It's crazy to me just how much use we've gotten out of this thing. 31 years old. I hope JWST can provide the same sort of longevity. I wonder if there are similar plans to have it be serviceable / upgradable now that we've regained the ability to put our own astronauts in space recently.
It probably won't ever be serviced or upgraded, for several reasons:
It's orbiting at the Earth-Sun L2 Lagrange point, with a perigee of 374,000 km
While we can put astronauts in space, we don't currently have any orbital vehicles with on-orbit satellite maintenance capabilities, since none of them have airlocks
The latter could very well change over the next few decades though, and the former may become economical, so I guess it can't be entirely ruled out.
But the landscape of the space industry is changing very rapidly. With a fleet of hundreds of reusable rockets floating around, the accessibility of the Hubble may change.
Of course, at that point it might be better to just send up a bigger instrument.
I'm interested in this too. I know the planned mission duration for JWST is just 10 years, but I also wonder if its orbit or something else about the mission parameters will prevent it from lasting as long as Hubble.
"JWST needs to use propellant to maintain its halo orbit around L2, which provides an upper limit to its designed lifetime, and it is being designed to carry enough for ten years. The planned five year science mission begins after a 6-month commissioning phase. An L2 orbit is only meta-stable, so it requires orbital station-keeping, or the telescope will drift away from this orbital configuration." [0]
There's no mention of lifetime for the cryocooler @ [1], but if that thing becomes ineffective for whatever reason (helium refrigerant leak?), I think the telescope becomes somewhat useless.