The film begins in 1985, when engineers involved in an industrial project to irrigate the Gobi Desert accidentally unearth a mysterious and apparently artificial "spool". When found to be made of a material unknown on Earth, the spool is circumstantially linked to the Tunguska explosion of 1908. The "spool" is seized on as evidence that the explosion, originally blamed on a meteor, was actually caused by a spaceship. Professor Harringway deduces the alien craft must have come from Venus. The spool itself is determined to be a flight recorder, and partially decoded by an international team of scientists led by Professor Sikarna and Dr. Tchen Yu. When radio greetings sent to Venus go unanswered, Harringway announces that a journey to Venus is Earth's only alternative. The recently completed Soviet spaceship Cosmostrator I (Kosmokrator in the original), intended to voyage to Mars, is redirected to Venus, a 30–31 day trip. During the voyage, Sikarna works furiously to translate the alien message on the disc using the ship's computer.
When the ship nears Venus, radio interference from that planet cuts the crew off from Earth. By then, Sikarna's efforts lead to a stunning discovery—the spool describes a Venusian plan to irradiate the Earth's surface, with the extermination of mankind being the prelude to an invasion. Rather than a "cosmic document" as had been expected, the spool bears a cold-blooded message of destruction. Harringway convinces the crew to press on towards Venus rather than return to Earth with news that would cause panic.
With the ship's robot Omega, American astronaut Brinkman pilots a one-man landing craft. On the ground, he encounters an industrial complex and finds small recording devices that look like insects. The rest of the crew follows when Cosmostrator lands, but find no Venusian life forms. Journeying across the planet, they find the remains of a deserted and blasted city centered around a huge crater—signs of a catastrophic explosion so intense, shadowy forms of humanoid Venusians are permanently burned into the walls of surviving buildings.
While the Venusians are gone, their machines remain functioning, including the radiation-bombardment machine intended for Earth. One of the scientists accidentally triggers the radiation weapon, leading to a frantic effort by the Earthmen to disarm it. Tchen Yu lowers Talua—the ship's communication officer—into the Venusian command center. When Tchen Yu's suit is punctured, Brinkman goes out to save him. Before he can reach Yu, Talua succeeds in reversing the radiation weapon. Unfortunately, this reverses the planet's gravitational field, flinging Cosmostrator into space. Brinkman is also repelled off the planet, beyond reach by Cosmostrator, while Talua and Tchen Yu remain marooned on Venus. The surviving crew members return home, where they warn the people of Earth about the danger of atomic weapons.
- Yoko Tani as Sumiko Ogimura
- Oldrich Lukes as Professor Harringway
- Ignacy Machowski as Professor Durand
- Julius Ongewe as Talua
- Michail N. Postnikow as Professor Orloff
- Kurt Rackelmann as Professor Sikarna
- Gunther Simon as Raimund Brinkmann
- Tang Hua-Ta as Tchen Lu
- Lucyna Winnicka as Joan Moran
- The film was based on a novel by noted Polish sci-fi novelist Stanislaw Lem, better known for the novel Solaris, on which the 1972 Russian film (and 2002 American remake) were based. 
- In the 1962 USA release version, on the film soundtrack, in a scene in the control room of the Kosmostrator rocket, we hear a music track titled "In Outer Space" from Destination Moon by Leith Stevens, and later in the movie, in the scenes of eerie destruction of the Venusian city, we hear a music track titled "Metaluna Catastrophe" from This Island Earth by Herman Stein. Both of these uses of music were uncredited and unlicensed, and unauthorized by the copyright holders.
- In the original German version, "Brinkman(n)" isn't American but East German, and the "Durand" character is a Soviet cosmonaut by the name of "Prof. Arsenjew" (Arsenyev), "the man who steered the first rocket to the moon".
- In the US version of this film, produced by Crown International Pictures, several pieces of music from the The Wolf Man can be heard in multiple scenes throughout the movie.
- The German version contains a reference to one of the professors having his career stalled when he was thrown out of the university by the Nazis. Director and co-writer Kurt Maetzig had his career stalled by the Nazis because his mother was Jewish.
- This large scale East German-Polish co-production was the first to be shot in the Totalvision widescreen process.
- Although it was a co-production with a Polish company, it was still the most expensive production for DEFA up to that time.
- The writing process involved 3 writing teams and 12 screenplays before a final script was acceptable to the studio and the government.
- At one point DEFA intended to establish a co-production with a French company for financing and scriptwriting. Part of the plan was to use French actors Yves Montand and Simone Signoret. However, Communist government officials disapproved of DEFA's pursuit of Western partners.
- For the U. S. release of First Spaceship on Venus in 1962, the film was edited to 79 minutes and was double billed with the Japanese kaiju film Varan the Unbelievable. All references to the bombing of Hiroshima were edited out of this release. The American character Hawling became a Russian named Orloff. And, the Russian character named Arseniev became an American named Herringway, while the Polish character Soltyk became the Frenchman named Durand.
- The large explosion in Siberia in June 1908 actually occurred -- the explosion is usually referred to as the Tuguska event. The movie accurately describes its effect. The actual cause of the explosion is still unknown, but the most likely explanation remains that it was a meteor strike.