USA-94

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American navigation satellite used for GPS

title: "USA-94" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["spacecraft-launched-in-1993", "gps-satellites", "usa-satellites"] description: "American navigation satellite used for GPS" topic_path: "general/spacecraft-launched-in-1993" source: "https://en.wikipedia.org/wiki/USA-94" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary American navigation satellite used for GPS ::

::data[format=table title="Infobox spaceflight"]

Field	Value
name	USA-94
names_list	Navstar 2A-13
GPS IIA-13
GPS II-22
GPS SVN-35
image_size	290px
mission_type	Navigation
operator	US Air Force
COSPAR_ID	1993-054A
SATCAT	22779
mission_duration	7.5 years (planned)
22.66 years (achieved)
spacecraft	GPS IIA
spacecraft_type	GPS Block IIA
manufacturer	Rockwell International
launch_mass	840 kg
dimensions	5.3 m of long
power	710 watts
launch_date	30 August 1993, 12:38:00 UTC
launch_rocket	Delta II 7925-9.5
(Delta D222)
launch_site	Cape Canaveral, LC-17B
entered_service	1 October 1993
disposal_type	Graveyard orbit
deactivated	10 June 2016
orbit_reference	Geocentric orbit
orbit_regime	Medium Earth orbit
(Semi-synchronous)
orbit_slot	B4 (slot 4 plane B)
orbit_periapsis	20074 km
orbit_apoapsis	20221 km
orbit_inclination	54.9°
orbit_period	716.0 minutes
apsis	gee
programme	Global Positioning System
previous_mission	USA-92 (GPS IIA-12)
next_mission	USA-96 (GPS IIA-14)
::

| launch_date = 30 August 1993, 12:38:00 UTC | launch_rocket = Delta II 7925-9.5 (Delta D222) | launch_site = Cape Canaveral, LC-17B

| entered_service = 1 October 1993 | disposal_type = Graveyard orbit | deactivated = 10 June 2016

| programme = Global Positioning System | previous_mission = USA-92 (GPS IIA-12) | next_mission = USA-96 (GPS IIA-14) ::callout[type=note] the satellite ::

USA-94, also known as GPS IIA-13, GPS II-22 and GPS SVN-35, was an American navigation satellite which formed part of the Global Positioning System. It was the thirteenth of nineteen Block IIA GPS satellites to be launched.

Background

Global Positioning System (GPS) was developed by the U.S. Department of Defense to provide all-weather round-the-clock navigation capabilities for military ground, sea, and air forces. Since its implementation, GPS has also become an integral asset in numerous civilian applications and industries around the globe, including recreational used (e.g., boating, aircraft, hiking), corporate vehicle fleet tracking, and surveying. GPS employs 24 spacecraft in 20,200 km circular orbits inclined at 55.0°. These vehicles are placed in 6 orbit planes with four operational satellites in each plane.

GPS Block 2 was the operational system, following the demonstration system composed of Block 1 (Navstar 1 - 11) spacecraft. These spacecraft were 3-axis stabilized, nadir pointing using reaction wheels. Dual solar arrays supplied 710 watts of power. They used S-band (SGLS) communications for control and telemetry and Ultra high frequency (UHF) cross-link between spacecraft. The payload consisted of two L-band navigation signals at 1575.42 MHz (L1) and 1227.60 MHz (L2). Each spacecraft carried 2 rubidium and 2 Cesium clocks and nuclear detonation detection sensors. Built by Rockwell Space Systems for the U.S. Air force, the spacecraft measured 5.3 m across with solar panels deployed and had a design life of 7.5 years.

Launch

USA-94 was launched at 12:38:00 UTC on 30 August 1993, atop a Delta II launch vehicle, flight number D222, flying in the 7925-9.5 configuration. The launch took place from Launch Complex 17B (LC-17B) at the Cape Canaveral Air Force Station (CCAFS), and placed USA-94 into a transfer orbit. The satellite raised itself into medium Earth orbit using a Star-37XFP apogee motor.

Mission

On 1 October 1993, USA-94 was in an orbit with a perigee of 20074 km, an apogee of 20221 km, a period of 716.0 minutes, and 54.9° of inclination to the equator. It broadcast the PRN 5 signal, and operated in slot 4, and later 5, of plane B of the GPS constellation. The satellite had a mass of 840 kg and a design life of 7.5 years. It was initially decommissioned on 26 March 2009 and then kept as a residual satellite. SVN 35 was then recalled to replace SVN 30 in the active constellation on 16 August 2011.

It was then decommissioned again on 1 May 2013, after almost 20 years in orbit, and finally placed in a disposal orbit approximately 1000 km above the operational constellation and deactivated on 10 June 2016.

References

(14 May 2020). "Display: Navstar 2A-13 1993-054A". NASA.
McDowell, Jonathan. "Launch Log". Jonathan's Space Report.
McDowell, Jonathan. "Launch List". Jonathan's Space Report.
Krebs, Gunter. "GPS-2A (Navstar-2A)". Gunter's Space Page.
(14 May 2020). "Trajectory: Navstar 2A-13 1993-054A". NASA.
Wade, Mark. "Navstar". Encyclopedia Astronautica.
"NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2009023". United States Coast Guard.
"NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2011062". United States Coast Guard.
"2SOPS Takes Over IIF-2, Moves to Replace SVN-30 with Spare". Inside GNSS.
"NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2013027". United States Coast Guard.
"Obituary: Farewell to SVN-35". United States Air Force.

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::