I think you're giving them too much credit. Happy that it didn't "unsuspend disbelief" for you, but it's too easy to make creative excuses for movie fridge logic.

Christopher Nolan seems like a pretty smart guy. It must have crossed his mind at some point.

Plus, the ship's engines don't appear to use propellant - they use the standard sci fi "eeire blue glow" trope. Seems like antimatter is the best explanation to me.

> Christopher Nolan seems like a pretty smart guy. It must have crossed his mind at some point.

Also, he had Kip Thorne as an advisor. I remember criticism of the "slow-time planet" (including by Bad Astronomy) being shot down by Kip pointing out he actually calculated it as an edge-case solution for a specific rotating black hole.

Except if the antimatter engines were so reliable, why risk blowing up your last hope to conserve the obvious surplus of antimatter you had for the mission anyway?

There were several plotpoints about how there was NOT surplus of antimatter (or whatever propellant they used).

And in case of "blowing up" they could use those am engines as LAS (they apparently had enough thrust), so what risk are you speaking about?

Seriously, bitching about science stuff in Interstellar, very large but actually very well crafted scifi is kind of dumb. It's big enough that you find SOME mistakes, but most of the time you'll be wrong (or blaming them for not explaining every detail), and it has pretty correct science overall. Just hating for sake of hating.