STS-48

STS-48 was a Space Shuttle Discovery mission that launched from Kennedy Space Center on the evening of September 12, 1991, and landed at Edwards Air Force Base on September 18 after 81 orbits. Commander John Creighton, pilot Kenneth Reightler and mission specialists Charles Gemar, James Buchli and Mark Brown deployed the Upper Atmosphere Research Satellite, a NASA observatory of the ozone layer and upper atmosphere that went on to operate for 14 years.

The flight's UFO reputation comes from NASA Select television, which relayed live shuttle video over cable and satellite. Viewers who taped the feed found several sequences of moving lights. The best known, recorded on September 15, looks down at the night side of Earth, with city lights, lightning and the glowing horizon. Points of light drift across the frame; a bright flash fills the screen, streaks appear from the left, and one object traveling parallel to the horizon turns sharply and speeds off. A 1992 report for the Houston UFO Network by Vince Johnson argued that objects moving in different directions could not have been pushed by one thruster, and that Earth did not shift in the frame as an attitude-jet firing should cause; he concluded the events "can only be classified as UFOs, in the strict sense of the term." The tape reached national television in June 1992, when Don Ecker of UFO Magazine showed it on Hard Copy and then on Larry King's CNN program.

Ecker's opponent on King's show on June 26 was James Oberg, a space engineer and author who had worked in Mission Control during the flight as a NASA contractor. Oberg said spacecraft "are surrounded by clouds of debris," and that when the shuttle's jets fire, "the jets hit pieces. They change direction." Ecker countered that debris tumbles and that the whole picture would have moved had a jet fired. In a written analysis two days later, Oberg identified the flash as a reaction-control jet igniting, noting that such jets "may flash when they ignite if the mixture ratio is not quite right," and wrote that drifting particles caught in the plume "are violently accelerated away from the jet." NASA's own explanation was the same, ice particles reacting to the jets, and astronomer Philip Plait endorsed it in his 2002 book Bad Astronomy. Vince DiPietro, a Goddard Space Flight Center engineer who had analyzed the tape, called in to say the scientists and engineers he consulted all described it as ice, while adding that he could not explain one object Ecker raised.

The clip has never left UFO media, and in 2026 it gained a new frame. In May the NewsNation program Reality Check aired an episode titled "The footage the Pentagon has not explained," in which host Ross Coulthart and physicist Max Derakhshani went through it frame by frame; according to a promotional post for the episode, Derakhshani disputed Avi Loeb's suggestion that cosmic rays explain the anomaly. Reddit posts in September labeled the clip "DEW-SBL" and described the flash and streaks as a weapons engagement.

Some recirculated claims do not match the mission record. An April 2026 post on X attached to STS-48 a supposed radio call from "shuttle commander John Blaha" about an "alien spacecraft" under observation, dated to a launch on March 13, 1989. That is the launch date of a different Discovery flight, STS-29, on which Blaha served as pilot; he was not on the STS-48 crew. The 1991 video remains a NASA television recording that the space agency and Mission Control veterans attribute to thruster-driven ice, while its promoters still argue that the light moves too purposefully to be debris.