolauncher only need a really long runway assuming the rocket is fueled on the ground?  Phrased differently, could a lighter load use more common, shorter runways? 

Probably, but I'd think the huge wingspan would be a more serious limitation than the length of the runway required.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/19/2011 03:19 PM
Does the stratolauncher only need a really long runway assuming the rocket is fueled on the ground?  Phrased differently, could a lighter load use more common, shorter runways? 

Probably, but I'd think the huge wingspan would be a more serious limitation than the length of the runway required.

Bingo
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: as58 on 12/19/2011 03:27 PM
Also - can anyone guess at what the velocity of the aircraft would be, when releasing the rocket? What initial velocity would that rocket have, as it ignites its engines? (Sorry if the answer was already posted, because I didn't see it anywhere.)
A guess, (an only a guess :) ) @30,000ft to around 40,000ft and around Mach-0.87 or so (645)

Like you, I'm just guessing, but I doubt it would be that fast. The wing seems to be completely straight (no wing sweep), so it doesn't seem to be built for fast flight.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: mrmandias on 12/19/2011 05:02 PM
Launch flexibility is a big one, bigger than the performance improvement you get with airlaunch. They're looking to target orbital human spaceflight at relatively high launch rates. At high launch rates, it really starts making sense to try to do first-orbit rendezvous. There are considerably more opportunities for that if you have the flexibility of airlaunch.

As far as the advantages of first-orbit rendezvous with a space station, imagine if Soyuz didn't have to have the orbital module, didn't need solar arrays, and didn't need consumables for several days waiting for orbital phasing. It'd be considerably less massive (probably around 30% less mass, maybe even more).

Or, more pertinently, imagine what first-orbit rendezvous would do for Dragon... Dragon could get by without needing the trunk (just relying on Dragon's thermal mass or maybe some phase-change material for thermal control) except for structure. Also, it could well be that fitting 7 people for 2 or 3 days in a Dragon may be too crowded (and so could only do 4 or 5 or so), but if you have first-orbit rendezvous, they can withstand a few hours cramped in the Dragon capsule. Plus fewer consumables, no significant food provisions, etc, etc. And happier customers, since they get to the roomier space station with the big windows and the full toilets a lot sooner.

This all adds up to a significant reduction in mass for the spacecraft (and perhaps even along with an increase in viable crew size from 4 to 7) and better responsiveness and more reusability for the Dragon spacecraft itself (don't need to build new solar arrays or radiators each trip). That will probably end up being much more valuable than a small reduction in cost per kg to orbit compared to a Falcon 9. Remember, people are their big target market and spacecraft are generally more expensive than launch vehicles, so improving that side of the equation may well have more opportunity for improving the economics of the whole thing than just the cost-per-kg-to-LEO part.

If you can get almost twice as many people into space with the same IMLEO and a lot faster, that's a pretty big difference. Launch On Need would be an easier capability, as well, with the launch flexibility that airlaunch provides.

So . . . Stratalaunch is designed to ferry to Bigelow?  Because right now the destination space station you describe isn't there.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/19/2011 05:18 PM
Launch flexibility is a big one, bigger than the performance improvement you get with airlaunch. They're looking to target orbital human spaceflight at relatively high launch rates. At high launch rates, it really starts making sense to try to do first-orbit rendezvous. There are considerably more opportunities for that if you have the flexibility of airlaunch.

As far as the advantages of first-orbit rendezvous with a space station, imagine if Soyuz didn't have to have the orbital module, didn't need solar arrays, and didn't need consumables for several days waiting for orbital phasing. It'd be considerably less massive (probably around 30% less mass, maybe even more).

Or, more pertinently, imagine what first-orbit rendezvous would do for Dragon... Dragon could get by without needing the trunk (just relying on Dragon's thermal mass or maybe some phase-change material for thermal control) except for structure. Also, it could well be that fitting 7 people for 2 or 3 days in a Dragon may be too crowded (and so could only do 4 or 5 or so), but if you have first-orbit rendezvous, they can withstand a few hours cramped in the Dragon capsule. Plus fewer consumables, no significant food provisions, etc, etc. And happier customers, since they get to the roomier space station with the big windows and the full toilets a lot sooner.

This all adds up to a significant reduction in mass for the spacecraft (and perhaps even along with an increase in viable crew size from 4 to 7) and better responsiveness and more reusability for the Dragon spacecraft itself (don't need to build new solar arrays or radiators each trip). That will probably end up being much more valuable than a small reduction in cost per kg to orbit compared to a Falcon 9. Remember, people are their big target market and spacecraft are generally more expensive than launch vehicles, so improving that side of the equation may well have more opportunity for improving the economics of the whole thing than just the cost-per-kg-to-LEO part.

If you can get almost twice as many people into space with the same IMLEO and a lot faster, that's a pretty big difference. Launch On Need would be an easier capability, as well, with the launch flexibility that airlaunch provides.

So . . . Stratalaunch is designed to ferry to Bigelow?  Because right now the destination space station you describe isn't there.
Bigelow or something else. There have been between 8 and 11 space stations in orbit so far (depending on how you count); ISS is only one of them, and is not likely to be the last. None have used Bigelow modules so far, and not all in the future will, either.

Also, the launch market they intend to serve that would warrant a new launch vehicle like this isn't really there, either. They want to launch humans (and a lot of them).
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: gin455res on 12/19/2011 10:19 PM
If the stratolaunch carrier plane carried a scaled up version of spaceshiptwo, that was powered by merlin engines, any idea how much payload it would be able to lift into an equivalent suborbit?

And if this suborbital payload was a third stage, what the final payload this might give to orbit?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Comga on 12/19/2011 10:46 PM
If the stratolaunch carrier plane carried a scaled up version of spaceshiptwo, that was powered by merlin engines, any idea how much payload it would be able to lift into an equivalent suborbit?

And if this suborbital payload was a third stage, what the final payload this might give to orbit?

Stratolaunch is in essence and appearance a scaled-up White Knight 2, the carrier for SpaceShip 2.

The rocket is probably using derivatives of the Merlin 1D engine with air start capability and engine bells optimized for high altitude.

The low Earth orbit capacity has been stated as 13,500 lb (6125 kg) IIRC. 

edited because I misread the question.  I doubt that any manned payload would be a much like SpaceShip 2, with the feather reentry, but that is certainly not my field.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: gin455res on 12/19/2011 10:55 PM
What I'm asking is, if the falcon is a placeholder, then removing the placeholder and reverting to the original spaceship1, spaceship2 concept, what a 3rd stage launched from a merlin powered spaceship3 (sized to the stratolaunch carrier), might be able to get to orbit?

Not sure why that is illogical, just a trade in payload for reusability.


Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/19/2011 11:08 PM
Do you mean a giant suborbital tourist "spacecraft" like a big spaceship 2?  Seating 100 instead of 6?  Or something like that?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Zed_Noir on 12/19/2011 11:31 PM
Wonder if Stratolaunch might attempt to improve the carrier aircraft's high altitude performance with either turbojets (e.g. J57) or low bypass turbofans (e.g. F414) mounted on over the wing pods.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: simonbp on 12/20/2011 12:24 AM
What I'm asking is, if the falcon is a placeholder, then removing the placeholder and reverting to the original spaceship1, spaceship2 concept, what a 3rd stage launched from a merlin powered spaceship3 (sized to the stratolaunch carrier), might be able to get to orbit?

The Falcon-based rocket isn't a placeholder (though the particular design of the wing may be), but rather the first and simplest of several potential vehicles which could be launched from the carrier aircraft. These other vehicles would only likely happen after the winged Falcon has successfully flown.

Since any first stage launched from the aircraft has to have wings, it's a logical assumption to have a runway-landing recoverable first stage. However, it's not a simple conversion, and the result first stage would be an almost completely new design. At that point, it would make sense to move to LH2, which would provide much more performance per take-off mass. Plus, you could leverage Scaled's SS2 experience to build it primarily from composites.

Thus, IMHO, a flyback first stage with one or two SSMEs would be an appropriate future upgrade. But there's long way to go before they'd even consider that.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jason1701 on 12/20/2011 12:30 AM
Why use SSMEs? That would throw away a flyback stage's advantage of rapid reuse. And there's the issue of airstarting SSMEs.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/20/2011 01:16 AM
Will the stratolaunch falcon 5 also fly from F9 pads? 

That is: will F5 be in competition with stratolaunch as well?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/20/2011 02:07 AM
Would a throttled-down middle engine be useful/helpful during takeoff?   
If they eventually do boost-back reusability (ala F9 & Grasshopper), the middle engine on F5 would probably be a sea-level optimized engine anyways for stratolauncher architecture. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: deltaV on 12/20/2011 04:21 AM
Will the stratolaunch falcon 5 also fly from F9 pads? 

That is: will F5 be in competition with stratolaunch as well?

Once you've paid for the launch aircraft using it one more time should be quite inexpensive. Ground launching the rocket sounds like a great way to add additional development costs and reduce payload to orbit for no obvious compensating benefit. Why on earth would SpaceX want to do that when they can either air-launch the Falcon 5 as it's designed or launch payloads using Falcon 9?

Would a throttled-down middle engine be useful/helpful during takeoff?   
If they eventually do boost-back reusability (ala F9 & Grasshopper), the middle engine on F5 would probably be a sea-level optimized engine anyways for stratolauncher architecture. 
Throttling down reduces rocket engine chamber pressure but atmospheric pressure doesn't throttle down to match. Consequently throttling increases the relative importance of back-pressure losses so sea level is not a good place to throttle unless you like poor specific impulse and possible flow separation. It would probably be better to just light a single Merlin at full throttle for a shorter period of time. The thrust of the aircraft/rocket combo would increase by a manageable 50% or so.

Starting one of the rocket engines on the ground sounds like a serious operational inconvenience and a non-trivial safety hazard. What's the benefit?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: gin455res on 12/20/2011 06:46 AM
Do you mean a giant suborbital tourist "spacecraft" like a big spaceship 2?  Seating 100 instead of 6?  Or something like that?

sort of, just the passengers are replaced by a 3rd stage, which goes to orbit.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: 93143 on 12/20/2011 07:32 AM
Starting one of the rocket engines on the ground sounds like a serious operational inconvenience and a non-trivial safety hazard. What's the benefit?

JATO.

Of course, the runway requirements are not seriously unreasonable as matters stand, so it might be superfluous.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: HappyMartian on 12/20/2011 11:59 AM

Yep. Pretty nifty. Lots of countries could eventually gain routine access to LEO. Stratolaunch could turn out to be better than ice cream on apple pie!


Cheers!

Edited.

No, there still is ITAR

Eventually Jim, eventually...

Cheers!

Nope, not in your lifetime, ITAR will always be around.  The issues now days is components and satellites.  This is an integrated system that does have military applications.  It is not going to be sold to anyone.

Jim, you seem to be assuming that I think it would be sold. I do not. Most small and medium sized countries would most likely prefer the cheaper option of renting the launch service from Stratolaunch when they need it. Non ITAR spacecraft are available. Most countries wouldn't have enough space traffic to justify owning such a Stratolaunch aircraft. 


And the spacecraft would come to the US to be launched vs Stratolaunch going to another country's airport.  That is how to work around ITAR.



Whatever is proper sounds good. There may be various ways to satisfy the ITAR folks.

"For practical purposes, ITAR regulations dictate that information and material pertaining to defense and military related technologies (for items listed on the U.S. Munitions List) may only be shared with U.S. Persons unless authorization from the Department of State is received or a special exemption is used."

And, "Concerns over connections between the Boeing 787 and the B-2 Spirit stealth bomber prompted Boeing to take elaborate steps cleansing the commercial jet of any military technology. The issue arose when Boeing engineers, fearing indictment and penalties, refused to sign forms declaring that the 787 was 'ITAR-free.' As a result Boeing conducted extensive research on the source of technology implemented on the 787. They removed all military technology and either found a commercial source for the same technology or replaced it with technology derived from a commercial source."
From: http://en.wikipedia.org/wiki/International_Traffic_in_Arms_Regulations


Cheers!
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/20/2011 12:58 PM
A rocket can not be cleansed.  It is what ITAR is restricting.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/20/2011 01:21 PM
Once you've paid for the launch aircraft using it one more time should be quite inexpensive. Ground launching the rocket sounds like a great way to add additional development costs and reduce payload to orbit for no obvious compensating benefit. Why on earth would SpaceX want to do that when they can either air-launch the Falcon 5 as it's designed ...What's the benefit?
For some launches, F5 from the ground might be capable enough.  The ground infrastructure for F5 is almost the same as for F9 (2-level strongback needed).  I assume F5 would have the same thrust structure and mostly common plumbing with F9. 
The benefit is that SpaceX might eventually make more $ doing the whole show with F9 (or F5) from their launch pads than by selling a F5 to stratolaunch. 
Also, the new Vandy pad will presumably have some vertical integration capability (IIRC, which I'm iffy on here).  If vertical integration is preferable for a smallish load, then maybe a ground F5 would be preferable to F9 and stratolaunch. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: fatjohn1408 on 12/20/2011 02:18 PM
To bad it´s a subsonic plane. Again.
Making assisted launch efficient will in my view require supersonic assist capabilities. The XCOR lynx Mark III is a far more superior concept in my view. If Allen had put his money in a greater and slightly faster lynx (i'm officialy coining the names leopard and lion for the follow ups) then it could even assist a single stage kerolox launcher to Leo. The small dimensions of such a kerolox stage could prove beneficial when trying to make it reusable.

But I digress. Stratolaunch is cool and exiting but it will only marginally survive in the market. Too slow, too low.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: yg1968 on 12/20/2011 02:47 PM
Could the Falcon 5 on the Stratolaunch be reusable and still have enough fuel to lift a crewed Dragon to space? I think that they said that initially reusability was not planned for the Falcon 5. But I am wondering if it could be added later on.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Garrett on 12/20/2011 02:54 PM
Do you mean a giant suborbital tourist "spacecraft" like a big spaceship 2?  Seating 100 instead of 6?  Or something like that?
Just jumping in here.
Has it been discussed yet about the possibility that Stratolaunch may be a prototype for an intercontinental suborbital passenger plane? From the announcement I thought I picked up on something along those lines.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/20/2011 03:08 PM
That would certainly fit with Elon's mention of advancing transportation by 3 or 4 generations and be a tremendous-sized market.  There's a thread in advanced concepts that discusses a lot of that (which started a bit side-tracked assuming batteries were a necessary condition).  Some very interesting thoughts on that thread though that would tie in with your idea.  The question then becomes "would it be horizontal landed?  Or vertically landed.  Pros and cons to either but I think vertical for a few reasons that are on that thread.  I'd elaborate now but I'm swamped at work.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Zed_Noir on 12/20/2011 03:23 PM
What I'm asking is, if the falcon is a placeholder, then removing the placeholder and reverting to the original spaceship1, spaceship2 concept, what a 3rd stage launched from a merlin powered spaceship3 (sized to the stratolaunch carrier), might be able to get to orbit?

The Falcon-based rocket isn't a placeholder (though the particular design of the wing may be), but rather the first and simplest of several potential vehicles which could be launched from the carrier aircraft. These other vehicles would only likely happen after the winged Falcon has successfully flown.

Since any first stage launched from the aircraft has to have wings, it's a logical assumption to have a runway-landing recoverable first stage. However, it's not a simple conversion, and the result first stage would be an almost completely new design. At that point, it would make sense to move to LH2, which would provide much more performance per take-off mass. Plus, you could leverage Scaled's SS2 experience to build it primarily from composites.

Thus, IMHO, a flyback first stage with one or two SSMEs would be an appropriate future upgrade. But there's long way to go before they'd even consider that.


I doubt anyone will consider using LH2 on an air-launched LV core stage anytime soon. The main issue with LH2 is it's a low density cryogenic fuel resulting in a bigger tank and vehicle as compared to a similar kerolox design.

The acquisition & operating costs of a Merlin compare to a SSME is quite low. Also the current SSME flavor (RS-25E) is not currently in production or anytime before 2018.

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/20/2011 03:25 PM
Could the Falcon 5 on the Stratolaunch be reusable and still have enough fuel to lift a crewed Dragon to space? I think that they said that initially reusability was not planned for the Falcon 5. But I am wondering if it could be added later on.
Possibly. It'd be a lot easier if they can get a higher Isp upper stage on it (whether staged combustion or, maybe less likely, another propellant like methane, propane, or something). Airlaunch offers a nice benefit in that you can "boost-forward" by launching up range of your stage landing point instead of having to cancel out and reverse your stage's velocity.

Second stage reusability is another matter.

Either way, it'll be interesting to see what happens with Grasshopper in 2012 (when we should see a first, short flight).

Stratolaunch opens up the trade space quite a bit. But we must keep in mind that this is NOT a SpaceX project. SpaceX is just a subcontractor (doesn't mean that wouldn't change in the future), so SpaceX isn't likely to base a huge investment in reusability on someone else's project unless they're getting paid for it.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: yg1968 on 12/20/2011 03:29 PM
Could the Falcon 5 on the Stratolaunch be reusable and still have enough fuel to lift a crewed Dragon to space? I think that they said that initially reusability was not planned for the Falcon 5. But I am wondering if it could be added later on.
Second stage reusability is another matter.

How so?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Tcommon on 12/20/2011 03:37 PM
I doubt anyone will consider using LH2 on an air-launched LV core stage anytime soon. The main issue with LH2 is it's a low density cryogenic fuel resulting in a bigger tank and vehicle as compared to a similar kerolox design.

It's also difficult to work with - the Shuttle had lots of delays due to hydrogen leaks for a program costing $200 million per month. I think the extra cost of using LH2 was around $1 billion based on that.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/20/2011 03:39 PM
Could the Falcon 5 on the Stratolaunch be reusable and still have enough fuel to lift a crewed Dragon to space? I think that they said that initially reusability was not planned for the Falcon 5. But I am wondering if it could be added later on.
Second stage reusability is another matter.

How so?
The heaviness of the reusability systems on a second stage eats more directly into the payload, of course. Not saying it's impossible, just more difficult. Also, reusability for a second stage doesn't gain as much from airlaunch compared to first stage reusability.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: deltaV on 12/20/2011 03:44 PM
Starting one of the rocket engines on the ground sounds like a serious operational inconvenience and a non-trivial safety hazard. What's the benefit?

JATO.

Of course, the runway requirements are not seriously unreasonable as matters stand, so it might be superfluous.

Is it easier to get permission to use a 12,000 foot runway for launch of an inert rocket or a roughly 9,000 foot runway for launch of an operating rocket? I have no idea, but as you say long runways are available so JATO is likely unnecessary.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: mrmandias on 12/20/2011 04:32 PM
Do you mean a giant suborbital tourist "spacecraft" like a big spaceship 2?  Seating 100 instead of 6?  Or something like that?
Just jumping in here.
Has it been discussed yet about the possibility that Stratolaunch may be a prototype for an intercontinental suborbital passenger plane? From the announcement I thought I picked up on something along those lines.


That might be enough of an upside payoff that it makes the funding worthwhile.  Intercontinental suborbital is *almost* as tough as orbital, but not quite.  Add that difference in delta-v to the extra delta-v that the carrier airplane buys you and a single-stage suborbital might just be possible.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/20/2011 04:55 PM
I doubt anyone will consider using LH2 on an air-launched LV core stage anytime soon. The main issue with LH2 is it's a low density cryogenic fuel resulting in a bigger tank and vehicle as compared to a similar kerolox design.

It's also difficult to work with - the Shuttle had lots of delays due to hydrogen leaks for a program costing $200 million per month. I think the extra cost of using LH2 was around $1 billion based on that.

Wrong, not a valid comparison
a.  Delta IV or Atlas V use it without major issues
b.  The shuttle did not have "a lot" of leaks
c.  it did not cost "extra"
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/20/2011 04:57 PM

I doubt anyone will consider using LH2 on an air-launched LV core stage anytime soon. The main issue with LH2 is it's a low density cryogenic fuel resulting in a bigger tank and vehicle as compared to a similar kerolox design.


Actually, it is the opposite.  LH2 is more suited for airlaunch and provides more benefits since it is less dense and therefore the vehicle weighs less.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/20/2011 05:07 PM

a. they aren't airlaunched
b. wrong (http://www.google.com/#hl=en&cp=20&gs_id=3s&xhr=t&q=hydrogen+leak+delays+space+shuttle+launch)
c. Incorrect


All wrong again. 

A. Launch methodhas no bearing on the subject.
b.  number of google hits is meaningless statistic.  there weren't "a lot"
c.  Whether there was a leak or not, shuttle ops still cost the same.  It did not add more costs. 



Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Tcommon on 12/20/2011 05:08 PM
c.  Whether there was a leak or not, shuttle ops still cost the same.  It did not add more costs.
Ok, then it reduced the number of possible launches, if that's the way you want to look at it, all the while costing $200 million per month. Or, if you prefer,  it increased the cost of each launch. That $200 million per month went somewhere.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Chris Bergin on 12/20/2011 05:16 PM
Hey, calm it down. Tcommon, you've lost a post and you'll lose more if you can't be civil.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: kfsorensen on 12/20/2011 05:16 PM

I doubt anyone will consider using LH2 on an air-launched LV core stage anytime soon. The main issue with LH2 is it's a low density cryogenic fuel resulting in a bigger tank and vehicle as compared to a similar kerolox design.


Actually, it is the opposite.  LH2 is more suited for airlaunch and provides more benefits since it is less dense and therefore the vehicle weighs less.

Jim is right, for an air-launched vehicle there's got to be a pretty strong argument AGAINST LH2 not to use it.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Tcommon on 12/20/2011 05:18 PM
c.  Whether there was a leak or not, shuttle ops still cost the same.  It did not add more costs.
Ok, then it reduced the number of possible launches, if that's the way you want to look at it, all the while costing $200 million per month. Or, if you prefer,  it increased the cost of each launch. That $200 million per month went somewhere.

Wrong again.  Know something before posting.

this applies to you

http://forum.nasaspaceflight.com/index.php?topic=27520.msg840823#msg840823

Ha Ha. I'm right and you know it. The only way months and months of delays due to Shuttle hydrogen leaks didn't cost money is if you think of the $200 million per month as an entitlement.

Hey, calm it down. Tcommon, you've lost a post and you'll lose more if you can't be civil.
10-4
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: kevin-rf on 12/20/2011 05:20 PM
For some launches, F5 from the ground might be capable enough.  The ground infrastructure for F5 is almost the same as for F9 (2-level strongback needed).  I assume F5 would have the same thrust structure and mostly common plumbing with F9. 
A Ground launched Falcon 5 would require different nozzles, and will be shorter than an F9, so the second stage hookups will be different. Though that may be as simple as a dedicated "F5" strongback.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: mmeijeri on 12/20/2011 05:33 PM
Actually, it is the opposite.  LH2 is more suited for airlaunch and provides more benefits since it is less dense and therefore the vehicle weighs less.

Mixed bag I think. Low density is bad, not good, it's the high Isp that makes LH2 interesting, not its low density. Boil-off is also very inconvenient. Some have even advocated the use of hypergolics for air-launch, because of high density and lack of boil-off, despite the handling difficulties and lower Isp. Conservation of inconvenience I guess, you can move it around but you can't eliminate it.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: baldusi on 12/20/2011 05:40 PM
Actually, it is the opposite.  LH2 is more suited for airlaunch and provides more benefits since it is less dense and therefore the vehicle weighs less.

Mixed bag I think. Low density is bad, not good, it's the high Isp that makes LH2 interesting, not its low density. Boil-off is also very inconvenient. Some have even advocated the use of hypergolics for air-launch, because of high density and lack of boil-off, despite the handling difficulties and lower Isp. Conservation of inconvenience I guess, you can move it around but you can't eliminate it.
It's a matter of optimization. If you assume that the airlaunch is not volume limited, but only GTOW limited. And you take into consideration that the (normally) low T/W of H2 stacks gets particularly high benefits from airlaunch. Then the maximum payload for a given GTOW will be achieved with an H2 rocket. Boil off can be mitigated with better insulation, and some fill up pumping on the flight.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/20/2011 06:12 PM
One benefit of airlaunch is the low aerodynamic drag once at altitude. This can greatly diminish hydrolox's drag penalty. The drag experienced near sea level occurs when under turbofan power so isn't expensive.

(This is in addition to the maximizing of the payload to orbit for a given carrier airplane because of the much higher Isp.)

The boiloff issue can be mitigated with really good MLI (see Jon Goff's latest post on it: http://selenianboondocks.com/2011/11/tooting-someone-elses-horn-quest-product-development-corps-advanced-mli-technologies/ ) or in-flight fueling of the rocket.


I doubt anyone will consider using LH2 on an air-launched LV core stage anytime soon. The main issue with LH2 is it's a low density cryogenic fuel resulting in a bigger tank and vehicle as compared to a similar kerolox design.


Actually, it is the opposite.  LH2 is more suited for airlaunch and provides more benefits since it is less dense and therefore the vehicle weighs less.

Jim is right, for an air-launched vehicle there's got to be a pretty strong argument AGAINST LH2 not to use it.

The biggest argument is that there isn't a very cheap hydrolox rocket that could be adapted relatively easily for this. SpaceX's vertically integrated nature means they're pretty good at developing a new rocket and manufacturing for cheap... (SpaceX's weakness is operations, which is being taken care of by Stratolaunch and their partners.) They're already used to manufacturing dozens of the rocket engines and several rocket bodies in a relatively short period of time (now if only they could launch them...).
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: mmeijeri on 12/20/2011 06:21 PM
If you assume that the airlaunch is not volume limited, but only GTOW limited.

Ah, but do we know that assumption is true? The AirLaunch people advocated storable propellants, because of boil-off, drag (?) and volume constraints associated with LH2 / cryogens in general.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RocketmanUS on 12/20/2011 06:29 PM
Does the mother ship make LOX inflight from the air to replace what is lost in the rocket stages do to boil off?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: baldusi on 12/20/2011 07:03 PM
If you assume that the airlaunch is not volume limited, but only GTOW limited.

Ah, but do we know that assumption is true? The AirLaunch people advocated storable propellants, because of boil-off, drag (?) and volume constraints associated with LH2 / cryogens in general.
Airlaunch proposed to increase the height of wheels of a stock 747. They where volume limited, too. The Stratolauncher isn't. In fact, they show it with a full 5.2m fairing. So it would not be an issue. Plust, the double bodies have lots of internal space. Airlaunch and Stratolauncher are very different vehicles. Even different payload sizes.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: HMXHMX on 12/20/2011 07:48 PM
If you assume that the airlaunch is not volume limited, but only GTOW limited.

Ah, but do we know that assumption is true? The AirLaunch people advocated storable propellants, because of boil-off, drag (?) and volume constraints associated with LH2 / cryogens in general.

Not sure I'd call LOX-Propane storable.  The reason it was chosen against the clearly superior (for air-launching) LOX-LH2 combination was partly volumetric, i.e., fitting inside the C-17 and partly operational i.e., the USAF didn't want to deal with LH2 in a combat situation.  Once we had that stage developed, there was no reason to do it all over again with LH2 for external carry on the 747 (for the t/Space 2006 NASA proposal).

Also, for those who think LH2 is hard to handle, I'd point out that the semiconductor industry uses a significant quantity each day, delivered by truck, and handled by folks who don't have PhDs.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Tcommon on 12/20/2011 07:53 PM
Also, for those who think LH2 is hard to handle, I'd point out that the semiconductor industry uses a significant quantity each day, delivered by truck, and handled by folks who don't have PhDs.
LH2 is harder and more expensive to handle than RP1 - but carry on, I'm enjoying this conversation immensely.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/20/2011 08:03 PM
In the vein of fuel safety and handling conversation,  if we were to reset the clock for motor vehicles and their use of gasoline and dispensing at filling stations. Throw in the context of government regulations, liability and a litigious society; we never might have had gasoline powered automobiles in modern times. One only needs to compare ordinary common gasoline vapor to the explosive equivalent of TNT.
In other words if someone came up with the idea of gasoline powered cars today, they would be called nuts…
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: mmeijeri on 12/20/2011 08:14 PM
Not sure I'd call LOX-Propane storable.

I think I recall a paper by Sarigul Klijn advocating hypergolics, but I couldn't quickly find it just now.

Quote
Also, for those who think LH2 is hard to handle, I'd point out that the semiconductor industry uses a significant quantity each day, delivered by truck, and handled by folks who don't have PhDs.

On the other hand, I remember evacuating a research lab because there was a leaking LH2 truck next to it. Not that I'd preferred hypergolics or anything...
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: MP99 on 12/20/2011 08:46 PM
Not sure I'd call LOX-Propane storable.

I think I recall a paper by Sarigul Klijn advocating hypergolics, but I couldn't quickly find it just now.
Quote

Also, for those who think LH2 is hard to handle, I'd point out that the semiconductor industry uses a significant quantity each day, delivered by truck, and handled by folks who don't have PhDs.

On the other hand, I remember evacuating a research lab because there was a leaking LH2 truck next to it. Not that I'd preferred hypergolics or anything...

I think you'd evacuate for a leaking hypergolic truck, too?

Cheers, Martin
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: mmeijeri on 12/20/2011 08:48 PM
I think you'd evacuate for a leaking hypergolic truck, too?

You bet I'd try, but it might be too late by the time you noticed.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: muomega0 on 12/20/2011 08:49 PM
I doubt anyone will consider using LH2 on an air-launched LV core stage anytime soon. The main issue with LH2 is it's a low density cryogenic fuel resulting in a bigger tank and vehicle as compared to a similar kerolox design.

It's also difficult to work with - the Shuttle had lots of delays due to hydrogen leaks for a program costing $200 million per month. I think the extra cost of using LH2 was around $1 billion based on that.

Wrong, not a valid comparison
a.  Delta IV or Atlas V use it without major issues
b.  The shuttle did not have "a lot" of leaks
c.  it did not cost "extra"

LH2 Consumption During Space Station Program (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110008561_2011008946.pdf)  was 54M lbs (24.5M kg)  times $5/kg =  $122M over its lifetime. 

Further, 29.6M On board quantity vs 54M purchased, so heat leaks and leaks accounted for 46% of the total.  Do you mean leaks or heat leaks (heat loss)?

So you seem to be stating that it took $200M/month labor to maintain the *leaks* and handling of LH2, yes or no?  Seems rather high ::)

Can anyone give the rate of replenishment of the External tank once it enters stable replenish (is this T-3 hrs?).
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: MP99 on 12/20/2011 08:52 PM
It's a hard and fast rule of NASASpaceflight.com's forum: As soon as some hardware development is announced, users will immediately ask how to make it bigger...

So very, very true.

Cheers, Martin
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/20/2011 09:15 PM

I doubt anyone will consider using LH2 on an air-launched LV core stage anytime soon. The main issue with LH2 is it's a low density cryogenic fuel resulting in a bigger tank and vehicle as compared to a similar kerolox design.


Actually, it is the opposite.  LH2 is more suited for airlaunch and provides more benefits since it is less dense and therefore the vehicle weighs less.

I'm with Jim.  LH2 has more challenging insulation requirements for air launch, but technology is catching-up with the challenges (see my insulation article on selenian boondocks).  And for air launch you have a hard GTOW restriction, and you're at a point in the trajectory where most of the gravity/drag losses have been taken care of (if you do your flight path angle right), so most of the disadvantages of LH2 go away.

~Jon
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: sanman on 12/20/2011 09:49 PM
I know it sounds silly, but could this Stratolaunch approach be used for military purposes? Hey, people have tried sillier things.

Remember the MX missile and the idea of circulating it around on a railroad car?

Well, could you have Stratolaunch planes each carrying an ICBM around, like Cold War alert bombers? Here the plane wouldn't have to contend with penetrating enemy airspace like the bomber does, because it's just launching the missile. At the same time, it's mobile and more elusive than a fixed silo or ground-based launcher. It's not as well-hidden as a ballistic submarine, but it's more mobile than one.

If you were a 3rd world country, Stratolaunch could become part of a cheap deterrent system.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/20/2011 09:52 PM
Also, for those who think LH2 is hard to handle, I'd point out that the semiconductor industry uses a significant quantity each day, delivered by truck, and handled by folks who don't have PhDs.
LH2 is harder and more expensive to handle than RP1 - but carry on, I'm enjoying this conversation immensely.

I think Gary's point was that unless you're dumber than the average Praxair delivery guy, LH2 is not a showstopper.  Just another consideration to be factored into the performance/cost/operability trades.

I can think of several things in Kero's favor (ready availability at an airport if your engine can handle the lower-quality aviation kerosenes being the single biggest one).  But what wins out depends a lot on what you're trying to achieve.  I think the anti-LH2 bent that a lot of people have in New Space is somewhat amusing.  To be fair I've never used anything much worse than LOX myself (though I have many friends who have LH2 experience and few of them think it's the devil-juice that some make it out to be).

~Jon
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/20/2011 11:18 PM
I know it sounds silly, but could this Stratolaunch approach be used for military purposes? Hey, people have tried sillier things.

Remember the MX missile and the idea of circulating it around on a railroad car?

Well, could you have Stratolaunch planes each carrying an ICBM around, like Cold War alert bombers? Here the plane wouldn't have to contend with penetrating enemy airspace like the bomber does, because it's just launching the missile. At the same time, it's mobile and more elusive than a fixed silo or ground-based launcher. It's not as well-hidden as a ballistic submarine, but it's more mobile than one.

If you were a 3rd world country, Stratolaunch could become part of a cheap deterrent system.


Huh?  wrong, that capability exists now, with current aircraft.  Stratolaunch isn't anything new.    The Stratolaunch aircraft is not going to be sold to just anyone.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/20/2011 11:23 PM
I know it sounds silly, but could this Stratolaunch approach be used for military purposes? Hey, people have tried sillier things.

Remember the MX missile and the idea of circulating it around on a railroad car?

Well, could you have Stratolaunch planes each carrying an ICBM around, like Cold War alert bombers? Here the plane wouldn't have to contend with penetrating enemy airspace like the bomber does, because it's just launching the missile. At the same time, it's mobile and more elusive than a fixed silo or ground-based launcher. It's not as well-hidden as a ballistic submarine, but it's more mobile than one.

If you were a 3rd world country, Stratolaunch could become part of a cheap deterrent system.


Huh?  That capability exists now.  Stratolaunch doesn't change anything
Stratolaunch isn't going to be cheap. Missiles on a mobile launcher would be a lot cheaper and probably stealthier (can hide in caves).
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: baldusi on 12/21/2011 01:26 AM
Sorry, but isn't the B-52 already doing this?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: rdale on 12/21/2011 01:35 AM
Sorry, but isn't the B-52 already doing this?

I've never heard of a B52 launching space missions, do you have any examples?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Danderman on 12/21/2011 01:47 AM
The 45 minute climb to altitude prior to launch is going to generate a lot of boiloff for an LH2 fueled vehicle.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jongoff on 12/21/2011 01:50 AM
The 45 minute climb to altitude prior to launch is going to generate a lot of boiloff for an LH2 fueled vehicle.

Depends strongly on the design, and amount of applied engineering cleverness...

~Jon
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/21/2011 02:29 AM
Sorry, but isn't the B-52 already doing this?

I've never heard of a B52 launching space missions, do you have any examples?

First 5 Pegasus missions.  Also, some might say the X-15 missions where the pilot earned astronaut wings.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: rdale on 12/21/2011 02:38 AM
So it "did it" - that's far different that "doing it" :)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: simonbp on 12/21/2011 02:41 AM
Just for reference WRT masses, the mass of a loaded Delta IV first stage is 226 tonnes, while the Atlas V first stage masses 307 tonnes. They have almost the same total delta v, so that's a mass savings of 26%. That's pretty significant, and much more than to account for the extra mass from a recovery system.

LH2 certainly has its issues (not least engine availability), but for a recoverable system, I think they'll have to go there to keep the first stage mass down.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: truth is life on 12/21/2011 03:09 AM
Huh?  wrong, that capability exists now, with current aircraft.  Stratolaunch isn't anything new.    The Stratolaunch aircraft is not going to be sold to just anyone.

Well, I know about Airborne Minuteman (C-5s carrying Minuteman missiles around and dropping them out the back for launch--there was even a demonstration) and Skybolt, but I didn't know anyone had an operational Air Launched Ballistic Missile?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/21/2011 10:02 AM
Huh?  wrong, that capability exists now, with current aircraft.  Stratolaunch isn't anything new.    The Stratolaunch aircraft is not going to be sold to just anyone.

Well, I know about Airborne Minuteman (C-5s carrying Minuteman missiles around and dropping them out the back for launch--there was even a demonstration) and Skybolt, but I didn't know anyone had an operational Air Launched Ballistic Missile?

Change  capability to ability
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: fatjohn1408 on 12/21/2011 03:44 PM
One benefit of airlaunch is the low aerodynamic drag once at altitude. This can greatly diminish hydrolox's drag penalty. The drag experienced near sea level occurs when under turbofan power so isn't expensive.

To be fair, lower aerodynamic drag would open up the possibility of designing a much less slender kerolox launcher. Near circular tanks would lead to significant construction mass reductions.

This effect is very important when looking to other launch assist concepts such as that of XCOR´s lynx, where release conditions would be so fast and high that the assisted vehicle would better be a single stage. In this scenario each pound saved in construction mass would add a pound to payload capability.

Another problem with the LH2 density is that there is only a limited space beneath the wings, so a hydrolox launcher of the same mass as the kerolox launcher would be three times as long. Imagine the bending load the rocket´s hull has to withstand.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/21/2011 03:49 PM
I think you mean "nearly spherical" not "near circular" tanks. ;)

It's true that spherical tanks would, in "spherical cow land," have a better mass fraction for a pressure vessel. (And spherical tanks also would need less insulation for a given boil-off rate... not counting aerodynamics there). Whether there's a real benefit after everything is taken into account is a lot more difficult question to answer. There's also "ease of manufacturing" and "ease of transportation" considerations.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: mmeijeri on 12/21/2011 05:27 PM
I'm with Jim.

A wise default choice in general, but I wonder if we know enough to make a pronouncement either way. Is it obvious that one is superior to the other? I don't even know which way I would bet if I had to. Same with kerolox + hydrolox as with Atlas vs all hydrolox as with Delta. Which is better? Conventional wisdom says kerolox is better for first stages, so you could say Atlas is more technically capable, but how much economic benefit comes from having identical propellant combinations on both stages? And what about all kerolox as with Falcon? In the end only experience and markets can tell us what is best overall, and the answer may be different for various niches.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: mmeijeri on 12/21/2011 05:33 PM
I think the anti-LH2 bent that a lot of people have in New Space is somewhat amusing.

I find it amusing to hear there is an anti-LH2 attitude in New Space. In my experience if anything they're preaching the gospel of LH2, not bad-mouthing it. At the same time they are practicing less challenging things for now, and haven't even moved far beyond pressure-fed systems as far as I know.

Quote
To be fair I've never used anything much worse than LOX myself (though I have many friends who have LH2 experience and few of them think it's the devil-juice that some make it out to be).

We must travel in different circles. I've never heard anyone describe LH2 as devil juice. It's a standard industrial commodity.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Tcommon on 12/21/2011 05:46 PM
I think the anti-LH2 bent that a lot of people have in New Space is somewhat amusing.

I find it amusing to hear there is an anti-LH2 attitude in New Space. In my experience if anything they're preaching the gospel of LH2, not bad-mouthing it. At the same time they are practicing less challenging things for now, and haven't even moved far beyond pressure-fed systems as far as I know.

Quote
To be fair I've never used anything much worse than LOX myself (though I have many friends who have LH2 experience and few of them think it's the devil-juice that some make it out to be).

We must travel in different circles. I've never heard anyone describe LH2 as devil juice. It's a standard industrial commodity.

Yah, this argument has gotten 'entertaining'. LH2 has advantages and disadvantages. They should be dispassionately discussed. But when I  mentioned the months of Shuttle delays caused by Hydrogen leaks, one of its disadvantages, there seemed to be a lot of emotions.

"devil-juice" ... Never heard that one before

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: mmeijeri on 12/21/2011 05:48 PM
"devil-juice" ... Never heard that one before

Sounds like a more appropriate term for hydrazine or NTO.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/21/2011 05:57 PM
I think the anti-LH2 bent that a lot of people have in New Space is somewhat amusing.

I find it amusing to hear there is an anti-LH2 attitude in New Space. In my experience if anything they're preaching the gospel of LH2, not bad-mouthing it. At the same time they are practicing less challenging things for now, and haven't even moved far beyond pressure-fed systems as far as I know.

Quote
To be fair I've never used anything much worse than LOX myself (though I have many friends who have LH2 experience and few of them think it's the devil-juice that some make it out to be).

We must travel in different circles. I've never heard anyone describe LH2 as devil juice. It's a standard industrial commodity.
Join the ARocket mailing list.

We're talking about the little New Space folk, many who have lots of experience in the amateur realm.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: mmeijeri on 12/21/2011 06:00 PM
Join the ARocket mailing list.

I have, but maybe I need to read more closely.

Anyway, back to Stratolaunch. I don't think we've seen any indication they are planning for LH2. SpaceX has also stopped talking very much about moving beyond kerolox and to the degree they still do they're talking about LOX/CH4, not LH2.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/21/2011 09:40 PM
I think the anti-LH2 bent that a lot of people have in New Space is somewhat amusing.

I find it amusing to hear there is an anti-LH2 attitude in New Space. In my experience if anything they're preaching the gospel of LH2, not bad-mouthing it. At the same time they are practicing less challenging things for now, and haven't even moved far beyond pressure-fed systems as far as I know.

Quote
To be fair I've never used anything much worse than LOX myself (though I have many friends who have LH2 experience and few of them think it's the devil-juice that some make it out to be).

We must travel in different circles. I've never heard anyone describe LH2 as devil juice. It's a standard industrial commodity.

Yah, this argument has gotten 'entertaining'. LH2 has advantages and disadvantages. They should be dispassionately discussed. But when I  mentioned the months of Shuttle delays caused by Hydrogen leaks, one of its disadvantages, there seemed to be a lot of emotions.

Because you are blatantly wrong, again.
LH2 is not difficult to deal with and your example didn't nothing to disprove it.  Have you worked with LH2 or any other propellant?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Tcommon on 12/21/2011 09:52 PM
Yah, this argument has gotten 'entertaining'. LH2 has advantages and disadvantages. They should be dispassionately discussed. But when I  mentioned the months of Shuttle delays caused by Hydrogen leaks, one of its disadvantages, there seemed to be a lot of emotions.
Because you are blatantly wrong, again.
OK, Jim. The Shuttle didn't have months and months of delays over Hydrogen leaks. Wouldn't want you to get worked up or lose any sleep over the truth, would we?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Lee Jay on 12/21/2011 09:58 PM
LH2 is not difficult to deal with and your example didn't nothing to disprove it.

I'm sure it's more difficult than room-temperature liquids.  Heck, any knucklehead can fill a container at the pump and re-fill their Kerosene heater.

But that leads me to a question.  Which liquids commonly used in rocketry are harder to handle than LH2?  I would think the Hypergols certainly are, probably a good number of the oxidizers, and maybe even liquid helium.  Is that correct, Jim?  Any others?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/22/2011 12:36 AM
Almost any oxidizer, for the simple fact that one mistake can produce a high explosive.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: iamlucky13 on 12/22/2011 02:20 AM
Sorry, but isn't the B-52 already doing this?

I've never heard of a B52 launching space missions, do you have any examples?

I read the question as being in relation to the previous 3 out of 4 comments that were about flying deterrence missions.

To the best of my knowledge, we haven't conducted deterrence flights of nuclear-armed bombers in several decades. Rather, the bombers wait on the ground, and rapid response falls to the responsibility of the Minutemen and Titan missiles.

Anyways, the Stratolauncher aircraft would be rather oversized for the task. The Peacekeeper's were huge as ICBM's go, but still half the mass of the Falcon V being discussed. The smaller Minutemen are about 1/6th the mass.

Air-launched ballistic missiles was a concept the military largely rejected in the 60's as submarine launched missiles gained credence:

http://en.wikipedia.org/wiki/GAM-87_Skybolt

Someone else mentioned the C-5 + Minuteman test:

http://en.wikipedia.org/wiki/Air-launched_ballistic_missile
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Zed_Noir on 12/22/2011 04:09 AM
Anyways, the Stratolauncher aircraft would be rather oversized for the task. The Peacekeeper's were huge as ICBM's go, but still half the mass of the Falcon V being discussed. The smaller Minutemen are about 1/6th the mass.

Not really. You could have kinetic penetrator packages on Midgetman size ballistic missiles hung from a multiple ejector rack. Giving you the option to cover multiple targets and/or do a successive follow on attacks on more robust or large targets.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Chris Bergin on 12/22/2011 03:55 PM
I like this ;D

http://www.youtube.com/watch?v=n5tM2YhoWvQ&feature=channel_video_title
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: JohnFornaro on 12/23/2011 01:56 PM
Wow. 43 pages and 46K views since December.

I take it that the idea is that WhiteKnight was the demo project? And that now is the time to scale up the effort?  After all, Mr. Allen has three commas in his checkbook, and much startup cred, so investment capital can feel that risk is adequately covered?  More power to him.

A structural aside.  F9, or what, F5?, as currently manufactured, is not engineered to be hung from its mid-point.  So those assymetrical loads must be accounted for inside the geometry of the fairing itself.  Seems to me that the shape of the rocket would be more ellipsoidal, around its horizontal axis, than circular.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: hop on 12/23/2011 06:10 PM
I take it that the idea is that WhiteKnight was the demo project?
Huh ? Where do you get that from ? The success of the SS1 project and  successful (so far) development of SS2 may have given them confidence, but I don't see any indication there was some overall plan from the start. It wouldn't make sense without something like F9 already being developed, which was not the case when they set out to do SS1
Quote
Seems to me that the shape of the rocket would be more ellipsoidal, around its horizontal axis, than circular.
No. They explicitly stated it would be a shortened F9 stage. Cylinders are great for light, rigid structures. They may need to add structure, but they aren't going to change the whole shape.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: JohnFornaro on 12/24/2011 12:41 AM
I take it that the idea is that WhiteKnight was the demo project?
Huh ? Where do you get that from ? (1) The success of the SS1 project and  successful (so far) development of SS2 may have given them confidence, but I don't see any indication there was some overall plan from the start. ...
Quote
Seems to me that the shape of the rocket would be more ellipsoidal, around its horizontal axis, than circular.
No. (2) They explicitly stated it would be a shortened F9 stage. Cylinders are great for light, rigid structures. They may need to add structure, but they aren't going to change the whole shape.

(1)  From my own brain, mostly. I notice the parallels in the launch scheme.  Then I bactracked and thought, huh.  They turned this into a plan?  Not a plan from the start, but a plan from the workability of SS1.  YMMV.

(2)  Understood.  Just my intuitive design sense.  So the internal structure must be accomodated within the cylindrical fairing.  Not my design.  Not judging either.  Asking only.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: JAFO on 12/24/2011 01:43 AM
If it was anyone but Burt Rutan I'd think "Not a chance.". But I'll bet Rutan has done "black projects" that won't see the light for decades, and if anyone can do it....
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: HMXHMX on 12/24/2011 02:36 AM
If it was anyone but Burt Rutan I'd think "Not a chance.". But I'll bet Rutan has done "black projects" that won't see the light for decades, and if anyone can do it....

Earlier, I said I wouldn't comment about Stratolaunch, but I have an view to share (that is carefully worded to avoid issues with proprietary or private confidences). 

First, people are ascribing way too much involvement by Burt (and maybe others like Griffin and Elon) to the Stratolaunch venture.  This is a Vulcan project that seems to have its center of gravity located in Huntsville. 

When I saw Burt a few days ago, he was very clear that he has no management role whatever, and only sits on the Board; otherwise he strongly reiterated "I'm retired."  He has said this publicly before, so this doesn't constitute betraying a confidence.  But people don't listen.

He didn't design the aircraft, he has no real part in the launch vehicle, and he has no role in day-to-day Stratolaunch management.  Plus Scaled is on their own with this aircraft; Burt is not working on it.

(Also, I don't interact with Griffin at all, but I get the impression from his equivocal statements at the press conference that he too is only a Board member and has no management role.  Elon has in the past disparaged air-launching, and I see no reason to think he has changed his view.  SpaceX is quite willing to sell stuff to legitimate purchasers, so when Stratolaunch asked for a launch system, SpaceX apparently said "yes."  They're in business, after all.)

So Stratolaunch might be a good idea or a bad idea, but Burt is not sprinkling Rutan Pixie Dust over the project.  It will stand or fail on engineering and business choices, and those choices won't be made by Burt.  That's my opinion.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Hotdog on 12/24/2011 05:41 AM
From comments made by Burt Rutan in the press conference and in the past, he was not responsible for designing WK2/SS2. He did the concept design but left the detailed engineering to be performed by the Scaled Composites team. For Stratolaunch, he said he performed the concept design prior to his retirement (they are now at PDR level) and the Scaled team will do the detailed engineering. I am sure he will still have some sort of oversight role though as he remains chairman emeritus.

My point is that he has obviously created a very capable team at Scaled. The success of WK2/SS2 so far gives the indication that they may be capable of scaling up WK2 to the monster carrier aircraft required for Stratolaunch.

If it was anyone but Burt Rutan I'd think "Not a chance.". But I'll bet Rutan has done "black projects" that won't see the light for decades, and if anyone can do it....

Earlier, I said I wouldn't comment about Stratolaunch, but I have an view to share (that is carefully worded to avoid issues with proprietary or private confidences). 

First, people are ascribing way too much involvement by Burt (and maybe others like Griffin and Elon) to the Stratolaunch venture.  This is a Vulcan project that seems to have its center of gravity located in Huntsville. 

When I saw Burt a few days ago, he was very clear that he has no management role whatever, and only sits on the Board; otherwise he strongly reiterated "I'm retired."  He has said this publicly before, so this doesn't constitute betraying a confidence.  But people don't listen.

He didn't design the aircraft, he has no real part in the launch vehicle, and he has no role in day-to-day Stratolaunch management.  Plus Scaled is on their own with this aircraft; Burt is not working on it.

(Also, I don't interact with Griffin at all, but I get the impression from his equivocal statements at the press conference that he too is only a Board member and has no management role.  Elon has in the past disparaged air-launching, and I see no reason to think he has changed his view.  SpaceX is quite willing to sell stuff to legitimate purchasers, so when Stratolaunch asked for a launch system, SpaceX apparently said "yes."  They're in business, after all.)

So Stratolaunch might be a good idea or a bad idea, but Burt is not sprinkling Rutan Pixie Dust over the project.  It will stand or fail on engineering and business choices, and those choices won't be made by Burt.  That's my opinion.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: HMXHMX on 12/24/2011 06:07 AM
From comments made by Burt Rutan in the press conference and in the past, he was not responsible for designing WK2/SS2. He did the concept design but left the detailed engineering to be performed by the Scaled Composites team. For Stratolaunch, he said he performed the concept design prior to his retirement (they are now at PDR level) and the Scaled team will do the detailed engineering. I am sure he will still have some sort of oversight role though as he remains chairman emeritus.

My point is that he has obviously created a very capable team at Scaled. The success of WK2/SS2 so far gives the indication that they may be capable of scaling up WK2 to the monster carrier aircraft required for Stratolaunch.

If it was anyone but Burt Rutan I'd think "Not a chance.". But I'll bet Rutan has done "black projects" that won't see the light for decades, and if anyone can do it....

Earlier, I said I wouldn't comment about Stratolaunch, but I have an view to share (that is carefully worded to avoid issues with proprietary or private confidences). 

First, people are ascribing way too much involvement by Burt (and maybe others like Griffin and Elon) to the Stratolaunch venture.  This is a Vulcan project that seems to have its center of gravity located in Huntsville. 

When I saw Burt a few days ago, he was very clear that he has no management role whatever, and only sits on the Board; otherwise he strongly reiterated "I'm retired."  He has said this publicly before, so this doesn't constitute betraying a confidence.  But people don't listen.

He didn't design the aircraft, he has no real part in the launch vehicle, and he has no role in day-to-day Stratolaunch management.  Plus Scaled is on their own with this aircraft; Burt is not working on it.

(Also, I don't interact with Griffin at all, but I get the impression from his equivocal statements at the press conference that he too is only a Board member and has no management role.  Elon has in the past disparaged air-launching, and I see no reason to think he has changed his view.  SpaceX is quite willing to sell stuff to legitimate purchasers, so when Stratolaunch asked for a launch system, SpaceX apparently said "yes."  They're in business, after all.)

So Stratolaunch might be a good idea or a bad idea, but Burt is not sprinkling Rutan Pixie Dust over the project.  It will stand or fail on engineering and business choices, and those choices won't be made by Burt.  That's my opinion.

I have no doubt Scaled can build the aircraft; I know the folks working on it well and have worked with them on other efforts.  I'm just pointing out Scaled doesn't manage the LV effort, Stratolaunch does.  The aircraft is fairly straightforward compared to the LV and ASE.  Scaled will deliver the aircraft if they are paid to do so.  You can bank on that.

But Burt has no oversight role of which I am aware.  He no longer even has an email address at Scaled.  The man has earned his retirement and now I am pretty sure intends to enjoy it – we should all let him.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: NotGncDude on 12/25/2011 06:40 AM

I doubt anyone will consider using LH2 on an air-launched LV core stage anytime soon. The main issue with LH2 is it's a low density cryogenic fuel resulting in a bigger tank and vehicle as compared to a similar kerolox design.


Actually, it is the opposite.  LH2 is more suited for airlaunch and provides more benefits since it is less dense and therefore the vehicle weighs less.

Jim is right, for an air-launched vehicle there's got to be a pretty strong argument AGAINST LH2 not to use it.

True. Given that you're already going through the pain in the a** of airlaunching, may as well use LH2.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Patchouli on 12/25/2011 06:53 AM

True. Given that you're already going through the pain in the a** of airlaunching, may as well use LH2.

Development cost for one the Merlin engine already is existing and lox and kerosene are much easier to handle.

Plus they're going for best possible cost per pound vs maximum performance from the system.

For a two stage system hydrocarbon seems to be cheaper then hydrogen for a given payload.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/25/2011 08:14 PM
...
For a two stage system hydrocarbon seems to be cheaper then hydrogen for a given payload.
The situation is not the same for ground launch vs. air launch in that regard. With ground launch, if you get a better, upgraded thrust first stage engine, you can firm up the structure a bit, stretch the tank, and get significantly more performance out of it. For airlaunch, you're severely limited by max carry weight. A higher thrust engine helps you in no way. If you run into performance issues or find you need a little extra performance to serve a considerably more profitable part of the market, you can't just increase first stage thrust and stretch your tank, like Falcon 9 is doing (and did a similar thing with the transition from Falcon 5 to Falcon 9). Because your carrier aircraft is so expensive, there's a very strong motivation to maximize your return on that investment by getting the highest performance you can from your rocket for a given takeoff weight.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Zed_Noir on 12/25/2011 08:44 PM

I doubt anyone will consider using LH2 on an air-launched LV core stage anytime soon. The main issue with LH2 is it's a low density cryogenic fuel resulting in a bigger tank and vehicle as compared to a similar kerolox design.


Actually, it is the opposite.  LH2 is more suited for airlaunch and provides more benefits since it is less dense and therefore the vehicle weighs less.

Jim is right, for an air-launched vehicle there's got to be a pretty strong argument AGAINST LH2 not to use it.

True. Given that you're already going through the pain in the a** of airlaunching, may as well use LH2.

Actually I agree with Jim that LH2 is a better air-launched propellant. Just that the large development cost of a new cryogenic engine stage as compare to the relative simple conversion of a ground launched kerolox stage make it less likely to be realize.

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: neilh on 12/25/2011 11:14 PM

I doubt anyone will consider using LH2 on an air-launched LV core stage anytime soon. The main issue with LH2 is it's a low density cryogenic fuel resulting in a bigger tank and vehicle as compared to a similar kerolox design.


Actually, it is the opposite.  LH2 is more suited for airlaunch and provides more benefits since it is less dense and therefore the vehicle weighs less.

Jim is right, for an air-launched vehicle there's got to be a pretty strong argument AGAINST LH2 not to use it.

True. Given that you're already going through the pain in the a** of airlaunching, may as well use LH2.

Actually I agree with Jim that LH2 is a better air-launched propellant. Just that the large development cost of a new cryogenic engine stage as compare to the relative simple conversion of a ground launched kerolox stage make it less likely to be realize.



If/when Raptor is developed, I wonder if it would be at all practical to use Stratolaunch to launch a LH2 rocket using Raptor engines on both stages.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: NotGncDude on 12/25/2011 11:44 PM

True. Given that you're already going through the pain in the a** of airlaunching, may as well use LH2.

Development cost for one the Merlin engine already is existing and lox and kerosene are much easier to handle.

Plus they're going for best possible cost per pound vs maximum performance from the system.

For a two stage system hydrocarbon seems to be cheaper then hydrogen for a given payload.


Agreed. I'm sort of making fun of purely theoretical statements detached of practical reality. So, to continue in that vein:

Aw c'mon, RL-10's and SSME's are already developed. What are you talking about?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: baldusi on 12/26/2011 12:43 AM
...SSME's are already developed. What are you talking about?
SSME can't be air launched AND needs to be vertical to ignite. So it's no use. Keep in mind that the max launcher weight would be around 500klbs, thus, needing something between 600klbf to 750klbf in thrust. The SSME is too small (as a single engine) or too powerful (for clustering). The RS-68 is sort of a shoe in, though. And two J-2X would be about just right, too.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Patchouli on 12/26/2011 04:58 AM
The situation is not the same for ground launch vs. air launch in that regard. With ground launch, if you get a better, upgraded thrust first stage engine, you can firm up the structure a bit, stretch the tank, and get significantly more performance out of it. For airlaunch, you're severely limited by max carry weight. A higher thrust engine helps you in no way. If you run into performance issues or find you need a little extra performance to serve a considerably more profitable part of the market, you can't just increase first stage thrust and stretch your tank, like Falcon 9 is doing (and did a similar thing with the transition from Falcon 5 to Falcon 9). Because your carrier aircraft is so expensive, there's a very strong motivation to maximize your return on that investment by getting the highest performance you can from your rocket for a given takeoff weight.

The big issues here is cost there simply are not any low cost air startable hydrogen engines in the right thrust class.
The closest hydrogen engine for the target payload would be the J-2X but this would not be low cost.

If they need future improvements they could add a hydrogen upper stage later on.

But adopting Falcon gets them a low cost rocket quickly they also could have used a cut down Atlas CCB.
The RD-180 would be over kill in that case they could use the RD-191.

As for hydrocarbons being no use for airlaunch at subsonic speeds.
If this was 100% true the Russians would not have bothered with developing the RD-701.

http://www.buran.ru/htm/molniya6.htm

Actually if I were to start with a clean sheet air launch system vs adopting an existing booster I'd go with the RD-701 or just go with a simple pressure feed system like QuickReach.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: simonbp on 12/26/2011 01:41 PM
The closest hydrogen engine for the target payload would be the J-2X but this would not be low cost.

That's in the eye of the beholder. If you had a recoverable first stage, I bet you could make J-2X just as "reusable" as SSME (i.e. requiring a complete teardown after every flight), if not much more reusable.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Patchouli on 12/26/2011 06:51 PM
The closest hydrogen engine for the target payload would be the J-2X but this would not be low cost.

That's in the eye of the beholder. If you had a recoverable first stage, I bet you could make J-2X just as "reusable" as SSME (i.e. requiring a complete teardown after every flight), if not much more reusable.


I heard the J-2S could be made reusable not sure how different it is from the J-2X.
The weakest link to reusability on the J-2X probably is the nozzle extension.
Maybe if funds were unlimited ie a government project add TAN  nozzle with hydrocarbon for use early in flight.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Downix on 12/26/2011 06:53 PM
The closest hydrogen engine for the target payload would be the J-2X but this would not be low cost.

That's in the eye of the beholder. If you had a recoverable first stage, I bet you could make J-2X just as "reusable" as SSME (i.e. requiring a complete teardown after every flight), if not much more reusable.
SSME hasn't needed a complete teardown after each flight for years, part of the Block IIa upgrade.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Zed_Noir on 12/26/2011 07:35 PM
So anyone could estimate the unit procurement cost for about a dozen RS-68A, 2 dozen J2X and 5 dozen Merlin-1D for a dozen flights deployed from the Stratolaunch carrier.

Never mind the additional development cost of a new LV, especially the more costly hydrolox versions.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: baldusi on 12/26/2011 07:58 PM
So anyone could estimate the unit procurement cost for about a dozen RS-68A, 2 dozen J2X and 5 dozen Merlin-1D for a dozen flights deployed from the Stratolaunch carrier.

Never mind the additional development cost of a new LV, especially the more costly hydrolox versions.

The fundamental variable is how many per year?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: simonbp on 12/26/2011 08:53 PM
The fundamental variable is how many per year?

Well right, but that applies to everything. If the flight rate isn't above a certain number, the company will fold. If it's between that minimum number and a second larger number (say 3x the minimum), then it makes sense to stay with the winged Falcon. Above the 3x minimum flight rate (or so), then reusability can become profitable and a flyback LH2 first stage makes sense.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Zed_Noir on 12/27/2011 12:41 AM
So anyone could estimate the unit procurement cost for about a dozen RS-68A, 2 dozen J2X and 5 dozen Merlin-1D for a dozen flights deployed from the Stratolaunch carrier.

Never mind the additional development cost of a new LV, especially the more costly hydrolox versions.

The fundamental variable is how many per year?

For the purposes of this estimate, 6 flights per year for 2 years.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Downix on 12/27/2011 03:03 AM
So anyone could estimate the unit procurement cost for about a dozen RS-68A, 2 dozen J2X and 5 dozen Merlin-1D for a dozen flights deployed from the Stratolaunch carrier.

Never mind the additional development cost of a new LV, especially the more costly hydrolox versions.

Based on the numbers I have:

RS-68A : $25 mil per launch
J-2X: $40 mil per launch
Merlin 1D: $35 mil per launch
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Lurker Steve on 12/27/2011 02:29 PM
So anyone could estimate the unit procurement cost for about a dozen RS-68A, 2 dozen J2X and 5 dozen Merlin-1D for a dozen flights deployed from the Stratolaunch carrier.

Never mind the additional development cost of a new LV, especially the more costly hydrolox versions.

Based on the numbers I have:

RS-68A : $25 mil per launch
J-2X: $40 mil per launch
Merlin 1D: $35 mil per launch

So it's technically possible to build a Delta core cheaper than a F5/F9 core, or are there significant additional costs going from a 3.x m diameter core to 5.x m diameter core ? The LH2/LOX tanks are relatively inexpensive compared to the engines, right ?

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: deltaV on 12/27/2011 04:23 PM
So anyone could estimate the unit procurement cost for about a dozen RS-68A, 2 dozen J2X and 5 dozen Merlin-1D for a dozen flights deployed from the Stratolaunch carrier.

Never mind the additional development cost of a new LV, especially the more costly hydrolox versions.

Based on the numbers I have:

RS-68A : $25 mil per launch
J-2X: $40 mil per launch
Merlin 1D: $35 mil per launch

That Merlin 1D figure of $7 million per engine sounds at least a factor of two too high. If that's right the 28 engines on Falcon Heavy would cost $196 million, which is about twice the price of an entire launch!
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/27/2011 04:41 PM
So anyone could estimate the unit procurement cost for about a dozen RS-68A, 2 dozen J2X and 5 dozen Merlin-1D for a dozen flights deployed from the Stratolaunch carrier.

Never mind the additional development cost of a new LV, especially the more costly hydrolox versions.

Based on the numbers I have:

RS-68A : $25 mil per launch
J-2X: $40 mil per launch
Merlin 1D: $35 mil per launch

That Merlin 1D figure of $7 million per engine sounds at least a factor of two too high. If that's right the 28 engines on Falcon Heavy would cost $196 million, which is about twice the price of an entire launch!

Agreed. They can churn those things out like sausages. What's their marginal cost for producing extra, plus a healthy profit? I don't know, but based on the purported cost of a Falcon Heavy launch, I don't see how they could be more than, say, $2 or $3 million at most probably while making a profit.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Zed_Noir on 12/28/2011 02:30 AM
So anyone could estimate the unit procurement cost for about a dozen RS-68A, 2 dozen J2X and 5 dozen Merlin-1D for a dozen flights deployed from the Stratolaunch carrier.

Never mind the additional development cost of a new LV, especially the more costly hydrolox versions.

Based on the numbers I have:

RS-68A : $25 mil per launch
J-2X: $40 mil per launch
Merlin 1D: $35 mil per launch

IMO as @DeltaV and @Robotbeat stated above, $7M per Merlin-1D sounds high. Since that would meant roughly $70M just for the 9 Merlin-1D plus the Merlin-1D Vac engines on a Falcon 9 Block II.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Downix on 12/28/2011 02:57 AM
So anyone could estimate the unit procurement cost for about a dozen RS-68A, 2 dozen J2X and 5 dozen Merlin-1D for a dozen flights deployed from the Stratolaunch carrier.

Never mind the additional development cost of a new LV, especially the more costly hydrolox versions.

Based on the numbers I have:

RS-68A : $25 mil per launch
J-2X: $40 mil per launch
Merlin 1D: $35 mil per launch

IMO as @DeltaV and @Robotbeat stated above, $7M per Merlin-1D sounds high. Since that would meant roughly $70M just for the 9 Merlin-1D plus the Merlin-1D Vac engines on a Falcon 9 Block II.

I'm just using what numbers I have, which are extrapolated from current launch costs.  Remember, this is for a vac engine, so would be technically for the Merlin 1DV, which would be more expensive than the ground-lit units.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jimvela on 12/28/2011 04:05 AM
I'm just using what numbers I have, which are extrapolated from current launch costs.  Remember, this is for a vac engine, so would be technically for the Merlin 1DV, which would be more expensive than the ground-lit units.

Roughly 3x as much cost for air start and a nozzle optimized for ignition at FL430?  Not likely...

Not that I see SpaceX selling Stratolaunch individual engines.  That's not the SpaceX way- they'll likely sell an integrated launch vehicle.   I suspect that there is better margin in tankage (when part of an integrated vehicle) than in merlins, anyway- a fact certainly not lost on SpaceX.

Between making some margin on selling the launcher, and being paid to develop component technologies that benefit the overall SpaceX vision, that's the reason for SpaceX to be in this game.  IMHO.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Downix on 12/28/2011 04:40 AM
I'm just using what numbers I have, which are extrapolated from current launch costs.  Remember, this is for a vac engine, so would be technically for the Merlin 1DV, which would be more expensive than the ground-lit units.

Roughly 3x as much cost for air start and a nozzle optimized for ignition at FL430?  Not likely...

Not that I see SpaceX selling Stratolaunch individual engines.  That's not the SpaceX way- they'll likely sell an integrated launch vehicle.   I suspect that there is better margin in tankage (when part of an integrated vehicle) than in merlins, anyway- a fact certainly not lost on SpaceX.

Between making some margin on selling the launcher, and being paid to develop component technologies that benefit the overall SpaceX vision, that's the reason for SpaceX to be in this game.  IMHO.
Quite true, but remember, I'm also considering a start-date of 2017, so keep inflation in mind here.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Lars_J on 12/28/2011 04:47 PM
I'm just using what numbers I have, which are extrapolated from current launch costs.  Remember, this is for a vac engine, so would be technically for the Merlin 1DV, which would be more expensive than the ground-lit units.

Roughly 3x as much cost for air start and a nozzle optimized for ignition at FL430?  Not likely...

Not that I see SpaceX selling Stratolaunch individual engines.  That's not the SpaceX way- they'll likely sell an integrated launch vehicle.   I suspect that there is better margin in tankage (when part of an integrated vehicle) than in merlins, anyway- a fact certainly not lost on SpaceX.

Between making some margin on selling the launcher, and being paid to develop component technologies that benefit the overall SpaceX vision, that's the reason for SpaceX to be in this game.  IMHO.
Quite true, but remember, I'm also considering a start-date of 2017, so keep inflation in mind here.
That's very selective inflation at work, there. Otherwise one might assume that you intended to make a case for RS-68 or J-2X, and just made up numbers to make your point. Or?   ;)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: kfsorensen on 12/28/2011 06:41 PM
I just found Stratolaunch's corporate office, not too far from where I work.  Rang the bell but no one appeared to be there today and no cars in the parking lot.  Most people are on holiday this week anyway.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RanulfC on 12/29/2011 05:29 PM
If it was anyone but Burt Rutan I'd think "Not a chance.". But I'll bet Rutan has done "black projects" that won't see the light for decades, and if anyone can do it....

Earlier, I said I wouldn't comment about Stratolaunch, but I have an view to share (that is carefully worded to avoid issues with proprietary or private confidences). 

First, people are ascribing way too much involvement by Burt (and maybe others like Griffin and Elon) to the Stratolaunch venture.  This is a Vulcan project that seems to have its center of gravity located in Huntsville. 

When I saw Burt a few days ago, he was very clear that he has no management role whatever, and only sits on the Board; otherwise he strongly reiterated "I'm retired."  He has said this publicly before, so this doesn't constitute betraying a confidence.  But people don't listen.

He didn't design the aircraft, he has no real part in the launch vehicle, and he has no role in day-to-day Stratolaunch management.  Plus Scaled is on their own with this aircraft; Burt is not working on it.

(Also, I don't interact with Griffin at all, but I get the impression from his equivocal statements at the press conference that he too is only a Board member and has no management role.  Elon has in the past disparaged air-launching, and I see no reason to think he has changed his view.  SpaceX is quite willing to sell stuff to legitimate purchasers, so when Stratolaunch asked for a launch system, SpaceX apparently said "yes."  They're in business, after all.)

So Stratolaunch might be a good idea or a bad idea, but Burt is not sprinkling Rutan Pixie Dust over the project.  It will stand or fail on engineering and business choices, and those choices won't be made by Burt.  That's my opinion.
Opinion noted and thanks for the info sir! ;)

Note that I'm not casting doubts about Scaled's abilities, but strangely enough I happened across these two studies on an Air-Launched LV that just "happen" to have a really, really similar Carrier Aircraft in the Eclipse:
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19940020540_1994020540.pdf

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19940020387_1994020387.pdf

Enjoy all! :)

Randy
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Comga on 12/29/2011 05:46 PM
First, people are ascribing way too much involvement by Burt (and maybe others like Griffin and Elon) to the Stratolaunch venture.  This is a Vulcan project that seems to have its center of gravity located in Huntsville. 

An excellent and informative post.  Thank you.

Question from someone with apparently limited familiarity with the subject: Why do you cal it "a Vulcan project"?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 12/29/2011 05:53 PM
First, people are ascribing way too much involvement by Burt (and maybe others like Griffin and Elon) to the Stratolaunch venture.  This is a Vulcan project that seems to have its center of gravity located in Huntsville. 

An excellent and informative post.  Thank you.

Question from someone with apparently limited familiarity with the subject: Why do you cal it "a Vulcan project"?


"Vulcan Capital is the private investment group that oversees Paul G. Allen's multi-billion dollar portfolio across diverse industry sectors and asset classes. Investments range from early-stage ventures to public equity value investing, leveraged buyouts, acquisitions, and distressed situations."
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/29/2011 06:11 PM
strangely enough I happened across these two studies on an Air-Launched LV that just "happen" to have a really, really similar Carrier Aircraft in the Eclipse:
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19940020540_1994020540.pdf
Indeed.  Page 12 of chapter 1 has an uncanny diagram that perhaps most people would mistake for Allen's Stratolaunch at a glance. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RanulfC on 12/29/2011 06:24 PM
strangely enough I happened across these two studies on an Air-Launched LV that just "happen" to have a really, really similar Carrier Aircraft in the Eclipse:
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19940020540_1994020540.pdf
Indeed.  Page 12 of chapter 1 has an uncanny diagram that perhaps most people would mistake for Allen's Stratolaunch at a glance. 
"I" am NOT accusing anyone of anything.... Except maybe "Scaled" of hireing some of the grads? ;)

Randy
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RanulfC on 12/29/2011 06:32 PM
Alternate/Informaton question on engine cost;
I seem to recall the RL-10 was somewhere between $10 and $20 million PER engine, anyone recall if this is accurate or not?

Randy
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/29/2011 11:58 PM
Looks like Colorado might be next for Stratolaunch. 

Also, presumably fast intercontinental transportation is the big market here.  That's the logical assumption anyways.   

The article in this link is well worth reading with lots of interesting nuggets!  Among other things, talks about skiing in Colorado in the morning and surfing in Australia after lunch.  Includes some history in the growth of thoughts surrounding what I think is referring to Stratolaunch.  This article is Dec 8th (before Stratolaunch announcement).   



http://www.parabolicarc.com/2011/12/08/look-out-spaceport-america-heres-comes-colorado/

"The impetus for applying for spaceport certification now is the result of serious interest on the part of out-of-state companies preparing for future space tourism, said Tom Clark, CEO of the Metro Denver Economic Development Corp.

The companies, which Clark would not identify, are working on a spacecraft that takes off horizontally from a runway like a plane but then, tens of thousands of feet into the air, lights a booster rocket capable to taking passengers past the upper reaches of the atmosphere, Clark said."

"That would open up the possibility not just of space travel to ordinary — but wealthy — people, but also of ultrafast travel to points on Earth, he said."

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: docmordrid on 12/30/2011 12:23 AM
Could also be a Skylon derivative with a passenger cabin.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: HMXHMX on 12/30/2011 12:59 AM
Alternate/Informaton question on engine cost;
I seem to recall the RL-10 was somewhere between $10 and $20 million PER engine, anyone recall if this is accurate or not?

Randy

$10-12M was the last I heard, for 2015 deliveries.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/30/2011 01:01 AM
Could also be a Skylon derivative with a passenger cabin.

He talks about the companies (plural) working on this.  I think skylon is just worked on by 1 company.           ...unless he means Reaction Engines Limited as one of the companies.
"The companies... are working on a spacecraft that takes off horizontally from a runway like a plane but then, tens of thousands of feet into the air, lights a booster rocket capable to taking passengers past the upper reaches of the atmosphere,"

The discussion of the runway length and extension are more pertinent to stratolaunch as I understand it. 

The timing and location also make me suspicious that this is stratolaunch. 
Timing: 5 days before stratolaunch announcement.  Skylon's been on the drawing board for 30 years. 
Location: Kimbal Musk lives in Boulder and Elon has connections there.   Also, IIRC, the proteus was built in Colorado and Scaled Technology Works is in Colorado also (correct me if I'm wrong). 

Anyway, skylon is only 24 passengers vs. potentially a few hundred that might be possible with stratolaunch/F5.  24 people at a time would be very challenged economics vs. hundreds of people per flight which might have a market size  big enough to be revolutionary to the average upper-middle class Joe or Jane. 

Not that I dislike skylon or anything.  I wish the skylon people success as well!  Just seems less likely to me for those reasons.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Patchouli on 12/30/2011 01:18 AM
Alternate/Informaton question on engine cost;
I seem to recall the RL-10 was somewhere between $10 and $20 million PER engine, anyone recall if this is accurate or not?

Randy

$10-12M was the last I heard, for 2015 deliveries.

A single J-2X might be cheaper then.

I wonder if the Ares I US could have flown as a SSTO in the Delta II payload class if air launched?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/30/2011 01:26 AM
It's even possible that stratolaunch test program would take off from near Denver, fire off the rocket over the ocean off California, then land in New Mexico or elsewhere until they've built up enough flight history to be allowed to overfly populated areas on a tower of flame.  I assume that if they are deemed safe enough to fly passengers commercially and in quantity, that they would be deemed safe enough to overfly populated areas.  Is that a bad assumption?   

Might they be able to fire the rocket somewhere above the desert in the US SW and try to thread a careful path over nearly unpopulated areas between towns until they make it above water during their test program?   

How much time elapses between stratolaunch takeoff and 40000 feet or so?  Any guesses?  Just curious how big of a portion of the inter-continental travel time climb time might be. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Zed_Noir on 12/30/2011 02:13 AM
It's even possible that stratolaunch test program would take off from near Denver, fire off the rocket over the ocean off California, then land in New Mexico or elsewhere until they've built up enough flight history to be allowed to overfly populated areas on a tower of flame.  I assume that if they are deemed safe enough to fly passengers commercially and in quantity, that they would be deemed safe enough to overfly populated areas.  Is that a bad assumption?   

Might they be able to fire the rocket somewhere above the desert in the US SW and try to thread a careful path over nearly unpopulated areas between towns until they make it above water during their test program?   

How much time elapses between stratolaunch takeoff and 40000 feet or so?  Any guesses?  Just curious how big of a portion of the inter-continental travel time climb time might be. 

IIRC Stratolaunch operates at 30000 feet for launching the F4/F5. My WAG is about 2 hours to operational altitude.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/30/2011 04:19 AM
My WAG is about 2 hours to operational altitude.
That seems pretty slow to me, but if true could account for more than half of the total time in the air(2 hours clipped on, 2 hours hypersonic rocket phase).  It would however align well with covering ground to get to the ocean to release.  From Denver, that's only 23000 feet up, but about 1000 miles to the Pacific.  At 500 miles per hour...    2 hours might be required anyways.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/30/2011 12:43 PM
It's even possible that stratolaunch test program would take off from near Denver, fire off the rocket over the ocean off California, then land in New Mexico or elsewhere until they've built up enough flight history to be allowed to overfly populated areas on a tower of flame.  I assume that if they are deemed safe enough to fly passengers commercially and in quantity, that they would be deemed safe enough to overfly populated areas.  Is that a bad assumption?   

Might they be able to fire the rocket somewhere above the desert in the US SW and try to thread a careful path over nearly unpopulated areas between towns until they make it above water during their test program?   

How much time elapses between stratolaunch takeoff and 40000 feet or so?  Any guesses?  Just curious how big of a portion of the inter-continental travel time climb time might be. 

Nope, not possible and bad assumptions.

Also, Denver is a bad choice for its attitude and weather
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/30/2011 12:47 PM
Could also be a Skylon derivative with a passenger cabin.

He talks about the companies (plural) working on this.  I think skylon is just worked on by 1 company.           ...unless he means Reaction Engines Limited as one of the companies.
"The companies... are working on a spacecraft that takes off horizontally from a runway like a plane but then, tens of thousands of feet into the air, lights a booster rocket capable to taking passengers past the upper reaches of the atmosphere,"

The discussion of the runway length and extension are more pertinent to stratolaunch as I understand it. 

The timing and location also make me suspicious that this is stratolaunch. 
Timing: 5 days before stratolaunch announcement.  Skylon's been on the drawing board for 30 years. 
Location: Kimbal Musk lives in Boulder and Elon has connections there.   Also, IIRC, the proteus was built in Colorado and Scaled Technology Works is in Colorado also (correct me if I'm wrong). 

Anyway, skylon is only 24 passengers vs. potentially a few hundred that might be possible with stratolaunch/F5.  24 people at a time would be very challenged economics vs. hundreds of people per flight which might have a market size  big enough to be revolutionary to the average upper-middle class Joe or Jane. 

Not that I dislike skylon or anything.  I wish the skylon people success as well!  Just seems less likely to me for those reasons.

Huh?  What hundreds of people per flight? 

Huh?  Skylon is likely?  Just shows you bias and love for everything Spacex
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: JohnFornaro on 12/30/2011 01:33 PM
Among other things, talks about skiing in Colorado in the morning and surfing in Australia after lunch.

Which is fine for the 0.1%, but has no practical applications for anyone else.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/30/2011 02:45 PM
Huh?  Skylon is likely?
As noted, to my knowledge, skylon isn't being worked on by multiple companies (unlike stratolaunch).  Nothing to do with bias.  I like skylon.  I just don't think this press release is as likely to be referring to skylon. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/30/2011 02:46 PM
Which is fine for the 0.1%, but has no practical applications for anyone else.
Just like airplanes and cars when they were new. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Danderman on 12/30/2011 02:59 PM
Which is fine for the 0.1%, but has no practical applications for anyone else.
Just like airplanes and cars when they were new. 

Or travel on the first jets, which gave rise to the term "jet setters".
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Lee Jay on 12/30/2011 03:04 PM
Also, Denver is a bad choice for its attitude and weather

Altitude, yes, but that's why the international runway at DIA is so long (a thousand feel longer than the SLF which is already enormous).

What's wrong with the weather?  While we have occasional problems with weather extremes, for the most part weather causes very few problems with air travel compared to other cities like Chicago and San Francisco.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/30/2011 03:16 PM
Attitude.  Not altitude.  The wealthy, high-tech large population base in and around Denver might be more important than physical geography if there is a work-around in mind.  Also, the Denver airport is a major major hub.  Accessing more passengers would be easier from that airport compared to Mojave or New Mexico since that infrastructure and travel paths are already set up there.

And yes, hundreds of people.  If you assume no passenger stage burn, and no payload above the second second (passenger) stage, the the fuel requirements for propulsive landing would be less than 1/15th of the 1st stage fuel requirements.  That leaves a lot of mass available for people, padded walls and floors for when the engines are on.  Much of the rest of the time people will just float around the cabin I would guess.  No chairs = less weight.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/30/2011 03:21 PM
Attitude.  Not altitude.  The wealthy, high-tech large population base in and around Denver might be more important than physical geography.

And yes, hundreds of people.  If you assume no passenger stage burn, and no payload above the second second (passenger) stage, the the fuel requirements for propulsive landing would be less than 1/15th of the 1st stage fuel requirements.  That leaves a lot of mass available for people, padded walls and floors for when the engines are on.  Much of the rest of the time people will just float around the cabin I would guess.  No chairs = less weight.

More unfounded conjecture.  Reality is the opposite of your posts.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/30/2011 03:24 PM
Attitude.  Not altitude.  The wealthy, high-tech large population base in and around Denver might be more important than physical geography.


It isn't unique wrt wealthy or high tech or even above median
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Lee Jay on 12/30/2011 03:26 PM
Attitude.  Not altitude.

That makes no sense.  Maybe Jim meant "Latitude" which is about 40 degrees.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/30/2011 03:27 PM
Also, Denver is a bad choice for its attitude and weather

Altitude, yes, but that's why the international runway at DIA is so long (a thousand feel longer than the SLF which is already enormous).

What's wrong with the weather?  While we have occasional problems with weather extremes, for the most part weather causes very few problems with air travel compared to other cities like Chicago and San Francisco.

And what US  launch vehicles have ground ops that operate in below freezing temp?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/30/2011 03:53 PM
And what US  launch vehicles have ground ops that operate in below freezing temp?
Why does it matter whether they are American launch vehicles?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/30/2011 03:58 PM
Attitude.  Not altitude.

That makes no sense.  Maybe Jim meant "Latitude" which is about 40 degrees.

That makes no sense in the context of sub-orbital transportation.  Lattitude only matters for orbital.  I think he meant that it's central location in the US is a negative because current rocket statistics don't allow you to overfly vast numbers of people.   The flip side is that Denver might be great initially in that it's a central hub that might be used for intercontinental transport by surrounding states as it's airport is already a very major hub with room to handle this growth (assuming the statistics about rocket failure change, allowing it's use).  Also, if it takes 2 hours to get up to operational altitude (rocket release altitude), you might be near the ocean already from Denver by then (mooting the overflight concern).     
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Lee Jay on 12/30/2011 04:10 PM
Also, Denver is a bad choice for its attitude and weather

Altitude, yes, but that's why the international runway at DIA is so long (a thousand feel longer than the SLF which is already enormous).

What's wrong with the weather?  While we have occasional problems with weather extremes, for the most part weather causes very few problems with air travel compared to other cities like Chicago and San Francisco.

And what US  launch vehicles have ground ops that operate in below freezing temp?

For how long does it have to be above freezing?  It's above freezing here far more than it's below.  It's 51F right now, and from the point of view of ice formation, the fact that the dew/frost points here are usually very low might be pretty beneficial.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/30/2011 04:10 PM
It (Denver area) isn't unique wrt wealthy or high tech or even above median
Having travelled hither and yon some in my time.  I disagree.  40% of people in Denver have a bachelor degree.  Ever spend time in Boulder? 

There has been a lot of money spent on high tech in the area (private sector and military).  Engineers and scientists usually teach their kids to be engineers and scientists.  High-tech has been a compounding there for decades.   

The reason Obama was ordered to his Denver bunker in Sept is because the rocks there are amenable to very deep tunnelling (from a geothermal gradient perspective and rock mechanics perspective).  Without spelling it out, I think that is one of the reasons so many engineers and scientist live in Denver.  It's distance from coastal attack was another historical reason so much $ goes there to be spent on high-tech. 

Here's a quote from the article on the subject:

"If and when that era begins, the Colorado spaceport would probably have an edge over Spaceport America in that it is close to more places that people would want to visit. The state also has a large population and is a major aerospace center."

From the Front range airport website:  "The state has the third largest space related economy, and ranks first in concentration of aerospace employees (Development Research Partners, 2010). Eight of the nation’s largest space-related contractors maintain a significant footprint in Colorado. In total, there are over 400 companies providing products and services. These companies employ over 163,000 personnel with a $2.8 billion annual payroll (Colorado Space Coalition, 2011). Colorado also ranks second in the nation for awarded Small Business Innovation Research Grants. The state has the second most educated workforce in the nation, and multiple universities offer graduate programs in space sciences. Finally, Colorado has an unequaled military presence with four commands in the state. These are Air Force Space Command, Army Space and Missile Defense Command/Army Forces Strategic Command, North American Aerospace Defense Command, and U.S. Northern Command. There are also three military bases exclusively conducting space activities; Buckley Air Force Base, Peterson Air Force Base, and Schriever Air Force Base."

"With the headquarters of the United States Air Force Space Command and the North American Aerospace Defense Command (NORAD) already here and operational in Colorado, there are already established and functioning assets
that could be utilized to provide command and control, as well as space tracking and warning capabilities"
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 12/30/2011 04:22 PM
I would have thought that a coastal location made more sense from a public safety perspective. I really have some pause about a fully fueled rocket attached to a massive one-off aircraft over flying populated areas. This is my opinion from a pilot’s perspective. I’m sure the FAA will have something to say about it…
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/30/2011 04:27 PM
I’m sure the FAA will have something to say about it…
That's certain. 

"Colorado has applied to the FAA of spaceport certification of Front Range Airport, which is about 22 miles from Denver and six miles from Denver International Airport."
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/30/2011 04:33 PM
Looks like Lockheed has a hand in this too:

"Key to an Aerospace Center is the designation of SpacePort and FTG is exploring the feasibility of such designation. An undertaking of this size requires a unified position and contributions from the full spectrum of aerospace participants.

One such participant and FTG friend is Allan Lockheed, whose father founded Lockheed Aircraft."

Also:  "Webster University and the EDC continue to promote the concept and garner industry support, potentially leveraging Lockheed Martin’s James H. Crocker’s support."

You will all have fun in this link too I imagine:
http://www.ftg-airport.com/spaceport.php
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/30/2011 04:38 PM
Another reason to think that there might not be much of a second stage burn on the passenger stage until landing is that the front range airport says "more than quadrupling the speed of sound".  True that this doesn't exclude mach 10, but it implies lower speeds. 

Does limiting to mach 4 or 5 imply a non-ballistic trajectory for intercontinental travel?   I think it does.  What might this second stage look like assuming that constraint? 

For one, I think it means that the 1st stage is proportionally smaller than an orbital version.  (If in fact there is a 1st stage)

Anyone with knowledge or experience on things like SR-71, X-15 or other high altitude aircraft/rocket planes care to speculate aloud?     

Does 'mach 4+' and note of 'sonic booms' flip a skylon derivative back into the "more likely" category? 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: HMXHMX on 12/30/2011 08:44 PM
Let's get real: Stratolaunch very likely won't get FAA/AST permission to overfly CONUS from inland spaceports.  They certainly won't get permission to launch over land.  And they won't be flying people on point to point excursions.

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/30/2011 10:41 PM
Let's get real: Stratolaunch very likely won't get FAA/AST permission to overfly CONUS from inland spaceports.  They certainly won't get permission to launch over land.  And they won't be flying people on point to point excursions.

http://www.parabolicarc.com/2011/12/08/look-out-spaceport-america-heres-comes-colorado/

If you have alternative theories as to what this is all about, please state them. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: mrmandias on 12/30/2011 10:42 PM
Attitude.  Not altitude.

That makes no sense.  Maybe Jim meant "Latitude" which is about 40 degrees.

That makes no sense in the context of sub-orbital transportation.  Lattitude only matters for orbital.  I think he meant that it's central location in the US is a negative because current rocket statistics don't allow you to overfly vast numbers of people.   The flip side is that Denver might be great initially in that it's a central hub that might be used for intercontinental transport by surrounding states as it's airport is already a very major hub with room to handle this growth (assuming the statistics about rocket failure change, allowing it's use).  Also, if it takes 2 hours to get up to operational altitude (rocket release altitude), you might be near the ocean already from Denver by then (mooting the overflight concern).     

Don't overthink this.  The number one reason a company would consdier Denver, by far, would be tax credits and subsidies.  That might not be it, but that would be the way to bet.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: HMXHMX on 12/30/2011 11:00 PM
Let's get real: Stratolaunch very likely won't get FAA/AST permission to overfly CONUS from inland spaceports.  They certainly won't get permission to launch over land.  And they won't be flying people on point to point excursions.

http://www.parabolicarc.com/2011/12/08/look-out-spaceport-america-heres-comes-colorado/

If you have alternative theories as to what this is all about, please state them. 

It is the usual arguments made by various promoters to find state or federal funding for spaceports.  There have been many such "proposals" made over the past ten or twelve years, including the Oklahoma spaceport.  How did that work out?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: JohnFornaro on 12/30/2011 11:05 PM
Which is fine for the 0.1%, but has no practical applications for anyone else.
Just like airplanes and cars when they were new. 
Or travel on the first jets, which gave rise to the term "jet setters".

Nice try guys.  But what you're also saying is that if you're told that now, you need to ski in the AM and surf in the PM across the world in order to be cool and pertinant and everything else that matters, then you gotta have Stratolaunch.  It just ain't the truth.

I'm thinking that the concept will never fly.  We tried supersonics with Concorde.  It didn't work.  I do not know what purpose the announcement of this scheme serves, however.

And what US  launch vehicles have ground ops that operate in below freezing temp?
Why does it matter whether they are American launch vehicles?

Think about weather or not weather makes a difference in travel schedules in the US, rather than about the country of manufacture of the plane.

The reason Obama was ordered to his Denver bunker in Sept is because the rocks there are amenable to very deep tunnelling ...  Its distance from coastal attack was another historical reason so much $ goes there to be spent on high-tech.

That's fine, but if you're going to go all survivalist here, you need to think of a bigger picture, that of the rest of the US after the coastal areas are hit.  "Picnic" is not the word one would use.  I grew up in DC during the peak of the Cold War, and we used to plan on how to get out of town should WWIII start.  I was talking to a new friend of mine, and she related how at about the same time, her husband and her planned to go to the Washington Monument at the start of WWIII, so as to avoid dealing with the aftermath.  Point is, there's plenty of viewpoints on that matter, none of which pertain to Stratolaunch or Denver.

And this is borderline nonsense:

Quote
If and when that era begins, the Colorado spaceport would probably have an edge over Spaceport America in that it is close to more places that people would want to visit. The state also has a large population and is a major aerospace center.

People might want to visit the Moon.  Denver's got nuthin on pretty much any other launch location.  It's not really closer to Mars, either.

And that Parabolic article is an example of what's known as poopo del toro del mercado.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 12/30/2011 11:56 PM
Nice try guys.  But what you're also saying is that if you're told that now, you need to ski in the AM and surf in the PM across the world in order to be cool and pertinant and everything else that matters, then you gotta have Stratolaunch.  It just ain't the truth.

I'm thinking that the concept will never fly.  We tried supersonics with Concorde.  It didn't work.  I do not know what purpose the announcement of this scheme serves, however.
Besides the obvious difference in speed between concorde and stratolaunch, a significant advantage in going above the atmosphere is a lack of trailing sonic boom across the landscape. 

Besides, supposedly, the Lockheed Martin "Quiet Supersonic Transport" would have a sonic boom 1% as strong as concorde.  Concorde's relevence to this conversation is tenuous imo. 

I don't think we've see the end of supersonic civilian transportation, and it appears that we might get to see the dawn of hypersonic civilian transportation (whether via stratolaunch, A2, or something else). 

Of course it might be all a waste of money and bizzaire goal-less posturing, but I think it's fair to say there is a non-zero chance of a shift in aerospace methods waiting in the wings.   

 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/31/2011 05:11 AM
It (Denver area) isn't unique wrt wealthy or high tech or even above median
Having travelled hither and yon some in my time.  I disagree.  40% of people in Denver have a bachelor degree.  Ever spend time in Boulder? 

There has been a lot of money spent on high tech in the area (private sector and military).  Engineers and scientists usually teach their kids to be engineers and scientists.  High-tech has been a compounding there for decades.   

The reason Obama was ordered to his Denver bunker in Sept is because the rocks there are amenable to very deep tunnelling (from a geothermal gradient perspective and rock mechanics perspective).  Without spelling it out, I think that is one of the reasons so many engineers and scientist live in Denver.  It's distance from coastal attack was another historical reason so much $ goes there to be spent on high-tech. 

Here's a quote from the article on the subject:

"If and when that era begins, the Colorado spaceport would probably have an edge over Spaceport America in that it is close to more places that people would want to visit. The state also has a large population and is a major aerospace center."

From the Front range airport website:  "The state has the third largest space related economy, and ranks first in concentration of aerospace employees (Development Research Partners, 2010). Eight of the nation’s largest space-related contractors maintain a significant footprint in Colorado. In total, there are over 400 companies providing products and services. These companies employ over 163,000 personnel with a $2.8 billion annual payroll (Colorado Space Coalition, 2011). Colorado also ranks second in the nation for awarded Small Business Innovation Research Grants. The state has the second most educated workforce in the nation, and multiple universities offer graduate programs in space sciences. Finally, Colorado has an unequaled military presence with four commands in the state. These are Air Force Space Command, Army Space and Missile Defense Command/Army Forces Strategic Command, North American Aerospace Defense Command, and U.S. Northern Command. There are also three military bases exclusively conducting space activities; Buckley Air Force Base, Peterson Air Force Base, and Schriever Air Force Base."

"With the headquarters of the United States Air Force Space Command and the North American Aerospace Defense Command (NORAD) already here and operational in Colorado, there are already established and functioning assets
that could be utilized to provide command and control, as well as space tracking and warning capabilities"

All the USAF info is meaningless, NASA HQ is in DC, are they launching rockets there?  Those USAF bases are control centers, they don't procure or launch space systems.

Most of the save employment is related to ULA and LM.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 12/31/2011 05:15 AM
And what US  launch vehicles have ground ops that operate in below freezing temp?
Why does it matter whether they are American launch vehicles?

Because it is a US spaceport.  It is no reason for foreign vehicles
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: JohnFornaro on 12/31/2011 01:38 PM
Quote from: JF
Nice try guys.  But what you're also saying is that if you're told that now, you need to ski in the AM and surf in the PM across the world in order to be cool and pertinant and everything else that matters, then you gotta have Stratolaunch.  It just ain't the truth.

Besides the obvious difference in speed between concorde and stratolaunch, a significant advantage in going above the atmosphere is a lack of trailing sonic boom across the landscape.

And as long as we're handwaving away the "dangers" of a sonic boom, we can handwave away the slight inconveniences of a  statistically small, gamed chance of rocket failure over populated areas, such as SF, roughly on the great circle from Denver to Margaret River.  And I see that branding is important too:  Concorde is so two thousand and three, while Stratolaunch is so two thousand and Glee.  If you want to be in order to be cool and pertinant and everything else that matters, then you gotta have the right brand; never mind what it is that you're doing, or where you're supposed to be while doing it.

I see that you acknowledge: "Of course it might be all a waste of money and bizzaire goal-less posturing, but I think it's fair to say there is a non-zero chance of a shift in aerospace methods waiting in the wings."  Which also pertains to my non-zero chance of hitting the lottery.  Not to mention that "Bizzaire" might be a good name for their new airline.

Having said all that, I still think I'm fairly near the spot.  Mr. Rutan demonstrated that air launch has some utility.  Stratolaunch would be a logical scaling up of the capability, and evidence of some kind of emerging business plan.  To me, those billionaires have talked themselves into believing in its utility at least to the point of making a web site.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 01/01/2012 02:22 AM
A successor to the current stratospheric observatory (SOFIA) would be an interesting application for stratolaunch (when it isn't busy)!

http://en.wikipedia.org/wiki/Stratospheric_Observatory_for_Infrared_Astronomy
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: JohnFornaro on 01/01/2012 02:02 PM
And speaking of Denver:  The December 27th issue of NYT had a feature "Frequent Flyer".  They interviewed a guy, Dave Alberga, chief of Active Network.

Quote
Q.  What's your least favorite airport?"

A. Denver.  Everything is too spread out.

I know.  Everybody's a critic.  But the Stratolaunch announcement is marketing hype, and speculation on Denver is subject to a lot of spin either way.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: hop on 01/01/2012 05:08 PM
A successor to the current stratospheric observatory (SOFIA) would be an interesting application for stratolaunch (when it isn't busy)!

http://en.wikipedia.org/wiki/Stratospheric_Observatory_for_Infrared_Astronomy
Why do you think there will be a successor to SOFIA ?
Who is going to fund it ?
How is the Stratolaunch carrier going to be better ?

SOFIA ended up costing as much as a pretty decent space telescope (and is close to the expected costs of 30 meter class ground based scopes), I don't think anyone is going to be in a hurry to repeat that particular debacle. It's a cool telescope with some unique capabilities, and will undoubtedly produce some interesting results, but I don't see a SOFIA 2 any time soon.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 01/02/2012 01:12 AM
Why do you think there will be a successor to SOFIA?
There may not be but if there is, it could be a lot larger, and less constrained in its design if clipped onto stratolaunch instead of jammed in a 747. 

Who is going to fund it ?
No Idea.  DLR/NASA again?

How is the Stratolaunch carrier going to be better? 
2 main reasons stratolaunch would be a better carrier:
SOFIA = 2.5 meter reflecting telescope (sized based on 747 constraints).   Statolaunch could have a much larger "light-bucket" (likely 4-30 times the light gathering power depending whether its done simply or fancy) and the aircraft could 'moonlight' as a rocket launcher and other things during daylight hours.   

SOFIA ended up costing as much as a pretty decent space telescope (and is close to the expected costs of 30 meter class ground based scopes)
Truly, I would much rather see funding go toward http://www.langorigami.com/science/technology/eyeglass/eyeglass.php
or a 100+m "Overwhelmingly Large Telescope". 
But usually prototypes and predecessors cost more per unit utility.  If the makers of SOFIA think they can bring the cost down significantly then it may be worth doing.   

It's a cool telescope with some unique capabilities
Agreed.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 01/02/2012 02:03 AM
Wrong, there is nothing than says Stratolauncher is going to have a larger diameter fuselage than a 747
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jason1701 on 01/02/2012 02:50 AM
Stratolauncher actually looks to be much narrower than a 747.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 01/02/2012 03:30 AM
Wrong, there is nothing than says Stratolauncher is going to have a larger diameter fuselage than a 747
I don't believe that it will. 
Stratolauncher actually looks to be much narrower than a 747.
The twin fuselages?  Agreed. 

The 747 couldn't open a large, unobstructed door straight up (without prohibitive modification).  So it was stuck with a 2.5 meter mirror even though a 747 fuselage is much bigger than that. 

In the simple case, I am assuming that stratolauncher can do a 5 meter mirror (4 times the light gathering compared to SOFIA) that faces straight up (or can be angled as needed), near the back of a telescope that is clipped on to the F5 attachment points.  One of the renderings (main page of their website) shows the F5 with what I assume is a 5 meter PLF.  I think it's reasonable to assume that is possible as a baseline (which would be the lowest cost option). 

In the fancy case, there are extra possibilities:  One is a very wide clip-on telescope that fills a lot of the space between the fuselages, with the mirror oriented to it's zenith but with less ability to tilt.  The whole thing would be shaped kind of like a boogie-board hanging down instead of a cylinder (so that it isn't too tall).  This could allow for a very large mirror and associated optics, but would require the "boogie board" to be almost as long as stratolaunch.  A counterweight out the front side would be required and it might as well be an additional mirror oriented in reverse to the rear one. 

Depending on how you wanted to do the telescope geometry, you could even have aerodynamic dobsonian extenders going up from it. 

A rocket can't have a kink in it, but a telescope can.  Even if the maximum diameter rocket possible on stratolaunch is 5 meters or less for take-off and landing clearance, a telescope can bend upward from the attachment points.  So a still fairly simple single mirror, perhaps 8 meters diameter should be possible.  Three of these, placed side by side hanging from the usual attachment points would be an impressive improvement over SOFIA. 

If you wanted to get really fancy with it, you could have mirrors and parts that unpack ala James Webb but in a complex aerodynamic configuration...

There are lots of possibilities when you have an attachment point that can hold half a million pounds and have about 75 feet between the fuselages.   

Stratolaunch could stargaze all night, pull in to the hanger, unclip its telescope, then clip on a rocket for its morning excursion.   
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 01/02/2012 04:13 AM
No, on the last line
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Patchouli on 01/02/2012 04:26 AM

A rocket can't have a kink in it, but a telescope can.  Even if the maximum diameter rocket possible on stratolaunch is 5 meters or less for take-off and landing clearance, a telescope can bend upward from the attachment points.  So a still fairly simple single mirror, perhaps 8 meters diameter should be possible.  Three of these, placed side by side hanging from the usual attachment points would be an impressive improvement over SOFIA.     

You might have just pointed out one of the reasons why they went with a kerolox rocket vs hydrogen as a hydrogen core that fully utilizes the payload of the aircraft may be too wide.


Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: HMXHMX on 01/02/2012 05:16 AM

A rocket can't have a kink in it, but a telescope can.  Even if the maximum diameter rocket possible on stratolaunch is 5 meters or less for take-off and landing clearance, a telescope can bend upward from the attachment points.  So a still fairly simple single mirror, perhaps 8 meters diameter should be possible.  Three of these, placed side by side hanging from the usual attachment points would be an impressive improvement over SOFIA.     


You might have just pointed out one of the reasons why they went with a kerolox rocket vs hydrogen as a hydrogen core that fully utilizes the payload of the aircraft may be too wide.




LOX-hydrogen at the full payload capability of the aircraft will fit fine; there is an S-IVB worth of diameter available so the overall length for the stage is only about 60-80 feet.  It was one of the early options for which I did a design for a previous version of the a/c about five years ago.  I wanted to go with a one-stage expendable SSTO approach but that turned out to be a bit radical for my colleagues so we punted to 2 stage LOX-hydrocarbon.  By the time you finish a real design, they both end up about the same length, since the interstage and second stage engine takes up a lot of length.

I'm certain the reason they ended up with the configuration they did was simply availability of an in-production propulsion option and the perception that it is easy enough to adapt an "existing" design to air-launch.  That's not true, but if you haven't delved into the details, it makes a good story to investors and customers.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 01/02/2012 06:16 AM
First off, SUPER COOL!  Thanks for sharing.
LOX-hydrogen at the full payload capability of the aircraft will fit fine; there is an S-IVB worth of diameter available so the overall length for the stage is only about 60-80 feet. 
  So a 6.6 meter diameter rocket would fit no sweat?  That's fascinating! 

I wanted to go with a one-stage expendable SSTO approach but that turned out to be a bit radical for my colleagues ... I'm certain the reason they ended up with the configuration they did was simply availability of an in-production propulsion option and ...perception
Any sense that selecting 2-stage might have also been for excess margin for stage recovery systems?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Patchouli on 01/02/2012 06:30 AM

A rocket can't have a kink in it, but a telescope can.  Even if the maximum diameter rocket possible on stratolaunch is 5 meters or less for take-off and landing clearance, a telescope can bend upward from the attachment points.  So a still fairly simple single mirror, perhaps 8 meters diameter should be possible.  Three of these, placed side by side hanging from the usual attachment points would be an impressive improvement over SOFIA.     


You might have just pointed out one of the reasons why they went with a kerolox rocket vs hydrogen as a hydrogen core that fully utilizes the payload of the aircraft may be too wide.




LOX-hydrogen at the full payload capability of the aircraft will fit fine; there is an S-IVB worth of diameter available so the overall length for the stage is only about 60-80 feet.  It was one of the early options for which I did a design for a previous version of the a/c about five years ago.  I wanted to go with a one-stage expendable SSTO approach but that turned out to be a bit radical for my colleagues so we punted to 2 stage LOX-hydrocarbon.  By the time you finish a real design, they both end up about the same length, since the interstage and second stage engine takes up a lot of length.

I'm certain the reason they ended up with the configuration they did was simply availability of an in-production propulsion option and the perception that it is easy enough to adapt an "existing" design to air-launch.  That's not true, but if you haven't delved into the details, it makes a good story to investors and customers.

I wonder if they looked at hydrogen options?

The only hydrogen engine options I know that could deliver the performance needed for their payload range are the J-2X,Vulcain 2,SSME,and RD-0120.


The J-2X seems to be a good match if they did go hydrogen and actually could carry a S-IVB sized stage.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: as58 on 01/02/2012 07:51 AM
There may not be but if there is, it could be a lot larger, and less constrained in its design if clipped onto stratolaunch instead of jammed in a 747. 
Do you honestly believe that SOFIA's delays and overruns were due to the lack of a large enough plane? Or that a (lot) larger telescope could be easily designed for Stratolauncher?

Quote
Who is going to fund it ?
No Idea.  DLR/NASA again?
SOFIA development has been a disaster much like JWST (and considering the science return, IMO much worse). I really doubt NASA is willing to go for it again.

Quote
It's a cool telescope with some unique capabilities
Agreed.
I agree, although it has come with a huge price.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: baldusi on 01/02/2012 10:34 AM

A rocket can't have a kink in it, but a telescope can.  Even if the maximum diameter rocket possible on stratolaunch is 5 meters or less for take-off and landing clearance, a telescope can bend upward from the attachment points.  So a still fairly simple single mirror, perhaps 8 meters diameter should be possible.  Three of these, placed side by side hanging from the usual attachment points would be an impressive improvement over SOFIA.     

You might have just pointed out one of the reasons why they went with a kerolox rocket vs hydrogen as a hydrogen core that fully utilizes the payload of the aircraft may be too wide.
Their renders did showed a SpaceX's standard fairing of 5.2m. If they can lengthen proportionally, a 5.2m core has 3 times the volume of a 3.65m, one. In other words, the volume difference of an hydrolox stage to a kerolox one. And you are already having a 5.2m drag, so nothing is lost there either. Hydrolox shouldn't be a problem for the Stratolauncher.
BTW, a Delta IV Medium is 550klb. And it's 5m wide. Or they could have gone the Liberty way, and studied a EPC+ECB. All sort of "simple" fits. I think they went with SpaceX both for price and the possibility of converting to a RLV in the near future.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: JohnFornaro on 01/02/2012 01:31 PM
Why do you think there will be a successor to SOFIA?
There may not be but if there is, it could be a lot larger, and less constrained in its design if clipped onto stratolaunch instead of jammed in a 747.

You do realize that you didn't answer his question, don't you?  Further, the 140 ton SLS, with perhaps a 10m fairing, will be even less of a mirror constraint.  Why wouldn't SLS be better?

Their renders did showed a SpaceX's standard fairing of 5.2m. If they can lengthen proportionally, a 5.2m core has 3 times the volume of a 3.65m, one.

Now you suggest making the rocket even longer than it is currently rendered.  I continue to struggle with acceptance of the idea of hanging a long, skinny rocket from its middle, without seeing what the hanging structure looks like.  The additional mass needed is ameliorated somehwhat by the prospect of launching it from such an altitude, but the only information there is to go on is an illustration on a website.

I didn't have this problem with WK2 and SS2 and all.  That LV is a stubby one, shaped for horizontal aerodynamics.   Stratolaunch should abandon the disposable rocket paradigm and focus on ther reusability of a winged craft, scaled along the lines of their large mass projections.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 01/02/2012 01:47 PM
Stratolaunch could stargaze all night, pull in to the hanger, unclip its telescope, then clip on a rocket for its morning excursion.
No, on the last line
If "roll-out to launch in <60 minutes" is a possibility for F9, then I don't see why this isn't. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 01/02/2012 01:52 PM
I wonder if they looked at hydrogen options?

He just said they did. 
LOX-hydrogen at the full payload capability of the aircraft will fit fine; ...  It was one of the early options for which I did a design for a previous version of the a/c about five years ago. 
Or do you mean whether they were considering developing a new engine (raptor stage?) instead of buying something already made.  He addressed that too: 

I'm certain the reason they ended up with the configuration they did was simply availability of an in-production propulsion option...perception
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 01/02/2012 02:02 PM
Do you honestly believe that SOFIA's delays and overruns were due to the lack of a large enough plane?
Mainly no.  But the configuration of the plane impacted its utility. 

Or that a (lot) larger telescope could be easily designed for Stratolauncher?
Yes.  Much more easily.  A lot of the issues were worked out during the birthing pains of SOFIA.  The next one would be easier to make, using a lot of the systems developed for SOFIA, and better (much more light gathering area).  The next one wouldn't involve a lot of technology development.

SOFIA development has been a disaster much like JWST (and considering the science return, IMO much worse)...it has come with a huge price.
No arguments from me there.  It was expensive.  It would be a shame if the stabilization, aircraft control systems, and lessons learned were only ever used on the one project.   

Once again, Ben Franklin after seeing the first hot air balloon flight was asked:  "What good is it?"  He replied, "What good is a newborn baby?"

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 01/02/2012 02:23 PM
You do realize that you didn't answer his question, don't you?
You caught me.  :)

Further, the 140 ton SLS, with perhaps a 10m fairing, will be even less of a mirror constraint.  Why wouldn't SLS be better?
Did you read the "fancy options" part?  "Boogie-board shape"?  Triple-binary 8m kinkers?  No need to pay for an SLS launch?  Designing the optics for the space environment?

I suspect that's a leading question to get me to spell out answers that you already know, but I'll comply.  Here's a comparison assuming monolithic mirrors and no folding parts (unlike JWST):

SLS telescope                         Stratolaunch telescope
launch cost (billion bucks?)      cost (nocturnal lease agreement)
140 ton max                           500 ton max         (irrelevant in both cases)
8 m mirror                              24mx2 mirrors (boogie) or 6 x 8m mirrors (three double-ended kinkers)
50 square meters                   900 square meters or 300 square meters 
repair cost (billion bucks?)        Access is free and easy
design everything for space       Don't design everything for space environment

Don't get me wrong, I like space telescopes.  Particularly km-wide fresnel lens ideas like this:  http://www.langorigami.com/science/technology/eyeglass/eyeglass.php

SOFIA (bless her little heart) is <5 square meters.

Now you suggest making the rocket even longer than it is currently rendered.  I continue to struggle with acceptance of the idea of hanging a long, skinny rocket from its middle, without seeing what the hanging structure looks like.
Your coat hanger keeps the shoulders of your coat supported...I suspect that the hangar will be more of a truss with multiple points of attachment along it than a big hook.  But you probably do too.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: HMXHMX on 01/02/2012 03:45 PM
I wonder if they looked at hydrogen options?

He just said they did. 
LOX-hydrogen at the full payload capability of the aircraft will fit fine; ...  It was one of the early options for which I did a design for a previous version of the a/c about five years ago. 
Or do you mean whether they were considering developing a new engine (raptor stage?) instead of buying something already made.  He addressed that too: 

I'm certain the reason they ended up with the configuration they did was simply availability of an in-production propulsion option...perception

They didn't look at alternatives to my knowledge, I did.  Different effort, but same a/c.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 01/02/2012 04:09 PM
Stratolaunch could stargaze all night, pull in to the hanger, unclip its telescope, then clip on a rocket for its morning excursion.
No, on the last line
If "roll-out to launch in <60 minutes" is a possibility for F9, then I don't see why this isn't. 

It isn't attaching the rocket to launch in <60 minutes
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: baldusi on 01/02/2012 04:28 PM
Their renders did showed a SpaceX's standard fairing of 5.2m. If they can lengthen proportionally, a 5.2m core has 3 times the volume of a 3.65m, one.

Now you suggest making the rocket even longer than it is currently rendered.  I continue to struggle with acceptance of the idea of hanging a long, skinny rocket from its middle, without seeing what the hanging structure looks like.  The additional mass needed is ameliorated some what by the prospect of launching it from such an altitude, but the only information there is to go on is an illustration on a website.
May be I didn't express myself correctly. (5.2/3.65)^3 is pretty close to 3. In other words, the rocket would be longer, but also wider. And it might be longer, but it would also be less dense. So it's quite probable that the bending moment from the own mass would be lower, proportionally. And if you take the mass cap, and put two J-2X it's sort of a shoe in. Put an RL10 on the US and you have a pretty nice combo. Those are existing or as close to existing engines as you can get anywhere. And they would probably have better performance for LEO, and significantly better performance to high energy orbits.
I'm not stating anything about the business advantages of any of this. I'm just stating that H2 in the Stratolauncher is quite doable and even with good performance, and can be done with existing tooling and parts.
I'm not stating it would be worth the development cost, nor that it would be the fastest nor the cheapest option. Probably the higher performance, though. But we've already stated that the reason of being of Stratolauncher is cost, not performance.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: simonbp on 01/02/2012 04:32 PM
OK guys, let's make a few things clear:

1) SOFIA uses a 747SP because they need the range; the typical operational profile is to take off from Palmdale and "chase the Sun" going West, with a landing in Hawaii or New Zealand. That's massively more range than Stratolaunch needs, and puts lots of extra constraints on aircraft.

2) For a large telescope like SOFIA, the primary mirror _must_ be open to the sky, and _must_ have a clear line of sight. Without seriously modifying the aircraft, that's going to restrict you to objects at greater than about 60 deg elevation, which is only a very small section of the sky.

3) Vibration is a killer for all optics, especially movable ones. The end of a Stratolaunch cargo pod is going to vibrating around all over the place from aero loads. That would then require a superstiff (read heavy) pod structure and connection to the aircraft. Stiffening up SOFIA after they cut a hole in it was the most expensive and time-consuming part of the conversion.

So, while technically possible, putting a telescope in a Stratolaunch cargo pod is not really practical.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 01/02/2012 09:13 PM
1) SOFIA uses a 747SP because they need the range; the typical operational profile is to take off from Palmdale and "chase the Sun" going West, with a landing in Hawaii or New Zealand. That's massively more range than Stratolaunch needs, and puts lots of extra constraints on aircraft.
Having far larger mirrors means the same or better images can be collected in less time.  So range is not a big issue. 

2) For a large telescope like SOFIA, the primary mirror _must_ be open to the sky, and _must_ have a clear line of sight. Without seriously modifying the aircraft, that's going to restrict you to objects at greater than about 60 deg elevation, which is only a very small section of the sky.
I don't understand your concern here.  The world is round so if your mirror can't tilt much you can fly to the part of the world that faces your target galaxy or whatever.  Also, the aircraft doesn't get modified for this.  This would be an aerodynamic telescope that clips into the hanger between the fuselages.  No modifcations to the stratolaunch aircraft would be needed or desireable.  Potentially, you could design it so the mirror(s) could swivel, even pointing down if needed (though a minimal degree of tilting for just enough capability to track objects for the duration of your flight would probably be simplest). 

3) Vibration is a killer for all optics, especially movable ones. The end of a Stratolaunch cargo pod ... would then require a superstiff (read heavy) pod structure and connection to the aircraft.
Fortunately, 500000 pounds of mass should be able to fix the issue (with margin).  SOFIA's mirror weighs 880 kg.  SOFIA in total weighs about 20000 kg.   

http://www.sofia.usra.edu/Science/telescope/sci_tele_character.html

So, while technically possible, putting a telescope in a Stratolaunch cargo pod is not really practical.
Why not?  Assuming that an aircraft like stratolaunch will exist, and will work, and could be purchased or leased or copied, then I don't understand what the show-stopper would be.  If a 900 square meter stratospheric telescope could be developed for a Gigadollar or so (using KISS wherever possible), I would view that as a positive development.  Right now the wolrd's largest telescope is 84 square meters (74 effective). 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: as58 on 01/02/2012 09:55 PM
[
So, while technically possible, putting a telescope in a Stratolaunch cargo pod is not really practical.
Why not?  Assuming that an aircraft like stratolaunch will exist, and will work, and could be purchased or leased or copied, then I don't understand what the show-stopper would be.  If a 900 square meter stratospheric telescope could be developed for a Gigadollar or so (using KISS wherever possible), I would view that as a positive development.  Right now the wolrd's largest telescope is 84 square meters (74 effective). 

Do you have any sources for your claims about how well suited Stratolaunch carrier would be for a airborne telescope? I don't know much about astronomical instrumentation, but to me your claims sound more than a bit fantastical.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Zed_Noir on 01/03/2012 02:44 AM
Stratolaunch could stargaze all night, pull in to the hanger, unclip its telescope, then clip on a rocket for its morning excursion.
No, on the last line
If "roll-out to launch in <60 minutes" is a possibility for F9, then I don't see why this isn't. 

It isn't attaching the rocket to launch in <60 minutes

Have to agree with Jim. Aircraft the size and complexity of the Stratolaunch carrier requires many manhours of maintenance between flights. Something similar would be a C5 Galaxy fully loaded on a maximum range roundtrip mission.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Comga on 01/03/2012 04:23 AM
Stratolaunch could stargaze all night, pull in to the hanger, unclip its telescope, then clip on a rocket for its morning excursion.
No, on the last line
If "roll-out to launch in <60 minutes" is a possibility for F9, then I don't see why this isn't. 

It isn't attaching the rocket to launch in <60 minutes

Have to agree with Jim. Aircraft the size and complexity of the Stratolaunch carrier requires many manhours of maintenance between flights. Something similar would be a C5 Galaxy fully loaded on a maximum range roundtrip mission.

While I don't want to be seen a supporting wild ideas, these are objections to a silly and inconsequential aspect of the post.  How about the rational objections to this if the changeover from observatory to launcher were allowed a week?   Justifying a megaplane launcher presupposes a significant launch rate, but capturing more than a launch every month would require some new market that isn't obvious, at least to me. 

So, if the plane is idle for 2-4 weeks at a time, what other technical objections remain, other than "been there, done that, can't even afford to buy the tee-shirt."
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Zed_Noir on 01/03/2012 06:19 AM
Stratolaunch could stargaze all night, pull in to the hanger, unclip its telescope, then clip on a rocket for its morning excursion.
No, on the last line
If "roll-out to launch in <60 minutes" is a possibility for F9, then I don't see why this isn't. 

It isn't attaching the rocket to launch in <60 minutes

Have to agree with Jim. Aircraft the size and complexity of the Stratolaunch carrier requires many manhours of maintenance between flights. Something similar would be a C5 Galaxy fully loaded on a maximum range roundtrip mission.

While I don't want to be seen a supporting wild ideas, these are objections to a silly and inconsequential aspect of the post.  How about the rational objections to this if the changeover from observatory to launcher were allowed a week?   Justifying a megaplane launcher presupposes a significant launch rate, but capturing more than a launch every month would require some new market that isn't obvious, at least to me. 

So, if the plane is idle for 2-4 weeks at a time, what other technical objections remain, other than "been there, done that, can't even afford to buy the tee-shirt."

Think you misunderstood my point, also maybe Jim's too. I don't think you can turnaround the Stratolaunch carrier like an airliner within a hour.

The plane turnaround downtime between missions would be roughly as short as several hours. It depends on how much monitoring instrumentation is installed on the plane.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Comga on 01/03/2012 02:41 PM
While I don't want to be seen a supporting wild ideas, these are objections to a silly and inconsequential aspect of the post.  How about the rational objections to this if the changeover from observatory to launcher were allowed a week?   Justifying a megaplane launcher presupposes a significant launch rate, but capturing more than a launch every month would require some new market that isn't obvious, at least to me. 

So, if the plane is idle for 2-4 weeks at a time, what other technical objections remain, other than "been there, done that, can't even afford to buy the tee-shirt."

Think you misunderstood my point, also maybe Jim's too. I don't think you can turnaround the Stratolaunch carrier like an airliner within a hour.

The plane turnaround downtime between missions would be roughly as short as several hours. It depends on how much monitoring instrumentation is installed on the plane.

I did not miss your point, but you may have missed mine.  You and Jim are (as ususal) correct that a one hour conversion is nowhere near possible.  My point was, given this reason to ignore that small part of the original post, which other reasons are fatal to the idea of using the Stratolaunch carrier aircraft as a host for a SOFIA successor?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Danderman on 01/03/2012 02:45 PM
While I don't want to be seen a supporting wild ideas, these are objections to a silly and inconsequential aspect of the post.  How about the rational objections to this if the changeover from observatory to launcher were allowed a week?   Justifying a megaplane launcher presupposes a significant launch rate, but capturing more than a launch every month would require some new market that isn't obvious, at least to me. 

So, if the plane is idle for 2-4 weeks at a time, what other technical objections remain, other than "been there, done that, can't even afford to buy the tee-shirt."

Think you misunderstood my point, also maybe Jim's too. I don't think you can turnaround the Stratolaunch carrier like an airliner within a hour.

The plane turnaround downtime between missions would be roughly as short as several hours. It depends on how much monitoring instrumentation is installed on the plane.

I did not miss your point, but you may have missed mine.  You and Jim are (as ususal) correct that a one hour conversion is nowhere near possible.  My point was, given this reason to ignore that small part of the original post, which other reasons are fatal to the idea of using the Stratolaunch carrier aircraft as a host for a SOFIA successor?

I am sure that the Stratolaunch carrier aircraft will be used as a cargo vehicle for many potential customers when it is not busy flying space missions.  However, it must be realized that its not a magic carpet, and significant work will have to be performed to adapt the aircraft to other customers. Its possible that some sort of container structure could be built for a flying telescope that would be compatible with Stratolaunch, but the problem is that Stratolaunch may not be able to provide a very long flying time, which telescopes need.  Also, its not clear if people can transfer from the main hull into a flown container, which may be a requirement for a telescope.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: as58 on 01/03/2012 02:52 PM
I did not miss your point, but you may have missed mine.  You and Jim are (as ususal) correct that a one hour conversion is nowhere near possible.  My point was, given this reason to ignore that small part of the original post, which other reasons are fatal to the idea of using the Stratolaunch carrier aircraft as a host for a SOFIA successor?

I completely agree that a very fast turnaround wouldn't be necessary. As I've said, I'm no expert, but I just don't see why the Stratolaunch carrier would be a particularly good choice. Would it really be that much easier than using a standard aircraft? I particular, go4mars's proposals seem to me like pure fantasy. I really, really, doubt you could build a 6x8 m or 2x24 metre telescopes that could carried on the Stratolauncher even if given all the money in the world. Even one 8 m telescope would be hard enough to build with the given mass constraints. And suppressing vibration enough to get good perfomance (e.g., diffraction limited imaging) seems like a herculean effort.

I seem to remember that you wrote somewhere that you've worked on HST and (or?) JWST, so you probably know a lot more about this than I do.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: hop on 01/03/2012 06:46 PM
Having far larger mirrors means the same or better images can be collected in less time.  So range is not a big issue. 
You lose much of the advantage of the big mirror then. It will also drive up your observing costs, since you have to turn around a flight for much less time in the air.

Another unique capability SOFIA has is observing things that are only visible from limited areas, like KBO and asteroid occultations. This requires range, especially if your carrier can only work out of a few airports.
Quote
I don't understand your concern here.  The world is round so if your mirror can't tilt much you can fly to the part of the world that faces your target galaxy or whatever.
Limited elevation range limits what you can observe and how long you can observe it. Flying to a different location won't help if the sun is up when the object is at an elevation you can observe. This strategy would also seem to negate the idea the carrier doesn't need long range.
Quote
Also, the aircraft doesn't get modified for this.  This would be an aerodynamic telescope that clips into the hanger between the fuselages.
If the telescope is sitting between the two fuselages of the Stratolaunch carrier, you have a limited range of directions you can point. Facing forward is presumably out of the question, so you have to look up or possibly back between the fuselages. The container stills needs a large opening in it, plays havoc with aerodynamics no matter how you cut it.

Anyway, you ignoring the big picture here. There is no demand for a SOFIA successor, nor anyone working one. Big telescope projects take many years from concept to first light. By the time  (if ever) anyone starts working seriously on a SOFIA successor, Stratolaunch will be old news. Even if the Stratolaunch carrier would be a good choice today, there's no saying what will be available by then.

The signal-to-noise of this forum would be greatly improved if people didn't spend so much time using threads about real stuff as a place to argue for pie-in-the-sky concepts that are only tenuously connected to the main topic.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 01/03/2012 10:12 PM
Do you have any sources for your claims about how well suited Stratolaunch carrier would be for a airborne telescope?
No.  But if you find some, please let me know. 
go4mars's proposals seem to me like pure fantasy. I really, really, doubt you could build a 6x8 m or 2x24 metre telescopes that could carried on the Stratolauncher even if given all the money in the world. Even one 8 m telescope would be hard enough to build with the given mass constraints.
Seems like fantasy based on what?  Why wouldn't it be possible?  Mass constraints?  Even dead mass of half a million pounds helps resist vibrations, but systems and software developed for SOFIA could be implemented.  SOFIA total mass = 20Mg. 

This requires range, especially if your carrier can only work out of a few airports.
That's a good point.  Regarding range, we don't know what it's final range will really be, and we don't know how heavy the telescope would really be.   
If the telescope is sitting between the two fuselages of the Stratolaunch carrier, you have a limited range of directions you can point. Facing forward is presumably out of the question, so you have to look up or possibly back between the fuselages. The container stills needs a large opening in it, plays havoc with aerodynamics no matter how you cut it.

Picturing it like the operculum on fenestral bryozoans, like Cheilostomata.  A Frontal lip for the wind keeps the opening lid/flap out of the turbulent airstream for the front one and back.  They wouldn't necessarily have to point only backwards. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 01/03/2012 10:16 PM
Big telescope projects take many years from concept to first light. By the time  (if ever) anyone starts working seriously on a SOFIA successor, Stratolaunch will be old news. Even if the Stratolaunch carrier would be a good choice today, there's no saying what will be available by then.
Why do anything that's uncertain?

The signal-to-noise of this forum would be greatly improved if people didn't spend so much time using threads about real stuff as a place to argue for pie-in-the-sky concepts that are only tenuously connected to the main topic.
I made one post suggesting the possibility.  If I suspected it would snowball I would have started a new thread.   
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Comga on 01/04/2012 02:19 AM
Picturing it like the operculum on fenestral bryozoans, like Cheilostomata. 

Surely you jest! "perculum on fenestral bryozoans, like Cheilostomata"  without so much as a wink or a link?  ::)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 01/04/2012 03:19 PM
Picturing it like the operculum on fenestral bryozoans, like Cheilostomata. 
Surely you jest! "operculum on fenestral bryozoans, like Cheilostomata"  without so much as a wink or a link?  ::)
Apologies.  I blame extreme sleep deprivation combined with having to suddenly rush off to something.  Had a period about a decade ago where I was keenly interested in invertebrate paleobiology and biomimicry has always been an interest.  Haven't found much with google image search.  Sorry.

Best I could find: http://www.ucmp.berkeley.edu/bryozoa/bryozoamm.html
http://en.wikipedia.org/wiki/Operculum_(bryozoa)
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: chrisking0997 on 01/04/2012 04:38 PM
hypothetical thread is hypothetical

I think Stratolaunch is going to have a hard enough time trying to figure out how to be successful launching rockets without people trying to strap on airborne telescopes or giant pony carriers or whatever else we pull out of our...heads to it.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 01/04/2012 07:21 PM
LOX-hydrogen at the full payload capability of the aircraft will fit fine; there is an S-IVB worth of diameter available so the overall length for the stage is only about 60-80 feet.  It was one of the early options for which I did a design for a previous version of the a/c about five years ago.  I wanted to go with a one-stage expendable SSTO approach but that turned out to be a bit radical for my colleagues
If you are allowed to say... Was your proposal intended to double as a F-X diameter upper stage called "raptor"? 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: HMXHMX on 01/04/2012 07:50 PM
LOX-hydrogen at the full payload capability of the aircraft will fit fine; there is an S-IVB worth of diameter available so the overall length for the stage is only about 60-80 feet.  It was one of the early options for which I did a design for a previous version of the a/c about five years ago.  I wanted to go with a one-stage expendable SSTO approach but that turned out to be a bit radical for my colleagues
If you are allowed to say... Was your proposal intended to double as a F-X diameter upper stage called "raptor"? 

No, had nothing to do with SpaceX or Raptor.  I can't say more about it.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: JohnFornaro on 01/05/2012 01:12 PM
While I don't want to be seen a supporting wild ideas, these are objections to a silly and inconsequential aspect of the post.  How about the rational objections to this if the changeover from observatory to launcher were allowed a week?   Justifying a megaplane launcher presupposes a significant launch rate, but capturing more than a launch every month would require some new market that isn't obvious, at least to me. 

So, if the plane is idle for 2-4 weeks at a time, what other technical objections remain, other than "been there, done that, can't even afford to buy the tee-shirt."

... I don't think you can turnaround the Stratolaunch carrier like an airliner within a hour.

The plane turnaround downtime between missions would be roughly as short as several hours. It depends ...

...  You and Jim are (as ususal) correct that a one hour conversion is nowhere near possible.  My point was, ... which other reasons are fatal to the idea of using the Stratolaunch carrier aircraft as a host for a SOFIA successor?

You all realize that discussing the turnaround time of an airplane which is only an image on a website has little practical application?

Then there's this:

There is no demand for a SOFIA successor, nor anyone working one.

However, if the point of the SOFIA discussion is to practice typing, then that's fine.  And speaking of typing, is it too much trouble to type the phrase "perculum on fenestral bryozoans, like Cheilostomata" into the internets?

... without people trying to strap on airborne telescopes or giant pony carriers or whatever else we pull out of our...heads to it.

Hold on there pardner.  What's wrong with ponies?  You sound like a typical nerfherder.

The most salient objection to this scheme is why isn't the angel investor bringing the inventor's proven, sub-scale RLV scheme to the proper and needed scale?

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: go4mars on 01/05/2012 01:37 PM
The most salient objection to this scheme is why isn't the angel investor bringing the inventor's proven, sub-scale RLV scheme to the proper and needed scale?
Are you talking about something Rutan came up with?  Musk?  A different inventor?  Do you mean a bigger spaceship2? 



Just to compete the geology nerdnition:  It's "operculum".  "An operculum (on an animal) is an anatomical feature, a stiff structure resembling a lid or a door that opens and closes, and thus controls contact between the outside world and an internal part of an animal. Example:

An operculum (gastropod), a single lid that (in its most complete form) closes the aperture of the shell when the animal is retracted, and thus protects the internal soft parts of the animal that are not completely covered by the shell. The operculum lies on the top rear part of the foot. When the foot is retracted, the operculum is rotated 180° and closes the shell."

In context, it saves me from making a drawing by showing the shape (fenestral bryozoans).  Lids would probably slide in toward the middle wing. 

But that doesn't matter.  This discussion of a SOFIA successor has snowballed completely out of proportion and is becoming distracting.  I propose further discussion of it be on a new thread if it must be examined further.  Start one if you must. 

I said something along the lines of "A SOFIA successor would be possible if stratolaunch existed", and got all kinds of "no it wouldn't", or "it wouldn't be worth it", or "where is the funding coming from", or "there are better alternatives", "how exactly would it work", "do you have supporting literature/studies",  "how is a stratospheric telescope better than ground based or space based", "could you draw an exact diagram of the optics stabilization mechanism", "have you done wind tunnel studies", "what would its exact weight be", "what is its exact operational range", "which routes and runways would work best for various celestial regions", "what is the idealized cruising altitude", "what would it be called", "what color should it be painted",etc. etc. etc. 

The exact details of how it would be done are a red herring.  But I think it's a valid point that it could technically be done in some form that is larger than SOFIA, and there might be some improvements in design and/or cost drawn from SOFIA.  I'm happy to leave it at that. 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Jim on 01/05/2012 02:13 PM

The exact details of how it would be done are a red herring.  But I think it's a valid point that it could technically be done in some form that is larger than SOFIA, and there might be some improvements in design and/or cost drawn from SOFIA.  I'm happy to leave it at that. 

Just as valid is that it couldn't be done technically
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Robotbeat on 01/05/2012 02:38 PM
...
However, if the point of the SOFIA discussion is to practice typing, then that's fine.
...
JohnFornaro wins.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: JohnFornaro on 01/06/2012 02:55 AM
Thanks.  Let's go out and have a bryozoan sometime.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: JohnFornaro on 01/06/2012 03:06 AM
The most salient objection to this scheme is why isn't the angel investor bringing the inventor's proven, sub-scale RLV scheme to the proper and needed scale? [and capability, I add.]

Are you talking about something Rutan came up with?  ...  Do you mean a bigger spaceship2?

Rutan.  SS3?  A real RLV?  At long last?  Mr. Allen is being totally hoodwinked by his advisors.  If I said that I was going to start launching rockets sideways, what do you think the typical reaction around here would be?  WWJS?

I'm going out on a limb when I say all that, I realize.  And by "limb", I mean ... well, this:

http://forum.nasaspaceflight.com/index.php?topic=27381.msg834088#msg834088
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Comga on 01/06/2012 11:15 PM
Pardon me, but I can't find where this article (http://www.transterrestrial.com/?p=39194) was linked. 

While I am usually adverse to conspiracy theories, this makes more sense than Stratolaunch for regular satellites.  Surprisingly, a friend, who moves in the high levels of American space programs and knows several of the people involved with Stratolaunch, agrees.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 01/07/2012 01:23 AM
This makes more sense to me…

http://up-ship.com/blog/?p=11633
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RocketmanUS on 01/07/2012 01:35 AM
Pardon me, but I can't find where this article (http://www.transterrestrial.com/?p=39194) was linked. 

While I am usually adverse to conspiracy theories, this makes more sense than Stratolaunch for regular satellites.  Surprisingly, a friend, who moves in the high levels of American space programs and knows several of the people involved with Stratolaunch, agrees.

Worth reading, not a conspiracy theory, well thought out and easy to read. Not saying it will or won't be. It is an interesting idea. But once a X-37 is in orbit can't it be tracked?

Is it faster to get a payload launch this way compared to using a launch pad? 
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: RocketmanUS on 01/07/2012 01:43 AM
This makes more sense to me…

http://up-ship.com/blog/?p=11633
From the FAA ( 2003 PDF )
http://www.faa.gov/library/reports/commercial_space/dev_concepts/media/newtech03_final.pdf

So maybe the X-37 would use the Stratolaunch.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: HMXHMX on 01/07/2012 02:43 AM
This makes more sense to me…

http://up-ship.com/blog/?p=11633

Top launch is higher risk for any number of reasons. It is something to be avoided if there is a belly launch, towed or twin-boom configuration option.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Danderman on 01/07/2012 03:51 AM
If something like an X-37 were the payload for Stratolaunch, it might be possible to inject the payload into a suborbital trajectory, and use the payload's own engine to attain the final orbit. In that case, the upper stage would never reach orbit, and so would theoretically be easier to recover.

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 01/07/2012 11:04 AM
This makes more sense to me…

http://up-ship.com/blog/?p=11633

Top launch is higher risk for any number of reasons. It is something to be avoided if there is a belly launch, towed or twin-boom configuration option.
Yes, I understand the preferred belly drop method is more acceptable for risk of re-contact. I see this as more sense if this was just for a rapid deployment military-spy mission for the X-37 and easier to conceal.  In a military context a higher risk is acceptable compared to civilian use… Now if cost is no object then you can go to a dedicated aircraft such as Stratolaunch.

Robert
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jimoutofthebox on 01/07/2012 04:37 PM
If something like an X-37 were the payload for Stratolaunch, it might be possible to inject the payload into a suborbital trajectory, and use the payload's own engine to attain the final orbit. In that case, the upper stage would never reach orbit, and so would theoretically be easier to recover.



I posted the following in a different thread.

There is a significant cost savings to be had from launching a booster from an aircraft.  For example Saturn V used almost 1/3rd of its launch weight in RP and LOX just to get to Mach 1.  I think air launch has the potential to dramatically reduce the cost of putting people in orbit.  Instead of the modified 747s proposed I would use a modified C5 aircraft with the floor removed so that the booster could be carried internally.  With a good redesign the C5 could probably carry 350,000 lbs.   
I would then create a booster based on a scaled up X-37.  The booster would consist of two parts the orbiter section would consist of an airframe with a LOX tank, crew compartment, and a pair of J2 engines as well as a pair of small engines for orbital insertion and reentry.  The orbiter would return for reuse.  The other section would be mounted to the nose of the main assembly and would consist of the LH fuel tank.  The LH fuel tank would also have solid rocket motors that would pull the tank away from the orbiter once the fuel was exhausted.  The tank would then burn up.  The small engines would place the orbiter in orbit just as was done with the shuttle.
There are several advantages to this proposal.  The passengers would not have to enter the orbiter until the aircraft got to altitude so in an emergency the booster could be jettisoned from the aircraft without endangering the passengers.  A lot of money could be saved because all the expensive stuff could be reused.
I estimate that the system outlined above would weigh 350,000 lbs when fully fuelled with a 90% fuel fraction.  It could carry 7 people to orbit or a robot version could carry a payload of 5,000lbs to orbit.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Comga on 01/07/2012 10:59 PM
Launching the X-37 on Stratolaunch was discussed over in the X37B thread. (http://forum.nasaspaceflight.com/index.php?topic=24323.msg841756#msg841756)

Stratolaunch is supposed to have a 13 mton payload and X37 is about 11 mton, so it sounds physically possible.

Anyone have any opinion on horizontal airlaunch of X37 without a fairing?   DreamChaser is shown launching on an Atlas without a fairing, but X37 used them.  There are issues with crosswinds and things, I think.  Wouldn't these be mitigated by flying into the wind at altitude?
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: HMXHMX on 01/07/2012 11:03 PM
This makes more sense to me…

http://up-ship.com/blog/?p=11633

Top launch is higher risk for any number of reasons. It is something to be avoided if there is a belly launch, towed or twin-boom configuration option.
Yes, I understand the preferred belly drop method is more acceptable for risk of re-contact. I see this as more sense if this was just for a rapid deployment military-spy mission for the X-37 and easier to conceal.  In a military context a higher risk is acceptable compared to civilian use… Now if cost is no object then you can go to a dedicated aircraft such as Stratolaunch.

Robert

I'd beg to differ about risk.  At AirLaunch we had to mitigate risk for the USAF C-17 on the order of 10 to the minus 10th, a full order of magnitude higher than the FAA would require for commercial air transport.  I'll take an FAA Restricted certification permit any day.

And the problem isn't risk of recontact.  For the configuration shown, the mated a/c Cg is quite high (there's 350-400K lbm of mass up there), the drag is high, there are always issues with tail flutter and you've got lots of dangerous propellants on top of the a/c.  That's not to say it won't work, but I believe there are better alternatives.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: HMXHMX on 01/07/2012 11:04 PM
Launching the X-37 on Stratolaunch was discussed over in the X37B thread. (http://forum.nasaspaceflight.com/index.php?topic=24323.msg841756#msg841756)

Stratolaunch is supposed to have a 13 mton payload and X37 is about 11 mton, so it sounds physically possible.

Anyone have any opinion on horizontal airlaunch of X37 without a fairing?   DreamChaser is shown launching on an Atlas without a fairing, but X37 used them.  There are issues with crosswinds and things, I think.  Wouldn't these be mitigated by flying into the wind at altitude?

13,500 lbm for the Stratolaunch system and 7-12K lbm for X-37, depending on propellant loadout.

And the wind is variable.  A winged body sees AoA-generated forces with any crosswind.  Flying unshrouded is a bad idea in general though it can be made to work with enough control authority.  I think it is fairly obvious that the large diameter fairing if meant for X-37.  It is the only payload in the world that requires both low mass and a 5M fairing.  That's a dead giveaway.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: Rocket Science on 01/07/2012 11:55 PM
This makes more sense to me…

http://up-ship.com/blog/?p=11633

Top launch is higher risk for any number of reasons. It is something to be avoided if there is a belly launch, towed or twin-boom configuration option.
Yes, I understand the preferred belly drop method is more acceptable for risk of re-contact. I see this as more sense if this was just for a rapid deployment military-spy mission for the X-37 and easier to conceal.  In a military context a higher risk is acceptable compared to civilian use… Now if cost is no object then you can go to a dedicated aircraft such as Stratolaunch.

Robert

I'd beg to differ about risk.  At AirLaunch we had to mitigate risk for the USAF C-17 on the order of 10 to the minus 10th, a full order of magnitude higher than the FAA would require for commercial air transport.  I'll take an FAA Restricted certification permit any day.

And the problem isn't risk of recontact.  For the configuration shown, the mated a/c Cg is quite high (there's 350-400K lbm of mass up there), the drag is high, there are always issues with tail flutter and you've got lots of dangerous propellants on top of the a/c.  That's not to say it won't work, but I believe there are better alternatives.
Hi Gary,
Yes, I totally agree about the high Cg, tail flutter as well as loss of stability due to aero blanking off of the empennage. I only put this forward as to what Boeing has considered with respect to air launch. I’m still of the belief that your proven methodology of being internally carried and launch procedure trumps this Boeing proposal in many respects including concealment from prying eyes. I can see this working great using your launch method from a C-17 or a C-5, if no clearance issues exist for the wings of the X-37 and a booster with swing wings and a folding vertical stabilizer if desired. Like you said there are better alternatives… I would add, including use of existing carrier aircraft and not having to wait for Statolaunch or spend the funds to build it. It is still hard to argue with a deliberately designed and dedicated aircraft where one would have fewer constraints…
Perhaps Boeing should consider your approach or perhaps they already have for the X-37? ;)
I wish you continued success for 2012!

Regards
Robert

Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: HMXHMX on 01/08/2012 12:45 AM
This makes more sense to me…

http://up-ship.com/blog/?p=11633

Top launch is higher risk for any number of reasons. It is something to be avoided if there is a belly launch, towed or twin-boom configuration option.
Yes, I understand the preferred belly drop method is more acceptable for risk of re-contact. I see this as more sense if this was just for a rapid deployment military-spy mission for the X-37 and easier to conceal.  In a military context a higher risk is acceptable compared to civilian use… Now if cost is no object then you can go to a dedicated aircraft such as Stratolaunch.

Robert

I'd beg to differ about risk.  At AirLaunch we had to mitigate risk for the USAF C-17 on the order of 10 to the minus 10th, a full order of magnitude higher than the FAA would require for commercial air transport.  I'll take an FAA Restricted certification permit any day.

And the problem isn't risk of recontact.  For the configuration shown, the mated a/c Cg is quite high (there's 350-400K lbm of mass up there), the drag is high, there are always issues with tail flutter and you've got lots of dangerous propellants on top of the a/c.  That's not to say it won't work, but I believe there are better alternatives.
Hi Gary,
Yes, I totally agree about the high Cg, tail flutter as well as loss of stability due to aero blanking off of the empennage. I only put this forward as to what Boeing has considered with respect to air launch. I’m still of the belief that your proven methodology of being internally carried and launch procedure trumps this Boeing proposal in many respects including concealment from prying eyes. I can see this working great using your launch method from a C-17 or a C-5, if no clearance issues exist for the wings of the X-37 and a booster with swing wings and a folding vertical stabilizer if desired. Like you said there are better alternatives… I would add, including use of existing carrier aircraft and not having to wait for Statolaunch or spend the funds to build it. It is still hard to argue with a deliberately designed and dedicated aircraft where one would have fewer constraints…
Perhaps Boeing should consider your approach or perhaps they already have for the X-37? ;)
I wish you continued success for 2012!

Regards
Robert



Oh, I believe there is a place for an alternative existing-aircraft approach in place of the M351 a/c.  I can think of at least two different ways to accomplish the Stratolaunch payload goal (whatever it may turn out to be) without building the new a/c.  But people like their toys.
Title: Re: Stratolaunch Announcement, Updates and Discussion
Post by: jimoutofthebox on 01/09/2012 02:24 PM