Doppelgänger

Also known as Journey to the Far Side of the Sun, Unfall im Weltraum, 決死圏ＳＯＳ宇宙船

“You will meet yourself face-to-face when Earth meets its duplicate in outer space!”

A planet is discovered in the same orbit as Earth's but is located on the exact opposite side of the sun, making it not visible from Earth. The European Space Exploration Council decide to send American astronaut Glenn Ross and British scientist John Kane via spaceship to explore the other planet.