WASHINGTON -- Here is a chronology of accidents and malfunctions since the United States and the Soviet Union first began the manned exploration of space.
July 21, 1961. Air Force Capt. Virgil Grissom's Mercury capsule sinks after an explosive blows the escape hatch off prematurely. Grissom swam from the capsule safely.
---
In 1962, NASA reported that free-world tracking stations indicated that seven Soviet cosmonauts had been killed in space.
---
May 16, 1963. Air Force Maj. Leroy Gordon Cooper landed his Mercury capsule, named Faith, by manual controls rather than automatic because two electrical connectors failed.
---
Oct. 25, 1965. Modified Agena rocket failed causing postponement of an attempt to have two-man Gemini 6 spacecraft rendezvous and dock with an Agena in orbit. Astronauts Navy Capt. Walter Schirra Jr. and Air Force Maj. Thomas P. Stafford were completing the count-down less than an hour before lift-off.
---
Mar. 16, 1966. Neil Armstrong and Air Force Maj. David Randolph Scott aboard Gemini 8 went into orbit to dock with an orbiting spacecraft, but a malfunction of a small maneuvering rocket forced them to cut short their flight and make an emergency landing in the Western Pacific.
---
June 3-6, 1966. Gemini 9 with Air Force Lt. Col. Thomas Patten Stafford and Navy Lt. Cmdr. Eugene Cernan forced to abandon docking with an orbiting target because a protective shroud obstructed the target's docking apparatus.
---
Jan. 27, 1967. three astronauts assigned to first Apollo space flight killed in fire during practice for Feb. 21 flight. Astronauts were:
-Air Force Lt. Col. Virgil Ivan (Gus) Grissom, 40, one of the seven original Mercury astronauts.
-Air Force Lt. Col. Edwin Higgins White II, 36, co-pilot of Gemini 4 and the second person to perform a space walk.
-Lt. Cmdr. Roger B. Chaffee, 31, who had not yet made a space flight.
-----
April 1967. crash of Soyuz 1 killed Cosmonaut Vladimir Komarov.
----
April 13, 1970. Three astronauts aboard Apollo 13, their oxygen and power in their command module reduced to dangerously low level because of a ruptured oxygen tank, used power from lunar landing craft to stay alive. They were able to circle the moon April 14 and return to Earth April 17.
---
June 30, 1971. Three Soviet crewmen died when their Soyuz 11 lost cabin pressure during re-entry.
Aug. 2, 1973. Oxidizer leaks detected in the second of four sets of small manuevering jets of the Apollo command module flown to the Skylab 2 and which was to take them back to Earth. A rescue mission was planned, but spacecraft was able to return on its own.
---
July 24, 1975. Failure to throw two switches caused a series of problems aboard an Apollo spacecraft returning from a successful link-up with a Soviet Soyuz spacecraft. Gaseous nitrogen tetraoxide vapors were sucked into the cabin causing coughing and eye irritation to the crew Vance Brand and Donald 'Deke' Slayton. Brig. Gen. Thomas Stafford attempted to give oxygen tofellow crewmembers after splashdown. Brand momentarily lost consciousness.
---
Mar. 19, 1981. Two workers killed and five others injured at Cape Canaveral when they enter a chamber in which oxygen had been flushed out and replaced by pure nitrogen in the space shuttle Columbia after a pre-flight test.
---
Nov. 14, 1981. Space shuttle Columbia returns to Earth after flight shortened because of malfunction of one of the craft's electricity-producing fuel cells. --- Mar. 22, 1982. Space shuttle Columbia launched with problems including flooded runways at Edwards Air Force Base, Calif., a faulty temperature guage that delayed launch. After launch one of the spacecraft's three auxiliary power units showed an abnormally high temperature and had to be shut off. Later it was discovered that the craft had lost or damaged heat-shielding tiles.
---
November 1982. Planned spacewalk outside space shuttle Columbia canceled because of malfunctions in the newly designed spacesuits. Also, difficulties with the on-board computers prevented landing the craft on automatic pilot.
---
Dec. 8, 1983. Problems with shuttle Columbia's computers force postponement of landing hours before scheduled touchdown at Edwards Air Force Base, Calif. The craft was able to land safely about eight hours later, but as soon as the wheels hit the landing strip one of the computers switched off again. NASA revealed that a small fire and subsequent explosion occurred aboard the Columbia as it made its landing.
---
June 26, 1984. Just four seconds from launch an engine fuel valve malfunctioned causing the delay of the maiden flight of the shuttle Discovery.
---
December 1985-January 1986 -- Columbia launch delayed 25 days because of equipment and weather problems. Its return was postponed three times, delaying Challenger's original launch date of Jan. 22.
---
Jan. 28, 1986. The space shuttle Challenger exploded in a massive ball of flame 72 seconds after blastoff and hurtled into the Atlantic Ocean. There appeared no chance that teacher Christa McAuliffe and her six crewmates could have survived.
On board the Challenger were commander Francis 'Dick' Scobee, 46, co-pilot Michael Smith, 40, Judith Resnik, 36, Ellison Onizuka, 39, Arnold McNair, 35, satellite engineer Gregory Jarvis, 41, and McAuliffe, the 37-year-old Concord, N.H., social studies teacher picked from 11,000 candidates to be the first private citizen in space.
