Dec. 18 (UPI) -- SpaceX has delayed the launch of its Falcon 9 rocket for a second time in two days.
The Falcon 9 rocket was originally scheduled to launch a GPS satellite into space on behalf of the U.S. Air Force at 9:34 Tuesday morning. The aerospace company announced a 24-hour delay shortly before launch.
On Wednesday, SpaceX took to Twitter to announce a second delay.
"Standing down from today's launch attempt of GPS III SV01 to further evaluate out of family reading on first stage sensors; will confirm a new launch date once complete," SpaceX tweeted.
When Falcon 9 does launch, it will be the private space company's first national security mission.
Encapsulated in the SpaceX payload fairing is a GPS III satellite, the first of the next-generation of Global Positioning System satellites to be put into orbit.
The launch of the Lockheed Martin-designed GPS III SV01, named Vespucci, is the first step in a longterm plan to upgrade the GPS satellite constellation managed by the United States Air Force's Global Positioning Systems Wing.
"This is truly a momentous time of the U.S. Air Force," Steve Whitney, director of the Air Force's Global Positioning Systems Directorate, said in a call with reporters. "GPS III will be the first satellite to broadcast four civilian signals, and it will be three times more accurate and up to eight times more powerful than previous generations."
GPS III will also provide military users with M-Code capability, a stronger and more secure signal, less susceptible to jamming and spoofing.
"The launch of GPS III SV01 is a major milestone in the effort to modernize the GPS system," said Johnathon Caldwell, vice president for navigation systems at Lockheed Martin.
Vespucci is the first of ten planned GPS III satellites. Eventually, the Air Force plans to replace the old GPS satellite constellation with an entirely new constellation, but for now, new GPS III satellites will augment the current GPS constellation.
The new and improved signals provided by Vespucci will help U.S. military users, aiding navigation and guiding bombs, missiles and artillery, as well as civilians, guiding cars and providing the geolocation data used by industrial and agricultural sectors.
Though GPS III SV01 will assume its orbit around Earth this week, it will take several months for the new satellite to be integrated into the GPS constellation.
For the last decade, the United Launch Alliance, or ULA, has launched all of the Air Force's space-based missions.
"This marks the first competitive bid launch in over 10 years," said Col. Robert Bongiovi, director of the Launch Enterprise Systems Directorate at the Air Force's Space and Missile Systems Center in Los Angeles.
The Air Force has already awarded SpaceX with contracts for two more GPS III satellite launches.