[This article is taken from the (not yet posted) May 5 issue of the RocketSciRick Update, but with additional references.]
Following its part in the launch to the International Space Station on April 18, the first stage of Falcon 9 rocket turned around and performed a retro burn. Killing its horizontal velocity, its objective was a decelerated re-entry path back to the surface of the Atlantic. Specific location was not a priority, but SpaceX wanted it to reach zero velocity just above the water before shutting down.
The weather was particularly bad. The launch was almost cancelled. But it stayed clear long enough for the launch to happen. However, where the stage came down is where the bad weather had gone, with tall stormy waves on the ocean. No ships could be hired to go out to retrieve the stage. Even the Coast Guard refused to go out.
Telemetry from accelerometers on the rocket confirmed that the legs had deployed, and it hovered for a few seconds. Then the engine shut down, the stage dropped into the water. A few seconds later, telemetry stopped. The stage was subsequently ripped apart by the stormy wave action. An aircraft overhead received the telemetry and video. However, at the data rate required for the real-time video stream, there was too much interference from the weather. The result is that the video stream has a lot of holes in the data.
If you know what you are looking for, you realize that the camera is looking downward from somewhere on the first stage. You can sometimes make out the exhaust plume or the legs of the rocket as it nears the surface of the ocean. A couple of frames give a decent view of the deployed legs and the rocket exhaust blasting against the ocean. SpaceX attempted to do some in-house repair of other frames, but has now posted the raw MPEG data to its website. The company hopes that an interested and capable video expert will take notice, and take on the challenge of filling in the missing pieces. And in so doing, we will get a much more watchable video of the rocket, and perhaps even the legs in the process of deployment.
- MPEG data posted at: http://www.spacex.com/news/2014/04/29/first-stage-landing-video
- Codec settings: MPEG 4 Part 2, P/I 15, 15fps, NTSC, fixed bitrate
- Deep technical discussion of raw video repair at: http://forum.nasaspaceflight.com/index.php?topic=34597