Constellation Episode 1 kicks off with a captivating scene of Jo and her daughter, Alice, cruising through a snow-covered landscape in their car. The serene silence is interrupted by snippets of a mysterious voice emanating from the radio beside Jo. Alice's inquisitive voice breaks the tension, asking about the whereabouts of her father.
It transpires that they are in the heart of northern Sweden, a land of frozen wonders. As they step into a cozy house and settle in, Alice pulls out an iPad, her eyes glazed over with excitement. She watches a video of her mother, Jo, narrating a story from the International Space Station, seemingly preferring the digitized version of her mother to the flesh-and-blood one.
Meanwhile, Jo keeps a closely guarded, glowing package tucked away in a nearby shed. Suddenly, her attention is drawn to a shadowy figure lurking in the woods, sending a chill down her spine. Despite Alice's slumber, Jo can faintly hear her daughter's voice calling out to her, as if from a distance.
Flashing back five weeks, the scene shifts to a serene morning in Germany. Alice awakes and eagerly dials her mother on the ISS. Meanwhile, Paul, a crew member, is engrossed in the CAL experiment, conducting a live call with Henry Caldera, a leading scientist at the Rocket Propulsion Laboratory (RPL) in California. The experiment seems to be a success, but suddenly, an unexpected impact rocks the space station, triggering a devastating explosion.
Chaos erupts as flames lick the interior of the station. In the midst of this pandemonium, Jo and the crew scramble to reach an evacuation capsule. Despite the danger, Jo and another crew member brave the flames to rescue Paul, whose arm is trapped beneath a mangled piece of machinery.
On the ground, Henry, the Chief Scientific Consultant at the RPL, frantically coordinates with mission control officers Irena and Michaela from NASA, along with Frederic from the European Space Agency. His assistant rushes over with a report on the CAL experiment, the key to unlocking the mystery of what caused the disaster.
Meanwhile, Alice and her father, Magnus, embarked on their journey to school, unaware of the drama that awaited them in the vastness of space. At the space station, Jo received the unexpected task of venturing out for a spacewalk, tasked with repairing the evacuation capsule's power cables from the outer perimeter. She, along with her colleague Ilya, geared up in their protective suits and boldly stepped out into the void.
Henry, meanwhile, vehemently opposed the evacuation plan, while the other personnel on the line prioritized the lives of the astronauts above all else. His experiment, briefly activated by Paul, had revealed a hitherto unknown state of matter, a discovery that Henry believed could revolutionize the world.
In the vastness of space, Jo encountered a grim reality - the cables were beyond repair. Simultaneously, Paul's condition deteriorated, and he suffered a cardiac arrest. Urgently, Jo was instructed to navigate to another section of the ISS, known as the truss, to fix the secondary life support system. There, she stumbled upon a startling sight - the entangled remains of a female astronaut, a veteran from the USSR. But before Jo could secure the body, it loosened its grasp and drifted away, lost in the vastness of space. Ilya arrived shortly after, but the body had already drifted too far out of reach.
Back inside the ISS, the news of Paul's demise spread like a dark cloud. The situation was dire - only three individuals could escape in the Soyuz 2 capsule. One brave soul would have to stay behind, repair Soyuz 1, and depart using that capsule as their sole means of escape. Without hesitation, Jo volunteered to remain.
On Earth, Alice and her father, Magnus, were informed of Jo's plight as they made their way to school in a car. Magnus, with a heavy heart, broke the news to Alice that her friend Wendy's father, Paul, had perished. With a mixture of sorrow and resolve, Jo bid farewell to her crew as they departed in the Soyuz 2 capsule. She was left with the daunting task of repairing Soyuz 1, armed with only 19 hours of oxygen and a limited supply of new batteries.
To compound the challenge, the space station relied solely on solar energy, meaning Jo would be plunged into darkness for 45 minutes, followed by 45 minutes of fleeting power. She faced the unknown with courage and determination, knowing that her actions could potentially save the lives of her fellow astronauts.
With a mere ninety seconds of solar energy remaining, Jo ventures out of the capsule, her only sanctuary of oxygen, in a race against time to retrieve Alice's necklace. She manages to scramble back with precious seconds to spare, barely escaping the looming darkness as daylight fades and the station's power shuts down. Forced to endure a harrowing 45 minutes in the pitch-black, Jo hunkers down in the capsule beside Paul's lifeless body, sketching a haunting image of the Russian corpse she encountered.
Suddenly, her timer accelerates, ticking down to zero with alarming speed. Daylight returns, and power is restored, marking the end of her ordeal. She wastes no time in her search for the new batteries, but her mission is interrupted by Henry's persistent pleas from Mission Control. He insists that Jo bring back the CAL, insisting that the data it holds is of utmost importance.
Meanwhile, Alice and Magnus find themselves in Kazakhstan, near a mission control center. They are informed that they might have a chance to communicate with Jo before her power runs out. Elsewhere, the Soyuz 2 deploys its parachute and lands safely, its three astronauts emerging unscathed. Jo is briefed to retrieve the CAL experiment if time permits.
In Kazakhstan, Alice confides in Magnus about her awareness of the issues between him and Jo, expressing her desire for them to remain friends. As they arrive at the mission control center, however, their connection with Jo abruptly cuts out.
Back at the ISS, Jo returns to her capsule, determined to fix the batteries. But as she works, she seems to hear strange noises emanating from above. She braces herself with an oxygen mask and ventures out, only to find herself transported to a long corridor in a house. Alice's necklace hangs tantalizingly on a doorknob at the end, where the knocking sounds persist. Suddenly, Jo is yanked back to the ISS, where power has miraculously returned.
A scream from Alice jolts us back to the episode's opening scene. Jo trudges through a snowy forest, her steps heavy as she approaches a familiar house. Time seems to stand still as snowflakes freeze in mid-air, creating a surreal tableau. Then, as if released from a spell, Jo enters the house, which is eerily similar to the one she left Alice in.
She climbs a staircase, her heart pounding, and finds a passage with a cupboard at the end. Alice's necklace lies there, glistening in the dim light. Something is knocking from within the cupboard, and with a trembling hand, Jo opens it to reveal Alice, who asks her, with a mixture of confusion and relief, where she has been all this time. The question hangs in the air, leaving the viewer with a tantalizing cliffhanger at the end of Constellation Episode 1.
