USA-242, also known as GPS IIF-4, GPS IIF SV-5, Navstar-68 and Vega, is an American

navigation satellite A satellite navigation or satnav system is a system that uses satellites to provide autonomous geo-spatial positioning. It allows satellite navigation devices to determine their location (longitude, latitude, and altitude/elevation) to high pre ...

which was launched on 15 May 2013 and became operational on 21 June 2013. The fourth Block IIF GPS satellite, it forms part of the

Global Positioning System The Global Positioning System (GPS), originally Navstar GPS, is a satellite-based radionavigation system owned by the United States government and operated by the United States Space Force. It is one of the global navigation satellite ...

. USA-242 is a spacecraft, built by

Boeing The Boeing Company () is an American multinational corporation that designs, manufactures, and sells airplanes, rotorcraft, rockets, satellites, telecommunications equipment, and missiles worldwide. The company also provides leasing and ...

with a design life of 15 years. It operates from a semi-synchronous

medium Earth orbit A medium Earth orbit (MEO) is an Earth-centered orbit with an altitude above a low Earth orbit (LEO) and below a high Earth orbit (HEO) – between above sea level.

, at an altitude of an inclination of 55 degrees, in slot 5 of plane C of the GPS constellation. The new satellite was originally intended to replace the seventeen-year-old USA-117 satellite, but currently both USA-117 (SVN-33) and USA-242 (SVN-66) are in active use. USA-242 broadcasts its navigation signals using the PRN-27 signal modulation.

United Launch Alliance United Launch Alliance (ULA), legally United Launch Alliance, LLC, is an American spacecraft launch service provider that manufactures and operates a number of rocket vehicles that are capable of launching spacecraft into orbits around Earth, a ...

conducted the launch of GPS IIF-4, using an

Atlas V Atlas V is an expendable launch system and the fifth major version in the Atlas launch vehicle family. It was originally designed by Lockheed Martin, now being operated by United Launch Alliance (ULA), a joint venture between Lockheed Mart ...

401 carrier rocket. Launch took place from

Space Launch Complex 41 Space Launch Complex 41 (SLC-41), previously Launch Complex 41 (LC-41), is an active launch site at Cape Canaveral Space Force Station. As of 2020, the site is used by United Launch Alliance (ULA) for Atlas V launches. Previously, it had been use ...

at the

Cape Canaveral Air Force Station Cape Canaveral Space Force Station (CCSFS) is an installation of the United States Space Force's Space Launch Delta 45, located on Cape Canaveral in Brevard County, Florida. Headquartered at the nearby Patrick Space Force Base, the statio ...

, with liftoff occurring at 21:38 UTC on 15 May 2013, the beginning of an 18-minute

launch window In the context of spaceflight, launch period is the collection of days and launch window is the time period on a given day during which a particular rocket must be launched in order to reach its intended target. If the rocket is not launched wi ...

. The launch marked the first time since 1985 that a GPS satellite had launched on an Atlas rocket, or indeed any rocket other than a Delta.

References

Spacecraft launched in 2013 GPS satellites USA satellites Spacecraft launched by Atlas rockets {{US-spacecraft-stub