| R | BAR radius vector axis |
| R | DOT range rate to target, (+) opening, (-) closing |
| R | IMP minimum range to avoid plume impingement |
| R | Rankine |
| R | gas constant |
| R | radiometer |
| R | roentgen |
| R | yaw Rankine rate |
| R&CC | recorder and communication control |
| R&D | research and development |
| R&DO | Research and Development Operations (MSFC) |
| R&E | research and engineering |
| R&M | reliability and maintainability |
| R&P | reserve and process |
| R&PM | research and program management |
| R&QA | reliability and quality assurance |
| R&R | remove and replace |
| R&R | rendezvous and recovery |
| R&S | reliability and safety |
| R&T | research and technology |
| R&Z | range and zero |
| R-T | resistance test |
| R/A | radar altimeter |
| R/C | radio command |
| R/C | rate of climb |
| R/C | remote control |
| R/D | rate of descent |
| R/E | reentry |
| R/E | right-hand engine |
| R/I | receiving inspection |
| R/L | rate limited |
| R/L | remote/local |
| R/M | reliability/maintainability |
| R/O | roll-out |
| R/R | remove and replace |
| R/S | range safety |
| R/S | redundant set |
| R/T | real time |
| R/T | receive/transmit |
| R/T | receiver/transmitter |
| R/T | reference trajectory |
| R/T | room temperature |
| R/W | read/write |
| R/W | runway |
| R3 | rotary reciprocating refrigerator |
| R3S | rapid records retrieval system |
| RA | radar altimeter |
| RA | range area |
| RA | right aft |
| RA | right ascension |
| RAAB | remote amplifier acquisition and advisory box |
| RAAB | remote amplifier and adaptation box |
| RAAB | remote application and advisory box |
| RAAN | right ascension of ascending node |
| RABF | radio astronomy bandstop filter |
| RAC | Reliability Action Center |
| RACCS | remote automatic checkout and calibration system |
| RACF | Resource Access Control Facility |
| RACS | remote automatic calibration system |
| RACU | remote acquisition and control unit |
| RAD | radiation absorbed dose |
| RAD | research and advanced development |
| RAD | roentgen absorbed dosage |
| RADC | Rome Air Development Center |
| RADCC | Radiation Control Center |
| RADK | radiation conduction value |
| RADOP | radiator optimization computer code |
| RADVS | radar altimeter and Doppler velocity sensor |
| RAE | radio astronomy explorer |
| RAE | range, azimuth, and elevation |
| RAF | requirements analysis form |
| RAG | reusable agenda |
| RAHF-VT | Research animal holding facility verification |
| RAI | radar altimeter indicator |
| RAI | review action item |
| RAI | roll attitude indicator |
| RAJPO | Range Application Joint Program Office |
| RAL | responsibility assignment list |
| RALPH | reduction and acquisition of lunar pulse heights |
| RALT | radar altimeter |
| RAM | Reliability Assessment Model |
| RAM | radar absorption material |
| RAM | random access memory |
| RAM | requirements allocation matrix |
| RAM | research and applications module |
| RAM | resource allocation manager |
| RAM | responsibility assignment matrix |
| RAMA | recap and movement authorization |
| RAMAC | random access method of accounting and control |
| RAMCS | remote automatic measuring and calibration system |
| RAMP | replenishment activity management plan |
| RAMPS | resource analysis and mission planning system |
| RAN | Royal Australian Navy |
| RANC | radar absorption noise and clutter |
| RANN | research applied to national needs |
| RAP | reliability assurance program |
| RAP | reserve auxiliary payload |
| RAP | responsibility accounting program |
| RAPCON | radar approach and control |
| RAPP | Resource and Planning Program |
| RAR | resource accommodation report |
| RAS | reacquisition sensor |
| RAS | remote access set |
| RAS | requirements accounting system |
| RAS | requirements allocation sheet |
| RAS | reuse all systems |
| RASM | remote analog submultiplexer |
| RATCC | Radar Air Traffic Control Center |
| RATO | rocket-assisted takeoff |
| RAU | remote access unit |
| RAU | remote acquisition unit |
| RAUIS | remote acquisition unit interconnecting station |
| RAWS | role-adaptable weapons system |
| RAX | remote access computing system |
| RAX | remote access terminal |
| RAZEL | range, azimuth, and elevation |
| RB | radar beacon |
| RB | rubber base |
| RBA | radar beacon antenna |
| RBA | recovery beacon antenna |
| RBC | red blood cells |
| RBC | rotating beam ceilometer |
| RBDE | radar bright display equipment |
| RBE | radiation biological effectiveness |
| RBET | relative BET |
| RBK | right bank |
| RBL | right buttock line |
| RBMT | retrospective bibliographies on magnetic tape |
| RBN | radio beacon |
| RC | radio command |
| RC | radio control |
| RC | range command |
| RC | rate command |
| RC | reaction control |
| RC | recovery controller |
| RC | recurring cost |
| RC | reinforced concrete |
| RC | resistance-capacitance |
| RC | reverse current |
| RC | rotation control |
| RC | rotational control |
| RCA | Radio Corporation of America |
| RCA | remote control amplifier |
| RCAG | remote center air-ground |
| RCB | remote circuit breaker |
| RCC | Range Commanders' Council (DOD) |
| RCC | Regional Control Center |
| RCC | range control center |
| RCC | recovery control center |
| RCC | redundancy connection control |
| RCC | reinforced carbon-carbon |
| RCC | reusable carbon-carbon |
| RCC | rough combustion cutoff |
| RCCA | rough combustion cutoff assembly |
| RCCB | Rockwell Configuration Control Board |
| RCCB | remote central circuit breaker |
| RCCP | recorder and communications control panel |
| RCI | request for contract investigation |
| RCL | reliability control level |
| RCM | reliability-centered maintenance |
| RCN | Rockwell communication network |
| RCN | requirements change notice |
| RCP | Radiation Constraints Panel |
| RCP | right circular polarizer |
| RCR | requirements change request |
| RCR | retrofit configuration record |
| RCS | reaction control system (subsystem) |
| RCS | received command sync |
| RCS | reentry control system |
| RCS | requirements collection system |
| RCSC | reaction control subsystem controller |
| RCU | remote control unit |
| RCVS | remote control video switch |
| RCY | remaining cycles |
| RD | radiation detection |
| RD | reference designator |
| RD | released drawing |
| RD | requirements document |
| RD | root diameter |
| RDA | remote data access |
| RDA | resident data area |
| RDC | reference designator code |
| RDC | request for design change |
| RDC | request for document change |
| RDC | request for drawing changes |
| RDCS | reconfiguration data collection system |
| RDD | requirements definition document |
| RDF | radio direction finder |
| RDF | resource data file |
| RDGS | reconfiguration display generation system |
| RDL | reconfigurable design language |
| RDM | real-time data manager |
| RDO | relational data base operator |
| RDOC | reference designation overflow code |
| RDOS | real-time disk operating system |
| RDP | receive and data processor |
| RDP | requirements data plan |
| RDP | requirements development plan |
| RDR | raw data recorder |
| RDS | Rocketdyne digital simulator |
| RDT&E | research, development, test, and evaluation |
| RDW | response data word |
| RDW | return data word |
| RE | resolution element |
| RE | responsible engineer |
| RE&T | research engineering and test |
| REA | rocket engine assembly |
| REAM | rocket engine assembly module |
| RECON | remote console |
| RECP | request for engineering change proposal |
| RECS | representative environmental control system (Shuttle) |
| REDAC | Rockwell electronic design analysis code |
| REDB | Rockwell engineering data base |
| REFSMMAT | reference stable member matrix |
| REI | range from entry interface |
| REI | runway-end identification |
| REIL | runway-end identification lights |
| RELMAT | relative matrix |
| RELSAT | reliability for satellite (equipment in severe environment) |
| REM | release engine module |
| REM | release escape mechanism |
| REM | release-engagement monitor |
| REM | rocket engine module |
| REM | roentgen equivalent man |
| RETS | reconfigurable electrical test stand |
| REU | remote electronics unit |
| REVS | requirements engineering and validation system |
| RF | new risk factor |
| RF | radio frequency |
| RF | right forward |
| RF | risk factor |
| RF-TK | radio frequency tracking |
| RFA | RF authorization |
| RFA | request for action |
| RFB | ready for baseline |
| RFB | request for bid |
| RFC | radio frequency chart |
| RFC | request for change |
| RFCA | radiator and flow control assembly |
| RFCA | radiator flow control assembly |
| RFCP | request for computer program |
| RFD | requirements formulation document |
| RFDA | radio frequency deployed assembly |
| RFDU | radio frequency and digital unit |
| RFE | request for estimate |
| RFECP | request for engineering change proposal |
| RFEI | request for engineering information |
| RFHA | reusable flight hardware authorization |
| RFI | radio frequency interference |
| RFI | remote facility inquiry |
| RFI | remote file inquiry |
| RFI | request for information |
| RFO | request for order |
| RFP | request for program |
| RFP | request for proposal |
| RFP | requirements and formulation phase |
| RFPA | request for proposal authorization |
| RFQ | request for quotation |
| RFTCP | request for test change proposal |
| RFTS | radio frequency transmission system |
| RFU | radio frequency unit |
| RFW | request for waiver (deviation) |
| RG | radio guide |
| RG | rate gyro |
| RGA | rate gyro assembly |
| RGA | residual gas analysis |
| RGAL | rate gyro assembly, left SRB |
| RGAO | rate gyro assembly, orbiter |
| RGAR | rate gyro assembly, right SRB |
| RGP | rate gyro package |
| RGR | repairable generator rate |
| RGRF | repair generation rate forecast |
| RH | relative humidity |
| RH | right-hand |
| RHC | remote hand controller |
| RHC | rotational hand controller |
| RHCP | right-hand circular polarization |
| RHCP | right-hand circularly polarized |
| RHCTO | rotational hand controller takeover |
| RHEB | right-hand equipment bay |
| RHEC | radiation-hardened emulating computer |
| RHFEB | right-hand forward equipment bay |
| RHL | residual hazards list |
| RHP | right-hand panel |
| RHS | Rocketdyne hybrid simulator |
| RHS | right-hand side |
| RHSC | right-hand-side console |
| RHT | radiant heat temperature |
| RHU | radioisotope heater unit |
| RHW | response header word |
| RHW | router header word |
| RI | radioisotope |
| RI | record ID |
| RI | register immediate |
| RIADB | Rockwell integrity assurance data base |
| RIB | radioisotope/Brayton |
| RIB | recoverable item breakdown |
| RIB | right inboard |
| RIC | resistance, inductance, and capacitance |
| RICA | Rockwell interdivisional contract agreement |
| RICC | remote intercomputer communications |
| RICE | remote inertial and control equipment |
| RICMOS | radiation-hard inverse CMOS |
| RICP | real-time interactive computer program |
| RID | review item disposition |
| RIDI | receiving inspection detailed instruction |
| RIDS | Rockwell integrated defense simulator |
| RIE | right inboard elevon |
| RIF | relative importance factor |
| RIG | rate integration gyro |
| RIGA | rate-integrating gyro assembly |
| RIGI | receiving inspection general instruction |
| RIL | recoverable items list |
| RIL | repairable items list |
| RIM | resource inventory management |
| RIMS | RIM system |
| RIMSS | Rockwell International modular satellite system |
| RIPS | radar impact prediction system |
| RIQ | Rockwell International quote |
| RIR | reportable items report |
| RIS | reporting identification symbol |
| RISC | Rockwell Integration Support Contract |
| RISE-C | Rockwell International Shuttle equipment cradle |
| RISKAC | risk acceptance |
| RISNET | risk management analysis system |
| RISOP | red integrated strategic operations plan |
| RIT | request for interface tooling |
| RIU | remote interface unit |
| RJ/EC | reaction jet/engine control |
| RJC | reaction jet control |
| RJD | reaction jet device |
| RJD | reaction jet driver |
| RJDA | reaction jet driver aft |
| RJDF | reaction jet driver forward |
| RJE | remote job entry |
| RJOD | reaction jet/OMS driver |
| RL | reimaging lens |
| RL | return link |
| RLA | repair-level analysis |
| RLC | remote load controller |
| RLE | responsible lab engineer |
| RLEO | request for liaison engineering order |
| RLG | ring laser gyro |
| RLT | return line tether |
| RM | redundancy management |
| RM | reference mission |
| RM | relay mirror |
| RM | remedial maintenance |
| RM | remote manipulator |
| RM | rendezvous maneuver |
| RM | rescue module |
| RM | resource management |
| RM | resupply module |
| RM | right mid |
| RM&P | reliability, maintainability, and producibility |
| RM&QA | reliability, maintainability, and quality assurance |
| RM/AS | risk management/assessment system |
| RMA | reliability, maintainability, and availability |
| RMA | remote manipulator arm |
| RMC | redundancy management control |
| RME | radiation monitoring equipment |
| RMF | RCS module forward |
| RMG | right main gear |
| RMI | radio magnetic indicator |
| RMOP | resource management operation plan |
| RMP | risk management plan |
| RMRS | recoverable maintenance recall system |
| RMRS | repeatable maintenance recall system |
| RMS | random motion simulator |
| RMS | redundancy management system |
| RMS | remote maneuvering system |
| RMS | remote manipulator system (subsystem) |
| RMS | root mean square |
| RMU | remote maneuvering unit |
| RN | Reynold's number |
| RN | rate of change |
| RN | resource node |
| RNP | rotation, nutation, and precession |
| RNS | reusable nuclear stage |
| RNTS | regenerative nonventing thermal system |
| RO | radar operator |
| RO | readout |
| RO | receive only |
| RO | recovery operations |
| RO | rollover |
| ROADS | resource and operations analysis display system |
| ROB | right outboard |
| ROB | rigid optical bench |
| ROC | record of comments |
| ROC | request of change |
| ROCC | Range Operational Control Center |
| ROCC | Region Operational Control Center |
| ROCES | ranger orbiter crew escape system |
| ROD | remotely operated door |
| ROEU | remotely operated electrical umbilical |
| ROI | return on investment |
| ROL | remote operating location |
| ROM | read-only memory |
| ROM | rough order of magnitude |
| RORSAT | radar ocean reconnaissance satellite |
| ROS | Rosman, North Carolina (STDN site) |
| ROS | read-only storage |
| ROS | regulated oxygen supply |
| ROS | removable overhead structure |
| ROSES | Rockwell Operational Software Engineering System |
| ROSS | remote orbital servicing system |
| ROST | Rockwell operational system for trades |
| ROST | Rockwell operations system for trades |
| ROT | remaining operating time |
| ROTI | recording optical tracking instrument |
| ROTV | returnable orbital transfer vehicle |
| RP | relative pressure |
| RP | repair period |
| RP | rocket propellant |
| RPA | record and playback assembly |
| RPA | request for procurement action |
| RPA | request for procurement authorization |
| RPC | remote power control |
| RPC | remote power controller |
| RPD | Reconfiguration Production Department |
| RPE | reliability project engineer |
| RPF | rapid prototyping facility |
| RPIE | real property installed equipment |
| RPL | Rocket Propulsion Laboratory |
| RPL | rated power level |
| RPO | radiation protection officer |
| RPOC | Remote Payload Operations Center |
| RPP | reinforced pyrolytic plastic |
| RPP | reliability program plan |
| RPS | RMS planning system |
| RPS | record and playback system (subsystem) |
| RPSF | Rotation Processing and Surge Facility |
| RPT | resident provisioning team |
| RPT | rudder pedal transducer |
| RPTA | rudder pedal transducer assembly |
| RPV | remotely piloted vehicle |
| RQ | respiratory quotient |
| RR | range rate |
| RR | readiness review |
| RR | register to register |
| RR | rendezvous radar |
| RR | requirements review |
| RR | respiration rate |
| RRB | Requirements Review Board |
| RRDA | rendezvous radar deployment actuator |
| RRDCT | risk reduction data collection task |
| RREA | rendezvous radar electronics assembly |
| RREU | rendezvous radar electronics unit |
| RRL | rudder reference line |
| RRP | rudder reference plane |
| RRS | restraint release system |
| RRS | retrorocket system |
| RRT | rendezvous radar transducer |
| RRT | rendezvous radar transfer |
| RRT | rendezvous radar transponder |
| RS | Rawinsonde |
| RS | redundancy status |
| RS | redundant set |
| RS | refurbishment spare |
| RS | register to storage |
| RS | remote station |
| RS | right side |
| RS&S | receiving, shipping, and storage |
| RSA | rapid simulation aid |
| RSA | rate sensor assembly |
| RSA | rheometrics solids analyzer |
| RSB | rudder/speed brake |
| RSC | range safety command |
| RSC | range safety control |
| RSCIE | remote station communication interface equipment |
| RSCR | range safety command receiver |
| RSCS | rate stabilization and control system |
| RSCSS | range safety command shutdown system |
| RSD | range support document |
| RSD | requirements and specifications document |
| RSDB | Rockwell supplier data base |
| RSDP | remote site data processor |
| RSEAM | Rockwell system engineering analysis model |
| RSF | Refurbishment and Subassembly Facility (KSC) |
| RSF | receiving-safing facility |
| RSI | rate stability indicator |
| RSI | reusable surface insulation |
| RSIOP | Russian strategic integrated operational plan |
| RSIOP | red single integrated operations plan |
| RSL | requirement specification language |
| RSL | resource support list |
| RSLS | redundant set launch sequence |
| RSMM | redundant system monitor model |
| RSO | Radiological Safety Office |
| RSO | range safety officer |
| RSO | resident space object |
| RSOC | Rockwell Space Operations Company |
| RSPL | recommended spare parts list |
| RSR | release schedule record |
| RSRA | rotor system research aircraft |
| RSRB | redesigned solid rocket booster |
| RSRM | redesigned solid rocket motor |
| RSS | range safety switch |
| RSS | range safety system |
| RSS | reactant supply system |
| RSS | restart selectover system |
| RSS | rib structure station |
| RSS | root sum square |
| RSS | rotating service structure |
| RSSPO | Resident Space Shuttle Project Office |
| RST | recessed selectomatic terminal |
| RSU | remote service unit |
| RSV | ready storage vessel |
| RT | real time |
| RT | reference trajectory |
| RT | room temperature |
| RT/LO | receiver transmitter/local oscillator |
| RTAC | Research and Technology Advisory Committee |
| RTAW | Rockwell tandem arc weld |
| RTB | resistance temperature bulb |
| RTC | real-time clock |
| RTC | real-time command |
| RTC | real-time computer |
| RTC | room-temperature cure |
| RTCA | Radio Technical Commission for Aeronautics |
| RTCC | Real-Time Computer Center (NASA) |
| RTCC | real-time command controller |
| RTCC | real-time computer command (uplink) |
| RTCC | real-time computer complex |
| RTCE | rotation/translation control electronics |
| RTCP | real-time communications processor |
| RTCPS | real-time computer program system |
| RTCS | real-time computer system |
| RTD | real-time data |
| RTD | real-time display |
| RTD | resistance temperature device |
| RTD | resistance thermal device |
| RTDD | release to design development |
| RTE | responsible test engineer |
| RTF | return to flight |
| RTFSS | real-time flight safety software |
| RTG | radioisotope thermoelectric generator |
| RTG | range to ground |
| RTHC | rotational-translational hand controller |
| RTHS | real-time hybrid system |
| RTIF | real-time interface |
| RTLS | return to launch site |
| RTM | release to manufacturing |
| RTM | robot task measurement |
| RTO | rapid turn-on |
| RTOK | retest okay |
| RTOP | research and technology objectives and plans |
| RTOP | research and technology operating plan |
| RTPM | real-time program management |
| RTS | range tracking station |
| RTS | real-time subsystem |
| RTS | real-time supply |
| RTS | reliability test specimen |
| RTS | remote tracking station |
| RTSF | real-time simulation facility |
| RTSS | real-time simulation system |
| RTTV | real-time television |
| RTU | remote terminal unit |
| RTV | room-temperature vulcanizing |
| RTVM | requirements and test verification matrix |
| RU | remote unit |
| RV | recirculation valve |
| RV | recovery vehicle |
| RV | reentry vehicle |
| RV | relief valve |
| RVAO | reentry vehicle associated object |
| RVAS | requirements verification and accounting system |
| RVCF | remote vehicle checkout facility |
| RVCN | requirement verification completion notice |
| RVDISC | RV discrimination |
| RVDT | rotary variable differential transducer |
| RVDT | rotary variable differential transformer |
| RVN | requirements verification network |
| RVR | requirement verification revision |
| RVR | runway visual range |
| RVRS | requirements verification review sheet |
| RVTAPS | RV track and prediction simulation |
| RW | reaction wheel |
| RW | read and write |
| RW | response word |
| RW | runway |
| RWD | right wing down |
| RWE | read/write electronics |
| RWM | read and write memory |
| RYD | real-year dollars |
| RZ | return to zero |
| Rf | risk factor |
| Rnet | reconfiguration network |
| rms | radian means per second |
| rph | revolutions per hour |
| rpm | revolutions per minute |
| rpm | rotations per minute |
| rps | revolutions per second |