If Sputnik was build in KSP
Sputnik was the first ever satellite to orbit the earth. It launched on top of a variant of the R7 Rocket, that derivative is today also know as Soyus. It only lasted for a few weeks, before it went silent.
Today's guessing Question:
How does the rocket steer?
Hint: Not with the main engines.
Answer in the comment section!
The Rocket was replicated in Kerbal Space Program.
No mods were used, but DLC's might be required.