First GPS III satellite flies to historic perch in space

January 8, 2019  - By
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SpaceX’s Falcon 9 rocket orbited the first GPS III satellite on Dec. 23, 2018. (Photo: SpaceX)

SpaceX’s Falcon 9 rocket orbited the first GPS III satellite on Dec. 23, 2018. (Photo: SpaceX)

After several launch delays, the first GPS III satellite successfully deployed from a SpaceX Falcon 9 rocket, rising from Cape Canaveral on Dec. 23.

By Jan. 2, the satellite had circularized its orbit at an altitude of 12,550 miles to begin a period of checkout and testing that could last up to 18 months, before entering service. The satellite, built by Lockheed Martin, will serve in space for 15 years.

Known as GPS III SV01 and nicknamed “Vespucci,” it is the first in a new generation of GPS navigation stations with improved services and longer lifetimes to ensure the U.S. military-run network remains available to troops and civil users around the world for decades to come.

“Launch is always a monumental event, and especially so since this is the first GPS satellite of its generation launched on SpaceX’s first national security space mission,” said Lt. Gen. John Thompson, commander of the U.S. Air Force’s Space and Missile Systems Center and the Air Force’s program executive officer for space. “As more GPS III satellites join the constellation, it will bring better service at a lower cost to a technology that is now fully woven into the fabric of any modern civilization.”

The satellite’s earlier scheduled launch date of Dec. 18 was scrubbed, reportedly due to liquid oxygen thermal limit constraints aboard the SpaceX Falcon 9 Block 5 rocket’s first stage reaching safety limits.

A second attempt on Dec. 19 was also ruled out due to ongoing evaluations into the sensor issue. Then ensued three days of weather delay, awaiting favorable wind conditions, until Dec. 23.

After several delays, the first GPS III satellite has successfully deployed from the SpaceX Falcon 9 rocket, which launched from Cape Canaveral Air Force Station in Florida at 8:51 a.m. EST on Dec. 23. (Photo: Lockheed Martin)

After several delays, the first GPS III satellite has successfully deployed from the SpaceX Falcon 9 rocket, which launched from Cape Canaveral Air Force Station in Florida at 8:51 a.m. EST on Dec. 23. (Photo: Lockheed Martin)

GPS III SV01 was originally scheduled to ride aboard a United Launch Alliance (ULA) Delta IV M+ rocket. ULA and its prime partners, Lockheed-Martin and Boeing, have conducted every GPS satellite launch since the start of the program. However, due to an assortment of issues variously involving delayed technology development and lawsuits regarding competitive bidding, the Air Force re-opened the contract process as part of its Evolved Expendable Launch Vehicle (EELV) program — “evolved” signifying that the rocket can be recovered and reused.

Recycling Rockets. ULA did not bid on the re-opened contract, citing concerns over the selection process and potential risks with the anticipated lower launch cost. In 2016, the Air Force selected SpaceX to take over most GPS III launches.

SpaceX’s Falcon 9 for this launch used a new first stage core, the B1054. Although it has re-use capability, it flew in an expendable configuration this time, with no landing legs and no grid fins. It was disposed of into the Atlantic Ocean after separation from the second stage.

In other missions, after the satellite-bearing stage separates from the rest of the rocket, the remaining core launcher fires additional fuel to return intact to land or to sea aboard an Autonomous Spaceport Drone Ship (ASDS), a converted barge awaiting in the Atlantic or Pacific Ocean.

New Generation. The GPS III constellation, once fulfilled, will bring three times better accuracy and up to eight times improved anti-jamming capabilities. Spacecraft life will extend to 15 years, 25 percent longer than GPS satellites on-orbit today. GPS III’s new L1C civil signal also will make it the first GPS satellite broadcasting a compatible signal with other international global navigation satellite systems, like Galileo, improving connectivity for civilian users.

Lockheed Martin developed GPS III and manufactured GPS III SV01 at its GPS III Processing Facility near Denver. In September 2017, the Air Force declared the satellite “Available for Launch” (AFL) and had the company place it into storage.

In 2018, the Air Force called the satellite to Florida, and it was delivered on Aug. 20. At that time, the Air Force declared the second GPS III AFL and in November called it up for 2019 launch. GPS III satellites SV03-08 are now in various stages of assembly and test.

About the Author:


Alan Cameron is the former editor-at-large of GPS World magazine.

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