Astronauts, like other specialists, have developed a special language in which acronyms and other speech habits are used to improve efficiency by condensing words. These procedures should emphasize characteristics of clarity, redundancy, and feedback. That is, messages must be encoded or framed to take into account the receivers' abilities, training, and attitudes, remembering that successive generations of astronauts are likely to differ appreciably from each other. Redundancy or repetition should be employed to increase the opportunity for a message to be received and understood. Redundancy may involve repeating a message at two points in time, or transmitting a message to different people who have similar responsibilities or who perform similar functions.
Feedback assures the source or sender that a message has been received.
Certainly the simplest and probably most effective feedback procedure, when bidirectional verbal communication is possible, is to ask the receiver to restate the communication in his or her own words. Once the message has been correctly framed, the task of mission planners and managers is to identify the optimal level of redundancy needed and the type of feedback required. Presumably, for a given message, the need for redundancy is inversely related to the availability of feedback. Ethnic diversity and language barriers - Ethnically mixed crews, especially international crews, may experience serious language difficulties. After spending 1000 hr studying the language of the other, astronauts attempted to address the cosmonauts in Russian, and cosmonauts did their best to respond in English.