The script lacks in the science and engineering department, and the characters seem incompetent.
Within the first 20 minutes, we already know the main protagonist is an unreliable narrator who exudes whatever the opposite of confidence and leadership is. His crewmate is similarly unreliable, talking behind the captains back. The captain calls the spaceship an 'aircraft' and handwave-explains 'fatigue and buckling' despite there being no explanation for what would cause cyclic stresses on the structure. We also got in the first 30 minutes that their mission is to reach Titan's methane, to make fuel, to somehow solve climate change. It all just sounds like mumbo-jumbo written by an arts student.
You need something like Andy Weir's 'The Martian' or the upcoming Project Hail Mary adaption; i.e. The best-of-the-best astronauts being actually believable world-class highly trained and skilled experts and problem-solvers. The physics doesn't have to be 100% in a sci-fi (Interstellar worked pretty well throughout bar that one line about love transcending space and time), but for any deviations the characters have to 100% support the narrative for it to be believed by the audience. These astronauts are immediately whispering to each other about mutiny from the start... and keep forgetting that there's audiovideo recording in each room allowing the captain to hear the sceme. I can't believe that these characters are actually astronauts.
Please please please stop with this artificially induced drama hinging on main characters being incompetent, keeping secrets from each other, or scheming against each other for no good reaon. Stop with the secrets which the 3rd party witnesses... It's like where movies have 2 people talk or kiss, for the 3rd jealous person to spot it or to get the wrong impression. It's a frustrating cliche. If the drama would be resolved by one character speaking one sentence to another character, it's weak writing.
With Insterstellar, I felt awe that made my arm hairs stand on end. With Slingshot I just feel frustrated and claustrophobic. Slingshot is weak writing.
