Getting a person to Mars and back alive means solving a chain of problems that each depend on the last, and this joint investigation from the BBC and Imperial College works through them one at a time. Astrophysicists, aerospace engineers, and planetary scientists tackle propulsion, life support, radiation shielding, and landing technology in turn, treating the mission as a full round trip rather than a one-way stunt. Radiation gets particular attention: Mars has no protective magnetic field like Earth's, so a crew would face months of exposure both in transit and on the surface, and researchers describe the shielding materials being developed to manage it. The film also covers orbital mechanics, since Earth and Mars only align for an efficient launch window every 26 months, forcing the entire mission timeline around that gap. Landing gets its own segment, since the Martian atmosphere is too thin for the parachute systems that work on Earth, requiring new deceleration technology. The result is less a vision of Mars than an engineering audit of everything standing between here and there.