United Jet Diverted After Captain Feared Space Debris Cracked His Cockpit Windshield — It Was a Balloon

The Captain of the United Airlines Boeing 737 that diverted to Salt Lake City on Thursday reportedly thought his plane was hit by space debris. JonNYC was first to report this theory, along with photos of damage to the cockpit’s windshield and photos of the captain’s arm that sustained an injury. It looks like we now have an explanation for the impact.

HOLY CRAP!!! A MAX8 hit a falling object at FL360 yesterday!!! pic.twitter.com/OBx8eUiq4w

— Oeingo Boeing-Go (@oeingoboeing) October 18, 2025

Much of the world seemed to be blaming Elon Musk for a SpaceX satellite. Space debris is a defunct human-made object in Earth’s orbit—such as inactive satellites, spent rocket stages, and fragments from collisions or explosions—that no longer serve a purpose and may eventually fall back into Earth’s atmosphere. These can be like loose pebbles hitting your windshield on the highway, only here it was a cockpit windshield that cracked at 36,000 feet.

I was initially skeptical of the space debris hypothesis.

• The odds of space debris are incredibly low. An actual passenger injury from space debris has been deemed by the FAA to be less than a one in a trillion event.

• The captain reported seeing the incoming object just before impact. That made me even more skeptical, believing that if it were debris it would be tiny and dark by the time it reached the plane’s altitude, and wouldn’t reflect much light, likely blending into the sky and moving incredibly fast.

  By the time it was close enough to see, it would have already hit (a fraction of a second between being visible and impact at most). The captain would have to have been staring at exactly the right spot at exactly the right time to see it.

We now appear to know that it was a ballon that impacted the jet, not space debris. It was likely a Windborne Systems weather balloon. Windborne is taking responsibility.

We file NOTAMs, follow all specifications required by FAA 14 CFR part 101, and share all live balloon positions with the FAA via API and our website. That photo is old hardware, the current version operational is about 2x lighter. pic.twitter.com/LCXshmpiN9

— John Dean (@johndeanl) October 21, 2025

The system is designed to not pose a risk to human life in the worst case event of a collision. This is what the FAA 101 and ICAO weight limits are for. And indeed, there were no serious injuries and no depressurization event to my knowledge as a result of the collision.…

— John Dean (@johndeanl) October 21, 2025

As mentioned, we are working closely with the FAA on this. We haven't yet received any operational guidance. Regardless, we just deployed a software change to minimize time at active flight levels and are manually checking it across the full constellation. Additionally, we are…

— John Dean (@johndeanl) October 21, 2025

Yep, this is correct, and it's what we do. We use GPS to get position, and we telemeter it to the ground every 5-10 minutes using iridium. We then share location and predicted flight paths with the FAA and other airspace authorities via both a website and an API.

— John Dean (@johndeanl) October 21, 2025

Here's what the operational part of the @WindBorneWx weather balloon looks like – they use sand as ballast. And here's the plane, I now understand why the paint on the window frame looks like it's been sand blasted.

It does look like WindBorne are doing all the right things,… pic.twitter.com/xGtqlpHjMd

— Scott Manley (@DJSnM) October 21, 2025

WindBorne Systems deploys high-altitude balloons (‘Global Sounding Balloons’) paired with an AI forecasting system to gather real-time data from extreme storms and feed their machine-learning model. They believe they can extend forecasting horizons to 21 days with improved accuracy. Google’s DeepMind, Microsoft, and NVIDIA are all involved in AI weather forecasting. Windborne focuses on acquiring high resolution data from within storms (think 1996’s Twister but at altitude).

They have a huge network that they launch into the sky:

WindBorne's Constellation is […] nuts right now. pic.twitter.com/xA6GpCYgep

— John Dean (@johndeanl) August 16, 2025

Another community launch for the books! Thank you to everyone who came out, asked questions, & shared a slice w/ us.

Interested in seeing one in person?
Keep your eyes peeled for future community launches – coming to a flat piece of land near you ✨ pic.twitter.com/ZgZ17Z3EsQ

— WindBorne Systems (@WindBorneWx) July 24, 2025

Windborne communicates with the FAA, and designs their balloons not to pose risk to aircraft or passengers. However the impact to cockpit glass appears to have caused shards inside the cockpit to injure the captain. There are going to be lessons learned from this event both in terms of better avoiding conflict with aircraft, and in terms of safety in the event of an impact, because there are only going to be more objects flying through the atmosphere over time.