Intermediate eXperimental Vehicle

The Intermediate eXperimental Vehicle (IXV) is a European Space Agency (ESA) experimental suborbital re-entry vehicle. It was developed to serve as a prototype lifting body orbital return vehicle to validate the ESA's work in the field of reusable orbital return vehicles.

The European Space Agency has a program called Future Launchers Preparatory Programme (FLPP), which made a call for submissions for a reusable spaceplane. One of the submissions was by the Italian Space Agency, that presented their own Programme for Reusable In-orbit Demonstrator in Europe (PRIDE program) which went ahead to develop an initial test vehicle, Pre-X, followed the prototype named Intermediate eXperimental Vehicle (IXV) and the consequential Space Rider that inherits technology from its prototype IXV.

On 11 February 2015, the IXV conducted its first 100-minute suborbital space flight, successfully completing its mission upon landing intact on the surface of the Pacific Ocean. The vehicle is the first ever lifting body to perform full atmospheric reentry from orbital speed. Past missions have flight tested either winged bodies, which are highly controllable but also very complex and costly, or capsules, which are difficult to control but offer less complexity and lower cost.

During the 1980s and 1990s, there was significant international interest in the development of reusable launch platforms and reusable spacecraft, particularly in respect to spaceplanes, perhaps the most high-profile examples of these being the American Space Shuttle and Soviet Buran programmes. The national space agencies of European nations, such as France's Centre National d'Études Spatiales (CNES) and Germany's German Aerospace Center (DLR), worked on their own designs during this era, the most prominent of these to emerge being the Hermes spaceplane. Development of the Hermes programme, which was backed by the European Space Agency (ESA) for several years, was ultimately terminated in 1992 prior to any flights being performed in favour of a partnership arrangement with the Russian Aviation and Space Agency (RKA) to use the existing Soyuz spacecraft instead.

While work on the development of the Hermes vehicle was cancelled during the early 1990s, the ESA maintained its strategic long-term objective to indigenously develop and eventually deploy similar reusable space vehicles. Accordingly, in support of this goal, the ESA embarked upon a series of design studies on different experimental vehicle concepts as well as to refine and improve technologies deemed critical to future reentry vehicles. In order to test and further develop the technologies and concepts produced by these studies, there were clear needs to accumulate practical flight experience with reentry systems, as well as to maintain and expand upon international cooperation in the fields of space transportation, exploration, and science. Out of these desires emerged the Future Launchers Preparatory Programme (FLPP), an ESA-headed initiative conceived and championed by a number of its member states, which provided a framework for addressing the challenges and development of the technology associated with reentry vehicles.

It was recognised that, in order for significant progress to be made, FLPP would require the production and testing of a prototype reentry vehicle that drew on their existing research, technologies, and designs. By adopting a step-by-step approach using a series of test vehicles prior to the development of a wider series of production vehicles, this approach was seen to reduce the risk and to allow for the integration of progressively more sophisticated developments from the early relatively-low-cost missions.

In line with this determination, during early 2005, the Intermediate eXperimental Vehicle (IXV) project was formally initiated by the Italian Space Agency and the Italian Aerospace Research Centre under an Italian programme named PRIDE (Programme for Reusable In-orbit Demonstrator in Europe) Their main industrial contractor was Next Generation Launcher Prime SpA (NGLP) in Italy. The latter organisation is a joint venture entity comprising two major European aerospace companies, Astrium and Finmeccanica. The PRIDE programme had the support of various national space agencies, including the European Space Research and Technology Centre, Italian Space Agency (ASI), French space agency CNES, and Germany's DLR; by November 2006, the IXV was supported by 11 Member States: Austria, Belgium, France, Germany, Ireland, Italy, Portugal, Spain, Sweden, Switzerland, and the Netherlands. Of these, Italy emerged as the principal financial backer of the IXV programme.

The IXV project benefitted from and harnessed much of the research data and operational principles from many of the previously conducted studies, especially from the successful Atmospheric Reentry Demonstrator (ARD), which was test-flown during 1998. Early on, during the mission definition and design maturity stages of the project, thorough comparisons were conducted again between existing ESA and national concepts against shared criteria, aimed at evaluating the experiment requirements (technology and systems), programme requirements (technology readiness, development schedule and cost) and risk mitigation (feasibility, maturity, robustness, and growth potential). The selected baseline design, a slender lifting body configuration, drew primarily upon the CNES-led Pre-X the ESA's ARD vehicles. Development work quickly proceeded through the preliminary design definition phase, reaching a system requirements review by mid-2007.