Elon Musk says one of the “hardest engineering challenges” that exist is…

Elon Musk highlighted orbital refuelling and a reusable heat shield as major engineering challenges for SpaceX’s Starship program. He envisions Starship revolutionizing space travel by significantly reducing costs. Musk anticipates a possible crewed Starship flight to Mars by late 2024, with a more realistic uncrewed flight in about 3.