| B&P | budgetary and planning |
| B-L | bill of lading |
| B/A | barometric |
| B/A | boost/abort |
| B/A | buffer amplifier |
| B/C | bench check |
| B/L | baseline |
| B/M | bench maintenance |
| B/O | booster/orbiter |
| B/O | breakout |
| B/O | burnout |
| B/P | blood pressure |
| B/SC | brake/skid control |
| B/V | bleed valve |
| BA | bank angle |
| BA | breathing air |
| BAC | Boeing Aerospace Company |
| BAC | Boeing Aircraft Company |
| BAC | booster assembly contractor |
| BAC | budget at completion |
| BAC | buffer access card |
| BACS | body axis coordinate system |
| BAF | Barnes absorption filter |
| BAFO | best and final offer |
| BAI | barometric altitude indicator |
| BAIR | breathing air |
| BAN | budget allocation notice |
| BAROC | baroset correction |
| BARS | baseline accounting and reporting system |
| BAS | breathing air system |
| BASD | Ball Aerospace Systems Division |
| BASS | backup avionics system software |
| BATE | base activation test equipment |
| BATES | battlefield artillery tactical engagement system |
| BATSE | Burst and Transient Source Experiment |
| BAU | business as usual |
| BB | baseband |
| BB | brassboard |
| BB | breadboard |
| BBC | before-business clearance |
| BBN | Bolt, Beranek, and Newman |
| BBS | DEC all-in-one bulletin board system |
| BBXRT | broadband X-ray telescope |
| BC | base construction |
| BC | baseline configuration |
| BC | battery charge |
| BC | battery conditioner |
| BC | bell cord |
| BC | beta cloth |
| BC | between centers |
| BC | binary counter |
| BC | bolt center |
| BC | broadcast |
| BC | bus coupler |
| BCC | beacon control console |
| BCCT | break control command transducer |
| BCD | baseline concept definition |
| BCD | baseline configuration document |
| BCD | binary-coded data |
| BCD | budget change document |
| BCE | backup control electronics |
| BCE | burn control element |
| BCE | bus control element |
| BCH | base Chaudhuri-Hocquenghen |
| BCH | binary-coded hexadecimal |
| BCI | baseline configuration identification |
| BCID | baseline candidate item data base |
| BCLS | base cardiac life support |
| BCO | booster cutoff |
| BCP | base condemnation percent |
| BCP | benchmark control point |
| BCR | bar chart report |
| BCR | budget change request |
| BCRD | basic consolidated requirements document |
| BCRT | binary code range time |
| BCS | beam control system |
| BCT | bus configuration table |
| BCU | battery control unit |
| BCU | bus control unit |
| BCWP | budget costs for work performed |
| BCWS | budgeted cost for work scheduled |
| BD | binary decoder |
| BD | binary digit |
| BD | binary discrete |
| BDA | Bermuda Island (STDN) |
| BDA | backup drive amplifier |
| BDCR | baseline document change request |
| BDD | baseline definition document |
| BDD | burst detection dosimeter (IGS) |
| BDD | burst detector dosimeter |
| BDI | budget data and integration |
| BDP | burst detection processor (IGS) |
| BDP | burst detector processor |
| BDS-2 | booster phase detection system |
| BDT | block data transfer |
| BDW | EMP sensor |
| BDW | burst detector EMP sensor |
| BDX | burst detection X-ray sensor |
| BDX | burst detector X-ray sensor |
| BDY | burst detector optical sensor |
| BE | beam expander |
| BE | bell end |
| BEAF | beam expander alignment function |
| BEC | backup event controller |
| BECO | booster engine cutoff |
| BER | bit error rate |
| BESS | biomedical experiment scientific satellite |
| BESS | biomedical experiment support satellite |
| BEST | booster exhaust study test |
| BET | best estimate of trajectory |
| BET | best-estimate trajectory |
| BETA | ballistic exploitation and target acquisition |
| BF | back feed |
| BF | beat frequency |
| BF | body flap |
| BFC | backup flight control (controller) |
| BFC | body flap control |
| BFCS | backup flight control system |
| BFEC | Bendix Field Engineering Corporation |
| BFL | Bakersfield (TACAN station) |
| BFL | back focal length |
| BFN | beam-forming feed network |
| BFO | beat frequency oscillator |
| BFP | buyer-furnished part |
| BFRP | boron fiber-reinforced plastic |
| BFS | backup flight software |
| BFS | backup flight system |
| BFSPLP | BFS payload preprocessor |
| BFSS | backup flight software system |
| BG | back gear |
| BH/MP | breather hose/mouthpiece |
| BHN | Brinell hardness number |
| BHP | brake horsepower |
| BHS | base heat shield |
| BI | background information |
| BIA | booster insertion and abort |
| BIA | bus interface adapter |
| BIB | blocked impurity band |
| BIBIB | back-illuminated blocked impurity band |
| BIC | bus interface controller |
| BILBO | built-in logic block observer |
| BIS | biocide injection system |
| BISC | biomedical instrumentation, scientific and crew |
| BIT | built-in test |
| BITE | built-in test equipment |
| BITS | budget impact tracking system |
| BIU | buffer interface unit |
| BIU | bus interface unit |
| BJR | blockhouse junction rack |
| BKNO3 | boron-potassium nitrate |
| BLOW | booster lift-off weight |
| BLPG | buried long-period grating |
| BLS | bottom left side |
| BLV | bleed valve |
| BM | ballistic missile |
| BM | battle management |
| BM | bench maintenance |
| BM | body-mounted |
| BM | branch manager |
| BM | business manager |
| BM-TW/AA | ballistic missile tactical warning/attack |
| BM/C3 | battle management and command, control, and |
| BMA | body-mounted accelerometer |
| BMAG | body-mounted attitude gyro |
| BMAP | buffer map |
| BMAS | body-mounted accelerometer system |
| BMB | base maintenance building |
| BMB | bench maintenance building |
| BMC3 | battle management communications (three types) |
| BMD | ballistic missile defense |
| BMDATC | Ballistic Missile Defense Advanced Technology Center |
| BMDSCOM | Ballistic Missile Defense Systems Command |
| BME | bench maintenance equipment |
| BMEWS | ballistic missile early warning system |
| BMFT | German D-1 Spacelab payload |
| BMI | Battelle Memorial Institute |
| BMMD | body-mass measuring device |
| BMO | Ballistic Missile Office |
| BMO | ballistic missile organization |
| BMS | background measurement satellite |
| BMS | battle management simulation |
| BMTS | bench maintenance test set |
| BMU | bus monitor unit |
| BMVU | ballistic missile view |
| BN | ballistic number |
| BN | bullnose |
| BNS | bomb navigation system |
| BO | beating oscillator |
| BOA | broad ocean area |
| BOC | Base Operations Contract (contractor) |
| BOC | blowout coil |
| BOD | beneficial occupancy date |
| BOD | bright-object detector |
| BOE | break of entry |
| BOF | beginning of file |
| BOI | break of integrity |
| BOL | beginning of life |
| BOM | beginning of month |
| BOM | bill of material |
| BOP | baseline operations plan |
| BOP | basic overall polarity |
| BOPACE | Boeing plastic analysis capability for engines |
| BOS | backup operating system |
| BOS | bright-object sensor |
| BOSO | ballistic orbital support operations |
| BOT | beginning of tape |
| BOW | bill of work |
| BP | back pressure |
| BP | bandpass |
| BP | barber pole |
| BP | base plate |
| BP | bid and proposal |
| BP | blood pressure |
| BP | blueprint |
| BP | boilerplate |
| BP | boiling point |
| BP | budgetary and planning |
| BP | buttock plane |
| BPC | backpressure control |
| BPC | boost protective cover |
| BPD | baseline program document |
| BPD | baseline program documentation |
| BPI | boost phase intercept |
| BPMS | blood pressure measuring system |
| BPO | blanket purchase order |
| BPR | bimonthly progress report |
| BPR | bypass ratio |
| BPS | boost propulsion system |
| BPSK | biphase shift key |
| BPSK | biphase shift keying |
| BPT | body point |
| BPV | bipropellant valve |
| BR | bit rate |
| BRAVO | business risk and value of operation in space |
| BRCS | basic reference coordinate system |
| BRDF | bidirectional reflectance distribution function |
| BRF | band rejection filter |
| BRIL | budget receipt/issuance log |
| BRL | Ballistic Research Laboratory |
| BRM | baseline reference mission |
| BRM | biological research module |
| BRRS | Banana River Repeater Station |
| BRS | bottom right side |
| BS | backup subsystem |
| BS | beam splitter |
| BS | block specification |
| BSA | battery bus solar array |
| BSA | bus status/alternate bus table |
| BSC | brake skid controller |
| BSD | Ballistic Systems Division |
| BSDP | booster-stage discharge pressure |
| BSE | booster systems engineer |
| BSEE | Bachelor of Science degree in electrical engineering |
| BSGE | Bachelor of Science degree in general engineering |
| BSI | Boeing Services International |
| BSI | basic shipping instruction |
| BSI | booster situation indicator |
| BSM | beam-steering mechanism |
| BSM | booster separation motor |
| BSME | Bachelor of Science degree in mechanical engineering |
| BSP | business system planning |
| BSR | BITE status register |
| BSR | basic system release |
| BSRM | booster solid rocket motor |
| BSS | backup system services |
| BSTS | boost surveillance and tracking system |
| BSTS | boost surveillance tracking system |
| BSW | BFS software |
| BT | burn time (engine) |
| BTC | binary time code |
| BTC | bus tie contractor |
| BTE | bench test equipment |
| BTH | below the horizon |
| BTMS | body temperature measuring system |
| BTR | burn time remaining |
| BTR | bus transfer |
| BTU | bus terminal unit |
| BU&C/O | buildup and checkout |
| BUAER | Bureau of Aeronautics (Navy) |
| BUC | Buckhorn (GSTDN) |
| BUC | backup computer |
| BUFC | backup flight controller |
| BUIC | backup interceptor control |
| BUN | BITE update notice |
| BUORD | Bureau of Ordnance (Navy) |
| BUOU | backup optical unit |
| BUR | backup rate |
| BUSGEN | Bussin generator |
| BUSHIPS | Bureau of Ships |
| BV | balanced voltage |
| BV | boost vehicle |
| BV | booster vehicle |
| BVC | boost voltage converter |
| BW | bandwidth |
| BW | beam width |
| BW | bridge wire |
| BWG | Birmingham wire gauge |
| BWO | backward wave oscillator |
| Btu | British thermal unit |
| bpi | bits per inch |
| bpm | beats per minute |
| bps | bits per second |
| brpm | breath rate per minute |