Coverage started 2009 August 22
Updated 2009 August 27
After launch scrubs on August 25, 26, and 27, STS 128 (Discovery) is currently scheduled to launch from the Kennedy Space Center, Launch Complex 39A, to the International Space Station (ISS) at 23:59:35.000 Eastern Daylight Time on 2009 August 28 (03:59:35.000 UTC on August 29). To help illustrate this event, I created an AGI Viewer file for the ascent portion of the launch trajectory—from liftoff to main engine cutoff (MECO)—using data obtained from NASA.
As currently scheduled, this launch is set to go in the early morning hours of August 29 on the US East Coast, so it should be easily visible, weather—and sleep—permitting (be sure to take a nap). Of course, as luck would have it, I won't get a chance to watch this launch, either—after returning from two trips to the East Coast—but I am always interested to hear reports of successful sightings of the launch, so feel free to send them to me via e-mail, along with suggestions for how I could make this information more useful.
To give a sense of what can be seen in the AGI Viewer file, some selected screen shots are included below, along with a description of the information provided herein.
The scenario starts at 23:59:05.000 EDT, just 30 seconds before liftoff. New with this update, you can now view the scenario in real time starting when the launch countdown comes out of the hold at T-9 minutes. That means you can see things like the retraction of the orbiter access arm, as well as the tank vent cap and arm. Animating the launch sequence shows the ignition of the main engines at T- 6.6 sec followed by the SRB ignition at T-0. The scenario then proceeds through the roll program at T+11 sec to T+18 sec, SRB separation at T+2:03.04, and ends at MECO at T+8:35.04 (that's all the data we were able to get for this launch).
Screen shot from AGI Viewer file of STS 128 launch (T-0)
There are four predefined views with closeups of the space shuttle throughout the ascent phase: one from the side, one from the front, one from the back, and a new view from the RocketCam (see below). An example of the side view at T-0 is shown above. In the upper-left corner, each view shows the current local time, the latitude and longitude of the orbiter, the altitude (of the center of mass) of the orbiter above mean sea level (MSL), the orbiter's total speed, and the downrange distance. In the lower-left corner, there is information on the latitude, longitude, and altitude of the observation point, along with the distance to the space shuttle. The Mission Elapsed Time (MET) and time step are also shown here, along with a compass to give a basic idea of the oritation of the field of view.
A Google Earth location file of the launch scenario, is also available, but it doesn't have all the nice features of the AGI Viewer file. Information is contained in that file for how to use it.
Screen shot from AGI Viewer file of STS 128 launch (Overhead view)
Throughout the ascent phase, it is easy to see the launch from a variety of viewpoints, with full control of the vantage point and time—all without that pesky smoke from the SRBs—such as the view below as the space shuttle clears the launch tower.
Screen shot from AGI Viewer file of STS 128 launch (T+4)
Here's the view I added from the RocketCam on the External Tank. The shot below shows the RocketCam view looking down at Launch Complexes 39A and 39B, 30 seconds after liftoff.
Screen shot from AGI Viewer file of STS 128 launch (RocketCam on External Tank)
Of course, the AGI Viewer file gives you the ability to change viewpoints to more closely examine various aspects of a given event, such as SRB separation. The three images below show views from the front and rear of the orbiter, and from the RocketCam, just after SRB separation, using the front and rear predefined viewpoints. You can also see where key abort limits are reached during ascent in the first of these views.
Screen shot from AGI Viewer file of STS 128 launch (SRB separation, front view)
Screen shot from AGI Viewer file of STS 128 launch (SRB separation, rear view)
Screen shot from AGI Viewer file of STS 128 launch (SRB separation, RocketCam view)
There are also predefined viewpoints from 24 cities up and down the East Coast of the United States and Canada, as seen from the predefined home view for the scenario, just prior to MECO. The trajectories for both STS 128 and the HST show points at 30-sec intervals (e.g., at 00:01:05 EDT) to make it easier to determine their position at any particular time. The figure below also shows areas on the ground at each 30-sec point where STS 128 is above the local horizon.
Screen shot from AGI Viewer file of STS 128 launch (Space view, East Coast)
There are predefined views included from the following cities:
Each city view looks toward the space shuttle throughout ascent, showing when the orbiter will be above or below the local horizon, as seen in the sample view from Orlando below. Note that the thick portion of the ascent profile is from launch up to SRB separation and the thin portion is from that point until MECO.
Screen shot from AGI Viewer file of STS 128 launch (View from Orlando, Florida)
I hope you find this information both informative and helpful in sighting the launch of STS 128. If you have any questions, please feel free to ask.
For more information on the STS 128 mission, see:
Note: AGI Viewer is a free product which allows anyone with a Windows computer to view an STK (Satellite Tool Kit) scenario. With it, you can animate a scenario forward or backward, pause the animation, and zoom or pan the view for a more complete understanding of the event. Just like with Adobe Acrobat, where the authoring software requires a license but the Adobe Reader is free, STK can produce AGI Viewer files—also known as VDFs—which can then be viewed by anyone with the AGI Viewer software. You can find the free AGI Viewer on the AGI web site at http://www.agi.com/products/viewer/ (download here if you are experiencing problems with the AGI site). — TS
Dr. T.S. Kelso
Follow CelesTrak on Twitter @TSKelso
Last updated: 2009 August 27 19:29:01 UTC
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