Photos of the Shuttle Discovery launch

By Jack Williams ©2015

The photos in this gallery snow the first two minutes of the  Feb. 24, 2011 Space Shuttle Discovery launch. They were taken using a 300 mm lens from the media area at the Kennedy Space Center, Fla., which is approximately three miles from the launch pad.

Note that  from photo 6 to photo 9 in the gallery Discovery rolls so that the orbiter is no longer in view. Why shuttles roll on liftoff is explained in the answer to a question by a NASA aerospace engineer on the Aerospace.org Web site.

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I was at the launch doing some of the reporting for Weatherwise magazine story on weather forecasting for Shuttle launches. In addition, my next monthly Flight Training magazine weather for pilots column will be what general aviation pilots can learn from how NASA and its shuttle pilots handle the weather and shuttle flying. The Weatherwise assignment was good for press credentials for the launch. My wife went as my Weatherwise photographer.

Shuttle science

Since I believe one that any story–or photo gallery–about any aspect of the physical world isn’t complete without at least a little information about the numbers involved, I include information about Discovery’s height and speed in the captions for many of the photos. The basic data on Discovery’s post-launch timeline is from the Spaceflight now Ascent timeline.  This gives the time after liftoff in 10-second intervals, the altitude in feet, and the speed in the Mach number–Mach number 1 is the speed of sound.

I used the time on the metadata in each photo with the “liftoff” photo as zero to calculate the time after liftoff for each image. I then used the Ascent timeline–interpolating where necessary.

The speed of sound in air varies with the air’s temperature. Since the nearest and latest upper air atmospheric sounding, which includes  upper-air temperatures,  was from Daytona Beach, nine hours before the launch, I used the online DigitalDutch.com  Standard Atmosphere Calculator to find the speed of sound in knots at the various altitudes for the photos. This calculator uses the “standard” air temperature at each altitude. I then multiplied this figure by the Mach number for the altitude to get the speed in knots (the calculator doesn’t offer mph) I converted by multiplying the figures in knots by 1.15 to get mph. Thus, the figures for speeds are estimates but should be close to the actual values.

I explain the standard atmosphere in an article on it in the supplemental Web site for my AMS Weather Book: The Ultimate Guide to America’s Weather.

NASA’s Shuttle Basics page is a good source for more information about all aspects of the shuttles.

 

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