Clue 1: I was developed in the Soviet Union, now used by Russia.
Clue 2: I launched Salyut space stations and Mir modules.
Clue 3: I was first launched in 1965.
Clue 4: I am a heavy-lift launch vehicle using hypergolic fuels.
Clue 5: I delivered Zarya and Zvezda to the ISS.
Clue 6: My payload to low Earth orbit is 23,700 kg.
Clue 7: I am 53 meters tall with a diameter of 7.4 meters.
Yes, I am Proton.
I experienced a series of early failures but evolved into a reliable workhorse for heavy payloads.
