[_0w8t]

Still SpaceX routinely recovers the first stage after launching geostationary communication satellites. I thought GPS should be lighter as they are closer to Earth and needs to send much less information in their signal, so the power requirements and size of Solar panels should be lower.

[inamberclad]

Looks like GPS-III 3,880 kg at launch. That's fairly hefty, but Falcon 9 has launched other, more massive satellites all the way to GTO (Geostationary Transfer Orbit).

The only information I can find on why this one was so energy intensive has to do with the high inclination the GPS satellite has to be in (55 degrees), which is pretty far off from inclination of the launch pad in Florida.

Wikipedia says this launch was originally planned on a Delta IV. That would make sense because it has higher specific impulse hydrogen engines. The Falcon does well in LEO, but improved Isp really helps as you go farther out.

Here's a video comparing ULA's rockets to SpaceX: https://www.youtube.com/watch?v=QoUtgWQk-Y0

[marvin]

This sattelite was some 8000kgs, vs. 4000-ish kgs for the previous-generation GPS satellites, if I remember correctly.

[Roritharr]

Any idea why their weight increased so much?

[nradov]

The latest generation of GPS satellites has more antennas and more powerful transmitters. This improves signal reception and reduces the impact of jamming.

[walrus01]

GPS as received by a small hockey-puck sized antenna is a VERY weak signal, like -140 to -150dB. It only works because the channel size is so narrow and the modulation is very rudimentary. Having a satellite with much larger photovoltaic arrays and really powerful transmitters is one method to overcome regional jamming.

[tgsovlerkhgsel]

I wouldn't be surprised if the satellites had additional, classified capabilities.