oh damn it also only clicked with me now. Rocky insisting on giving Grace the astrophage fuel to get home, actually saves fucking,,, everyone. Like that one act of kindness, that one insistence of "no I will not let my friend die like this". "I could not save my crew but I sure as hell will save you." and that changes everything. this movie makes me unwelllllll
Like. Rocky gives Grace to fuel to go home, at the cost of reaching Erid 6 years slower. So, Grace starts the journey back with the samples, instead of just sending them back on drones and waiting to die - crucially, this allows him to realise that the samples are escaping their containers (and destroying/eating his fuel). If he had just sent the samples back in the drones by themselves, before containing them in something else, who knows if they would have reached earth intact. Grace would never have known that both missions have failed, leaving both him and Rocky to die alone in their respective ships.
Instead. Because Rocky gave that fuel to Grace, Grace can safely send the samples to Earth, return to Rocky, save him from the contamination of the samples (and the radiation goddammit), therefore also saving all of Eridian. Just because Rocky was like fuck you, you're going home. wow.
