Was the murder of the astronauts not the first intention?
Apologies if this has been addressed elsewhere, but there's too much to wade through.
I watched this again last week, and see it completely differently to how I saw it the first time.
Firstly, I don't think the other two astronauts were killed. It's more likely they were held, with the idea of killing them when all three were recaptured.
Secondly, was the heat shield failure rigged - or was it an unexpected glitch which meant the astronauts had to die. If that hadn't happened would they just have relied on the astronauts to keep quiet, maybe with a threat against their families to guarantee that?