The mother ship rolls out!!

a reply to: PhloydPhan

A bit more commentary on the rocket side of the Mothership:

www.parabolicarc.com...

originally posted by: anzha
a reply to: PhloydPhan

A bit more commentary on the rocket side of the Mothership:

www.parabolicarc.com...

Interesting read. The Stratolaunch carrier aircraft as a 21st century Glomar Explorer angle is one I have read about before. Frankly, I put a lot more stock in it before they settled on the Pegasus XL as their launch vehicle. If the powers that be wanted to air launch some super-secret payload using a Pegasus, they could just use a B-52, as was done for the first few Pegasus launches back in the early 90s.

Also, while the concept art with the Stratolaunch carrier lofting 3 separate Pegasus boosters looks really cool, there's no operational reason to ever do that. If the payloads are going to VERY different orbital planes, the aircraft doesn't have enough range to reposition after the first and second launches and then return to base. If the payloads are going to the same or nearly the same orbital plane, it would be cheaper to use a Falcon 9 (or, depending on the payload, even an Atlas V) than 3 Pegasus rockets.

Keep in mind some of these were taken out the window of a truck going 55 mph past the airport, and it was hot as hell today so we were dealing with a good bit of heat haze.

a reply to: Zaphod58

No cockpit windows?
Hmmm.. un-manned?
Looks a bit like a very LARGE mockup. Great photos Zaphod

Lol.. those Wind Turbines though.
Thanks so very much for taking these pictures. I realize you are busy with your traveling job.

a reply to: Zaphod58

Damn.

That thing is hugely huge, isn't it? Those engines are monstrous things, and there's six of 'em, kinda puts the sheer size of the thing into perspective...

In a word: Wow.

Thanks for the pictures, Z.

a reply to: Bigburgh

They're there. They're all the way down by the very tip of the nose. One side is cockpit, the other is launch control. Usually when it's in a hot area like that, they put up a sun shade inside the cockpit to keep it from overheating. That can make it look like there are no windows, especially in a shot from a distance like these are.

a reply to: seagull

That was my first reaction. I couldn't believe how big the thing is. I've been waiting two years for this thing to come out of the hangar, and it didn't disappoint.

The engines are PW4056s, each one generating 56,000 lbs of thrust. The 4056 is a 94 inch fan.

a reply to: Zaphod58

So each of those engines is almost 8' across, and there are six of 'em with what looks to be at least 7 to 8 feet between them, plus whatever out to the tip from the outboard, and what ever the distance to the fuselage--monstrous just about covers it...

If this aircraft replaces the first stage of a rocket, wouldn't the second stage have to burn for longer to get the projectile up to the speeds a first stage would have generated by the same height?

I cant see point if falcon 9 is a reusable first stage, isn't it better than this?

Still nice to see a new aircraft, I hope it does find a solution to the problem its trying to solve.

a reply to: Forensick

Less mass, perhaps?

Can't imagine they'd spend the kind of capital it must have taken to design and build this thing if there weren't decided advantages.

It looks like something outta Thunderbirds! F.A.B.!

originally posted by: Forensick
If this aircraft replaces the first stage of a rocket, wouldn't the second stage have to burn for longer to get the projectile up to the speeds a first stage would have generated by the same height?

I cant see point if falcon 9 is a reusable first stage, isn't it better than this?

Still nice to see a new aircraft, I hope it does find a solution to the problem its trying to solve.

What matters for getting into orbit is speed. Thus air launch can not replace the first stage. The advantage is mostly about being more flexible regarding target orbit and weather.

a reply to: Forensick

It requires less fuel to get into orbit. You aren't having to make that initial massive burn to break free from the ground and get through the denser air at low altitude, so you don't have to have as much fuel, or as many engines as you do with a larger rocket.

The principal advantage of a rocket being launched by a high flying airplane is that it need not fly through the low, dense atmosphere, the drag of which requires a considerable amount of extra work and thus mass of propellant. Higher densities at lower altitudes result in larger drag forces acting on the vehicle. In addition, thrust is lost due to over-expansion of the exhaust at high ambient pressure and under-expansion at low ambient pressure; a fixed nozzle geometry cannot provide optimal exhaust expansion over the full range of ambient pressure, and represents a compromise solution. Rockets launched from high altitude can be optimized for lower ambient pressure, thus achieving greater thrust over the entire operating regime.

Propellant is conserved because the air-breathing carrier aircraft lifts the rocket to altitude much more efficiently with the use of engines that do not require on-board storage of an oxidizer. This allows the launch system to conserve a significant amount of mass that would otherwise be reserved for fuel, reducing the overall size. A larger fraction of the rocket mass can then include payload, reducing payload launch costs. It is also possible to make use of higher-impulse fuels precluded from surface launches due to their toxicity, such as those containing beryllium or fluorine.

Air launch to orbit offers the potential for aircraft-like operations such as launch on demand, and is also less subject to launch-constraining weather. This allows the aircraft to fly around weather conditions as well as fly to better launch points, and to launch a payload into any orbital inclination at any time. Insurance costs are reduced as well, because launches occur well away from land, and there is no need for a launch pad or blockhouse.[citation needed]

Air launch to orbit also works well as part of a combination launch system such as a reusable air-launched Single Stage to Tether launch vehicle powered by a rocket or RBCC engine.

An additional benefit of Air launch to orbit is a reduced delta V needed to achieve orbit. This results in a greater payload to fuel ratio which reduces the cost per unit mass to orbit. To further leverage the Delta V advantage, supersonic air launch to orbit has been proposed.[1]

en.wikipedia.org...

a reply to: Zaphod58

This is something I know more than a bit about.

However, the very TLDR version is the primary advantage is the ability to tailor your orbit inclination. The aircraft can take off from many, many strips and then launch placing the sat at desired inclination immediately. Now, the sats have to spend more from both the rocket doing the best it can and then spending a while phasing itself into the orbit really desired. That uses fuel. Using the fuel shortens the life time of the sat. You can extend the sat life quite a while if you do an air launch.

However, to really reduce costs, assuming Burt and Mr Allen are doing this for commercial reasons, then they need to have a high launch rate. Otherwise, this falls into the shuttle trap: large overhead to take care of the craft even if its reusable.

Interestingly, the DreamChaser is supposed to fly off this. Why? IDK, but supposedly…

a reply to: Zaphod58

one word. MONSTER

Whats the total wingspan on this girl?

a reply to: BASSPLYR

Something like 368 feet.

a reply to: thebozeian

They use one tug. When they pulled it out of the hangar, it was under the right fuselage. The tug wraps around the nose gear instead of using a tow bar.

The tug wraps around the nose gear instead of using a tow bar.

Less jerk load on the landing gear these tugs have.Being a lot closer to the pivot point makes them a lot easier to maneuver on the ground as well.
Tug