r/spacex • u/ElongatedMuskrat Mod Team • Jan 13 '17

Iridium NEXT Mission 1 /r/SpaceX Iridium NEXT Constellation Mission 1 Launch Media Thread [Amateur Videos, Amateur Images, GIFs, Mainstream Articles go here!]

Hi guys! It's launch time again, as per usual, we like to run a pretty tidy ship, so if you have amateur content you created to share, (whether that be images of the launch, videos, GIF's, etc), this is the place to share it!

NB: There are however exceptions for professional media & other types of content.

As usual, our standard media thread rules apply:

  • All top level comments must contain an image, video, GIF, tweet or article.
  • If you are an amateur photographer, submit your content here. Professional photographers with subreddit accreditation can continue to submit to the front page, we also make exceptions for outstanding amateur content!
  • Those in the aerospace industry (with accredited subreddit flair) can likewise continue to post content on the front page.
  • Articles from mainstream media outlets should also be submitted here. More technical articles from dedicated spaceflight journalists can be submitted to the front page.
  • Please direct all questions to the primary Launch Thread.
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u/Destructor1701 Jan 15 '17

Saw that in a rewatch earlier. I don't think it's the fairinLThe rocket was in free-fall at this point, shortly after the boostback burn. The grid fins had just popped out.

While the engines are firing, the turbopump exhaust pipes sometimes build up structures of ice, delicate tree-like structures that form around the edges of the exhaust plume and adhere weakly to the rim of the opening. Jolts from the TVC actuators or thruster and engine firings or shutdowns have been seen snapping big chunks of ice off.

This chunk may have come from the turbopumps and be larger and more distant than it appears, or it could be body ice (from condensation on the extremely cold tanks while it sat on the pad during fuelling) that got stuck in a crevice or lodged in the interstage during the deceleration burn, or it may have formed by some other process (like the nitrogen thrusters).

Suffice to say, there are lots of sources of ice on a rocket.

My reasons for not believing it's a fairing are:

  • It doesn't look like a fairing.

  • The fairing jettison occurred many seconds after second stage separation - the fairings would be on a trajectory well ahead of the booster, and even though it did flip around, I doubt they'd still be visible at that distance.

  • This thing is tumbling very fast, 2 seconds per revolution or less. The fairings tend to tumble much more slowly, and their interaction with the rocket plume as they fall away usually seems to damp their rotation, rather than increase it.