Ep 3. Meteor

Five students go on a field trip to space on the spaceship Astra in the year 2063. The third episode of the season is called "Meteor". The crew picks up a distress signal from a ship that had been missing for years, apparently struck by a meteor. The crew, lead by the captain of the ship, Kanata Hoshijima, decides to investigate the wreckage to see if there are any survivors. They encounter many obstacles along the way, including a dead end in the spaceship and a lack of oxygen. However, the students work together to solve each problem and make progress towards their goal.

As they explore the broken down spaceship, they find many items that belonged to the original crew, including a mysterious cube that emits a strange energy. The cube has a unique way of reacting to certain individuals, causing strange visions and a feeling of unease. They have the idea to try and repair the ship so that they can use it to get home, should their own ship become unrepairable. They find a possible solution to their oxygen problem, which is running low, but require a specialist to help implement it, which they hope to find within the wreckage.

As they continue their search, they come across a door with a strange symbol on it that is giving off a weak radiation signature. While trying to figure out what it means, they hear noises coming from the other side of the door. They then receive an unexpected visitor- an alien life form with tentacles for hands. The creature seems to respond to their emotions by changing its color, and they refer to it as "Polina". Yuno is the only one who can understand Polina, thanks to a universal translation device she brought along. Polina guides them to the specialist they need, but becomes agitated and sometimes hostile when in the room with the cube. Eventually, they manage to get the device they need to repair their own spaceship's oxygen supply.

The crew gathers to discuss what they found on the abandoned ship, and decide to take a closer look at the cube. The cube seems to be linked to the energy field that is responsible for the teleportation of the spaceship, and they start working to decipher its mysteries. It is revealed that each individual crew member can activate a different side of the cube, based upon something inherent to their personality. As they explore the properties of the cube further, they start to think that it might be responsible for the strange events that have been happening to them since they started their journey.

Back on the Astra, the crew installs the oxygen machine they have recovered and it successfully filters air. They also install the cube, under the pretence of it being functional. As each member presses the cube, some sort of visual anomaly seems to be detected by the ship's science officer, revealing the true power of the cube. Amidst their discoveries, a message is intercepted by the ship, revealing that there is a potential traitor in their midst, who sabotaged the trip's food supply. With multiple revelations happening at once, the crew is left scrambling to fix their ship while also trying to identify the traitor within their midst.

Overall, this episode does a great job of setting up the series' conflicts and mysteries while still keeping the tension and pacing high. Viewers are left wanting more of Astra, and are eager to see where the crew’s journey will take them next.