1. If Russia knew the US faked the moon landings, they could have claimed that they were first and expose the US if we disputed it.
2. We have labs on Earth that can easily duplicate a 550 degree temp swing to test insulation.
3. We had nearly a decade of experience with thrusters and boosters in space before the Apollo missions. NASA developed the Gemini missions to practice the different procedures needed. The first US spacewalks happened during Gemini, in suits with sufficient insulation to keep the astronauts alive.
4. Space telescopes don't just wander about, there's no practical or logical way to send one to the moon to take pictures of stuff that is of no consequence to anybody. The Lunar Reconnaissance Orbiter has imaged all of the Apollo landing sites. They are there.
Here's a link to a detailed, very detailed, explanation of why Hubble can't see objects left on the moon by the Apollo missions
5. And yet, despite the tremendous black eye it would give the US space program, no other country officially disputes that the moon landings happened. The ESA (European Space Agency) didn't go to the moon or "pull off the hoax", yet they are one of the scientific partners mentioned in collecting data from the laser/mirror link above.