Question: Why do the Delta IV GPS launches head east towards a 41 degree inc. orbit and then increase back to the required 55 deg. orbit, instead of launching northeast directly towards a 55 deg. orbit (as Atlas V GPS launches do)? The 1st stage shouldn't travel far enough to hit Europe when launching NE...
Question: Why do the Delta IV GPS launches head east towards a 41 degree inc. orbit and then increase back to the required 55 deg. orbit, instead of launching northeast directly towards a 55 deg. orbit (as Atlas V GPS launches do)? The 1st stage shouldn't travel far enough to hit Europe when launching NE...
There is no land mass to over fly during any portion of power flight.
2 objects have been catalogued by USSTRATCOM
39533/2014-008A in 20451 x 20469 km x 54.99° (presumably the S/C)
39534/2014-008B in 20468 x 21710 km x 54.68° (presumably Delta-IV 2nd stage)
Question: Why do the Delta IV GPS launches head east towards a 41 degree inc. orbit and then increase back to the required 55 deg. orbit, instead of launching northeast directly towards a 55 deg. orbit (as Atlas V GPS launches do)? The 1st stage shouldn't travel far enough to hit Europe when launching NE...
There is no land mass to over fly during any portion of power flight.
Here are the Atlas 5-401 versus Delta 4M+4,2 GPS 2 ground traces. Atlas 5's Centaur performed a long first burn to reach a transfer orbit directly while Delta 4's DCSS performed two burns to reach a transfer orbit. Since the first stage burn times are similar, I would expect DCSS to be able to complete a long first burn like Centaur before hitting Europe. Perhaps the extra capability of the 4M+4,2 compared to the two-stage Atlas was used to keep the entire flight over water.
- Ed Kyle
This image posted on SpaceWeather.com by photographer Dennis Mammana captures fuel vent...
5th Boeing GPS IIF Spacecraft Sends Initial Signals from Space
EL SEGUNDO, Calif., Feb. 21, 2014 -- A Boeing [NYSE: BA] Global Positioning System (GPS) IIF satellite has sent initial signals from space after its launch Feb. 20, joining four other advanced versions of the spacecraft that are improving position, navigation and timing information for millions of civilian and military users around the world.
GPS IIF-5 launched at 8:59 p.m. Eastern time from Cape Canaveral Air Force Station, Fla., aboard a United Launch Alliance Delta IV rocket, and Boeing received the satellite's first signals approximately three and a half hours later. It will undergo on-orbit activation, checkout and testing before joining the active GPS constellation.
The GPS IIFs are providing greater navigational accuracy through improvements in atomic clock technology, a more resilient signal for commercial aviation and safety-of-life applications, and a longer design life of 12 years.
"Boeing launched the first GPS satellite in 1978 and has played an integral role in the ongoing enhancement of this vital technology ever since," said Craig Cooning, Boeing vice president and general manager of Space & Intelligence Systems. "The 42 satellites that we have deployed into service to date for the U.S. Air Force have accumulated more than 500 years of on-orbit operations, and the current system continues to meet or exceed all mission requirements."
This was the first GPS IIF satellite launch of 2014. The sixth GPS IIF is at the Florida launch site undergoing preparations for a second quarter launch. The remaining six are at the Boeing Satellite Development Center in El Segundo, Calif.
For now, SVN36 (IIA-24) in C6 slot with PRN6 is decommissioned, PRN6 code is assigned to D6 slot.
5th Boeing GPS IIF Satellite Joins Global Positioning System
GPS users benefit from more precise navigation data
EL SEGUNDO, Calif., April 8, 2014 -- The accuracy of the Global Positioning System (GPS) has been improved with the recent handover of a fifth Boeing [NYSE: BA] GPS IIF satellite to the U.S. Air Force. The newest addition to the GPS constellation increases the precision of position, navigation and timing data sent to users around the world.
http://boeing.mediaroom.com/Fifth-Boeing-GPS-IIF-Satellite-Joins-Global-Positioning-System
As the article said, it is for an extended Nav test. Per IS-GPS-200G, par. 6.2.2.2.5, "These SVs will
provide at least 60 days of positioning service without contact from the CS."
I would wager than it'll be set healthy approximately 60 days from that Nav in March.
