If residents of south-eastern California looked to the skies last Thursday morning, they might have seen something incredible – the world’s largest plane soaring at 14,000 feet.

The Stratolaunch carrier aircraft in question flew spectacularly over the Mojave for three hours, dazzling onlookers with its impressive size. The flight was only its second ever and came after a two-year hiatus from the air.

Thursday’s flight captured the dreams of late Microsoft founder Paul Allen, who established Stratolaunch in 2011. The carbon-composite aircraft was part of Allen’s vision for the private space market.

The Chief Technology Officer of Stratolaunch, Dr Daniel R. Millman, said, “Our flight today gets us another step closer to our promise of delivering the world’s premier hypersonic flight test service.”

How the test flight happened

After months of preparation, the Stratolaunch carrier took off from the Mojave Air and Space Port on April 9th at approximately 10:28 am EDT. Once in the air, the aircraft (nicknamed ‘Roc’) flew for three hours and 14 minutes, reaching a top speed of 199mph and a previously mentioned maximum altitude of 14,000.

Crowds of onlookers watched the massive aircraft touch down back home after it successfully completed its flight test manoeuvres. It was an exciting day for many who witnessed Roc in flight for the first time since April 14th, 2019.

The purpose of the flight was to test the aircraft’s capabilities and gather data ahead of future missions. Engineers wanted to see how the plane would cope with cabin pressurisation and an assortment of new safety features and hardware improvements. Pilots also worked to prepare Roc for launches of Talon-A – an upcoming hypersonic testbed vehicle.

The success of the test flight confirmed some of the aircraft’s handling and performance characteristics. It also demonstrated Roc’s payload capacity and some of its numerous enhancements, such as improvements made to the gear doors, safety systems, and pressurisation.

Roc can act as a mobile launch platform for hypersonic and aerospace vehicles, potentially pioneering the future of space travel. There are commercial benefits to offering in-air platforms for launching satellites into orbit.

Various US firms are competing in this area, including Space X and United Launch Alliance. However, so far, Stratolaunch has created the largest carrier aircraft, with Roc possessing a max load capacity of 1.3 million pounds.

Dr Zachary Krevor, Chief Operating Office of Stratolaunch, said that the test flight focused on safely releasing hypersonic vehicles from Roc and that the flight had provided “valuable insights”.

The world’s largest aircraft

One of the most striking features of Stratolaunch’s signature carrier aircraft is its sheer size. With a wingspan of 385 feet (longer than a football pitch), the aircraft breaks the wingspan record for any plane ever assembled before.

A carbon-fibre reinforced center wing offers the stability needed for the aircraft’s huge wingspan.  This can also support over 500,000lbs (226,796 kg) of weight from launch vehicles. Engineers specially designed the Stratolaunch’s high-wing layout and dual-fuselage to accommodate the safe release of launch vehicles.

A plane this size needs a lot of power, which is why the Roc has six Boeing 747 engines. These are responsible for the high altitudes the aircraft can reach – of up to 35,000 feet.

What’s next for Stratolaunch?

Engineers will now continue to prepare Roc for use with future launches of the upcoming hypersonic testbed vehicle, Talon-A. The most recent test launch was a vital step in the development of the Talon-A, which is an autonomous, liquid-powered hypersonic vehicle created by Stratolaunch.

When operational, the vehicle should provide more than 60 seconds of hypersonic flight test conditions. The Talon-A will have the capability to launch from the Roc and land on a conventional runway.

Only announced last year, Stratolaunch’s hypersonic program is already making massive leaps. Many are anticipating upcoming tests for the Talon-A ahead in the next years.

Words by Jonathan Ritchie