Speedy IIF Will Get There Faster

Speedy IIF Will Get There Faster
May 4, 2010
http://www.gpsworld.com/gnss-system/news/speedy-iif-will-get-there-faster-9901?print=1


Just before midnight on Thursday, May 20, the first of a new generation
has a date with destiny on the Cape Canaveral launch pad. GPS spacecraft
IIF-1 has a launch window extending from 11:29 to 11:48 p.m., Eastern
daylight time. It’s in a hurry. Instead of taking several days to reach
its orbital slot, the new satellite will make the journey in
three-and-a-half hours.

IIF-1 catches its breathless ride aboard a Delta 4 rocket from the
United Launch Alliance, a joint venture of Lockheed Martin and Boeing,
formed in late 2006.

Earlier GPS satellites rode on smaller Delta 2 rockets that, although
very reliable, did not possess the oomph to place space vehicles
directly into the orbiting constellation, 11,000 miles high. Delta 2s
put satellites into highly elliptical orbits looping from as low as 100
miles above Earth at perigee to the 11,000-mile apogee. At a strategic
point, a solid-fuel kick motor attached to the satellites pushed them
into position for circular orbit on high.

Like Space-Age William Tells, the more powerful Delta 4 will shoot the
IIFs directly into their destination slots. Future IIF launches may also
use Atlas 5 rockets, similarly endowed. The next one, GPS IIF-2, could
rise aboard an Atlas 5 as early as November this year.

The IIF generation, manufactured by Boeing, will broadcast the new civil
L5 signal. IIF satellites have a longer design life of 12 years, and
faster processors with more memory. A total of 12 IIF satellites will
make their contribution to getting the new L2C and L5 signals closer to
operational capability, before the GPS III generation takes over.