Some GNSS Progress Statements

From the recent Munich GNSS Summit.

GPS good news: The 2 GPS Block IIF satellites have less than 1/2 the range error compared to the current constellation. As more IIF satellites get up there this will show up in ground solutions.

GPS bad news: The next 2 Block IIF satellites have been put in storage. Launches will be stretched out? Compared to what, the 1 launch in 2010 and the 1 launch in 2011?

GPS satellites are very heavy because each includes a nuclear detonation detection device tha uses a lot of power. Plans were being made to build some GPS without that function which would have made them light enough to launch 2 at a time. The plans to put NDDs on other type satellites have been scratched so double launches are less likely. GPS IIIs may be light enough to dual launch. There is the posiibility of insuffient launch vehicles due to current budget cuts in the next few years. As a note, early on the Space Shuttle handled triple GPS launches, but when the Shuttle could not meet the original launch relaunch schedule, GPS payloads were shifted elsewhere.

GLONASS: GLONASS is now well funded, and by 2020 expects to have 24 satellites with old and newer frequencies. Plans are also underway to enable GLONASS to work with 30 active satellites. Later in 2012 the second next generation GLONASS-K will be launched. I do not have in front of me the number of GLONASS-Ms remaining in stock on the ground.

Galileo: Galileo has 26 satellites 2 in orbit, the resy on the ground or under contract. 2 are planned for a single 2012 launch. Plans for 2013 are for 3 Soyuz double launches. Plans for 2013 are for 2 Soyuz double launches and an Ariane 5 quadruple launch, with 2 Ariane 5 quadruple launches in 2015. Expectations are to declare it operational in 2014 with 18 satellites. Orbits can be filled up fast launching 4 at a time, but a launch failure can be very expensive. Anticipate using Galileo in 2016 on a close to 24/7 basis, 24 out of the 26 should do it. I had been unaware of the 4 satellite launch plans a few weeks ago. Hoping their economies can support the plans.

Paul in PA