Context.

The context to this conversation is the launch of a space shuttle that's supposed to carry a teacher to space. It has both enormous stakes and enormous political pressure to not delay/cancel. I'm unsure why that context makes the spherical cow version of "easy" a sensible one.

The context of that word "easy" was not a vacuum, it was part of a sentence which was part of a conversation. There is more than enough of this context to know what in particular was easy.

You can only fail to get this by not reading the thing you are responding to, or deliberate obtuseness, or perhaps by being 12 years old.