Tumino.qxd 11/9/06 4:32 PM Page 62 Reentry Technology Giorgio Tumino Future Launchers Preparatory Programme, Directorate of Launchers, Paris, France Yves Gerard Next Generation Launcher Prime S.p.A., Turin, IXV: the Intermediate Italy eXperimental Vehicle ith the objective of placing Europe Europe Among the among the world’s space players in Wthe strategic area of atmospheric reentry in future international transportation, World Players in exploration and scientific projects, several studies on experimental vehicle concepts and improvements of critical reentry technologies Atmospheric Reentry have paved the way for the flight of an experimental craft. The Intermedidate eXperimental Vehicle is building on previous achievements at the system (such as the Atmospheric Reentry Demonstrator) and technology levels, and providing a unique means of establishing Europe’s autonomous position in this international field. Introduction Returning to Earth from orbit is still a challenge, as the loss of Space Shuttle Columbia tragically underlined. Braking from 7.7 km/s through the atmosphere to a safe and precise landing calls for a wide range of demanding technologies to be mastered. The number of experimental reentry vehicles studied in recent years by ESA, France, Germany and Italy underlines Europe’s need for flight experience with reentry systems esa bulletin 128 - november 2006 63 Tumino.qxd 11/9/06 4:32 PM Page 62 Reentry Technology Giorgio Tumino Future Launchers Preparatory Programme, Directorate of Launchers, Paris, France Yves Gerard Next Generation Launcher Prime S.p.A., Turin, IXV: the Intermediate Italy eXperimental Vehicle ith the objective of placing Europe Europe Among the among the world’s space players in Wthe strategic area of atmospheric reentry in future international transportation, World Players in exploration and scientific projects, several studies on experimental vehicle concepts and improvements of critical reentry technologies Atmospheric Reentry have paved the way for the flight of an experimental craft. The Intermedidate eXperimental Vehicle is building on previous achievements at the system (such as the Atmospheric Reentry Demonstrator) and technology levels, and providing a unique means of establishing Europe’s autonomous position in this international field. Introduction Returning to Earth from orbit is still a challenge, as the loss of Space Shuttle Columbia tragically underlined. Braking from 7.7 km/s through the atmosphere to a safe and precise landing calls for a wide range of demanding technologies to be mastered. The number of experimental reentry vehicles studied in recent years by ESA, France, Germany and Italy underlines Europe’s need for flight experience with reentry systems esa bulletin 128 - november 2006 63 Tumino.qxd 11/9/06 4:32 PM Page 64 Launchers Reentry Technology and technologies in order to consolidate The layout of the Intermediate eXperimental Vehicle its position among the world’s space players in this strategic field. Europe must be able to play a more ambitious role in international cooperation in space transportation, exploration and scientific projects. ESA’s Future Launchers Preparatory Programme (FLPP) was conceived by its Member States to provide a framework for, among other technology challenges, the development of the Intermediate eXperimental Vehicle (IXV) by 2010. The IXV trajectory from launch to Mach 2 The current reference trajectory from Kourou to Kiruna Project Definition and Status ESA and its industrial prime contractor future operational vehicles (this explains protection and hot structures under vehicle, when the air molecules break Next Generation Launcher Prime SpA the Intermediate in the name). realistic flight conditions. These include apart to dissipate the high energies (I), a joint venture between Astrium (F, fall over uninhabited areas and the identified, assessed and mitigated at an IXV is a lifting reentry body, with its advanced ceramic and metallic assem- involved in reentry and the perfect-gas D) and Finmeccanica (I), assisted by experimental vehicle to fly over sparsely early stage in the project. shape resulting from the set of design blies, insulation, attachments, junctions laws are no longer valid. This complex ASI, CNES, DLR and ESTEC, initiated populated regions. A study is therefore under way by requirements, including the need to and seals, as well as advanced guidance situation affects the interaction between the IXV project at the beginning of 2005 The reference mission plans a launch industry as a first step in Phase-B1 to maximise the internal volume for navigation and control techniques. shockwave and boundary-layer flows, by defining the mission objectives and from Kourou (French Guiana) into an assess how the safety requirements carrying experiments. The goal is to get This verification of performance in the interaction between shockwaves, the maturing the design. orbit with a 70º inclination, followed by affect the mission, with a comparison of the most out of the vehicle while flight builds on previous efforts and transition from laminar-to-turbulent The objectives include the complete a landing in the North European all the feasible mission scenarios. The guaranteeing the mass (limited by Vega’s ground verification, and aims at boundary-layer flows, the transitional and deep identification of what Aerospace Test Range at Kiruna (S). landing scenario and area will soon be capacity) and centre-of-gravity location. maturing the technologies for operational boundary-layer separation, the heating experiments Europe needs in reentry The scenario is being refined (see selected by ESA with technical The primary objectives of the IXV space applications. of thermal protection materials by technology, with an optimised plan of below), and backup schemes leading to assistance from ASI, CNES, DLR, project can be grouped into three Reentry technology validation focuses turbulent boundary-layer flows, the flight experiments that trades cost a sea landing are also being considered. ESTEC and recommendations from categories: reentry system demonstra- on gathering representative reentry overheating owing to external cavities, against technology maturity needs. IXV will be delivered into an orbit of industry. tion, technology experimentation and performance data in order to investigate the behaviour of materials’ catalytic A thorough comparison has been 180 x 307.2 km, where Vega’s upper technology validation. aerothermodynamic phenomena and properties, the materials’ oxidation, the performed for all the existing ESA and stage will fire above the Pacific Ocean Reentry System and Technology The first focuses on gaining validate system design tools, evaluating reduction in efficiency of the control national concepts against shared off the coast of Chile to trigger reentry. From experience with ambitious experience in lifting and aerodynamic- the behaviour of air around a lifting surfaces through boundary-layer flow criteria, focusing on: experiment IXV will begin formal reentry 120 km experimental vehicles around the world, ally controlled reentry, which would be a body for atmospheric entry in the separation, and the efficiency of the requirements (technology and systems), above the Atlantic Ocean, at a speed of such as NASA’s series of X-vehicles, significant advance on earlier ballistic hypersonic regime (above Mach 5). The reaction control system. programme requirements (technology 7700 m/s and an angle of 1.19º below there is general consensus within and quasi-ballistic efforts, such as the most interesting phenomena stem from The experiment objectives are being readiness, development schedule and the horizontal. The reentry trajectory Europe’s space community that a step- Atmospheric Reentry Demonstrator the behaviour of the airflow around the translated into the vehicle design via an cost) and risk mitigation (design lasting around 20 minutes will be by-step flight programme is the best capsule flown by ESA in 1998. Europe feasibility, maturity, robustness and controlled by a combination of moving approach. It limits the risks, allows needs to go through the entire design growth potential). aerodynamic surfaces and thrusters stepped costs and ensures that progress- loop for such a complex system, specify The result of the trade-off has led to from hypersonic speeds at 120 km ively more sophisticated developments the entire system development phases in the selection of the slender lifting body altitude down to Mach 2.0, while benefit from the results of relatively low- detail, address the manufacturing and configuration. The baseline design builds travelling a surface distance of 7500 km. cost missions. assembly issues of critical reentry upon the extensive national (CNES/ All the while, it will gather large Since 2002, ESA has focused on an technologies, the integration of these Pre-X) and ESA (AREV: Atmospheric quantities of data to verify the optimised long-term scheme of flight key technologies at the system level Reentry Experimental Vehicle) efforts. performance of several critical reentry experiments. Further consolidation with (during the design, assembly, testing and The contractors are now working on technologies. industry in 2005 confirmed the operations), perform overall system Phase-B1 (preliminary design definition), IXV will then be slowed from Mach 2 Intermediate eXperimental Vehicle as integration and verification for a vehicle targeting a system requirements review by a set of parachutes deployed by the core of this effort.