The UA1093 Incident

Jonathan McDowell, 2025 Oct 20

On 2025 Oct 16 at 0645 MDT (1245 UTC) over 109.4W 38.6N the windshield of a United Airlines UA1093 airliner was damaged; the crew suggested that space debris was responsible. I do not have the expertise to rule out alternative explanations such as a meteorite or an internal structural failure. However, I can confirm that no *known* space debris reentries match this incident. One suggestion that the culprit was a WindBorne Systems high altitude balloon seems plausible.

Three tracked objects and one uncataloged one reentered on Oct 16 (a Starlink and two Chinese payloads, and a Falcon 9 upper stage). All are ruled out.

• 1) Starlink 1147 (45095, 2020-006BD)

  Space Force TIP reentry data reports reentry between 2352 UTC Oct 15 and 0152 Oct 16. Track in that period goes over Pacific Ocean, Indian Ocean, east Asia. Extrapolated orbit to time of airliner incident (just in case Space Force are wrong about the reentry) places S-1147 over the Indian Ocean at that time.

• 2) XJY-7 (47298, 2020-102C)

  Reentered over Canary Is. circa 16W 28N at 0157 UTC, reentry observed from ground. Space Force confirms reentry on Oct 16 but with no TIP reentry data.

• 3) WHSJW 6-01 (63428, 2025-067A)

  Reentered over Sakhalin 143E 49N at 1700 UTC based on Space Force TIP reentry data on space-track.org.

• 4) Falcon 9 second stage from Starlink 10-52 launch (uncataloged; GCAT A11656)

  Launched 0927 UTC from Canaveral to 260 x 270 km x 53 deg orbit. Deorbit burn at about 1120 UTC over Atlantic with reentry over Southern Ocean south of Australia at 1157 UTC. However, the extrapolated orbit did pass over Utah at 1235 UTC.

  One could come up with a deorbit misfire that sent the rocket stage to a high apogee before reentering circa 1245 UTC over Utah, but it's a highly implausible scenario and there is no evidence of it.

  Alternatively, what if a piece came off the rocket stage at SECO-1 (initial orbit insertion) in a circa 135 x 260 km orbit at 0935 UTC, survived first perigee at 1110 UTC, and reentered at second perigee around 1230 UTC? Such a reentry would very roughly match the place and time, as seen in the approximate track here:

  

  The ground track is 200 km off, but I haven't incorporated the effects of drag - perhaps someone can do a more accurate model.

  This is the only semi-plausible scenario I can come up with, but I emphasize it's not an expected outcome of the launch and I remain skeptical that the UA1093 incident was space debris related.

  One social media posting points the finger at a WindBorne Systems meteorological balloon which stopped reporting at around the right place and time (109.46W 38.53N 10.9 km alt, Oct 26 1236 UTC if I understand the report correctly).