3 ms·

I hate to tell you, but your list looks like it came straight out of the 1970's:) - Spaceflight (SpaceX Starship). - Supersonic airplanes (Boom). Been there,

• wongarsu 5y ago
  They are modern takes on the Space Shuttle and Concorde respectively, but with the benefit of hindsight as well as half a century of advances in material science and control systems. But really the defining feature is that the Space Shuttle and Concorde were government-funded prestige projects, while their modern incarnations are economically viable.