![LC-26B Thor-Able](https://upload.wikimedia.org/wikipedia/commons/d/da/LC-26B_Thor-Able.jpg)
The Thor-Able was an American
expendable launch system
An expendable launch system (or expendable launch vehicle/ELV) is a launch vehicle that can be launched only once, after which its components are either destroyed during reentry or discarded in space. ELVs typically consist of several rocket sta ...
and
sounding rocket
A sounding rocket or rocketsonde, sometimes called a research rocket or a suborbital rocket, is an instrument-carrying rocket designed to take measurements and perform scientific experiments during its sub-orbital flight. The rockets are used to ...
used for a series of
re-entry vehicle
Atmospheric entry is the movement of an object from outer space into and through the gases of an atmosphere of a planet, dwarf planet, or natural satellite. There are two main types of atmospheric entry: ''uncontrolled entry'', such as the entr ...
tests and
satellite
A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioisotope ...
launches between
1958 and
1960
It is also known as the "Year of Africa" because of major events—particularly the independence of seventeen African nations—that focused global attention on the continent and intensified feelings of Pan-Africanism.
Events
January
* Ja ...
. It was a
two-stage rocket
A rocket (from it, rocchetto, , bobbin/spool) is a vehicle that uses jet propulsion to accelerate without using the surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely fr ...
, consisting of a
Thor
Thor (; from non, Þórr ) is a prominent god in Germanic paganism. In Norse mythology, he is a hammer-wielding æsir, god associated with lightning, thunder, storms, sacred trees and groves in Germanic paganism and mythology, sacred groves ...
IRBM
An intermediate-range ballistic missile (IRBM) is a ballistic missile with a range of 3,000–5,500 km (1,864–3,418 miles), between a medium-range ballistic missile (MRBM) and an intercontinental ballistic missile (ICBM). Classifying b ...
as a first stage and a
Vanguard
The vanguard (also called the advance guard) is the leading part of an advancing military formation. It has a number of functions, including seeking out the enemy and securing ground in advance of the main force.
History
The vanguard derives fr ...
-derived
Able second stage. On some flights, an
Altair
Altair is the brightest star in the constellation of Aquila and the twelfth-brightest star in the night sky. It has the Bayer designation Alpha Aquilae, which is Latinised from α Aquilae and abbreviated Alpha Aql ...
solid rocket motor
A solid-propellant rocket or solid rocket is a rocket with a rocket engine that uses solid propellants (fuel/oxidizer). The earliest rockets were solid-fuel rockets powered by gunpowder; they were used in warfare by the Arabs, Chinese, Persia ...
was added as a third stage. It was a member of the
Thor family and an early predecessor of the
Delta
Delta commonly refers to:
* Delta (letter) (Δ or δ), a letter of the Greek alphabet
* River delta, at a river mouth
* D ( NATO phonetic alphabet: "Delta")
* Delta Air Lines, US
* Delta variant of SARS-CoV-2 that causes COVID-19
Delta may also ...
.
Launches
Sixteen Thor-Able were launched, nine on
sub-orbital
A sub-orbital spaceflight is a spaceflight in which the spacecraft reaches outer space, but its trajectory intersects the atmosphere or surface of the gravitating body from which it was launched, so that it will not complete one orbital re ...
re-entry vehicle test flights and seven on
orbital satellite launch attempts. Six launches resulted in failures, in which three of those failures were the result of an
Altair
Altair is the brightest star in the constellation of Aquila and the twelfth-brightest star in the night sky. It has the Bayer designation Alpha Aquilae, which is Latinised from α Aquilae and abbreviated Alpha Aql ...
upper stage added to the rocket to allow it to launch the spacecraft onto a
trans-lunar trajectory. All sixteen launches occurred from
Cape Canaveral Air Force Station
Cape Canaveral Space Force Station (CCSFS) is an installation of the United States Space Force's Space Launch Delta 45, located on Cape Canaveral in Brevard County, Florida.
Headquartered at the nearby Patrick Space Force Base, the statio ...
Launch Complex 17A.
Airframes
The Thor-Able vehicle had a stronger airframe than the standard Thor IRBM and had the inertial guidance system replaced by a radio guidance package mounted on the Able stages. It saw its first test on 23 April 1958 when Vehicle 116 was launched from LC-17A with a biological nose cone containing a mouse named MIA (Mouse In Able). At 19:10 EST, the Thor's engine roared to life and drove the Able stage and its tiny passenger into the evening sky. Two minutes and fifteen seconds after launch, at an altitude of 50 miles (80 km), the Thor exploded and sent the hapless rodent into the Atlantic Ocean instead of space. The cause of the failure was traced to a turbopump bearing coming loose and resulting in pump shutdown and instant loss of thrust. With no attitude control, the Thor pitched down and its LOX tank ruptured from aerodynamic loads. On 9 July, Thor 118 lifted off for a second attempt with a mouse named MIA II. The booster, including the unproven Able stage, performed successfully and the biological nose cone was driven back into the atmosphere for a splashdown in the South Atlantic, but recovery crews failed to locate the capsule and it sank into the ocean. A third attempt was made on 23 July. The press refused to call the mouse by the name of MIA III, so she was instead christened "Wickie", after a local female news reporter who had covered the space program at Cape Canaveral. Unfortunately, Wickie was no luckier than her predecessors when recovery crews once again failed to locate the capsule after splashdown, but telemetry data confirmed the mouse's survival from liftoff through reentry and proved comprehensively that living organisms could survive space travel. Attention now turned to Thor-Able 127 and
Pioneer 0
Pioneer 0 (also known as Able 1) was a failed United States space probe that was designed to go into orbit around the Moon, carrying a television camera, a micrometeorite detector and a magnetometer, as part of the first International Geophysical ...
, the world's first
lunar probe
The physical exploration of the Moon began when '' Luna 2'', a space probe launched by the Soviet Union, made an impact on the surface of the Moon on September 14, 1959. Prior to that the only available means of exploration had been observatio ...
. This flight took place on 17 August, but ended embarrassingly when the Thor exploded 77 seconds into the launch due to another turbopump malfunction. After an Atlas missile test a month later also failed due to the turbopumps, the Air Force Ballistic Missile Division quickly replaced the pumps in all of their missiles and this problem did not repeat itself again.
On 10 October,
Pioneer 1
Pioneer 1 (also known as Able 2) was an American space probe, the first under the auspices of NASA, which was launched by a Thor-Able rocket on 11 October 1958. It was intended to orbit the Moon and make scientific measurements, but due to a g ...
was launched on Thor 130. The second stage shut down too early and the probe did not have sufficient velocity to escape Earth's gravity. It re-entered the atmosphere and burned up 43 hours after launch.
Pioneer 2
Pioneer 2 (also known as Able 3) was the last of the three project Able space probes designed to probe lunar and cislunar space. The launch took place at 07:30:21 GMT on 8 November 1958. After Pioneer 1 had failed due to guidance system deficien ...
was launched on 8 November and reentered the atmosphere less than an hour after launch when the third stage failed to ignite.
The next six Thor-Able flights were suborbital tests for the Air Force (23 January, 28 February, 21 March, 8 April, 20 May, and 11 June 1959). All of these were successful except the first one, which failed to stage due to an electrical problem and fell into the Atlantic Ocean.
On 7 August,
Explorer 6
Explorer 6, or S-2, was a NASA satellite, launched on 7 August 1959, at 14:24:20 GMT. It was a small, spheroidal satellite designed to study trapped radiation of various energies, galactic cosmic rays, geomagnetism, radio propagation in the ...
(a scientific satellite) was launched on Vehicle 134 and successfully orbited.
On 17 September,
Transit 1A failed to orbit due to the third stage again failing to ignite.
On 3 November,
Pioneer 5
''Pioneer 5'' (also known as Pioneer P-2, and Able 4, and nicknamed the "Paddle-Wheel Satellite") was a spin-stabilized space probe in the NASA Pioneer program used to investigate interplanetary space between the orbits of Earth and Venus. It ...
was successfully launched. Intended originally as a Venus probe, technical delays caused it to be launched after the 1959 Venus window had closed so that it was instead sent into a heliocentric orbit.
The final Thor-Able launch orbited
Tiros-1
TIROS-1 (or TIROS-A) was the first full-scale weather satellite (the Vanguard 2 satellite was the first experimental/prototype weather satellite), the first of a series of Television Infrared Observation Satellites placed in low Earth orbit.
P ...
on 1 April 1960.
The
Able upper stage name represents its place as the first in the series, from the
Joint Army/Navy Phonetic Alphabet
The Allied military phonetic spelling alphabets prescribed the words that are used to represent each letter of the alphabet, when spelling other words out loud, letter-by-letter, and how the spelling words should be pronounced for use by the Alli ...
.
See also
*
List of Thor and Delta launches (includes Thor-Able)
*
Thor (rocket family)
Thor was a US space launch vehicle derived from the PGM-17 Thor intermediate-range ballistic missile. The Thor rocket was the first member of the Delta rocket family of space launch vehicles. The last launch of a direct derivative of the Thor mi ...
References
External links
Space Technology Laboratories Documents Archive
{{Thor and Delta rockets
Thor (rocket family)