Stratolaunch: ´World´s largest plane´ lifts off for the first time
BBC,
by
Staff
Original Article
Posted By: MissMolly,
4/14/2019 6:41:04 AM
The world´s largest aeroplane by wingspan has taken flight for the first time. Built by Stratolaunch, the company set up by the late Microsoft co-founder Paul Allen in 2011, the aircraft is designed to act as a flying launch pad for satellites. The idea is to fly the plane to 10 km (6.2 miles) before releasing satellites into orbit. Its 385 ft (117 m) wingspan is the length of an American football field. If successful, such a project would be a cheaper way to launch objects into space than rockets fired from the ground. The twin-fuselage six-engine jet flew
Reply 1 - Posted by:
GO3 4/14/2019 8:36:34 AM (No. 33489)
By my quick calculation, 6,2 miles is 32,700 feet. International flights I´ve been on go up to 35 - 36,000 feet as a matter of routine. What am I missing? That it´s really big?
18 people like this.
Reply 2 - Posted by:
jj1319 4/14/2019 8:38:40 AM (No. 33479)
Note that the gear remained down during the maiden journey. Plenty of time to retract when there are fewer cameras around.
10 people like this.
Reply 3 - Posted by:
Nevadadad46 4/14/2019 8:56:39 AM (No. 33485)
First, it is routine for the gear to remain in a landing/TO configuration during initial test flights. The purpose of the first flight is to gain critical flight characteristic information, control surface response, balance, and thrust/airspeed information, etc. Too many valuable one-off examples of experimental aircraft have been lost or severely damaged due to the failure of landing gear to extend and lock after being retracted on first flights.
That said, although this concept may seem awkward and fidgety, it makes sense. But, I am doubtful about it working efficiently on this scale. Anytime you add more complexity to the solution of a problem it tends to increase the chances of failure. It seems to me the KISS (Keep It Simple, Stupid) mantra has been ignored.
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Reply 4 - Posted by:
Dodge Boy 4/14/2019 9:42:04 AM (No. 33477)
I´d stick with a rocket myself.
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Reply 5 - Posted by:
chumley 4/14/2019 9:45:13 AM (No. 33478)
I saw it on tv last night and it is a beautiful aircraft. I miss the days when we made double boom or double fuselage machines. The newer designs may be faster, more efficient and even better, but they cant match the beauty of a P61, a P38 or a Twin Mustang. Or even the triple tail of the Lockheed Constellation.
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Another example of private enterprise advancing America´s space efforts. Of course, some think only the government can do this by tossing big bux around to cover increased overhead and contractors.
12 people like this.
Reply 7 - Posted by:
snakeoil 4/14/2019 12:26:06 PM (No. 33475)
I thought Howard Hughes Spruce Goose was the world´s largest plane. Been wrong before.
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Reply 8 - Posted by:
StormCnter 4/14/2019 12:33:21 PM (No. 33488)
For #7, who already knows the Hercules was the Spruce Goose:
"The Hercules is the largest flying boat ever built, and it had the largest wingspan of any aircraft that had ever flown until the Scaled Composites Stratolaunch first flew on 13 April 2019."
https://en.wikipedia.org/wiki/Hughes_H-4_Hercules
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Reply 9 - Posted by:
DVC 4/14/2019 1:22:37 PM (No. 33480)
A great event, and an old friend lead the production team on this aircraft. But, I wonder if it is stillborn without Mr. Allen to keep funding it. Lacking the appropriately designed matching boosters, it is just a first stage with no use. Until they find funding for the rockets, they are done and it is a literal white elephant.
The sad part is that apparently as soon as Allen was dead his widow pulled funding away from this project, an important one to Mr. Allen.
Sad that he didn´t rig it so she couldn´t cancel it after his death.
It appears that this is another example of the common situation, heirs grubbing for money and entirely uninterested in the goals and life´s work of the person who actually earned the money. I imagine Mr. Allen would be appalled. It is not absolutely clear how much the funding was stopped and exactly why, so perhaps I am wrong on why this happened, but knowing human nature, this is what it seems like at this point. I hope I am wrong and the project somehow continues.
Mr. Allen was a great friend to aviation and a space pioneer, and a historian who put a great deal of money into his crew who has been searching the deep Pacific for historic WW2 military wrecks, and found many of them.
Heirs disrespecting the dead has always saddened me, but many people are so greedy and all about themselves. Let´s hope that this isn´t actually what is happening, but it sure looks like it.
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Reply 10 - Posted by:
Skeptical1 4/14/2019 1:29:06 PM (No. 33486)
Richard Branson plans to launch his rockets from a 747. On the face of it, that seems more practical than developing an all new airframe. I did a little research but could not find any discussion of why Stratolaunch took this approach. Their website only mentions that the center wing provides a good platform to launch from. Paul Allen loved bold new technologies, and he was an early backer of Burt Rutan´s designs, so I have to wonder if the new airframe is because Allen´s money allowed them to do something they love.
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Reply 11 - Posted by:
OCJim 4/14/2019 2:08:22 PM (No. 33490)
Getting a payload launch even just six miles up saves considerable rocket size and fuel. There´s a Pegasus air-launch rocket this month of a low-earth satellite out of Cape Canaveral using a Lockheed L-1011. A technology in use for decades but for smaller payloads than envisioned for the Stratolaunch.
And poster noted, the Lockheed Constellation was one beautiful airplane. You need a tail on a plane for the rudder. Big planes require big tails for big rudders. The Connie spread its big rudder over three shorter vertical elements, contributing to its slim beauty, rather than one big & tall tail. Driving that design was the requirement for that large plane to fit under existing hangers of the time. Form and function.
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Reply 12 - Posted by:
snowoutlaw 4/14/2019 2:45:17 PM (No. 33487)
Now that rockets are re-usable this maybe less of a cost advantage than originally designed for.
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Reply 13 - Posted by:
DVC 4/14/2019 3:37:28 PM (No. 33481)
#10, Orbital Sciences started using a DC-10 almost 30 years ago to launch it´s small Pegasus winged rocket. I believe it is still active. The biggest payloads are under 4 ft in diameter, under 1000 lbs, very limited.
The problem with conventional passenger aircraft is that the clearance under the fuselage, or even their wings, is very limited, so any substantial sized rocket has to be hung off of a wing, so is an asymmetric load which is limited by control authority in addition to the more limited lifting power of the 747.
Roc has six 747 engines, and is designed to carry a large diameter rocket on centerline. So, if the L/D of the 747 wing and Stratolaunch wing are the same (not likely true, Roc is likely significantly better), Roc can lift 50% more weight, a huge difference. Likely, the longer wing and advance, totally composite (lighter) 50 years newer structure of Roc will permit more like twice the lifting capacity of a 747, and that is if the load was symmetrically located, which is not possible on a 747. Symmetry would limit weight, no doubt. And, the max diameter rocket hung under a 747 wing would be quite small due to low ground clearance, perhaps 7 or 8 ft., depending on length. Too long and too fat and the back of the rocket hits the ground as the plane rotates for takeoff. Not how the 747´s fuselage sweeps upward at the rear for this reason.
All in all, the 747 route is far, far more limited in diameter of payload, length of payload and weight of payload than Stratolaunch. This is the whole reason for building Stratolaunch.
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Reply 14 - Posted by:
DVC 4/14/2019 4:03:02 PM (No. 33491)
#12, not the case. As much as I admire the reuseable rockets, they are still massively less cost efficient.
A rocket lifts one pound for one pound of thrust. And the fuel and oxidizer are part of the weight which must be lifted.
Any modern, large winged aircraft has a lifting capability of 5 pounds of aircraft+payload+fuel per pound of thrust. And they do NOT have to lift their oxidizer, they are air-breathers, so the oxygen is there, free for the taking.
So, the first 50,000 ft and 300 kts or so of altitude and speed are gained with a winged air breather at about 6-10 times the useful lifting weight per pound of thrust (5X plus no oxygen lifting).
And guess what the cost of a pound of thrust from a modern commercial fanjet engine is compared to a pound of thrust from a modern rocket engine? I don´t know the correct number but would not be surprised if it was a factor of 250. It is certainly at least a factor of 50, likely more. So, 50 times less cost per pound of thrust and 6-10 times more useful lift per pound of thrust.
Those are not precise figures, but reasonably accurate, nevertheless. Call it 300-500 times less expensive (per lb lifted) for that first 50,000 ft and 300 kts of a space launch. That is only a part of the mission, but making even 1/3 of the mission 500 times less expensive is a BIG deal.
And let´s suppose I am off by a factor of 10 on these estimates (I doubt it)...it would still be 30-50 times less expensive for the first 50K ft.
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Reply 15 - Posted by:
DVC 4/14/2019 4:05:54 PM (No. 33476)
Oh, and my literal rocket scientist college roommate (General Dynamics, Atlas program) and I first discussed this air-breather, winged first stage 42 years ago and were entirely baffled why such an obvious engineering advantage was not being taken advantage of.
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Reply 16 - Posted by:
Rumblehog 4/14/2019 6:16:14 PM (No. 33483)
Paul Allen bought Scaled Composites from Burt Rutan in order to build Stratolaunch.
Orbital Sciences does it the old fashioned way from their L-1011. I answered some technical questions for them once...
https://en.wikipedia.org/wiki/Orbital_Sciences_Corporation#/media/File:KSC-04PD-2234.jpg
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Reply 17 - Posted by:
DVC 4/15/2019 2:14:13 AM (No. 33482)
#16, your information on Allen buying Scaled is not correct. A recent President is a friend, as was Rutan, from the early 80s. The company is owned by Northrop Grumman.
Allen funded a project that Scaled carried out to win the Ansari X Prize, which I was personally on site to witness the first flight to space with. Branson, who stood about 10 ft away from me at the first record breaking flight when Mike Melvill, another friend, flew the first suborbital flight with SpaceShipOne took over after the X prize was won to got the next step to commercialization with SpaceShipTwo.
Allen created Stratolaunch, and hired Scaled and some Scaled employees to build this aircraft.
Branson hired Scaled to design SpaceShipTwo, and created his own company to build it and test it, drawing from Scaled´s employees, too.
And, yes, Orbital Sciences has switched to Lockheed L-1011s from their earlier DC-10s for launch aircraft. The wings for the Pegasus have been built by Scaled, also.
6 people like this.
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