Case D - Emergency interrupts a planned downlink

Scenario

We've planned to downlink 4 images in Pass 1. But partway through, an urgent command comes in telling the satellite to capture a new image right now. That capture eats into the pass's downlink time, so fewer of the original 4 images actually get sent than we'd planned.

Related to: Q3 (what happens to planned-but-not-yet-sent data in an emergency) and our earlier work on how pausing a transfer actually works.

What we already know that applies here

• We already worked out how pausing and resuming a transfer works, and the difference between a deliberate pause and simply losing the link (see the pause/resume diagram).
• Early thinking (from a whiteboard discussion): pause the in-progress transfers rather than cancelling them outright - but this isn't locked in yet.
• One thing to watch out for: while a transfer is paused, it's not allowed to ask for missing pieces to be resent. So if a paused transfer already had some gaps, those gaps just sit there, unrepaired, for the entire time it's paused.

Not yet built

We still need to draw out the full sequence: the 4 images start sending → the emergency command arrives → the in-progress transfer(s) get paused → the new image gets captured → things resume → the remaining images continue.