Effective methodologies to derive strategic decisions from ESA technology roadmaps

Top priorities in future international space exploration missions regard the achievement of the necessary matura-tion of enabling technologies, thereby allowing Europe to play a role commensurate with its industrial, operational and scientific capabilities. As part of the actions derived from this commitment, ESA Technology Roadmaps for Exploration represent a powerful tool to prioritise R&D activities in technologies for space exploration and support the preparation of a consistent procurement plan for space exploration technologies in Europe. The roadmaps illus-trate not only the technology procurement (to TRL-8) paths for specific missions envisaged in the present timeframe, but also the achievement for Europe of technological milestones enabling operational capabilities and building blocks, essential for current and future Exploration missions. Coordination of requirements and funding sources among all European stakeholders (ESA, EU, National, Industry) is one of the objectives of these roadmaps, that show also possible application of the technologies beyond space exploration, both at ESA and outside. The present paper describes the activity that supports the work on-going at ESA on the elaboration and update of these roadmaps and related tools, in order to criticise the followed approach and to suggest methodologies of assessment of the Roadmaps, and to derive strategic decision for the advancement of Space Exploration in Europe. After a review of Technology Areas, Missions/Programmes and related building blocks (architectures) and operational capabilities, technology applicability analyses are presented. The aim is to identify if a specific technology is required, applicable or potentially a demonstrator in the building blocks of the proposed mission concepts. In this way, for each technology it is possible to outline one or more specific plans to increase TRL up to the required level. In practice, this translates into two possible solutions: on the one hand, approved mission concepts will be complemented with the required technologies if the latter can be considered as applicable or demo; on the other, if they are neither applicable nor demo, new missions, i.e. technology demonstrators based on multidisciplinary grouping of key technologies, shall be evaluated, so as to proceed through incremental steps. Finally, techniques to determine priorities in technology procurement are identified, and methodologies to rank the required technologies are proposed. In addition, a tool that estimates the percentage of technologies required for the final destination that are implementable in each intermediate destination of the incremental approach is presented

From the elasticity theory to cosmology and vice versa

The paper shows how a generalization of the elasticity theory to four dimensions and to space-time allows for a consistent description of the homogeneous and isotropic universe, including the accelerated expansion. The analogy is manifested by the inclusion in the traditional Lagrangian of general relativity of an additional term accounting for the strain induced in the manifold (i.e. in space-time) by the curvature, be it induced by the presence of a texture defect or by a matter/energy distribution. The additional term is sufficient to account for various observed features of the universe and to give a simple interpretation for the so called dark energy. Then, we show how the same approach can be adopted back in three dimensions to obtain the equilibrium configuration of a given solid subject to strain induced by defects or applied forces. Finally, it is shown how concepts coming from the familiar elasticity theory can inspire new approaches to cosmology and in return how methods appropriated to General Relativity can be applied back to classical problems of elastic deformations in three dimensions.Comment: 11 pages, 3 figure

THE IMPORTANCE OF TECHNOLOGY ROADMAPS FOR A SUCCESSFUL FUTURE IN SPACE EXPLORATION

Technology roadmaps are a powerful strategic tool, so as to meet the top priorities in future Space Exploration missions, in particular regarding the achievement of the required maturation of enabling technologies. However, updating such roadmaps could become an overwhelming task, due the continuous evolution of technologies and new mission concepts. To make these roadmaps as effective as possible, we propose a methodology that could help choose the best paths to develop, test, validate and employ a specific technology. In addition, this methodology is able to rank the proposed missions, thus determining priorities in technology procurement, optimizing the results

Lunar Relativistic Positioning System (LRPS) for human exploration

Abstract: The future of human spaceflight is oriented towards the exploration of planetary bodies beyond Low Earth Orbit (LEO). As on the Earth, the need for a navigation system becomes paramount, especially when we plan to build permanent planetary bases. In particular, this paper treats the case of a human outpost located at the lunar South Pole, and leverages a relativistic positioning algorithm in order to fulfill this goal. This mission is also intended as a test bed for similar future missions. Here, it is shown that it is possible to position users such as manned or unmanned rovers thanks to a constellation of 6 and then 12 nanosatellites orbiting around the Moon, with an accuracy of at most 100 m and 50 m respectively. In fact, the chosen highly elliptical frozen orbits provide coverage over an area centered at the South Pole and of 1500 km radius with at least 4 satellites always in view, which is the minimum number for our positioning algorithm to work. Each satellite is equipped with a clock so that it can emit pulse-like signals that are received by the user, which is equipped with another clock and so it is able to count the pulses emitted by the different nanosatellites. A ground station at the South Pole updates the ephemerides and the proper times of the satellites, transmitting them periodically to the users. In this paper we analyze the architecture of such a mission, describing in details the concept of operations, orbits, and nanosatellites subsystems, maximizing the use of components off the shelf. We also include an implementation plan and a cost model, highlighting the sustainability of the project. Finally, a set of ground tests to qualify this mission for lunar orbit is described, and its top five technical and programmatic risks are discussed