One of the last surviving architects of the Soviet space programme that put Yuri Gagarin into orbit half a century ago, has died aged 99, officials said.

Boris Chertok, who helped design the country’s first ballistic missiles, was a close colleague of the Soviet rocket design genius Sergei Korolyov, who is widely credited for giving the USSR the lead in the early space race.

Mr Chertok was considered one of the last living legends of the early years of human space flight who made Gagarin’s trailblazing 1961 flight a reality.

“He was the last of the ‘Mohicans’,” Mikhail Turchin, Mr Chertok’s assistant since 1965, said. “He was Korolyov’s last deputy.”

Mr Chertok was a close associate of Korolyov. He designed the country’s first satellites and spacecraft including the spaceship that took Gagarin around the globe on his historic 108-minute journey.

He died just two and a half months shy of his 100th birthday.

“We were preparing to celebrate his birthday,” the Energia spokesman said, adding that he impressed everyone around him with clarity of thought, even if he needed assistance getting to work in his last years.