On Feb 24, 6:41*pm, David Lesher wrote:
Me writes:
I know of those two; but picture MSFC 68-IND-1200-24 A
as seen on page 55 of Haynes shows "C band Radar" in the
IU, next to the air supply tank.

That is the transponder for the Range C band Radars

Ground-based tracking radar? That would make lots of sense to
me; I didn't understand why the heavy part wouldn't be on the
ground.

I assume there were 3+ sites so they could triangulate
the position.

Nope, just two, prime and backup. Radars don't requiret multiple
sites, only one is required.