 With insufficient fuel to reach Edmunds' planet, they use a slingshot maneuver so close to Gargantua that time dilation adds another 51 years.In the process, Cooper and TARS jettison themselves to shed weight and ensure "Endurance" reaches Edmunds' planet.Slipping through the event horizon of Gargantua, they eject from their respective craft and find themselves inside a massive tesseract, constructed by future humans.