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Samples of three GPS satellites' orbits over a five-year period (2013 to 2018) USA-242 · USA-239 · USA-151 · Earth As of 22 January 2025, 83 Global Positioning System navigation satellites have been built: 31 are launched and operational, 3 are in reserve or testing, 43 are retired, 2 were lost during launch, and 1 prototype was never launched. 3 Block III satellites have completed ...
N2YO provides real time tracking and pass predictions with orbital paths and footprints overlaid on Google Maps. [6] It features an alerting system that automatically notifies users via SMS and/or email before International Space Station crosses the local sky. The N2YO.com system powers ESA's, Space.com's and many other's satellite tracking web ...
There are two navigation message types: LNAV-L is used by satellites with PRN numbers 1 to 32 (called lower PRN numbers) and LNAV-U is used by satellites with PRN numbers 33 to 63 (called upper PRN numbers). [9] The two types use very similar formats. Subframes 1 to 3 are the same, [10] while subframes 4 and 5 are almost the same. Each message ...
These are used for Global Navigation Satellite System spacecraft, such as GPS, GLONASS, Galileo, BeiDou. GPS satellites orbit at an altitude of 20,200 kilometers (12,600 mi) with an orbital period of almost 12 hours. [8] Geosynchronous orbit (GSO) and geostationary orbit (GEO) are orbits around Earth matching Earth's sidereal rotation period.
USA-151, also known as GPS IIR-5, GPS SVN-44, and Navstar-48 is an American navigation satellite which forms part of the Global Positioning System. It was the fifth Block IIR GPS satellite to be launched, out of thirteen in the original configuration, and twenty one overall. It was built by Lockheed Martin, using the AS-4000 satellite bus. [2]
GPS Block III is the first series of third-generation GPS satellites, incorporating new signals and broadcasting at higher power levels. In September 2016, the United States Air Force awarded Lockheed Martin a contract option for two more Block III satellites, setting the total number of GPS III satellites to ten. [ 22 ]
GC number (Ground Control number, Russian: системный номер, номер по наземному комплексу управления) is the spacecraft number in almanac. [1] It only has to be unique during life time of each satellite. Numbers are subject to reuse. Some catalogs mistakenly used GC numbers for historical ...
A two-line element set (TLE, or more rarely 2LE) or three-line element set (3LE) is a data format encoding a list of orbital elements of an Earth-orbiting object for a given point in time, the epoch. Using a suitable prediction formula, the state (position and velocity) at any point in the past or future can be estimated to some accuracy.