Rocketry, Spaceflight, and Starbase | Acronyms and Glossary

There are many acronyms thrown around when discussing SpaceX, NASA, and the space industry. With all of the focus on Starbase Texas, many new people are becoming interested in spaceflight. We know these terms can get confusing so we put together a handy guide for some of the most commonly-used acronyms when talking rockets. (Remember Elon Musk's advice though before using too many acronyms!)

Space Industry & Rocketry Acronyms

301 Cr-Ni stainless steel (X10CrNi18-8): high tensile strength, good ductility
304L Cr-Ni stainless steel with low carbon (X2CrNi19-11): corrosion-resistant with good stress relief properties
30X SpaceX-proprietary carbon steel formulation (Thirty-X)
ACS Attitude Control System
ADCS Attitude Determination and Control System
AFSS Automated Flight Safety System
AIT Assembly, Integration and Testing
AoA Angle of Attack
AoE Area of Effect
AOS Acquisition of Signal
AR Area Ratio (between rocket engine nozzle and bell)
ASDS Autonomous Spaceport Drone Ship (floating landing platform)
ASOG A Shortfall of Gravitas, SpaceX's 3rd Droneship (see ASDS)
ASS Acronyms Seriously Suck
ATP Acceptance Test Procedure
ATV Advanced Technology Vehicle (a launcher for sub-orbital experiments)
AVI Avionics Operator
BEO Beyond Earth Orbit
BFR Big Falcon Rocket or Big F***ing Rocket
BN Booster Number (for Starship/Superheavy)
CAA Crew Access Arm (for transfer of crew on a launchpad)
Coefficient of Drag
CF Carbon Fiber
CFD Computational Fluid Dynamics
CLPS Commercial Lunar Payload Services
CoM Center of Mass
COPV Composite Overwrapped Pressure Vessel
COTS Commercial Orbital Transportation Services (NASA contract)
CRS Commercial Resupply Services (NASA contract)
DSG Deep Space Gateway (proposed by NASA for lunar orbit)
DSH Deep Space Habitat
DSN Deep Space Network
DUR Delightful Unscheduled Recovery
E2E Earth-to-Earth (suborbital flight)
EDL Entry/Descent/Landing
ELE Extinction-Level Event
EOI Earth Orbital Insertion maneuver
EOL End Of Life
ERP Effective Radiated Power
ERV Earth Return Vehicle
ETO Earth-To-Orbit transport of materials
F1 Falcon 1
F9 Falcon 9
FAA Federal Aviation Administration
FCC Federal Communications Commission
FFSC Full-Flow Staged Combustion
FFSCC Full Flow Staged Combustion Cycle
FMEA Failure-Mode-and-Effects Analysis
FOD Foreign Object Damage (debris)
FONSI Findings of No Significant Environmental Impact
FoS Factor of Safety for design of high-stress components (see COPV)
FRR Flight Readiness Review
FRSC Fuel-Rich Staged Combustion
FSW Friction-Stir Welding
FTS Flight Termination System
FTV Flight Test Vehicle
GAO Government Accountability Office
GEO Geostationary Earth Orbit (35786km)
GNC Guidance/Navigation/Control
GSE Ground Support Equipment
GTE Ground Test Equipment (as opposed to GSE, which supports actual launches)
GTO Geosynchronous Transfer Orbit
HEEO Highly Elliptical Earth Orbit
HEMO Highly Elliptical Mars Orbit
HEO High Earth Orbit (above 35780km), or Highly Elliptical Orbit
HIF Horizontal Integration Facility
HLS Human Landing System (Artemis)
HLV Heavy Lift Launch Vehicle (20-50 tons to LEO)
HPFTP High Pressure Fuel Turbopump
HPOTP High Pressure Oxidizer Turbopump
HPTP High Pressure Turbopump
HTS Horizontal Test Stand
HUD Heads-Up Display (often implemented as a projection)
ICT Interplanetary Colonial Transport (see ITS)
IFA In-Flight Abort test
ILC Initial Launch Capability
IM Initial Mass (deliverable to a given orbit, without accounting for fuel)
IRT Independent Review Team
ISAP In-Situ Air Production
ISEP In-Situ Electricity/Energy Production
ISFP In-Situ Food Production
ISL Inter-Satellite Link (communication between satellites in orbit)
Specific impulse (basically the fuel economy of a rocket)
ISPP In-Situ Propellant Production
ISRU In-Situ Resource Utilization
ISWP In-Situ Water Production
ITAR International Traffic in Arms Regulations (US-only)
ITN Interplanetary Transport Network
ITS Interplanetary Transport System (see MCT)
JRTI Just Read The Instructions, SpaceX's 1st landing barge (see ASDS)
KSC Kennedy Space Center, Florida
KSP Kerbal Space Program
LAS Launch Abort System
LC-13 Launch Complex 13, Canaveral (SpaceX Landing Zone 1)
LC-39A Launch Complex 39A, Kennedy (SpaceX F9/Heavy)
LCC Launch Control Center
LCH4 Liquid Methane
LDRO Lunar Distant Retrograde Orbit
LEO Low Earth Orbit (180-2000km)
LES Launch Escape System
LH2 Liquid Hydrogen
LLO Low Lunar Orbit (below 100km)
LMO Low Mars Orbit
LMP Lunar Module Pilot (for Apollo missions)
LN2 Liquid Nitrogen
LNG Liquefied Natural Gas
LOS Loss of Signal | Line of Sight
LOV Loss Of Vehicle
LOX Liquid Oxygen
LPFTP Low Pressure Fuel Turbopump
LPG Liquified Petroleum Gas
LRR Launch Readiness Review
LSA Launch Services Agreement
LSP Launch Service Provider
LV Launch Vehicle (aka "Rocket")
LZ Landing Zone
LZ-1 Landing Zone 1, Cape Canaveral (see LC-13)
LZ-2 Landing Zone 2, Vandenberg (see SLC-4W)
M1d Merlin 1 Kerolox rocket engine, revision D (2013), 620-690kN, uprated to 730 then 845kN
M1dVac Merlin 1 Kerolox rocket engine, revision D (2013), vacuum optimized, 934kN
MaxQ Maximum aerodynamic pressure
MCC Mission Control Center
MCF Main Component Failure
MCT Mars Colonial Transporter (see ITS)
MECO Main Engine Cut-Off
MEO Medium Earth Orbit (2000-35780km)
MES Main Engine Start
MET Mission Elapsed Time
MLP Mobile Launcher Platform
MLV Medium Lift Launch Vehicle (2-20 tons to LEO)
MMH Mono-Methyl Hydrazine, (CH3)HN-NH2 (part of NTO/MMH hypergolic mix)
MOI Mars Orbital Insertion maneuver
MZ Nickname for Yusaku Maezawa (first confirmed passenger for Starship)
NEO Near-Earth Object
NET No Earlier Than
NOAA National Oceanic and Atmospheric Administration
NORAD North American Aerospace Defense command
NOTAM Notice to Airmen (of flight hazards)
NSF NasaSpaceFlight (forum)
NSSL National Security Space Launch
NTO diNitrogen TetrOxide, N2O4 (part of NTO/MMH hypergolic mix)
OCISLY Of Course I Still Love You, SpaceX's 2nd Droneship (see ASDS)
OFT Orbital Flight Test
OLIT Orbital Launch Integration Tower
OMS Orbital Maneuvering System
ORSC Oxidizer-Rich Staged Combustion
OSM Operations Safety Manager
OTV Orbital Test Vehicle
PDR Preliminary Design Review
PDV Powered Descent Vehicle (for retro-propulsive landing)
PGO Probability of Go
PICA-X Phenolic Impregnated-Carbon Ablative (heatshield compound, as modified by SpaceX)
PLF Payload Fairing
PMD Propellant Management Device
PMF Propellant Mass Fraction
PPE Power and Propulsion Element
QA Quality Assurance/Assessment
QD Quick-Disconnect
RCS Reaction Control System
RFP Request for Proposal
RLV Reusable Launch Vehicle
Roomba Remotely-Operated Orientation and Mass Balance Adjuster (used to clamp down a stage on the ASDS)
RTF Return to Flight
RTLS Return to Launch Site
RUD Rapid Unscheduled Disassembly
RUS Raptor-powered Upper Stage, and/or ground equipment to support same
SECO Second-stage Engine Cut-Off
SF Static fire
SHLV Super-Heavy Lift Launch Vehicle (over 50 tons to LEO)
SLC-37 Space Launch Complex 37, Canaveral (ULA Delta IV)
SLC-40 Space Launch Complex 40, Canaveral (SpaceX F9)
SLC-41 Space Launch Complex 41, Canaveral (ULA Atlas V)
SLC-4E Space Launch Complex 4-East, Vandenberg (SpaceX F9)
SLC-4W Space Launch Complex 4-West, Vandenberg (SpaceX F9, landing)
SLS Space Launch System (orange rocket)
SN Serial Number (used for Raptor and Starship)
SOP Standard Operating Procedure
SPoF Single Point of Failure
SRB Solid Rocket Booster
SRP Supersonic Retro-Propulsion
SSH Starship + SuperHeavy (see BFR)
SSO Sun-Synchronous Orbit
SSP Space-based Solar Power
SSTO Single Stage to Orbit
STA Special Temporary Authorization (issued by FCC for up to 6 months)
STLS South Texas Launch Site, Boca Chica
T/E Transporter/Erector launch pad support equipment
TCM Trajectory Correction Maneuver
TE Transporter/Erector launch pad support equipment
TEA-TEB Triethylaluminium-Triethylborane, igniter for Merlin engines; spontaneously burns with a green flame
TEI Trans-Earth Injection maneuver
TEL Transporter/Erector/Launcher, ground support equipment (see TE)
TFR Temporary Flight Restriction
TLI Trans-Lunar Injection maneuver
TMI Trans-Mars Injection maneuver
TPA TurboPump Assembly, feeds fuel to a rocket engine
TPS Thermal Protection System
TRL Technology Readiness Level
TS Thrust Simulator
TVC Thrust Vector Control
TWR Thrust-to-Weight Ratio
UDMH Unsymmetrical DiMethylHydrazine (liquid hypergolic propellent)
ULA United Launch Alliance (Lockheed/Boeing joint venture)
USAF United States Air Force
VAB Vehicle Assembly Building
VAFB Vandenberg Air Force Base, California
VIF Vertical Integration Facility
VLEO Very Low Earth Orbit
VTOL Vertical Take-Off and Landing
VTS Vertical Test Stand
WDR Wet Dress Rehearsal (with fuel onboard)

If you see any acronyms we're missing, please let us know at!