A concise index of satellite-comm data, with pointers to deeper references.
Orbits
Satellites operate in various orbits depending on coverage, latency, and mission needs. LEO is common for low-latency internet (e.g., Starlink), while GEO supports broadcast and continuous regional service12.
| Type | Altitude | Notes | Uses |
|---|---|---|---|
| LEO | 160–2 000 km | Low latency; dense constellations | Earth obs; Starlink; Iridium; IoT |
| MEO | 2 000–35 786 km | Higher latency; radiation zone | GNSS (GPS, Galileo, GLONASS, BeiDou) |
| GEO | ~35 786 km | Fixed view; continuous coverage | Broadcast TV; SATCOM; meteo sats |
| GSO | ~35 786 km | Inclined orbit; same period as Earth | Custom coverage zones (e.g. India) |
| HEO | 500 km–>50 000 km | Long apogee dwell; elliptical | Molniya/Tundra; Arctic, surveillance |
Frequency Bands
Different frequency bands are used for satellite communications depending on throughput needs and environmental resistance. Lower bands like L/C offer resilience; higher bands like Ka enable broadband but suffer rain fade34.
| Band | Range (GHz) | Antenna Size | Rain Fade | Typical Use |
|---|---|---|---|---|
| L | 1–2 | Very large | Very low | GNSS, mobile SATCOM2 |
| S | 2–4 | Large | Low | Mobile, telemetry, tracking |
| C | 3.4–7.0 | Large | Low | TV backhaul, maritime, enterprise |
| X | 7–11.2 | Medium | Medium | Military SATCOM |
| Ku | 12–18 | Smaller | Med-High | DTH TV, VSAT, aircraft broadband |
| Ka | 17.3–40 | Smallest | High | HTS, 5G backhaul, space-to-ground laser links |
Notable Systems
Recent missions illustrate trends toward higher data rates, miniaturization, and optical links. TBIRD and LCRD showcase compact laser comms payloads achieving hundreds of Gbps56.
| Mission | Year / Agency | Rate | Mass | Power | λ (nm) / Modulation |
|---|---|---|---|---|---|
| SOTA | 2014 / NICT | 1–10 Mbps | ~6 kg | 1.7–30 W | 976/800/1549 nm; OOK |
| TBIRD | 2022 / MIT Lincoln | up to 200 Gbps | <3 kg | 100 W | ~1550 nm; QPSK |
| LCRD | 2021 / NASA | up to 622 Mbps | ~300 kg | >400 W | Optical comm relay |
| Artemis | 2001 / ESA | 50 Mbps | ~3100 kg | >2000 W | Optical + RF hybrid |
Satellites
This overview outlines the main types of satellites, highlighting the objectives and examples. They are categorized based on their specific applications and the services they provide.
| Types | Objective | Example |
|---|---|---|
| Communication Satellites | Facilitate the transmission of data, television, telephony, and high-speed internet access. Reduce the need for terrestrial infrastructure. | Intelsat: Provides global telecommunications services with a vast network of satellites in GEO. |
| Earth Observation Satellites | Collecting environmental images and data for monitoring changes in the Earth’s surface, predicting weather, and conducting environmental impact studies. | Sentinel (Copernicus program): Captures multispectral data for monitoring climate change and environmental disasters. |
| Navigation Satellites | Designed for astronomical studies, climate analysis, and exploration of physical phenomena in space. | Hubble Space Telescope: An astronomical observatory placed into LEO to record images in different wavelengths. |
| Military Satellites | Carry out surveillance, espionage, secure communications, and tactical support activities. | Milstar: Jamming-resistant satellite uses for military communications. |
| Nanosatellites and Cubesats | A compact solution for space mission. Widely adapted in scientific, educational and commercial applications. | SBUDNIC (SATCAT 52774): Addressing the long term, existential problem of space junk. |
| Commercial and Government Satellites | This covers all the satellites mentioned above. | --- |
Space Cybersecurity
Securing space assets is vital given long lifespans, limited patching, and critical functions. Standards like SPD-5 and NIST SP 800-53 guide resilience and controls78.
| Framework | Scope |
|---|---|
| SPD-5 & CISA | U.S. cybersecurity principles for space |
| SPARTA | Threat-vulnerability matrix for space TTPs |
| NIST SP 800-53 | Controls baseline for information systems |
| Zero Trust (ZTA) | Ground-space-ground security architecture |
Terminology: The following terms are used in the context of satellite communications and cybersecurity.
| Term | Definition |
|---|---|
| Transmission security (TRANSEC) | Controls preventing interception, deception, or analysis of signal characteristics (e.g. modulation, timing) to protect confidentiality and integrity. |
| Emanating Spurious Transmissions (TEMPEST) | Protecting against data theft through the interception of electromagnetic radiation |
Glossary of Terms
Short definitions of common satellite-comm acronyms:
- TT&C: Telemetry, Tracking & Command
- VSAT: Very Small Aperture Terminal (Ku/C bands)
- HTS: High Throughput Satellite (often Ka band)
- ISL: Inter-Satellite Link (RF or optical)
- Ground Segment: Gateways, NOCs, mission control
References
Footnotes
-
Catalog of Earth Satellite Orbits – NASA Earth Observatory (2009)
https://earthobservatory.nasa.gov/features/OrbitsCatalog ↩ -
Satellite frequency bands – European Space Agency (2022)
https://www.esa.int/Applications/Connectivity_and_Secure_Communications/Satellite_frequency_bands ↩ ↩2 -
Satellite Communications, 3rd ed. – Wiley (2019)
https://www.wiley.com/en-us/Satellite%2BCommunications%2C%2B3rd%2BEdition-p-9781119482178 ↩ -
“LEO and GEO Satellites: Differences, Advantages and Challenges in Satellite Connectivity” – Interseas Connect (2024)
https://interseas.es/en/leo-and-geo-satellites-differences-advantages-and-challenges-in-satellite-connectivity/ ↩ -
M. 1036: Frequency arrangements for IMT (IMT-2020) – ITU (2023)
https://www.itu.int/rec/R-REC-M.1036/en ↩ -
“TBIRD: TeraByte InfraRed Delivery” – NASA NTRS (2022)
https://ntrs.nasa.gov/api/citations/20220012887/downloads/TBIRD_v5_AT.pdf ↩ -
Space Policy Directive-5: Cybersecurity Principles for Space Systems – The White House (2020)
https://www.whitehouse.gov/briefing-room/presidential-actions/2020/06/04/space-policy-directive-5/ ↩ -
Space Systems Cybersecurity Guide – CISA (2021)
https://www.cisa.gov/publication/space-systems-cybersecurity-guide ↩