True ... and in this case, you don't have to worry about getting the spacecraft into space. The mechanical challenges are quite a bit simpler (steering antennas to track the space-craft). Perhaps we should make a high-level list of what needs to be done?

1) Find/track the spacecraft

2) Steer antennae to follow the spacecraft

3) Create transmitter and receiver hardware capable of communicating with the spacecraft's radio equipment (perhaps software radios).

4) Write software capable of handling the transmit and receive protocols.

5) Write software that captures the state of the spacecraft.

6) Write software that can control the spacecraft.

7) Decide where the spacecraft should go (hopefully, if we were to reestablish communications, perhaps NASA would help with the physics).

I think the bulk of the project consists of performing the research required to actually "speak the spacecraft's language". Fortunately, this part of the project is most conducive to crowd-sourcing and collaboration.

The problem is, how do you intend to introduce collaboration in this? It may be worth the shot, but it'd expect there's a big chance you won't be able to achieve that -- the "control space" of valid commands is likely very large and unstructured. You can't risk brute forcing it and seeing what happens because of the low rate and risk of failure from a bad command. There's also the responsibility of issuing a bad command. For such a scientific reverse-engineering you also need proper tools to observer the aircraft behavior which I imagine can be quite difficult -- what if a command sets the rotation rate of the aircraft to +1 arcsec/hr and that causes an antenna misalignment?

Unless, of course, you get full specification from relevant agencies and check with them before issuing any command. But that implies they're willing to apply resources on this project, which is another though barrier.

Anyway, sounds like quite an adventure. My sincere good luck.

Good points ... I don't intend to try this devoid of all NASA input (I've already reached out to a contact I have at SWIFT). I'm assuming two things right now:

1. That the documentation for the commands exists and that it's available to the project.

2. That NASA (or someone with sufficient knowledge) helps avoid issuing dangerous commands (e.g. running the spacecraft into the ISS).

Otherwise, it's probably better to do nothing. As I noted above, I view this more as crowd-sourcing the expensive "reengineering".

5.5) Determine how much fuel it still has. Per Wikipedia, "a [2008] status check revealed that all but one of its 13 experiments were still functioning, and it still has enough propellant for 150 m/s of ΔV. ".

I'm guessing that is not much. (Amazing that it still had any at all)!