Stratolaunch: General Company and Development Updates and Discussions

[Jim]

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

[go4mars]

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.     

[mmeijeri]

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".

[mmeijeri]

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.

[sanman]

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?

[Carreidas 160]

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.

[Robotbeat]

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.)

[Rocket Science]

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…

[Robotbeat]

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).

[Rocket Science]

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….

[hop]

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.

[Rocket Science]

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.

[kevin-rf]

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.

[yg1968]

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.

[edkyle99]

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).

-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

[yg1968]

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.

[Robotbeat]

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.

[RanulfC]

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

[HappyMartian]

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!

[RanulfC]

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