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-   -   Stratolaunch flies (https://www.pprune.org/rumours-news/620498-stratolaunch-flies.html)

Nige321 13th Apr 2019 18:36

Stratolaunch flies
 
It flies...

Verge report


The world’s largest airplane took flight for the first time ever on Saturday morning. Built by rocket launch company Stratolaunch, the 500,000-pound plane with a 385-foot wingspan lifted off shortly after 10AM ET from Mojave Air and Space Port in Mojave, California. It’s a critical first test flight for the aircraft, designed to launch rockets into orbit from the air.The inaugural flight is expected to last a few hours. The dual-fuselage Stratolaunch is designed to fly to an altitude of 35,000 feet, where it can drop rockets that ignite their engines and boost themselves into orbit around the planet. There is no rocket on this particular flight. But the company has already signed at least one customer, Northrop Grumman, which plans to use Stratolaunch to send its Pegasus XL rocket into space.


meleagertoo 13th Apr 2019 19:58

Despite the blurb above it was, of course,actually built by Scaled Composites and is clearly one of their designs.

PAXboy 13th Apr 2019 21:28

What I find interesting about the design is that the tailplanes are not linked. Thus, all the angular stress has to be handled by the wing - which must be mighty strong. I guess that, as it is designed to have various rockets hung off it - then it must be tough!

Carbon Bootprint 13th Apr 2019 22:23


Originally Posted by PAXboy (Post 10446952)
What I find interesting about the design is that the tailplanes are not linked. Thus, all the angular stress has to be handled by the wing - which must be mighty strong. I guess that, as it is designed to have various rockets hung off it - then it must be tough!

That was my impression as well -- the Mother of All Wing Spars!

A fair amount of discussion about the lack of a tailplane link in the JB thread on this, FWIW.

Nige321 13th Apr 2019 22:32

I do wonder if the secret to this is in the wing section.
If it has a reflex section, and is efectively a flying wing, the tails are maybe there for pitch control rather than stabilty...

darkbarly 13th Apr 2019 22:52

CRM must be tricky...

newairly 13th Apr 2019 22:59

It is designed to carry a total payload of 350 tonnes under the wing centre. That is some load!

meleagertoo 13th Apr 2019 23:04

I've just looked up the spec of this thing. It's simply breath-taking! It's HUUUGE! Those excellent videos don't even begin to do it justice.

Wingspan damn near double that of a 747-400 ( 119m vs. 68m)
MTOW 50% greater! almost 600tons vs 400

Six 747 engines. 747 landing gear. What a toy!

KKoran 14th Apr 2019 01:43


Originally Posted by darkbarly (Post 10446975)
CRM must be tricky...

The crew occupy the right cockpit; the left cockpit is empty or can house electronic gear.

Captain Kaboom 14th Apr 2019 03:11

That must be indeed tough with the CRM, I told you to land on centerline!, but I did land on centerline!

Servo 14th Apr 2019 05:33

Some of the best formation flying I have seen between the two halves! Impressive. Like it was joined...................

crewmeal 14th Apr 2019 05:49

Whilst it's an impressive looking beast which airport in the world would be able to handle it?

KKoran 14th Apr 2019 06:09


Originally Posted by Captain Kaboom (Post 10447050)
That must be indeed tough with the CRM, I told you to land on centerline!, but I did land on centerline!

Mojave has painted a black line down the runway where the right fuselage is when the Stratolaunch is on the centerline.


Carbon Bootprint 14th Apr 2019 12:25


Originally Posted by crewmeal (Post 10447094)
Whilst it's an impressive looking beast which airport in the world would be able to handle it?

Given its mission I believe it's pretty much destined to live and work where it was yesterday, the Mojave Air and Space Port.

But point taken, there aren't many places that can (or would want to) handle this dude.

bumpy737 14th Apr 2019 12:46

Anybody got a better flight deck picture? I’ve found only this one:

https://www.google.com/amp/s/www.gee...es-mojave/amp/

737 Driver 14th Apr 2019 12:55

"Everyone grab a throttle, we're going around!" :p

tdracer 14th Apr 2019 21:20


Originally Posted by Carbon Bootprint (Post 10447249)
Given its mission I believe it's pretty much destined to live and work where it was yesterday, the Mojave Air and Space Port.

But point taken, there aren't many places that can (or would want to) handle this dude.

Having to land at Mojave would limit it's usefulness. One of the carrots of not being tied to a specific launch sites is that it makes different orbital trajectories move viable (that was the whole idea behind the ill-fated Sealaunch venture). Having a few other airports where it can operate - even if it's just to refuel - would increase it potential market quite a bit (especially since I doubt it can carry a lot of fuel when loaded with a 350 ton launch vehicle).

etudiant 15th Apr 2019 01:01

Mojave is not that far from the ocean, so there is probably some reasonable launch flexibility.
The problem is that there is no appropriate launch vehicle for this aircraft to carry. Pegasus is a fraction of the right size and the internal launcher development effort was halted. So the project has achieved engineering success, but not economic viability.
The team must be scrounging desperately to find a practical use that can pay the bills going forward.

Captain Kaboom 15th Apr 2019 02:17


Originally Posted by KKoran (Post 10447100)
Mojave has painted a black line down the runway where the right fuselage is when the Stratolaunch is on the centerline.

Aha, makes a lot of sense... thanks

wiggy 15th Apr 2019 18:10


Originally Posted by etudiant (Post 10447679)
Mojave is not that far from the ocean, so there is probably some reasonable launch flexibility....

In terms of launch azimuths that's true though I guess any easterly azimuths might be a bit problematic, plus of course Mojave is at what ? 35 N ? compared with Canaveral's 28 and a bit north, which is potentially a penalty for some launches;

I'm sure cost vs.benefit on all that has been done by people with big big brains but I can see where tracer is coming from with his remark..

flysmiless 14th May 2019 07:22

Stratolaunch is one of the four largest aircraft
 
The saddest part is, large planes struggle to survive for long,, or they operate very rarely,, May be due to economy issues.


sceh 14th May 2019 13:47

And the point is?
 
Given that SpaceX can launch anything cheaply and land on land anywhere or at sea, what exactly is the point of this beast? Blue Origin has yet to reach orbit but when it does it will also be cheap. Using this beast to launch a rocket from 35000 feet seems silly now



Torquelink 14th May 2019 14:23


Mojave has painted a black line down the runway where the right fuselage is when the Stratolaunch is on the centerline
And if they have to land on the reciprocal? :)

Luc Lion 14th May 2019 19:36


Originally Posted by sceh (Post 10471071)
Given that SpaceX can launch anything cheaply and land on land anywhere or at sea, what exactly is the point of this beast? Blue Origin has yet to reach orbit but when it does it will also be cheap. Using this beast to launch a rocket from 35000 feet seems silly now

The delta-v speed acquired in low atmosphere is the most expensive in terms of fuel factor, mostly because of drag.
For most rockets, the dynamic pressure starts to decrease around 13 km of altitude.
To put things in perspective, the burn-out altitude of Ariane V solid rocket booster is 66.7 km with a speed of 2020 m/s. For a smaller rocket like Atlas V 551, it is 37.7 km. So, for an even smaller rocket, starting from stratospheric limit can mean avoiding the complexity of attaching a solid propellant rocket.
Also, when climbing to a LEO orbit, the decrease in geopotential energy is almost linear. This means that starting from 10 km is a 2.5% saving on geopotential energy.
​​​

tdracer 14th May 2019 22:15


Originally Posted by flysmiless (Post 10470802)
The saddest part is, large planes struggle to survive for long,, or they operate very rarely,, May be due to economy issues.

While true for the other 3 aircraft listed in the video, I think you'll find the Boeing Dreamlifter (aka Large Cargo Freighter or LCF) and Airbus Beluga stay quite busy. Average utilization for the Dreamlifter fleet (four aircraft) is around 1000 hours/month.

Stratolaunch is an interesting (and valid) concept, but I wonder if anything will ever become of it, especially after the death of Paul Allen.



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