[wideminded]

Although some aspects of this program are being declassified, the basic details have been public knowledge for a long time. I always wondered how they could manage to time the plane flights precisely enough to catch film dropped from space.

[HiTech RedNeck]

Reads here like they were encapsulated into dedicated re-entry vehicles, plopped into the ocean and grabbed by ship.

[Alas Babylon!]

Well, by the late 70's, we had the ability to track a single bolt or nut orbiting in space, so tracking Big Bird and her "eggs" was pretty much mathematically precise:

I once watched an entire lunar eclipse from the roof of this thing, ten stories high!

[tanknetter]

I always wondered how they could manage to time the plane flights precisely enough to catch film dropped from space.

Reentry mathematics and mechanics were pretty well-known at that point, being used also in how we were able to target our ICBMs (and particularly the later Minuteman series with MIRVs) and land the Mercury/Gemini/Apollo space capsules so close to the recovery ships. All the planes had to do was orbit within a set coordinate box, then aim for the parachutes.

[Roccus]

IIRC, that’s exactly how we recovered the first chimp we sent into space. (Able?)
A prop driven, Air Force plane either had a slingshot-shaped device on its nose or dragged a “U” shaped sling behind in order to snag the parachute shrouds in mid-air.