June 18


Gravity Probe A, a joint experiment of NASA and the Smithsonian Astrophysical Observatory, is launched from Cape Canaveral aboard a Scout rocket. Gravity Probe A was used to confirm Einstein’s theory that gravity slows the flow of time, part of his theory of general relativity.


Fred Haise and Gordon Fullerton become the first crew to fly in the space shuttle Enterprise, a forerunner of the shuttle fleet that was never launched, but used instead to verify various shuttle systems while flying through the atmosphere attached to a NASA Boeing 747 aircraft and in later missions in a free-flight glide back to the landing strip after being released from the 747. In this test, Enterprise stayed attached to the 747 for a 56-minute flight to test the Orbiter Flight Control System.


The Space Shuttle Columbia on the mission designated STS-7 delivers to orbit Indonesia’s Palapa B1 telecommunications spacecraft, an HS 376 model built by Hughes Space & Communications Co.


Russia successfully launches seven low-Earth-orbiting commercial communications satellites for Iridium from the Russian-run BaikonurCosmodrome in Kazakhstan aboard a Proton rocket.

June 19


The Space Shuttle Columbia on the mission designated STS-7 delivers into orbit the Anik C2 telecommunications satellite for Telesat Canada.

June 20


The Delta Clipper (DC-X) experimental, a one-third scale model of a single-stage-to-orbit vehicle built by McDonnell Douglas for the Strategic Defense Initiative Organization, is flown to an altitude of 870 meters and makes a successful vertical landing under rocket power. The DC-X was later renamed the Clipper Graham in honor of U.S. Army Lt. Gen. Daniel O. Graham, who is considered the father of the Strategic Defense Initiative.


NASA’s Quick Scatterometer (QuikScat) satellite is launched. Its SeaWinds instrument measures wind speed and direction above the surface of bodies of water. Although the original mission was supposed to be only two years, the SeaWinds measurements proved to be very useful for predicting the path and intensity of hurricanes, and forecasters are eager to replace the satellite, which is well past its design life.

June 21


The U.S. Federal Communications Commission grants WorldSpace Corp. of Washington the first U.S. license to deploy a satellite for digital audio broadcasting. The license was for the construction, launch and operation of an experimental small satellite for WorldSpace subsidiary Afrispace Inc., which planned to use it for broadcasts to small inexpensive radio receivers distributed throughout Africa and parts of Asia.

June 22


The USSR launches the Salyut 5 space station from BaikonurCosmodrome. It was later visited by the crews of the Soyuz 21 and Soyuz 24 missions.