How Close Are We To Hypersonic Travel?

[dexter]

Flying at hypersonic speed could revolutionize transportation, but there are incredible engineering and logistical challenges we need to get through first. So, how close are we to hypersonic travel?

 

[TruthSeeker]

Whether hypersonic travel becomes commonplace depends on whether or not anthropogenic climate change is a real crisis for humankind or it is not. If it is, then the chemical changes to the upper atmosphere that widespread hypersonic travel would cause cannot be justified against the climate change damage these chemical changes would bring.