GPS IIF-3 Satellite Now Transmitting L1, L2 Signals

A Delta IV rocket lifts-off into the blue skies over Cape Canaveral on Thursday with an advanced GPS satellite. (Credit: ULA/Atkeison).

Video of launch.

UPDATE: The SVN65/PRN24 L5 transmitter has now been switched on. L5 is the civilian safety-of-life GPS signal, designed to meet demanding requirements for safety-of-life transportation and other high-performance applications.

UPDATE: The GPS Block IIF-3 satellite, SVN65, began transmitting L1 and L2 signals as PRN24 on October 8. A number of stations of the International GNSS Service are now tracking the satellite. The satellite is included in broadcast almanacs although it is set unhealthy and will continue to be so until satellite commissioning is completed. The satellite is still drifting towards its designated orbital position of Slot 1 in Plane A.

Meanwhile, SVN27/PRN27 was decommissioned from active service on October 6 and removed from the broadcast almanacs. However, the L-band
transmitters of SVN27 remain active, presumably for end-of-life testing.

UPDATE: According to Boeing, the satellite manufacturer, SVN65 is on orbit and performing as expected. A Boeing press release stated that “Controllers confirmed initial contact with the spacecraft at 11:43 a.m. Eastern time. The satellite’s GPS signals will be turned on and tested within a few days.”

Incidentally, the launch occurred exactly 55 years to the day after the launch of the world’s first satellite, Sputnik I, on October 4, 1957. It was Doppler tracking of that satellite that gave rise to the Transit navigation system and subsequently, its successor, GPS.

The launch of the GPS Block IIF-3 satellite took place as scheduled October 4 at 12:10 UTC (8:10 a.m. EDT), aboard a United Launch Alliance Delta IV rocket from Cape Canaveral, Florida. Spacecraft separation was reported at 16:27 UTC.

The Boeing-built spacecraft is designed to improve network coverage for both civilian and military networks, including a new L5 signal for improved commercial and civil aviation users.

The satellite, also known as SVN65, will be positioned in orbital slot 1, which is in plane A and will use the PRN24 ranging codes. Slot 1 was recently occupied by a Block IIA satellite, SVN39, operating as PRN09. SVN39 is one of the oldest operating satellites in the GPS fleet, having been launched on 26 June 1993. SVN39 underwent an initital Delta-V on September 27 to move it close to SVN38/PRN08 in slot 3 in plane A, making room for the new Block IIF satellite.

“Congratulations to the entire team on today’s successful launch of the GPS 2F-3 satellite,” Jim Sponnick, ULA vice president, Mission Operations, said in a post-launch press release.

“ULA and our mission partners have a rich heritage with the GPS program and we are proud to have served alongside the government and contractor teams over the last two decades to provide important Global Positioning System capabilities for our national defense and for millions of civilian and commercial users around the world.”

A Delta IV rocket lifts-off with an advanced GPS satellite from Cape Canaveral on Thursday. (Credit: ULA/Atkeison).

An NANU announcing the launch has been issued:

NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2012062
SUBJ: SVN65 (PRN24) LAUNCH JDAY 278
1.     NANU TYPE: LAUNCH
NANU NUMBER: 2012062
NANU DTG: 041222Z OCT 2012
SVN: 65
PRN: 24
LAUNCH JDAY: 278
LAUNCH TIME ZULU: 1210

2. GPS SATELLITE SVN65 (PRN24) WAS LAUNCHED ON JDAY 278.
A USABINIT NANU WILL BE SENT WHEN THE SATELLITE IS SET ACTIVE TO
SERVICE.

3. POC: CIVILIAN – NAVCEN AT 703-313-5900, HTTP://WWW.NAVCEN.USCG.GOV
MILITARY – GPS OPERATIONS CENTER AT HTTPS://gps.afspc.af.mil/
GPSOC , DSN 560-2541,
COMM 719-567-2541, GPS_SUPPORT@SCHRIEVER.AF.MIL , HTTP://gps.afspc.af.mil/GPSOC/GPS
MILITARY ALTERNATE – JOINT SPACE OPERATIONS CENTER, DSN 276-3514.
COMM 805-606-3514.
JSPOCCOMBATOPS@VANDENBERG.AF.MIL