STS-48 Discovery — NASA Footage, Anomalous Objects

On September 15, 1991, during Space Shuttle Discovery's STS-48 mission, NASA's onboard cameras captured footage of the Earth's limb showing multiple luminous objects moving in various directions against the backdrop of Earth's atmosphere. One object, moving in a consistent direction, abruptly changes course and accelerates upward at a sharp angle. Simultaneously, a streak of light crosses the frame and a flash occurs. The footage was included in NASA's live public broadcast feed. Physicist Dr. Jack Kasher of the University of Nebraska analyzed the footage extensively and published a peer-reviewed analysis concluding that the movements of the objects — including the abrupt directional change — were inconsistent with ice particles ejected from the shuttle's reaction control system (the official NASA explanation). Kasher's analysis found the acceleration implied by the directional change was too high to be consistent with thruster ejecta. James Oberg, a NASA mission operations specialist, provided the official counteranalysis supporting the ice particle explanation. The debate between Kasher and Oberg was published in scientific correspondence. The footage remains publicly available in NASA archives. The STS-48 event is considered one of the most technically analyzed NASA UAP incidents alongside the earlier STS-75 tether incident.