Oh I see your question now. Yes, the USSF owns and operates GPS. It does not necessarily have a PNT requirement in LEO. There are emerging requests for PNT at GEO and cis-lunar travel. So there seems to indeed be some use for traveling to the moon :)

Despite the other guy’s snarky comment about system system, he’s right that they are being added to the current system. They will replace aging satellites and join the current constellation of 31 operational satellites. You’re also right that there is a minimum number of satellites required for high availability globally. The geometry of the MEO constellation creates certain thresholds for different levels of availability. As we add capabilities to new satellites, it takes time to replace older ones and proliferate the new capabilities across the constellation for global availability.

Distance/altitude does attenuate the signal, but these are planned for MEO—not LEO. There are other improvements on these satellites that improve signal strength rather than just going to lower orbits.

Galileo is great. It’s effective and relatively inexpensive. It unfortunately requires a lot more maintenance of uploading ephemeris data than GPS does. GPS gets daily ephemeris updates but can go as long as a week without it and still have okay accuracy. Galileo operates with multiple uploads per hour and if a satellite misses updates for a day, as happened in 2019, the whole constellation turns off. The two systems perform different roles so it’s a bit unfair to compare them directly. All of NATO uses GPS so Galileo doesn’t have as strict resiliency requirements; therefore, they can be made differently and cheaper. It’s an excellent system for what it does with its public/private signals though.

It’s unlikely GPS will be entirely replaced. Lots of platforms and equipment use the precise timing of its signals to do all of the functions they need. We already have requests for PNT in GEO and cis lunar space for accurate positioning on scientific, military, and commercial vehicles, which cannot be done from LEO. However, PNT data on Earth can be backed out of starlink signals as an unintended use of their service, but I believe that signal still requires GPS data from the aft antenna. There are at least two other programs actively developing PNT from proliferated LEO as well. The additional platforms providing PNT augment GPS signals to improve signal accuracy, minimize jamming effects, and provide redundancy to minimize adversarial ROI for attacking a GPS satellite.

Full replacement of GPS is possible, but won’t happen in this generation of satellites. My guess is we will have layers of PNT from mobile terrestrial ground beacons, proliferated LEO for resiliency, legacy MEO with the most accurate timing, and a persistent GEO layer for omni-present coverage to lower orbits and region-specific interests such as indo-pacom.

Nope. GPS III SV06 is scheduled to launch January 18th. The first IIIF doesn’t even start assembly until August 2023. We’re building the IIIF non-flight test bed now. SV11 (the first IIIF) will finish testing right around the same time GPS III SV10 is launching.

$250M per SV isn’t bad. The IIIs have historically ranged from $250M-$330M, depending on how you account for total program costs.

These are going to MEO :)

It’s possible he meant Launch & Early Orbit checkout… but it’s hard to tell. SDA are the only Space Force org looking at putting PNT in LEO.

You’re close, but a couple of clarification points: We’re not going to launch IIIFs before the rest of the IIIs. At least no discussions to do so yet, but we have discussed pushing SVs 11 and 12 (the first two IIIFs) to launch right after SV10. The first two IIIFs are largely the same as the IIIs anyway. The primary constraining factor to our SVs on the ground is the shelf life of the batteries. It’s better now that we’ve switched to Li instead of NiH2, but still are a life cycle concern if they are in extended cold storage instead of regular charging/discharging as designed.