Explorer S-45 was a NASA satellite, which was lost in a launch failure in February 1961. The satellite was intended to operate in a highly elliptical orbit, from which it was to have provided data on the shape of the ionosphere,[1] and on the Earth's magnetic field.[2] It was part of the Explorer program, and would have been designated Explorer 10 had it reached orbit. A second identical satellite, Explorer S-45A, also failed to achieve orbit when it was launched.[2]
![]() Explorer S-45 satellite before launch | |
Names | Explorer S-45 NASA S-45 |
---|---|
Mission type | Ionospheric research |
Operator | NASA |
COSPAR ID | EXS-451 |
Mission duration | Failed to orbit |
Spacecraft properties | |
Spacecraft | Explorer S-45 |
Spacecraft type | Science Explorer |
Bus | S-45 |
Manufacturer | Goddard Space Flight Center |
Launch mass | 33.6 kg (74 lb) |
Power | Solar cells and batteries |
Start of mission | |
Launch date | 25 February 1961, 00:13:16 GMT |
Rocket | Juno II (AM-19F) |
Launch site | Cape Canaveral, LC-26B |
Contractor | Army Ballistic Missile Agency |
End of mission | |
Destroyed | Failed to orbit |
Orbital parameters | |
Reference system | Geocentric orbit (planned) |
Regime | Highly elliptical orbit |
Perigee altitude | 221 km (137 mi) |
Apogee altitude | 181,100 km (112,500 mi) |
Inclination | 33.0° |
Period | 5013.90 minutes |
Instruments | |
Beacon | |
Explorer program |
Explorer S-45 was launched aboard a Juno II launch vehicle, serial number AM-19F. The launch took place from Launch Complex 26B at the Cape Canaveral Air Force Station (CCAFS) at 00:13:16 GMT on 25 February 1961.[3] The launch vehicle malfunctioned after the second stage separated, and contact with the payload was lost.[4] The third stages subsequently failed to ignite, resulting in the satellite failing to achieve orbit.[5]
Explorers Program | |||
---|---|---|---|
List of Explorers Program missions | |||
Missions | ![]() | ||
Proposals |
| ||
|
← 1960 · Orbital launches in 1961 · 1962 → | |
---|---|
Samos 2 | Tyazhely Sputnik | Venera 1 | Explorer 9 | Discoverer 20 | Discoverer 21 | Transit 3B · LOFTI-1 | S-45 | Korabl-Sputnik 4 | Korabl-Sputnik 5 | Explorer 10 | Discoverer 22 | Discoverer 23 | Vostok 1 | Mercury-Atlas 3 | Explorer 11 | S-45A | Discoverer 24 | Discoverer 25 | Transit 4A · SOLRAD 3 · Injun 1 | S-55 | Discoverer 26 | TIROS-3 | Midas 3 | Discoverer 27 | Discoverer 28 | Vostok 2 | Explorer 12 | Ranger 1 | Explorer 13 | Discoverer 29 | Samos 3 | Discoverer 30 | Mercury-Atlas 4 | Discoverer 31 | Discoverer 32 | Midas 4 · Westford 1 | Discoverer 33 | DS-1 No.1 | Mercury-Scout 1 | Discoverer 34 | Discoverer 35 | Transit 4B · TRAAC | Ranger 2 | Samos 4 | Mercury-Atlas 5 | Zenit-2 No.1 | Discoverer 36 · OSCAR 1 | DS-1 No.2 | FTV-2203 | |
Payloads are separated by bullets ( · ), launches by pipes ( | ). Crewed flights are indicated in underline. Uncatalogued launch failures are listed in italics. Payloads deployed from other spacecraft are denoted in brackets. |