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)
Chinese as a foreign language China. After this period, only Cantonese and Mandarin remained as the most influential variants of Chinese, the former due to the importance of maritime trade in Guangzhou and the emergence of Hong Kong as a key economy in East Asia. Chinese departments in the West were largely centered on Cantonese due to British colonial rule over Hong Kong until the opening of communist-ruled China starting in the 1970s. The teaching of Chinese as a foreign language in the People's Republic of China started in 1950 at Tsinghua University, initially serving students from Eastern Europe. Starting with Bulgaria in 1952, China