The Space Mouse’s Tale
The story of the Thor Able rocket and its tiny passengers.
Imagine strapping a tiny mouse into a 27-metre ballistic missile and blasting it 600 miles above the Earth.
If you’re thinking that it might not end well for the mouse… well, you would be right.
In 1957 the Soviet Union launched Sputnik. The disconcerting “beep, beep, beep” of the world’s first artificial satellite left America feeling exposed to missile attacks from space. This heralded the beginning of the Space Race. Top of the agenda was the development of a missile that could be launched from the safety of the United States with the capability of reaching Russia.
This formidable weapon is known as an Intercontinental Ballistic Missile (ICBM). Primarily, it is designed to carry nuclear warheads. Its trajectory takes it up in an arc above the atmosphere and hurtling back through it at 20 times the speed of sound. This inevitably creates a tremendous amount of heat.
Previously, missiles often used a heat sink to prevent the outside from melting. This works by conducting heat away from the surface to a material that can soak it up fast, such as copper. However, this has the disadvantage of adding extra weight to the missile. Another option is to build the nosecone out of ablative material, which erodes in layers when heated. Like the way sunburn peels away to reveal fresh skin underneath.
At the time, no one knew if ablative material could survive the faster re-entry speeds and higher temperatures that an ICBM would have to endure. So, a test was required. A new two stage rocket, made from a Thor missile and the second stage of a Vanguard rocket, was created to do just that. Its name was Thor Able.
On 23 April 1958 Thor Able was poised to launch for the first time from Cape Canaveral, Florida. Instead of a warhead, this rocket carried something a lot less threatening and a lot more furry. Yep, you guessed it, our space mouse.
And reportedly along for the ride was a two-ounce container of Old Grandad bourbon, carrying the label “Aged in Space.” The story goes that the Air Force Project Manager found out about the contraband whisky at the last minute and ordered it removed.
Our mouse, however, was not afforded such a lucky escape. The head of bioastronautics from the Space Technology Laboratories of Los Angeles, Laurel van der Wal, had managed to persuade the Air Force Ballistic Missile Division to include a single mouse to test how a living creature would react to spaceflight conditions. This experiment was known as Project Mouse-In-Able or MIA.
The mouse, nicknamed Minnie, was housed inside a small capsule which had an air generation system. She was secured in place with strips of acetone-sensitive paper, which is pliable in acetone but keeps its form when it dries. A few strips were strapped around her body, like tiny seatbelts.
A recovery team waited in Trinidad, where the Navy boats were due to arrive once they had recovered the nosecone of the rocket after splashdown. Crews were briefed on opening the capsule, preserving the data, and were given mouse care manuals. But all of this turned out to be in vain as Thor Able exploded 146 seconds after lift-off.
The second and third launches of Thor Able faired a bit better. The second mouse, called Laska, reached a higher altitude than any other living organism in an American rocket. Only to be surpassed by mouse number three, Wickie, who was named after a Cape Canaveral reporter Wickham Wilson, who covered much of America’s early space programme.
Both the rockets soared nearly 6,000 miles at speeds of 15,000 miles an hour before splashing down in the South Atlantic.
Instruments measuring the mice’s heart rates showed that they reacted quite differently to their separate ordeals. Laska’s heart rate increased in line with the acceleration of the rocket, which reached up to 17 g’s. Wickie’s remained the same until she experienced weightlessness. At this point her heart rate shot up.
Radio signals confirmed the nosecones survived re-entry intact and the prospect for recovering the mice alive looked good.
Sadly, it was not to be. The recovery teams failed to locate them in the vastness of the ocean. Wickie was sealed in a waterproof capsule or “mouse house” with sufficient food, water and oxygen for several weeks. However, the search for her was called off after two days and both mice were sadly lost to the sea.
This saw the end of the prophetically named MIA project. Although these unfortunate mice didn’t make it, many more have flown to space and back again as unwitting “guinea pigs” in our quest for knowledge.
Following these initial three launches, variations of Thor Able rockets, often with an additional third stage, moved on from launching mice to put several early satellites into space.
These included some of the early Pioneer missions, which were the first attempts by the United States to send a probe to the Moon.
Thor Able ultimately evolved into the Delta rocket family, which became one of the most reliable and longest-lived series of satellite launchers.
An example of a Thor Able rocket is on display at the National Space Centre. Along with Blue Streak, it stretches 26 metres high in the Rocket Tower.
About the author: Hannah Baker is the Collections Officer at the National Space Centre.