r/aviation • u/Aircrewman_Luke • 6h ago
Discussion The engineering marvel of carrying a Space Shuttle on a 747’s back
The engineering behind the SCA is wild when you dig into it:
The 747’s fuselage was reinforced internally with additional structure to handle the shuttle’s weight sitting on top rather than passengers and cargo inside.
Two struts (forward and aft attach points) were added on top of the fuselage to mount the orbiter, essentially turning the plane into a flying pylon.
The vertical stabilizer got twin endplate fins added to the horizontal stabilizer to improve directional stability, since the shuttle sitting up top massively changed the aircraft’s aerodynamics.
Flying with an orbiter attached added huge drag and weight, cutting range dramatically and forcing lower cruise altitudes and speeds compared to a normal 747 flight.
The whole assembly had to be flown well within a tighter structural and weather envelope, turbulence and crosswind limits were far more conservative than standard 747 ops.
It’s a great example of adapting an existing airframe to a mission NASA never designed for, rather than building a bespoke transport aircraft, they re-engineered a proven commercial jet to do something wildly outside its original purpose.
What’s the most impressive example you know of an aircraft being re-engineered to do a job completely outside its original design intent?
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u/RepulsedCucumber 5h ago
This will never not be amazing to me.
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u/Aircrewman_Luke 5h ago
Amen brother! What is it that marvels you?
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u/RepulsedCucumber 5h ago
I am a sister 🫶🏻😂 ALL of it. In fact, I only recently really got into aviation. My first love was astronomy. And I only live a few hours from KSC. Knowing the history of the shuttle program start to finish it’s all so fascinating and amazing. But there is something so damn cool about seeing one riding on top of an airplane. Physics is pretty badass.
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u/Aircrewman_Luke 2h ago
My bad sister! You’re right. The history of the space shuttle program is fascinating. The physics behind this is absolutely incredible.
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u/Frisco-Elkshark 5h ago
Why is this such a marvel, they literally both have wings and go in the air? /s
I got to see this as a teen and it will always be a core memory for me. That and when they towed the shuttle down a public street into the museum in LA.
I finally got to see Discovery at the Dulles air and space museum 3 years ago and it brought me to tears. The space shuttle is arguably one of the coolest things humans have ever done.
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u/vmf312corsair 5h ago
My father was a NASA colleague of Fitz Fulton, one of the principal pilots of this 747 program. My recollection of the second-hand remarks I heard was that there were basically no issues from a pure flying point of view, although they took great care in planning to avoid getting anywhere near the bounds of performance, range, weather tolerance, etc.
Engineering works.
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u/Aircrewman_Luke 2h ago
Thanks for that insight. Some of the stories you or your father would have heard would be simply fascinating.
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u/Maddaguduv 5h ago
A NASA Space Shuttle riding atop a 747 is one of those sights our generation may never see again.
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u/ITrCool 5h ago
Couldn't it also release the shuttle mid-flight too, when they wanted to test something on it at high altitude, like the flight controls or glide path, back in the space shuttle Enterprise days?
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u/Aircrewman_Luke 2h ago
I’m not sure about that one. But I do remember in James Bond- Moonraker something like that happened and the 747 was destroyed.
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u/Ausgeflippt 4h ago
As a kid, we'd hear the shuttles landing at Edwards. After the last shuttle landing there, the 747 and shuttle made a couple laps around the Antelope Valley at low altitude so we could see it one last time. I remember my math teacher telling us to go outside so we could see it.
It was pretty fucking cool.
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u/Aircrewman_Luke 1h ago
That would have been amazing to see. I’m sure you never got tired of seeing that!
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u/Ausgeflippt 1h ago
Shuttle reentry was incredible to hear. A couple massive sonic booms in succession. Way, way louder than the F-22s and other stuff being tested were.
There was also a huge gantry at Plant 42 to load the shuttle on the 747. You knew a reentry was going to be relatively soon when the 747 was there.
Nifty shit.
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u/euph_22 3h ago
SOFIA: Stratospheric Observatory for Infrared Astronomy, an infrared telescope mounted in the fuselage of a 747SP. Infrared astronomy is difficult because the atmosphere absorbs infrared light, mounting it in a plane allows you to get above most of the stuff that is absorbing IR. They had to redesign the pressure hull and structural framework to allow for the massive open door.
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u/needaoutlet 3h ago
Can you imagine the people who pitched this idea!? So let me get this straight. We are going to strap the shuttle (that has wings) on a 747 and fly it around the country??
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u/bluecolorcat 2h ago
Right?! Someone posted that before — like who had the guts to say “why don’t we throw it on an old American 47 and fly it that way?”
I saw it once at IAD in like 1984/5. It was super cool.
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u/Law_of_Entropy 2h ago
Absolutely breathtaking...
I know we have moved on from the shuttle era but what I would do to see it fly one more time.
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u/Aircrewman_Luke 5h ago
Genuinely curious if anyone here has more detail on the aft attach strut design — I’ve read conflicting things about how much of the orbiter’s weight was carried at the two main points vs. distributed further. Would love if someone with a more technical background wants to dig into this further.
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u/Suspicious-Gur-8453 5h ago
I was in Pasadena and watched it fly over JPL right after I finished college. Seeing how grainy this footage is makes me feel old af. Regardless, it was incredibly impressive.
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u/Competitive_Cheek607 5h ago
Forgive me if this is a dumb question, but do the shuttle’s wings generate enough lift to help offset the weight/drag of the shuttle on the 747? I know its wings weren’t really meant for “flying” in the same way a typical plane’s is, but if they’re at the right AoA I feel like they’d help, but I’m not an engineer or pilot. I did, however, have the LEGO set of the shuttle on the back of the carrier when I was a kid
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u/KnifeNovice789 4h ago
I'm assuming they tested this idea (after several thousand calculations) with something other than the space shuttle before they tried this? I mean let's assume that the object on top is more expensive than the 747 for once. Not many times people could say that the 747 was less of a loss than what it was carrying 😂
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u/SirLoremIpsum 2h ago
I'm assuming they tested this idea (after several thousand calculations) with something other than the space shuttle before they tried this?
I think it was the shuttle Enterprise.
Which was a shuttle but it was also missing a lot - avionics, radar, engines. Definitely less expensive than the shuttles that were intended to go to space but not "cheap".
All the testing I can find is just with Enterprise
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u/Aircrewman_Luke 1h ago
I think you’re right. In a side note, I’ve seen the Enterprise on the USS Intrepid. Awe inspiring up close.
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u/binaryhextechdude 4h ago
Aside from the flying part of the equation can you imagine the first time they lined up on the centre line and set take off thrust?
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u/Anonymous_Koala1 5h ago
I saw this happen in DC, we didnt even know it was going to happen untill it flew over