Challenging early on due to friction and heat, "hypersonic" spacecrafts are now on the United States Military's project radar travelling anywhere from to five to ten times Mach 1. "The new Lockheed Skunk Works project, called the SR-72, is a proposal envisioning an unmanned aircraft that cruises at Mach 6—roughly twice as fast as the 2,300-mile-per-hour SR-71—meaning 'an adversary would have no time to react or hide,' Lockheed Martin says in its promotional materials." These efforts would not only allow for worldwide access within three hours, but also offer commercial benefits for many companies looking "to launch constellations of small satellites...[such as] Elon Musk's SpaceX."
2,300 MPH is Now a Speed of the Past