From Kerbal Space Program Wiki
The Jumping Flea is the most Basic rocket that can be built, It is able to be built in Science or Career mode without unlocking anything else in the [tree]
|“|| The Jumping Flea was originally named after the carnival ride that we salvaged most of its parts from. It might not get us all the way to space, but it will definitely get us started there with a bang!
- Despite being called a Jumping Flea, it never jumps again after jumping for the first time.
- It's impossible to steer.
- It is a Solid Rocket Booster only Rocket, Making throttle impractical