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Topic: Speed Limits On 747 Space Shuttle Carrier
Username: Max Q
Posted 2012-04-19 17:29:18 and read 6066 times.

Trying to find out what the speed / mach and altitude limits are on the Nasa 747SCA with a space shuttle attached for ferry flights.



Also, are there any speed / mach / altitude limits on the SCA when it is not carrying the Shuttle ?


Just wondered if those struts and different vertical tail set up might affect it.

Topic: RE: Speed Limits On 747 Space Shuttle Carrier
Username: rwessel
Posted 2012-04-19 18:24:24 and read 6044 times.

NASA says 250kts/.60M with or without a Shuttle on top. They don't list a maximum altitude, but mention "typical" cruise altitudes of 13-15,000ft (mated) and 24-36,000ft (unmated). I'd expect that with the huge drag of the Orbiter, and the significant fall-off in engine performance with increasing altitude, the maximum achievable altitude (mated) is not that far beyond the 15,000ft listed.

http://www.nasa.gov/centers/dryden/news/FactSheets/FS-013-DFRC.html

Topic: RE: Speed Limits On 747 Space Shuttle Carrier
Username: Max Q
Posted 2012-04-19 18:51:21 and read 6033 times.

I knew they had some pretty restrictive limits while carrying the Shuttle i'm just surprised the restriction remains when
it is not carrying it.

Topic: RE: Speed Limits On 747 Space Shuttle Carrier
Username: Sinlock
Posted 2012-04-20 05:19:18 and read 5866 times.

Quoting Max Q (Reply 2):
I knew they had some pretty restrictive limits while carrying the Shuttle i'm just surprised the restriction remains when
it is not carrying it.

From reading http://www.nasa.gov/centers/dryden/news/FactSheets/FS-013-DFRC.html
I'd venture a guess that the speed restriction relates to the two extra vertical stabilizers and the altitude restriction related to the tempature limit of 15F(-9C) degs.

Topic: RE: Speed Limits On 747 Space Shuttle Carrier
Username: Dreadnought
Posted 2012-04-20 10:40:09 and read 5769 times.

Quoting rwessel (Reply 1):

NASA says 250kts/.60M with or without a Shuttle on top. They don't list a maximum altitude, but mention "typical" cruise altitudes of 13-15,000ft (mated) and 24-36,000ft (unmated). I'd expect that with the huge drag of the Orbiter, and the significant fall-off in engine performance with increasing altitude, the maximum achievable altitude (mated) is not that far beyond the 15,000ft listed.
http://en.wikipedia.org/wiki/Approach_and_Landing_Tests

During the early tests with Enterprise, the mated pair got up to above 30,000 feet, and 474 mph. The highest altitude the Enterprise was released at was 26,000 feet.

Topic: RE: Speed Limits On 747 Space Shuttle Carrier
Username: francoflier
Posted 2012-04-20 13:35:11 and read 5678 times.

Quoting Max Q (Thread starter):
Trying to find out what the speed / mach and altitude limits are on the Nasa 747SCA with a space shuttle attached for ferry flights.

I would say around 7 Miles/second and around 250 mi high...
 

I'm also guessing the limiting factors are all the appendages added to the SCA to carry the orbiter and stabilize the airflow around the 'assembly'. I doubt either airframe would mind going higher or faster, especially the one on top.


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