Friday, July 15, 2022

CRS-25 Launch Was a Treat

Last night's SpaceX launch of the CRS-25 mission was a visual treat here.  Lifting off at 8:44 EDT, that was pretty much 20 minutes after sunset here, which means it's both relatively dark at ground level while bright and sunny up around 40 to 50 miles where the Falcon 9 drops its booster.  Because of that, we got to see another example of the phenomenon called a Space Jellyfish, which happens when the exhaust plume of the second stage is illuminated by the sun, staying bright against the dark sky.  The plume spreads as the second stage continues to speed up and separate from the booster, while the booster maneuvers to land on the waiting drone ship.  The booster continues to climb on its previous trajectory while it maneuvers as shown here.

It's a fun fact to me that the Cargo Dragon was carrying nearly 5,900 pounds of supplies to the ISS, but that's a light enough load to a Falcon 9 that they didn't need to deploy drone ship ASOG (A Shortfall Of Gravitas) as far downrange as it needs to go for heavier payloads.  As result, the booster could have enough fuel after separation to do some maneuvering.  

The best image I've seen of this is from Richard Angle for Teslarati, except the orientation is wrong.  From my view point, this is sideways.  The brightest dot, which is the accelerating second stage, was at the bottom instead of the far right. 

The other bright dot, about 1/8 of the way behind the second stage, is the first stage.  

We were able to watch the booster until the start of its entry burn, a 20 or 30 second burn perhaps a minute before the final landing burn.  It was a dark enough sky for the entry burn to be easily seen - until it went behind some distant trees.  

Despite the excellent picture above, the best coverage of this mission that I've seen hasn't been the Teslarati coverage, but rather Spaceflight Now's.  What sets their coverage apart is that they embed their own videos, posted separately on Twitter, of key parts of the mission including showing this contrail developing and the booster landing on ASOG. 



4 comments:

  1. ya' know I'm only 100 miles or so to your south, but I never get to see the launches. Too close to where all the people are, and the sky is always bleached out at night I guess.

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    1. By extreme coincidence a commenter to one of the places I was reading said they live in Ft. Lauderdale and saw it from their yard. That's quite a bit south of you. My brother lives in Boca Raton and says he has seen launches from his yard. Those were Falcon 9 launches going south offshore the east coast. The biggest difference between here and farther south is they'll go higher in the sky.

      Night launches like last night should be the best to try to see because bright, moving lights are easier to pick out. To start with the obvious, one, make sure you're looking in the right directions. Remember the coast moves west as you go north from around the Palm Beach/Jupiter area. The Cape is west of north from where I think you are. If they're launching to the NE, that's another problem.

      Next mission is Sunday, but 10:50 in the morning, so not a good time to look.

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  2. That launch was a great show. Watched it from the front deck of our boat at Kennedy Point Marina, in Titusville, across the lagoon from the launch pad. Thanks for the link.
    John in Indy

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  3. Thanks for posting this. I've seen the odd launches from Vandenberg AFB over the Pacific and they're spectacular, but rare in their frequency.

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