747 Shuttle Carrier Aircraft (SCA) approaching Endeavor

This 37 second movie clip shows the 747 Shuttle Carrier Aircraft (SCA) approaching Space Shuttle Endeavour suspended in the Mate-Demate Device (MDD).

NASA uses two modified Boeing 747 jetliners, originally manufactured for commercial use, as Space Shuttle Carrier Aircraft (SCA). One is a 747-100 model, while the other is designated a 747-100SR (short range). The two aircraft are identical in appearance and in their performance as Shuttle Carrier Aircraft.

Category:

Autos & Vehicles

Tags:

• nasa
• space
• shuttle
• endeavor
• sca
• mdd
• 747

[NikitasGuitars]

Enough to lift itself at that airspeed and angle of attack obviously. Im done arguing about this. We obviously both know we're right. Have a good one.

[mach25man]

The 747 can lift almost twice the weight of the orbiter. Its not really doing anything it cant already do. I tend to believe the guy who actually caculates this. Yes the orbiter glides as it sinks but how much lift is it producing ?

[NikitasGuitars]

The orbiter has wings and can fly, why wouldn't they let it do that? It only has to lift itself.

[NikitasGuitars]

It seems to me from watching the separation videos that they separate right around 250 kts or so. It appears they fly a shallow dive to gain speed and to also provide the 747 with an easier escape after separation. So nose down attitude or otherwise the orbiter seems to glide just fine at around 250 kts. 30 less than your stated 280 for ferry flights. Plus it just doesn't make sense to me from a structural or a fuel economy standpoint to have all the load on the 747's wings.

[mach25man]

Well, 30 years ago when they separated for landing tests, the 747 was flown is a shallow dive or nose down attitude. That profile is not flown for cross country ferry flights. It has not done separation flights since the late 70's.

[NikitasGuitars]

Explain to me how they separate the two midair then.

[mach25man]

I know the guy who calculates the weight & CG for these ferry flights. He says there is only about a 1000 lbs of lift created in the equation. Its a delta wing, the air flow is not exactly right bolted to th 747 and they only do about 280 kts or so.

[NikitasGuitars]

How exactly can drag outweigh lift? Obviously there is a lot more drag, sure, and the engines have to work harder. Maybe this is a question of semantics... I think it's more accurate to say the orbiter is being "pulled" rather than "lifted" by the 747. Remember the orbiter is technically a glider...

[mach25man]

I know this is a year old but I had to comment. There is very minimal lift from the orbiter. The drag caused by being mounted to the 747 far out weighs any lift by the orbiter. The 747 is doing all the work here.

[NikitasGuitars]

the 747 is really only providing forward thrust. the shuttle actually flies on its own to some extent thanks to being mounted on the 47 at a much higher angle of attack. So the 747 isnt "carrying" it per se.