Roscosmos chief Dmitry Rogozin congratulates Elon Musk following the successful test flight of SpaceX's commercial astronaut capsule Crew Dragon.

Also known as the Dragon 2, the capsule carried out its first unmanned test flight to the International Space Station last week. It ended with a safe splashdown in the Atlantic Ocean near Florida.

Roscosmos Chief Congratulates SpaceX CEO

The apparently impressed Russian space agency chief took to Twitter to congratulate SpaceX CEO Elon Musk and NASA chief Jim Bridenstine.

"Dear colleagues... On behalf of Roscosmos I congratulate you on the first successful test flight of a new spacecraft," Rogozin tweeted.

He believes that building alternative space transportation systems that will transport cargo and astronauts ensure the safety and stability of international teams working at the ISS.

"Thank you on behalf of SpaceX! We have always admired your rocket/spacecraft technology," the SpaceX CEO replied to return the favor.

Elon Musk Praises Russia

Earlier this week, Elon Musk praised Russia via Twitter for its excellent rocket engineering and best engine, referring to the RD-180 liquid-fueled engine. The Russian-built RD-180 liquid-fueled rocket engine is used to power the first stage of the US Atlas V rocket. The SpaceX chief also added that a reusable version of the Angara rocket would be great.

Musk's tweet was his response to an article published by Ars Technica about Russia's reaction regarding the successful test flight of the Crew Dragon and its docking to the ISS. The uncrewed mission of Crew Dragon capsule, which means no human onboard, is the first American spacecraft to reach the orbital station since the shutdown of the Space Shuttle Program in 2011.

Since then, American astronauts were sent into orbit on the Soyuz spacecraft that takes off from Baikonur in Kazakhstan. Crew Dragon is built by SpaceX under the guidance of the National Aeronautics and Space Administration, America's space agency.

The Angara rocket family is designed to carry between 3.8 and 24.5 tonnes into low-Earth orbit. It was the first orbit-capable rocket developed by Khrunichev State Research and Production Space Center in Moscow.

In August last year, Rogozin said that the third launch of the Angara rocket from the Plesetsk Cosmodrome for Russia's Defense Ministry will be this year. The Russian Federal Space Agency, which is also known as Roscosmos and abbreviated as FKA and RKA, is Russia's equivalent of the United States' NASA.

Photo: Dan Taylor | Flickr