Space Industry Glossary: 69 Essential Terms Every Professional Should Know
From apogee to zero-gravity, from ITAR to TRL: the definitive glossary of space industry terms for professionals, investors, and enthusiasts.
The space industry has its own language. Whether you're joining from finance, tech, or policy, mastering the terminology is essential for credibility and efficiency. Here are the 69 terms you'll encounter most often.
Orbital Mechanics
- LEO (Low Earth Orbit): 200-2,000 km altitude. Home to ISS, Starlink, and most Earth observation satellites. Orbital period: ~90 minutes
- MEO (Medium Earth Orbit): 2,000-35,786 km. GPS and navigation constellations operate here
- GEO (Geostationary Earth Orbit): 35,786 km. Satellites appear stationary over one point. Used for communications and weather
- TLE (Two-Line Element): Standardized format for describing a satellite's orbit. Used by the SGP4 propagation model
- Delta-V: Change in velocity needed for an orbital maneuver. The fundamental currency of spaceflight
- Apogee/Perigee: Highest/lowest point in an elliptical orbit around Earth
Business & Investment
- NewSpace: The commercial space industry wave driven by private investment and entrepreneurial companies (vs. traditional government/prime contractors)
- Space Economy: All economic activity related to space: $686B in 2025, according to the Space Foundation (July 2026)
- SBIR: Small Business Innovation Research, non-dilutive government grants for technology development
- TRL (Technology Readiness Level): NASA's 1-9 scale for technology maturity. TRL 1 = basic research. TRL 9 = flight-proven
- Flight Heritage: Proven track record of a technology or component operating successfully in space
Week in Space Data, every Friday
One free email on Fridays: launches flown, funding rounds, hiring and schedule slips from our own trackers, plus next week's launches. One click to leave.
Regulatory & Compliance
- ITAR: International Traffic in Arms Regulations, US export controls on defense-related space technology
- EAR: Export Administration Regulations, US controls on dual-use commercial space technology
- FCC: Federal Communications Commission licenses satellite spectrum and orbital slots for US operators
- ITU: International Telecommunication Union coordinates global spectrum allocation
Explore the full interactive glossary with 69 terms across 12 categories at SpaceNexus Glossary. Or browse our Space Acronyms directory with 126+ entries.
What's next
The next launch anywhere.
Next launch anywhere
GOThu, Nov 12, 19:50 UTC · Jiuquan Satellite Launch Center
Fri, Nov 13, 3:50 AM GMT+8 at the pad
Launches in 9 hours 38 minutes
Keep reading
- Analysis4 NovStarlink Goes Dark for Ukrainian Forces: Space CISOs, Seven-Minute Imagery and a New NRO Cyber Office Show Where Dependence Becomes RiskA service disruption that left Ukrainian forces without Starlink and Starshield during combat has pushed industry security chiefs to demand clear service terms and sovereign control. The same week, Vantor showed...SpaceNexus Desk · AI-drafted
- Article3 NovNASA's Swift Observatory Re-Entered Over Indonesia: What to KnowNASA's Neil Gehrels Swift Observatory, launched in 2004 to catch gamma-ray bursts, re-entered Earth's atmosphere over Indonesia on November 4. When and where it came down, how close the forecasts were, what it did, and...SpaceNexus Desk · AI-drafted
- Analysis12 NovThree Pentagon Loans Totaling $450 Million, a Self-Funded Anduril Satellite and a $115 Million Viasat Task Order: Who Is Paying for Defense Space CapabilityThe Department of Defense announced three loans totaling $450 million to U.S. space companies, reportedly driven by a fiscal-year-end deadline, as Anduril showed a satellite built with its own capital and Viasat won a...SpaceNexus Desk · AI-drafted