I'm trying to make a list of the 10 oldest active space probes.

-- Must be a probe (including telescopes and other scientific instruments) not a comsat
-- Must be "active", meaning it's still using power, sending data back, and carrying out a mssion.

Here's my first list:

1. Voyager 1
2. Voyager 2
3. Wind (1994)
4. SOHO (1995)
5. ACE (1997)

6. Chandra (1999)
7. Terra (1999)
8. XMM-Newton (1999)
9. Cluster II (2000)
10. Mars Odyssey (2001)

So: is this a reasonably correct / accurate list? Have I missed anything?

Many thanks in advance --

Depends on your definition of "probe". I personally wouldn't count any Earth orbiter and not any Earth-observing satellite. If you allow Earth orbiters, why count Chandra and not HST?

HST is a fair cop!

Tiny quibble, Voyager 2 launched first and has therefore been 'active' longer than Voyager 1 and so takes the laurels by a couple of weeks.