A plane bigger than a football pitch has been spotted carrying a jet capable of firing hypersonic weapons.
The Stratolaunch aircraft, which has a mega 117-metre wingspan, carried a 28-foot-long Talon A hypersonic test aircraft capable of shooting payloads at five times the speed of sound.
The plane took over the Mojave desert in California and flew for five hours and six minutes, reaching altitudes of 7,000 metres.
A test flight proved that it is capable of launching hypersonic aircraft in mid-air and even into outer space, pending further tests.
Dr Zachary Krevor, CEO of space company Stratolaunch, said: "Testing and production are accelerating as we push forward to meet our commitment of providing hypersonic flight test service to our customers next year.
"Our team will continue accomplishing more complex test milestones as we progress to our first hypersonic flight."
The plane weighs around 230,000kg but could potentially lift off carrying more than 589,000kg.
It's almost twice the size of a Boeing-747 jet, and is designed to one day launch hypersonic research vehicles into orbit.
Hypersonic flight is widely considered the next frontier for aviation and the private space industry, as it could drastically cut down flight times.
There have been suggestions a new high-speed nuclear plane could drastically cut down flight times.
A plane from London to New York could only take 80 minutes if Spanish designer Oscar Viñals gets his way.
The "Hyper Sting" would fly at nearly three times at the speed of sound thanks to the design.
He said: “The fuselage would have the shape of a ‘big sting’ with a very sharp ‘nose’, that would have the function to control the front airflow (pressure/speed), in order to redistribute it over the central part and over the wings.”
The Hyper Sting, although not yet officially tried, could reach staggering speeds of 2,664mph.
To put that into context that is more than four times the speed of a normal aircraft, which reach speeds of up to 460-575mph.
The Hyper Sting would carry around 130-170 passengers for a trip to New York from London and is 328ft long.
A trip to New York would be cut from seven to eight hours to just over an hour.
However, the “cold fusion nuclear reactor” which is needed to power the aircraft is just a concept at this moment.
But, according to Mr Viñals, he has big plans for the jet to reach a Mach 3.5 capability - which would be able to power the four generation hybrid turbojets and ramjet engines.
The new flight time would surpass the current three hour record for the fastest flight from London to New York which was made on a Concorde, who operated between 1976 and 2003.