The spy satellite that SpaceX launched about six weeks ago appears to have buzzed the International Space Station in early June. The fly-by was made by a dedicated group of ground-based observers who continued to track the satellite after it reach outer space. Ars Technica reports: One of the amateur satellite watchers, Ted Molczan, estimated the pass on June 3 to be 4.4km directly above the station. Another, Marco Langbroek, pegged the distance at 6.4km. "I am inclined to believe that the close conjunctions between USA 276 and ISS are intentional, but this remains unproven and far from certain," Molczan later wrote. One expert in satellite launches and tracking, Jonathan McDowell, said of the satellite's close approach to the station, "It is not normal." While it remains possible that the near-miss was a coincidence due to the satellite being launched into similar orbit, that would represent "gross incompetence" on the part of the National Reconnaissance Office, he said. Like the astronaut, McDowell downplayed the likelihood of a coincidence. Another option is that of a deliberate close flyby, perhaps to test or calibrate an onboard sensor to observe something or some kind of activity on the International Space Station. "The deliberate explanation seems more likely, except that I would have expected the satellite to maneuver after the encounter," McDowell said. "But it seems to have stayed in the same orbit."