Context: Opening narrationAn explanation that our knowledge of Venus is very incomplete and only by imagination can we glimpse the planet, but the producers of the film believe the heroic Soviet people will see the planet with their own eyes.Opening sceneThree soviet spaceships CCCP Sirius Vega and Capella approach Venus after completing a 200 million kilometer journey. Suddenly before anyone can react Capella is destroyed with all hands by a stray meteor. The crew of the Sirius are devastated by the news, and reflect on how close they came only to die within sight of their destination. A message received from Earth advises that a replacement for Capella is launching soon and will reach Venus in 4 monthsAlexi ( ) one of the crew from Sirius doesnt want to wait and suggests they modify the robot glider on Vega, so. Venus needs to be seen by human eyes. He explains if anything happens he will not call for help. His life is his, to do with as he desires.Mr Kern (Georgi Tejkh) On board Vega must have the final say on the launch. Rather than use the glider he recommends landing the two ships rather than wait for the spare ship from Earth, but first he has to check the figures for the safety margins. To do this he activates the ships robot JohnThe robot proposes a different plane. Three crew members go down in the glider, three more go down in the Sirius, leaving Vega in orbit manned by Masha (Kyunna Ignatova) Masha feels cheated by the plan but realizes it is the only way the mission can succeed As they plan to land a strange red light is seen through the cloud cover. They decide to try and land close to that position. It is decided the glider will go down first, and try and identify a good landing place. Sirius will followThe glider finds a location but as it drops the beacon to mark the spot for Sirius it is blown off course and heads for a dangerous landing in a swampy region. From orbit Sirius cant re-establish contact. Unsure what may have happened Sirius decides to land at the beacon and try and find the crew of the gliderThe Sirius lands successfully and begins testing the environment to see if they can go outside. Using an external microphone they listen to the sounds of Venus. At one point they hear what sounds like a womans voice singing. Understanding that little can be accomplished from the ship they decide to outside and explore. As Alexi explores away from the ship he is attacked by some strange tentacle creature. The other crew dont realize the danger and continue to check instruments for signs of the glider. They discover two distinct signals. One they suspect is the glider, and one that is moving should be JohnFinally the others realize Alexis situation and rescuing him from the plant like creature. The creature responds by first releasing Alexi then encloses itself in a protective shellIn the meantime Masha has confirmed the other crew is alive and has pin-pointed their location, approximately 32 kilometers away. The fact John is active proves crew members must have survived because hed been disassembled for the flight downAt the other landing site Kern, working with the partially completed robot search for parts of the robot to complete the job of assembly. One of the other crew is firing ant strange reptilian creatures that keep attacking Meanwhile the crew of Sirius have gotten their rover working and set off to help the crew of Vega. On the way they see a brontosaurs and stop to take a blood sample from the slow moving creature. While doing this, Masha confirms that the Vegas crew is moving towards the Sirius location.The crew from the Vega begin to feel ill and fevered, they are concerned that the rips in their suit may have allowed them to get sick from Venusians germs. The crews of the Sirius reach the shore of a large body of water and decide to cross it rather than go around. As they prepare to submerge they hear the same strange womans voice. Pausing to investigate, they find nothing and press onBack with the Vega crew they have been caught in a rain storm and John cautions that he may soon malfunction because of the water. Schebra (Yuri Sarantsev) Is 
 Question: What are Sirius, Vega, and Capella?
Output: three soviet spaceships