GPS IIF-9 Launches Wednesday
A patch for the upcoming GPS satellite launch shows a stylized GPS IIF-IX formed by the Delta 4 rocket and the constellation Cygnus (Latinized Greek word for swan). The satellite is nicknamed Deneb, the brightest star in the constellation and one of the 57 stars used in celestial navigation. The patch also indicates that the satellite is SV-10 and 71. The SV-10 identifier may indicate that it is the 10th satellite off the IIF assembly line. Photo: US Air Force
The U.S. Air Force’s ninth GPS Block IIF satellite (GPS IIF-9) is set to launch Wednesday at 2:36 p.m. EDT (1836 GMT) from Space Launch Complex 37 at Cape Canaveral Air Force Station, Fla.
The GPS IIF-9 will ride aboard a United Launch Alliance (ULA) Delta IV rocket, marking the 29th Delta IV launch and the 57th operational GPS satellite to launch on a ULA or heritage launch vehicle.
To follow the launch countdown, dial the ULA launch hotline at 1-877-852-4321 or join the conversation on Facebook, Twitter or Instagram. A Delta IV GPS IIF-9 Mission Overview Brochure is available here. See images of the launch preparations here.
GPS IIF-9 is one of the next-generation GPS satellites, incorporating various improvements to provide greater accuracy, increased signals, and enhanced performance for users.
UPDATE (April 17, 2015): The USCG Navigation Center has confirmed that SV-10 was launched instead of SV-9. The Air Force discovered a problem with SV-9, so it was pulled from the launch and SV-10 was sent into orbit in its place. SV-9 will be used in a future launch.
Constellation Changes. The Air Force Second Space Operations Squadron (2 SOPS) indicates that IIF-9, SVN-71/PRN-26, will replace SVN-35 (currently being operated in Launch, Anomaly Resolution and Disposal Operations [LADO]) in the B plane slot 1F. SVN-38/PRN-08 will be taken out of the operational constellation prior to SVN-71 payload initialization and sent to LADO. PRN-08 will be assigned to SVN-49 in May and set to test, but is tentatively scheduled for assignment to IIF-10 to launch June 16. SVN-35, launched on August 30, 1993, has been in a residual status since March 2013 in an expanded node slot in the B plane and successfully served 21.5 years, 14.0 years beyond its designed service life, due to the diligent efforts of the men and women of the U.S. Air Force. SVN-51 is still in a re-phase journey from E1 (GLAN=146 °) to an auxiliary node at E7 (GLAN=60.7 °) scheduled to arrive sometime this summer.
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This is 9th IIF but the logo says SV10 … What does I miss?
Nothing.
Mission number and SV number are different.
This is the 9th *launch* of a GPS satellite, but it will be the 10th satellite *built*.
The SVN for this once, as mentioned in the article, is SVN-71. SVN-70 (SV-9) is getting skipped, likely because of an issue found during manufacturing or testing.