Explorer 1, America's first satellite, finds belts of radiation around Earth
Its radiation counter found charged particles trapped by Earth's magnetic field. They were named the Van Allen belts after the physicist who built the counter.
Juno I puts Explorer 1 into orbit on the night of January 31, giving the USA its first satellite; the instruments detect what becomes known as the Van Allen radiation belts. Vanguard reaches orbit in March on its third attempt, carrying a grapefruit-sized sphere still tracked today — the oldest artificial object in orbit.
Its radiation counter found charged particles trapped by Earth's magnetic field. They were named the Van Allen belts after the physicist who built the counter.
Its solar cells kept its radio sending until 1964. Tracking the grapefruit-sized satellite showed Earth is slightly pear-shaped.
Its 12 instruments studied cosmic rays, magnetic fields and the upper atmosphere. It was about 100 times heavier than any US satellite then flying.
It fell short of orbiting the Moon, but it flew higher than any spacecraft before it. NASA had started work 10 days earlier.
It played a taped Christmas greeting from the president wishing peace on Earth. Ground stations also used it to relay voice and teletype messages.
Quick filters
63 launches
| January | ||||
Jan 10, 1958 | ICBM test USA • Atlas A | |||
Jan 28, 1958Failure | Missile test USA • Thor DM-18 | |||
Jan 29, 1958Failure | M1-11 Russia • R-7 | |||
| February | ||||
Feb 1, 1958 | Explorer 1 USA • Juno I | |||
Feb 5, 1958Failure | Vanguard TV3 Backup USA • Vanguard | |||
Feb 7, 1958Failure | ICBM test USA • Atlas A | |||
Feb 20, 1958Failure | ICBM test USA • Atlas A | |||
Feb 28, 1958Failure | Missile test USA • Thor DM-18 | |||
| March | ||||
Mar 5, 1958Failure | Explorer 2 USA • Juno I | |||
Mar 17, 1958 | Vanguard TV4 USA • Vanguard | |||
Mar 26, 1958 | Explorer 3 USA • Juno I | |||
Mar 29, 1958 | M1-10 Russia • R-7 | |||
| April | ||||
Apr 4, 1958 | M1-12 Russia • R-7 | |||
Apr 5, 1958Failure | ICBM test USA • Atlas A | |||
Apr 19, 1958Failure | Missile test USA • Thor DM-18 | |||
Apr 24, 1958Failure | RTV test USA • Thor DM-18 Able | |||
Apr 27, 1958Failure | D1 s/n. 1 Russia • Sputnik | |||
Apr 29, 1958Failure | Vanguard TV5 USA • Vanguard | |||
| May | ||||
May 15, 1958 | Sputnik 3 Russia • Sputnik | |||
May 18, 1958 | AM-5 USA • Jupiter | |||
May 24, 1958Failure | B1-3 Russia • R-7 | |||
May 27, 1958Failure | Vanguard SLV-1 USA • Vanguard | |||
| June | ||||
Jun 3, 1958 | ICBM test USA • Atlas A | |||
Jun 4, 1958 | Missile test USA • Thor DM-18 | |||
Jun 13, 1958 | Missile test USA • Thor DM-18 | |||
Jun 26, 1958Failure | Vanguard SLV-2 USA • Vanguard | |||
| July | ||||
Jul 10, 1958Failure | B1-4 Russia • R-7 | |||
Jul 10, 1958 | RTV test USA • Thor DM-18 Able | |||
Jul 13, 1958 | Missile test USA • Thor DM-18 | |||
Jul 17, 1958 | AM-6B USA • Jupiter | |||
Jul 19, 1958Failure | ICBM test USA • Atlas B | |||
Jul 23, 1958 | RTV test USA • Thor DM-18 Able | |||
Jul 26, 1958Failure | Missile test USA • Thor DM-18 | |||
Jul 26, 1958 | Explorer 4 USA • Juno I | |||
| August | ||||
Aug 2, 1958 | ICBM test USA • Atlas B | |||
Aug 6, 1958 | Missile test USA • Thor DM-18 | |||
Aug 17, 1958Failure | Pioneer 0 USA • Thor DM-18 Able-I | |||
Aug 24, 1958Failure | Explorer 5 USA • Juno I | |||
Aug 27, 1958 | AM-7 USA • Jupiter | |||
Aug 29, 1958 | ICBM test USA • Atlas B | |||
| September | ||||
Sep 14, 1958 | ICBM test USA • Atlas B | |||
Sep 18, 1958Failure | ICBM test USA • Atlas B | |||
Sep 23, 1958Failure | Luna 1958A Russia • Luna | |||
Sep 26, 1958Failure | Vanguard SLV-3 USA • Vanguard | |||
| October | ||||
Oct 10, 1958Failure | AM-9 USA • Jupiter | |||
Oct 11, 1958Failure | Pioneer 1 USA • Thor DM-18 Able-I | |||
Oct 11, 1958Failure | Luna 1958B Russia • Luna | |||
Oct 23, 1958Failure | Beacon satellite USA • Juno I | |||
| November | ||||
Nov 5, 1958Failure | Missile test USA • Thor DM-18A | |||
Nov 8, 1958Failure | Pioneer 2 USA • Thor DM-18 Able-I | |||
Nov 18, 1958Partial failure | ICBM test USA • Atlas B | |||
Nov 26, 1958Partial failure | Missile test USA • Thor DM-18A | |||
Nov 29, 1958 | ICBM test USA • Atlas B | |||
| December | ||||
Dec 4, 1958Failure | Luna 1958C Russia • Luna | |||
Dec 6, 1958Partial failure | Pioneer 3 USA • Juno II | |||
Dec 6, 1958Partial failure | Missile test USA • Thor DM-18A | |||
Dec 13, 1958 | Biological nose cone w/ squirrel monkey USA • Jupiter | |||
Dec 16, 1958 | Missile test USA • Thor DM-18A | |||
Dec 17, 1958 | Missile test USA • Thor DM-18A | |||
Dec 18, 1958 | SCORE USA • Atlas B | |||
Dec 24, 1958 | ICBM test USA • Atlas C | |||
Dec 24, 1958Failure | B3-16 Russia • R-7 | |||
Dec 31, 1958Failure | Missile test USA • Thor DM-18A | |||