IRL

Vanguard 1 Was the fourth satellite launched into orbit, or the second American satellite.
Launched by Vanguard, it is its first successfull flight out of three successes, out of 11 flights
It was the first craft that used solar panels in orbit, which is why it was so small, it didn't need to carry large batteries

In game

Keep AG1 On
The Vanguard is slightly overkill for the stock system, sending a probe to escape velocity. Yet I tried giving it the most realism I could. Engines have correct thrust in vaccum and correct specific impulse, the stages have approximately the right weight and as such the rocket is 2kg off the actual rocket weight
It includes many staging events due to the seperation of the nose cone, the spin table, the retrorockets of stage 2, the spin reduction mechanism before the seperation of the satellite and so on...
It features a fully detailed X405 first stage engine, a kinda detailed second stage engine, a fully detailed logo on the third stage, and others.
The first two pictures are stage one.
The third picture is stage 3 being seperated thanks to retrorockets
The fourth pic is the third stage with the logo
The fifth pic is the spin reduction mechanism
Also, don't mind the last 440m/s deltaV, it's just the spin reduction
And as Scott Manley would say...

Fly safe