NASA has confirmed the origin of a piece of space junk that crashed through an unwitting Floridian's home last month. After analyzing the object at the agency's Kennedy Space Center laboratory, scientists verified that it had come from EP-9, a pallet released from the International Space Station (ISS) in March 2021.
Because the ISS doesn't offer a ton of storage space, agencies are constantly working with astronauts aboard the station to manage excess or defunct equipment. Sometimes spare parts are kept on external stowage platforms (ESPs), or pallets that hang onto the station's exterior. When parts need to be discarded, the ISS loads them onto external pallets to be jettisoned into the vast expanse of space. The pallets involved in both of these processes are known as EPs.
On March 11, 2021, the ISS released EP-9, a pallet packed with discarded nickel-hydrogen batteries. NASA mission controllers used the station's Canadarm2 robot to ready EP-9 for two to four years of Earth orbit, after which the pallet would "burn up harmlessly in the atmosphere." After all, that's what space junk does when it reenters Earth's' atmosphere…usually.
On March 8, 2024, Florida homeowner Alejandro Otero and his son were spooked by an object that came crashing through their roof and the home's two floors. Otero found out via astrophysicist Jonathan McDowell's X account that the object had likely come from EP-9, which was supposed to reenter the atmosphere that day. The pair coordinated the object's delivery to NASA, which shared the object's official origin on Monday.
The 1.6-pound chunk of Inconel that punched a hole through Otero's house indeed belonged to EP-9, NASA says. The object was a stanchion, or support bar, from the flight support equipment used to mount retired batteries onto EP-9. Inconel is a metal alloy used to withstand extreme temperatures, pressure, and mechanical loads, but that doesn't explain why the stanchion didn't burn upon atmospheric reentry.
"The International Space Station will perform a detailed investigation of the jettison and reentry analysis to determine the cause of the debris survival and to update modeling and analysis, as needed," NASA said. "NASA specialists use engineering models to estimate how objects heat up and break apart during atmospheric reentry. These models require detailed input parameters and are regularly updated when debris is found to have survived atmospheric reentry to the ground."
This likely comes as good news for Otero, whose primary concern after the collision—besides recouping the cost to fix his house—was avoiding similar occurrences in the future. If Otero or his son had been standing elsewhere inside their home, the stanchion's damage could have been a lot worse, and that's something NASA definitely wants to avoid.
