A jet that can fly Paris to Tokyo in 2.5 hours

"To land, the pilot cuts the engines and glides down to Earth before reigniting the regular engines before landing."

What happens if the engines don't restart as planned? An interesting idea, but it seems to have a high risk factor.

Overall, it reminds me of the "semi-ballistic" transports described in Robert Heinlein's book "Friday."

"...rocket plane it hopes will be able to fly from Paris to Tokyo in 2.5 hours by around 2050" ಠ_ಠ