[Onelifetogive]

There are planes on the drawing board that could take off from St. Louis and land back in St. Louis in less than 10 minutes.

Let's assume an "around the world" between those two.

Distance 25,000 miles. Time 1/6 Hour. Average speed 150,000 mph. This means linear acceleration for 5 minutes from 0 to 300,000 mph, then the same decelleration. V = at. a = 3,600,000 m/h2. a = 1,466.67 ft/s2 = 45.8 g

Is this right?

[dead]

Let's assume an "around the world" between those two.

Oh, no. I was leaving that part out. That would make it really too difficult.

[TalonDJ]

And in reality it would need to go a few hundred extra miles up and then back down to get out of the atmosphere. Unless the plane can handle er... like mach 180 at sea level? That speed will vaporize all know materials and kill millions with the shockwave.