Astronaut propulsion unit Astronaut propulsion unit An astronaut propulsion unit (or astronaut maneuvering unit) is used to move an astronaut relative to the spaceship during a spacewalk. The first astronaut propulsion unit was the Hand-Held Maneuvering Unit (HHMU) used on Gemini 4. The Hand-Held Maneuvering Unit was the EVA "zip" gun used by Ed White on the Gemini 4 mission in 1965. The hand-held gun held several pounds of nitrogen, and allowed limited movement around the Gemini spacecraft. It was also used by astronaut Michael Collins on the Gemini 10 mission in 1966. The United States Air Force (USAF) Astronaut Maneuvering Unit (AMU)
What Is Intelligence? What Is Intelligence? What Is Intelligence?: Beyond the Flynn Effect is a book by psychologist James R. Flynn which outlines his model for an explanation of the eponymous Flynn effect. The book summarizes much of the work of Flynn in this area, as well as that of his colleague William Dickens of the Brookings Institution. The book begins with a description of what has generally become known as "the Flynn effect": the steady rise from one generation to the next in average scores on IQ tests over time. Flynn notes that this effect apparently contradicts some fundamental beliefs about IQ