Hopper was a proposed European Space Agency (ESA) orbital spaceplane and reusable launch vehicle. The Hopper was a FESTIP (Future European Space Transportation Investigations Programme) system study design. Hopper was one of several proposals for a reusable launch vehicle (RLV) developed by the ESA. The proposed reusable launch vehicles were to be used for the inexpensive delivery of satellite payloads into orbit as early as 2015. A prototype of Hopper, known as (EADS) Phoenix, was a German-led European project which involved the construction and testing of a one-seventh scale model of the proposed Hopper. On 8 May 2004, a single test flight of the Phoenix was conducted at the North European Aerospace Test range in Kiruna, Sweden, which was followed by more tests later that month. Development Background From the 1980s onwards, there was growing international interest in the development of reusable spacecraft; at the time, only the superpowers of the era, the Soviet Union and the United States, had developed this capability. European nations such as the United Kingdom and France embarked on their own national programs to produce spaceplanes, such as HOTOL and Hermes, while attempting to attract the backing of the multinational European Space Agency (ESA). While these programs ultimately did not garner enough support to continue development, there was still demand within a number of the ESA's member states to pursue the development of reusable space vehicles. During the 1990s, in addition to the development and operation of several technology demonstrator programs, such as the Atmospheric Reentry Demonstrator (ARD), the ESA were also working on the production of a long-term framework for the eventual development of a viable reusable spacecraft, known as the Future Launchers Preparatory Programme (FLPP). Under FLPP, the ESA and European industrial partners performed detailed investigations of several partially-reusable launch vehicle concepts; the aim of the program was to prepare a suitable vehicle to, upon a favorable decision by the ESA's member-nations, proceed with the production of a Next Generation Launcher (NGL). A total of four launch concepts were studied: the Horizontal Take-Off (HTO) Hopper, the Vertical Take-Off (VTO) Hopper, the Reusable First Stage (RFS), and the liquid fly-back booster. Each of these concept vehicles consisted of a reusable winged booster, which was paired with an expendable upper stage, to deliver a payload in geostationary transfer orbit. The HTO Hopper variant was designed for horizontal take-off, the first portion of which was to