SpaceX Dragon Re-Entry Viewing

• SpaceX Dragon Re-Entry Viewing by ChrisC on 12 Mar, 2024 01:23
• This post (and subsequent discussion thread) is intended to provide basic guidance on viewing the return of a Dragon capsule, whether Cargo Dragon or Crew Dragon.
  
  Most Dragon capsule flights go to and from the International Space Station (ISS), which necessitates an orbital inclination of 51.6 degrees.  Since SpaceX supports nominal returns only to ocean splashdown locations around the Florida peninsula, this means that the Dragon will usually be approaching on a southeasterly track, OR a northeasterly track.  The southeasterly track will have the Dragon executing the final minutes of the (flame-y) re-entry across the southeastern US, typically over Tennessee, Alabama and Georgia.  The northeasterly track will put those final minutes over the Gulf Of Mexico.
  
  To determine which of those tracks is being followed by a Dragon that has just left ISS, use an ISS tracker app to look up the ISS flyover that is happening around the splashdown time.  Because the Dragon will have pretty much the same orbit as the ISS (certainly the same inclination), the ISS will fly over Florida within minutes of the splashdown, even if the Dragon had departed a day or two earlier.  The direction that the ISS flies over Florida (NW-to-SE, or SW-to-NE) will match the Dragon's track.  However, most ISS tracker apps only show sightings in pre-dawn or evening skies, not in the middle of the day or middle of the night when ISS won't be visible anyway.  Therefore, it's better to use NASA's excellent Eyes On The Solar System simulator; search for ISS, then use the time controls to fast-forward to the splashdown time.
  
  The rare Dragon flights that do not go to the ISS, such as the Inspiration 4 or Polaris Dawn missions, could approach on any easterly track, but usually they'll be in lower inclination orbits (e.g. 28.5 degrees) and thus will be approaching Florida from due west (heading due easterly).  This means those final minutes will happen over the Gulf or along the Gulf Coast (along the northern edge of the Gulf -- the LA / MS / AL coasts), depending on which of the seven zones has been targeted.
  
  Obviously any re-entry over land has the potential to be visible to people on the ground.  Assuming clear skies, nighttime flyovers should be easy to spot -- you just need to look for the bright spot, with a glowing trail behind it, moving across the sky a bit faster than a jet.  Where in the sky depends on where you are, and which of the seven splashdown sites SpaceX is aiming at, but you may not know that ahead of time.  So it's best to scan the entire sky for those several minutes, especially if you think you'll be directly underneath it, because a small left or right crossrange variation by the capsule could put it on one side of the sky or the other for you.
  
  Daytime flyovers are harder to spot due to the background sky, but with very clear skies, and some knowledge of which splashdown site they are targeting, you can know which way to look.
  
  In general, your viewing location should be a spot where you can see as much sky as possible, but especially the southeastern sky.  LOOK UP and scan the ENTIRE sky, looking for a slow streak moving across the sky (likely from the northwest to southeast, per discussion above).  Even if you do spot it and it departs down below the southern horizon towards Florida, stick around for an extra two minutes because a sonic boom will "trail" the capsule.  You can visualize the sonic boom as the capsule dragging a cone behind it, and when that cone passes over you, well after the capsule has passed overhead, you'll hear the boom.
  
  Regardless of the exact track, a sonic boom will definitely be audible if the capsule has descended far enough into the atmosphere, typically within 1000 miles of the splashdown site.  So even if you have cloudy skies, you should be listening for the boom about 5-15 minutes before the planned splashdown time, depending on how far up-track you are from Florida.  the boom will likely sound like a distant thud, like a explosion far away, and typically generates attention on social media -- and even regular media.  ("Uhhh, did you hear that?")
  
  Typical timeline, referenced against splashdown time:
  S minus 51 minutes: deorbit burn starts
  S - 37 minutes: deorbit burn completes
  S - 15 minutes: entry interface (capsule's first encounter with atmosphere)
  S - 13-14 minutes: fireball / streak across sky starts (~1200 miles up-track)
  S - 6-9 minutes: fireball / streak across sky ends (near Florida)
  S - 4 minutes: drogue parachutes deploy
  S - 3 minutes: main parachutes deploy
  S - 0 minutes: splashdown   79:30
  
  NASA will typically announce the planned splashdown time.  You should then back that up by 10-15 minutes to estimate when the capsule will be flying over, then be outside and scanning the skies 5 minutes before that, especially if you are well up-track from Florida (e.g. in Tennessee, Louisiana, Mississippi, Alabama, or Georgia).  If you are even further up-track (Arkansas, Oklahoma, Missouri, Kansas, Nebraska, Colorado) you should go outside a couple minutes sooner.
  
  Resources:
  - NASA TV on Youtube
  - NASA Eyes on the Solar System (see guidance above)
  The following Twitter feeds sometimes post a ground track with time markers:
  - NASA on Twitter ( TWstalker repeater )
  - Trevor Mahlmann on Twitter ( TWstalker repeater )
  - FlightClub.IO (Declan) on Twitter ( TWstalker repeater )
  (the "TWstalker" links work even if you don't have a Twitter account, or aren't signed into Twitter)
  
  (I will monitor this thread for a bit after creating it, and will edit any resources provided by others into this first post.  Then during future Dragon returns, especially Crew Dragon, I'll come back here for reference but also to see if anyone's added anything more. - ChrisC)
  

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• #1 by ChrisC on 12 Mar, 2024 01:40
• Hi all ... As you can see above, I've written a reference post to explain to people how to see an reentering Dragon capsule.  I'm in north Georgia and have seen this zero times and heard it twice   I'll be outside tonight (early tomorrow) to try again, and this time I'll be noting the exact timing, so I can improve the writeup above.  (There's no need to comment on tonight's visibility for me personally; I'm following the Crew-7 thread and I'm aware of the track.)
  
  If you observe this reentry, or any re-entry for that matter, please document the following:
  A) which direction you were facing (e.g. southeast)
  B) about how high up over the horizon it peaked (e.g. one hand-width with your fingers spread, two of them, etc.)
  C) EXACTLY what time (to the second) you saw it -- beginning, peak height, and end
  D) exact time you heard the sonic boom
  E) where you were -- just the city / region is fine.
  
  A few things other things that I could use help with:
  - if anyone knows the entry interface time (yy above), let me know and I'll edit in (EDIT: done)
  - I could also use an NSF-sourced graphic for the landing zones (the only one I found was a webp file, and this forum rejects that upload) (EDIT: done)
  - I'd like to provide a graphic for a typical descending-node entry path to the Atlantic side of Florida (I used a FlightClub.IO graphic here that shows a Pensacola splashdown, and linked to the tweet in the text)  (EDIT: still needed)
  
  Finally, if anyone is savvy enough to create some custom graphics to illustrate these entry paths and their visibility, go for it!  I link to several images in the text, but I'm sure some here can do better.
• #2 by Ron Lee on 12 Mar, 2024 08:46
• I saw it on the original map timing from Colorado Springs, CO area.
  
  Initially almost due north up about 5-10 degrees around 3:36:10 AM MDT then as it was passing northeast a visible trail...fading about 5 degrees elevation around azimuth 110 degrees at about 3:37:50 AM MDT.
  
  Reddish tint.
  
  Before it faded from view totally it was getting dimmer which logically seems to be because I was not looking at the heat shield area from the front like when I first saw it or even the side when it was passing to the northeast.  It might be better to the southeast (since I was west of the ground track) if I were in Arkansas but not closer to the beginning of the plasma phase from my location.
• #3 by ChrisC on 12 Mar, 2024 18:18
• Thank you Ron!  Looking at a map, I'd say that you were about 165 miles off the forecasted ground track.  Would you say the peak altitude (over your horizon) was around 10 degrees?  And it's unlikely, but did you wait around to try to hear the sonic boom?
  
  My own report:  I saw it!  From 200 miles away in Atlanta, I went to a spot with a perfect view of the southwest horizon (a neighborhood overlook) and saw the glowing trail about 4 degrees above the horizon.  It was right on schedule at 5:41am ET -- I was unable to note more accurate timing due to it happening so quickly.  Anyway, take that, NASA visibility graphic ... I do wish they would add another contour to those graphics for 5-10 degrees altitude; 5 degrees is totally visible if you just move to a decent spot, and as low as just 2 degrees is possible.
  
  I waited a bit for the sonic boom, but then realized with cross-range distance of 200 miles, it would a) take 15 minutes to get to me and b) would have totally dissipated by then.  I do hope to eventually find out (in this thread) what's the farthest cross-range distance we should expect to hear the boom, and then I'll document it above.

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• #4 by Ron Lee on 12 Mar, 2024 21:36
• It may have been about 15 degrees but consider that approximate.  Around that time I was trying to video it and did not check a nearby star (in Cygnus?) to get the actual elevation.  I did not think to wait for a sonic boom.   Big mistake but I was excited to see it.  Next time will be better.  Currently I am trying to characterize the deorbit burn and propellant dump from Starlink 6-xx launches.
  
  A key takeaway of my observation and probably yours is that the elevation estimate and times were close enough for most people to see it.  Allow for scanning left and right and up and down, plus being outside ten minutes or so to let your eyes adapt to the darkness, and looking several minutes early and late just in case, and people can see the next one.
  
  What got me were the postings saying that splashdown was three minutes earlier than expected.  So I was looking perhaps five - seven minutes early.
• #5 by Bob Niland on 13 Mar, 2024 00:55
• Rural, no yard light, near Abilene KS, just happened to need to be up at reentry time (making an airport run), and sky was pretty clear, so went out to see what might be seen.
  A bright star-like spot appeared on schedule low in the NW sky, which turned into a larger, obviously reentering object, and made its way to the SE, leaving a glowing plasma trail, perhaps 25-30° above the horizon. I wasn't able to hang around long enough to see if there was a sonic boom.
  The presentation was both brighter and faster than I expected, but that's based on never having previously watched a controlled spacecraft reentry, although I have seen many meteorites, a couple of skippers, and what might have been some retrograde space junk.
  No effort was made to get photos or video, as this would have required figuring out how to override the auto-exposure and auto-white-balance on the phone, and some advance testing. Maybe next time.
• #6 by ChrisC on 20 Mar, 2024 02:48
• Here is a collection of observations of the Crew-7 reentry from around the internet, sorted roughly uptrack to downtrack:
  
  Colorado Springs: see comment above
  video: reentry early this morning over southwest Nebraska
  photo: capsule reentry early this morning from our hometown, Salina, KS
  Abilene KS: see comment above
  news report with video: Oklahomans could see SpaceX Crew-7 making re-entry early Tuesday morning (OKC?)
  video: SpaceX Crew 7 on Dragon Endurance Reentering over Tulsa, OK
  news report with video: Saw something in the sky overnight in Arkansas?
  news report with video: Four State residents watch the re-entry of SpaceX Dragon capsule (Joplin MO)
  video: Off I-10 in Alabama mile marker 44 looking west
  photo: Crew 7's reentry seen from New Orleans, LA
  (twitter URLs replaced with twstalker to suppress embeds)
  
  If anyone has some suggestions for my writeup guidance above, let me know.  For the next reentry I'll polish up the formatting, splitting it into titled sections.  Eventually this should be good enough to be made into a sticky thread, like the how-to-see-a-launch threads.  See you all at the next one!
• #7 by ChrisC on 28 Apr, 2024 18:49
• With the CRS-30 cargo mission coming to an end, we'll have another Dragon re-entry, but for now this appears to NOT be one that will be visible / audible to most* people.  (EDIT: yes, Ron's corner case is why I said "most" )  But here's a link to the CRS-30 thread; if there any visual reports there I'll copy them here.  EDIT: none.
  
  

  Quote from: Ron Lee on 28 Apr, 2024 17:58

  If the CRS-30 splashdown is roughly 1:00 AM EDT on 30 April 2024, then that will be a southwest to northeast ground track.  If it is an Atlantic Ocean splashdown then far more people will have the opportunity to see it than if it goes to a Gulf of Mexico zone.
• #8 by Ron Lee on 28 Apr, 2024 21:07
• People may be able to see it even if going to the Tampa or other Gulf of Mexico (GOM) sites.  A few years ago someone at Shell Point beach south of Tallahassee photographed the CRS-21 entry going to Tampa.   It was low but since it was dark it should be easy to see.  The same should apply to other GOM sites.
  
  This is from the Shell Point beach for CRS-21 return:
  
  
• #9 by ChrisC on 26 Jul, 2024 23:30
• Weeeellll with today's announcement that SpaceX will transition Dragon recovery operations to the West Coast (to minimize trunk debris threat), the days of these overland returns are now numbered
  
  In the Crew-9 press conference, SpaceX's Sarah Walker said "we hope for [the transition to West Coast returns] to be complete shortly after Crew 9's return".  Looking at the manifest, that appears to mean we'll see four more of these:
  
  Aug-Sep 2024: Crew-8 return
  Oct 2024: CRS-31 return (launch expected Sep 2024)
  Jan 2025: CRS-32 return (launch expected Dec 2024)
  Feb-Mar 2025: Crew-9 return (launch expected Aug 2024)
  
  She also said that there would be a fleet transition period when the fleet would be split across both coasts, so maybe we'll see more or less than those.
  
  Obviously I hope one or more of these will be descending node entries that pass over CONUS where we can see and hear them!
  
  Notes:
  Apr 2025: CRS-33 return (launch expected Mar 2025)
  Sep 2025: Crew-10 return (launch expected Feb 2025)