People in the eastern United States will get a great opportunity, weather permitting, to see the Space Shuttle Discovery launched into orbit Wednesday evening, March 11.
The Shuttle flight (STS-119) will be the 28th to rendezvous and dock with the International Space Station (ISS) and the glow of its engines will be visible along much of the Eastern seaboard of the United States.
To reach the ISS, Discovery must be launched when Earth's rotation carries the launch pad into the plane of the ISS's orbit. For mission STS-119, on March 11 that will happen at 9:20:10 p.m. ET, resulting in NASA's first Shuttle flight of 2009 and its second consecutive nighttime (the previous shuttle flight, last November 14, was also a nighttime launch). This launch will bring the Shuttle's path nearly parallel to the U.S. East Coast.
What to expect
For most locations, Discovery will be visible by virtue of the light emanating from its three main engines. It should appear as a very bright, pulsating, fast-moving star, shining with a yellowish-orange glow.
Based on previous night missions, the brightness should be at least equal to magnitude -2; somewhat brighter than Sirius, the brightest star in the sky, which shines brilliantly in the south-southwest during the evening hours. Observers who train binoculars on the Shuttle should be able to see the rapidly moving shuttle resembling a tiny V-shaped contrail.
In the Southeast United States, depending on a viewer's distance from Cape Canaveral, Discovery will become visible anywhere from a few seconds to 2 minutes after it leaves Pad 39-A. The brilliant light emitted by the two solid rocket boosters will be visible for the first 2 minutes and 4 seconds of the launch out to a radius of some 520 statute miles from the Kennedy Space Center.
No matter where you're located, keep in mind that the Shuttle will not get very high above the horizon. In most cases, it will range from roughly 5 to 10 degrees. To get an idea of how high this is, make a fist and hold it out at arm's length. Place the bottom of your fist on the horizon; the top of your fist is 10 degrees
By location:
- Southeast U.S. coastline: Anywhere north of Cape Canaveral, I suggest viewers initially concentrate on the south-southwest horizon (if you are south of the Cape, look low toward the north-northeast).
- Mid-Atlantic region: Look toward the south about 3 to 6 minutes after launch.
- Northeast (Washington, Philadelphia, New York, Boston): Concentrate your gaze low toward the south or south-southeast about 6 to 8 minutes after launch. Of course, as the shuttle gets closer, its azimuth very quickly swings over to the southeast, where in most cases, the point of maximum altitude occurs. I suspect most people will be scanning the horizon from south-southeast in the final couple of minutes of powered ascent . . . if so, you shouldn't miss out on sighting Discovery.
Discovery will seem to flicker, then abruptly wink-out 8 minutes and 23 seconds after launch as the main engines shut-down and the huge, orange, external tank is jettisoned over the Atlantic at a point about 870 statute miles uprange (to the northeast) of Cape Canaveral and some 430 statute miles southeast of New York City. At that moment, Discovery will have risen to an altitude of 341,600 feet (64.7 statute miles), while moving at more than 17,000 mph and should be visible for a radius of about 770 statute miles from the point of Main Engine Cut Off, or MECO.
Should the launch of Discovery be scrubbed on Wednesday, March 11, the launch will be rescheduled on a daily basis, but the time of the launch will occur roughly 23 minutes earlier for each day the launch is delayed (launch window times through March 16).
Before hoping to see the Shuttle streak across your local sky, make sure it has left the launch pad! Watch a television news outlet to verify that Discovery has been launched, or you can watch the launch on your computer via streaming video from NASA-TV.
Good Luck!