Two of the German military’s new spy satellites appear to have failed in orbit

It sounds like it does radar and that it's the radar antennas at issue, and there's some separate antenna that they can use to communicate.

Also, a previous satellite of the same design that was manufactured by Airbus worked. So they know the likely system and that it's a manufacturing problem. They don't need to design a replacement from scratch, just manufacture it. They have one satellite up. And while their older satellites in the previous constellation are past their design life and aren't as good, they're apparently still functioning, and hopefully will for several years.

So it doesn't sound that bad.