- Covering the Past, Present and Future of
Written and Edited by Cliff Lethbridge
Note: The original Thor-Able is also referred to as the Thor-Able 0 (zero).
Classification: Research Rocket/Space Launch Vehicle
Length: 90 feet
Diameter: 8 feet
Using the Thor IRBM as a core booster, the Thor-Able rocket was introduced in 1958. The vehicle was originally designed to support high-altitude U.S. Air Force and civilian re-entry vehicle research.
The Thor-Able was later modified to carry small satellites into orbit, and became the first Thor-based variant to do so. Thor-Able was the first generation of what would become the Delta family of space launch vehicles which remain in use today.
The Thor-Able employed a Rocketdyne first stage engine which burned liquid oxygen/RP-1 (kerosene) liquid fuel and could produce 150,000 pounds of thrust at launch.
The second and third stages were adapted directly from the Vanguard rocket. An Aerojet second stage engine burned IRFNA/UDMH solid fuel and could produce a 7,575-pound thrust.
An Altair solid-fueled third stage engine could produce a thrust of 2,760 pounds.
The first three Thor-Able rockets were launched from
For this reason, Thor-Able rockets were selected to produce high speed re-entry data of the ablative-type heat resistant material proposed for Atlas missile nosecones.
But in addition to supporting the tests of vital Atlas missile hardware, these Thor-Able flights also carried out some groundbreaking biological research. Each of the three nose cones launched in this test series carried a lone mouse as passenger.
Electronic monitoring of these mice would determine whether or not animals could survive a long-range missile flight. These tests would prove to be significant since the mice would reach maximum altitudes of 600 to 1,000 miles above Earth during their journey, and experience long periods of weightlessness and gravity stress.
These Thor-Able flights did provide useful data on ablative nose cone technology, but the mice did not fare so well. The first of these Thor-Able rockets carried a mouse named "Mouse-In-Able-1" (MIA-1), nicknamed "Minnie Mouse" and was launched on April 23, 1958. The rocket exploded due to a first stage gearbox failure.
The second of these Thor-Able rockets carried a mouse named "Mouse-In-Able-2" (MIA-2) and was launched on July 9, 1958. The mouse survived its entire flight, but recovery crews were not able to locate the nose cone.
The last Thor-Able mouse, named "Wickie
Mouse" in honor of the nickname of
Even though the nosecones were not recovered in the two successful Thor-Able research flights, the fact that flights of 6,000 miles were achieved prompted Douglas Aircraft to propose an ICBM version of the Thor called Thor-Intercontinental, or "Thoric".
Proposals for a Thoric missile were quickly rejected by the U.S. Air Force, however, since development of the Atlas and Titan ICBM weapons systems were already well underway.
Thor-Able research rockets were, however, modified to carry out satellite launching missions. Each Thor-Able was capable of carrying a maximum 300-pound payload into low-Earth orbit.
Since the Thor-Able ultimately evolved into a series of space launch vehicles, the initial version is referred to by some sources as Thor-Able-Zero in order to distinguish it from later variants.
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