Glossary

R

ramjet A jet engine with no mechanical compressor, consisting of specially shaped tubes or ducts open at both ends, the air necessary for combustion being shoved into the duct and compressed by the forward motion of the engine

RCRA Resource Conservation and Recovery Act

real-time Immediate, as an event is occurring

red shift Shift of spectral lines toward the red end of the spectrum, indicating motion away from the observer in the lines of sight

resolution With reference to satellites, a term meaning the ability to sense an object; thus, an 80-meter resolution indicates the ability to detect an object of at least 80 meters in diameter

Reynolds number A nondimensional parameter representing the ratio of the momentum forces in fluid flow, named for English scientist Osborne Reynolds (1842-1912); among other applications, the ratio is vital to the use of wind tunnels for scale-model testing, as it provides a basis for extrapolating the test data to full-sized test vehicles

RFP Request for Proposals

RHU Radioisotope Heater Unit

RLV Reusable Launch Vehicle

RME Relay Mirror Experiment (satellite) (DoD)

RMS Remote Manipulator System-a remotely controlled arm, developed by Canada and controlled from the orbiter crew cabin, used for deployment and/or retrieval of payloads from the orbiter payload bay

ROSAT Roentgen Satellite

RSA Russian Space Agency

RTG Radioisotope Thermoelectric Generator