Proton (rocket family)

The Proton is a Russian rocket family used for launching satellites and other spacecraft. It was developed by the Soviet space program and its first launch happened in 1965. Even today in 2026, an improved version called the Proton-M is still in use, making it one of the most successful heavy rockets ever made.

Parts of the Proton rocket are built in Moscow and Voronezh, then taken to the Baikonur Cosmodrome to be put together. The rocket can carry about 22.8 tonnes to low Earth orbit and about 6.3 tonnes to a special path called geostationary transfer orbit. Many important missions have used the Proton, including Venera and Mars probes, space stations like Salyut, and parts of the International Space Station.

Although the Proton was expected to stop flying before 2030, it is still scheduled for a few more launches in 2029. Russia is working on new rockets like the Angara A5 to replace the Proton, but the Proton remains a key part of space history.

History

The Proton rocket was originally designed as a very large missile for carrying big weapons very far. Though it was built for this purpose, it was never used that way. Instead, it became a powerful rocket for launching things into space.

It was created to compete with another rocket design meant to send people around the Moon. Over time, Proton helped launch many important spacecraft, including space stations and satellites used for communication. It has been used for both government and commercial missions for many years.

Proton K

Main article: Proton-K

The Proton K rocket used special fuels that could catch fire when mixed together, so it didn’t need an ignition system. This made the rocket easier to store and prepare for launch. Unlike some other rockets that need cold fuels, Proton K could stay ready for a long time.

It had different versions of its last part, called Blok D, for different kinds of space missions. The first full test of the Proton K happened in 1967. It helped build many important space stations, like the Soviet Salyut stations and parts of the Mir space station, as well as some pieces for the International Space Station. Its last flight was in 2012.

Proton-M

Main article: Proton-M

The Proton-M rocket can carry about 3 to 3.2 tonnes into a special orbit called geostationary orbit, or about 5.5 tonnes into another orbit called geostationary transfer orbit. It can also carry up to 22 tonnes into a low orbit close to Earth, which is where the International Space Station flies.

The Proton-M was improved to be lighter and stronger. It uses a special upper stage called Briz-M, which makes launching easier and more efficient. These rockets are built by a company in Moscow called Khrunichev, which also helps manage many parts of the Proton production.

Phase III

A newer version called the Phase III Proton-M/Briz-M was tested in 2009 and used for the first time in 2010. This version can carry a bit more weight into space than the older versions.

Phase IV

Work began on even newer improvements for the Proton-M to keep up with growing needs. These improvements were finished in 2016, allowing the rocket to carry a bit more weight into space than before.

Future developments

Work on improving the Proton rocket was paused when a new rocket called the Angara was introduced in 1992. One big planned upgrade was called the KVRB stage, which would have used very cold fuels and could carry more. The engine for this stage was built, but changing the rocket to use these new fuels would have needed many changes.

The Angara rocket is meant to be simpler and cheaper than the Proton. It will use different fuels and be designed to work with another stage called KVTK. It will also have supplies of liquid oxygen ready at the launch pad.