direct thrust over a range of angles. This was developed side by side with an airframe, the Hawker P.1127, which became subsequently the Kestrel and then entered production as the Hawker Siddeley Harrier, though the supersonic Hawker Siddeley P.1154 was canceled in 1965. The French in competition with the P.1154 had developed a version of the Dassault Mirage III capable of attaining Mach 1. The Dassault Mirage IIIV achieved transition from vertical to horizontal flight in March 1966, reaching Mach 1.3 in level flight a short time later. V/STOL The Harrier is usually flown in STOVL mode, which enables it to carry a higher fuel or weapon load over a given distance. In V/STOL the VTOL aircraft moves horizontally along the runway before taking off using vertical thrust. This gives aerodynamic lift as well as thrust lift and permits taking off with heavier loads and is more efficient. When landing the aircraft is much lighter due to the loss of propellant weight and a controlled vertical landing is possible. An important aspect of Harrier STOL operations aboard naval carriers is the "ski jump" raised forward deck, which gives the craft additional vertical momentum at takeoff. The March 1981 cover of Popular Science showed three illustrations for its "Tilt-engine V/STOL - speeds like a plane, lands like a copter" front-page feature story.; a followup story was part of the April 2006 issue that mentioned "the fuel-consumption and stability problems that plagued earlier plane/copter." Retired from the British Royal Navy in 2006, the Indian Navy continued to operate Sea Harriers until 2016, mainly from its aircraft carrier . The latest version of the Harrier, the BAE Harrier II, was retired in December 2010 after being operated by the British Royal Air Force and Royal Navy. The United States Marine Corps and the Italian and Spanish navies all continue to use the AV-8B Harrier II, an American-designed equivalent version. Replacing the Harrier II/AV-8B in the air arms of the US and UK is the STOVL variant of the Lockheed Martin F-35 Lightning II, the F-35B. Rockets SpaceX developed several prototypes of Falcon 9 to validate various low-altitude, low-velocity engineering aspects of its reusable launch system development program. The first prototype, Grasshopper, made eight successful test flights in 2012–2013. It made its eighth, and final, test flight on October 7, 2013, flying to an altitude of before making its eighth successful VTVL landing.<ref name=sx20131012fb>{{cite