Tuesday, July 26, 2005

Return to Flight:

Much anxiety surrounded the return to space for the Shuttle today. I watched the launch on a Mac desktop widget linked to the KSC NASA TV transmission over a wireless connection while sitting in a meeting at the Brazilian Space Research Institute, INPE. Of course the NASA TV server was getting hammered pretty hard, so I only got a screen refresh every minute or so. But it was enough to do a series of frame grabs, and see the view from the camera placed on the External Tank (ET). Despite the stuttering video, an impressive display of what today's communications technology can do.

The sequence I was able to capture shows the changes in vehicle attitude throughout the ascent quite nicely. There was no on-screen countdown, so I am not sure exactly where in the sequence these scenes occur, but a lot can be deduced from what is in sight, what angles they appear at, sun angle, etc.

The first two shots are simply the required shot of the shuttle just after clearing the gantry on LC-39B, and a view from one of the off-track spotting scopes (which gives you an idea of the poor visual resolution we generally have of launches) ...


Sequence 1 Posted by Picasa


Sequence 2 Posted by Picasa

Now to the feedline fairing camera on the ET, which gives a very nice view of the underside of the orbiter, the ET and right SRB. At his point in the ascent, there are several things to note in the scene: the Florida shoreline is just above the elevon line, reflecting the shuttle-down attitude used on ascent. The SRB exhaust flames are visible, as are their reflections off the aft tile acreage.


Sequence 3 Posted by Picasa

In this next scene, the main change is the ascent attitude, with the shoreline creeping up the tail, as the shuttle's velocity vector slowly shifts from vertical to horizontal, in order to give it enough speed to achieve orbit. That may be a glimpse of LC-39A or B visible between the bipod:


Sequence 4 Posted by Picasa

In this next scene, the main change in the sun angle, which is causing saturation of the image.


Sequence 5 Posted by Picasa

In this next scene several things have already happened: the SRBs have already separated (so we are beyond 127 seconds into the mission), and the horizon is in view. The shuttle is now using the main engines to stabilize and circularize its orbit, probably over Europe and Northern Asia by this point. This is more or less the time when the largest piece of foam was seen drifting off. There was more lost at various points in the ascent, some earlier, some later.

The largest piece, about 3 feet by 1 foot, came off the LH2 Protuberance Air Load Ramp, which is just outboard of the piping and ducting that can be seen on the left running along the ET. This apparently occurred about 127 secs into mission, which is coincident with the SRB jettison. I have not heard any analysis of this yet (an interesting read is the Return To Flight Task Force Report, large PDF).


Sequence 6 Posted by Picasa

As the nose dips toward the horizon, the tail comes up...


Sequence 7 Posted by Picasa

Big attitudinal changes now - The shuttle has executed a roll, so the Earth is below the belly now, rather than above.


Sequence 8 Posted by Picasa

And finally, ... jettisoning of the ET. In comparison with the previous scene, we can see that the orbiter is actually the part that has changed attitude most - the horizon has not moved much from the ET's point of view. Nice view of the orbiter underbelly, I wish I had been able to see more of this. NASA does not have any of this footage easily available.


Sequence 9 Posted by Picasa

...and now, a view from the orbiter of the ET.


Sequence 10 Posted by Picasa

Here is a gallery of photos of the ET from this flight, including some nice close-ups of the foam loss locations. Here's some video of the ET from previous missions.

I did find a link to footage from a camera in the SRBs on this launch - several things to note: just before SRB separation, you can see pitting occur in the ET insulation; after the separation, the opposing SRB is visible tumbling at almost the same rate - it stays at a constant angle in the field of view; nice views of the Florida coast, and all the way to splashdown. Mac-hostile links: Left SRB footage. Right SRB footage.

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