of the launcher was a solid Kick Motor developed by Korea, which included the Inertial Navigation System; the power, control, and flight safety systems; plus the nose fairing. South Korea launched its next rocket, the KSLV-2 in 2021. The first stage of KSLV-II has 4 clustered engines, each of which has a 75 metric ton thrust. All three stages use indigenously developed rocket engines. Satellite programs The KAIST's SaTReC, responsible for the nation's small scientific satellites. Korean Lunar Exploration Program The Korean Lunar Exploration Program (KLEP) is divided in two phases. Phase 1 incorporates the launch and operation of a lunar orbiter called Korea Pathfinder Lunar Orbiter (KPLO), which will be the first lunar probe by South Korea, meant to develop and enhance South Korea's technological capabilities, as well as map natural resources from orbit. In December 2016, KARI signed a lunar exploration technical cooperation with NASA which increased the possibility of exploration success greatly. Phase 2 will include a lunar obiter, a lunar lander, and a rover to be launched together on a KSLV-II South Korean rocket from the Naro Space Center, by 2030. Regional Navigation Satellite System (RNSS) Korea Positioning System (KPS) South Korea plans to spend 4 trillion won ($3.56 billion) on building KPS by 2035 by launching seven new satellites — three into geosynchronous orbit and four into inclined geosynchronous orbit. South Korea and the U.S. signed an agreement on “civil global navigation satellite systems cooperation,” under which the U.S. will support South Korea developing its own GPS, named Korean Positioning System (KPS). The two governments plan to work together to ensure compatibility and enhance interoperability of GPS and KPS for civil purposes. Aircraft Stratospheric airship A 10-year program to develop a stratospheric airship for telecommunication relays and ground observations at 20 km altitude has started in December 2000. Smart Tilt Rotor UAV In late 2011, KARI unveiled its tiltrotor Unmanned Aerial Vehicle (UAV) that can fly at around 400 km/hr. High Altitude Long Endurance (HALE) Solar-powered Unmanned Aerial Vehicle (UAV) KARI is developing an electric-driven HALE UAV in order to secure system and operational technologies since 2010. Optionally Piloted Personal Air Vehicle (OPPAV) KARI leads the research and development program to develop a one-seat class electric VTOL (eVTOL) demonstrator. Flight tests of a sub-scale technology demonstrator will be started by 2021. Gallery See also Naro Space Center Korea Astronomy and Space Science Institute (KASI) List