Project Albert was an experiment to send a rhesus monkey into space to observe the effects of weightlessness on an organism. The project conducted six missions with six successive monkeys, each named Albert and encased in the nose of a rocket. Scientists concluded that monkeys can survive in low gravity, though all the animals lost their lives due to faulty pre-lift and landing procedures. Roach uses the project to discuss one of the early unknowns of space travel: Can humans survive without gravity?

Gravity is the force of attraction between two objects that is relative to mass and distance. Thus, whereas an object’s mass does not change relative to the force of gravity (mass measures the static amount of substance an object has), weight does (weight is the effect of gravity on an object’s mass). Roach clarifies that the term “zero gravity” is technically inaccurate, since the Earth’s gravitational pull is still minutely acting upon objects in orbit. In any case, since gravity is a fundamental force, scientists were necessarily fretful of unforeseen complications that could arise from sending a human into space, such as damage to organ functions, senses, and cognitive abilities.

To ascertain the effects of weightlessness on a human subject, two German scientists, Fritz and Heinz Haber, developed parabolic flight in 1950.