On November 9th, 1970, NASA did something they had never done before. Packed away in a tiny little satellite sat two bullfrogs, completely unaware of the one-way journey they were about to take.
A team of researchers at NASA launched these two frogs along with a variety of technical sensors into space to study the effects of gravity. For six days, the frogs orbited the Earth while being monitored by scientists back on the ground.
The mission to send frogs to space
This absurd sounding experiment was first contrived in 1965 by Dr. Torquato Gualtierotti, a scientist assigned to the Ames Research Center. He and others on his team wanted to understand how the frog's inner ear balance mechanism, called an Otolith, would function in microgravity. It was believed that understanding this would allow us greater comprehension of how the human body is affected in similar situations.
The mission was dubbed OFO 1, technically meaning Orbiting Frog Otolith 1. These two unlucky frogs weren't just thrust into space freely on a rocket; they were encapsulated by a custom-designed pod filled with life support equipment and a variety of monitors feeding data back to the control station on Earth.
The engineering of the frog capsule
Each frog was surgically fitted with an ECG sensor, neutral buoyancy electrodes, and a preamplifier to strengthen the signal from these components. Then, the frogs were strapped into a module mounted to a centrifuge that found its home in a small, 30-inch by 47-inch spacecraft. The centrifuge was used to spin the frogs and apply small bursts of gravity to establish controls for the researcher's data.
Diving even further to how complex this bullfrog satellite was, each frog's capsule was surrounded by water, and each frog had their own artificial lung and heater helping keep them in steady living balance. As for whether the frogs could move or not, during preflight surgery, scientists disconnected their ability to move through their nerve endings.
All this may sound like a lot of trouble to go to just to figure out how frogs reacted to gravity in space, but the experiment was successful. Electrocardiography measured from the ECG sensors showed that the frogs maintained good health throughout the entire flight. Even with two equipment malfunctions during the flight, the satellite and all components were able to function the entire 6-day mission.
After the researchers were able to examine the data, they found that after a few days, the frog's otoliths had normalized, suggesting that they are capable of acclimatizing to microgravity. In turn, NASA was able to move forward with a clearer picture of how humans might react to prolonged stays in space.
So, in 1970 NASA sent a satellite filled with water and two frogs into space to study gravity, and because of it, we know exactly how frogs react to weightlessness. Science is weird like that sometimes...