MICROSCOPE mission analysis, requirements and expected performance

The MICROSCOPE mission aimed to test the Weak Equivalence Principle (WEP) to a precision of $10^{-15}$. The WEP states that two bodies fall at the same rate on a gravitational field independently of their mass or composition. In MICROSCOPE, two masses of different compositions (titanium and platinum alloys) are placed on a quasi-circular trajectory around the Earth. They are the test-masses of a double accelerometer. The measurement of their accelerations is used to extract a potential WEP violation that would occur at a frequency defined by the motion and attitude of the satellite around the Earth. This paper details the major drivers of the mission leading to the specification of the major subsystems (satellite, ground segment, instrument, orbit...). Building upon the measurement equation, we derive the objective of the test in statistical and systematic error allocation and provide the mission's expected error budget.Comment: References update

MICROSCOPE mission: first results of a space test of the equivalence principle

According to the weak equivalence principle, all bodies should fall at the same rate in a gravitational field. The MICROSCOPE satellite, launched in April 2016, aims to test its validity at the 10−15 precision level, by measuring the force required to maintain two test masses (of titanium and platinum alloys) exactly in the same orbit. A nonvanishing result would correspond to a violation of the equivalence principle, or to the discovery of a new long-range force. Analysis of the first data gives δ(Ti,Pt)=[−1±9(stat)±9(syst)]×10−15 (1σ statistical uncertainty) for the titanium-platinum Eötvös parameter characterizing the relative difference in their free-fall accelerations

The Effects of Technology-as-Knowledge on the Economic Performance of Developing Countries: An Econometric Analysis using Annual Publications Data for Botswana, Namibia, and South Africa, 1976-2004

Extant literature indicates that technology, and by implication its underlying knowledge base, determines long-run economic performance. Absent from the literature with respect to developing countries are quantitative assessments of the nexus between technology as knowledge and economic performance. This paper imposes a simple production function on annual pooled observations on Botswana, Namibia, and South Africa over the 1976-2004 period to estimate the marginal impacts of technology as knowledge on economic performance. It finds that capital (k), openness to trade (τ), and even the share of government expenditure of GDP (G) among other factors, influence economic performance. However, the economic performance of countries like Botswana, Namibia, and South Africa depends largely on technology, technological change, and the basic knowledge that forms the foundation for both. For instance, measured as a homogenous “manna from heaven”, technology is the strongest determinant of real per capita income of the three nations. The strength of technology as a determinant of performance depends on the knowledge underpinnings of technology measured as the number of publications (Q, q). Both Q and q are strongly correlated with the countries’ performance. This suggests that the “social capability” and “technological congruence” of these countries are improving, and that developing countries like Botswana, Namibia, and South Africa gain from increased investment in knowledge-building activities including publishing. Obviously there is room for strengthening results, but this analysis has succeeded in producing a testable hypothesis

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Microscope: A Microsatellite for Equivalence Principle Measurement in Space

The MICROSCOPE mission is developed in the frame of the CNES Myriade micro satellite family. The project is currently ending its Phase B, the Preliminary Design Review has been held in March 2011 and the launch is planned in 2015. The scientific objective of the mission consists in a test of the Equivalence Principle (EP) between gravitational mass and inertial mass with a relative accuracy of 10-15; the payload is composed of a set of two 6-axis differential accelerometers developed by ONERA. To achieve this goal, a drag free control of the satellite has to be achieved in order to limit the non-gravitational accelerations on the payload below 3.10-10 ms-2*Hz-1/2. This paper begins with a introduction of the mission and the payload, explaining how mission requirements and payload I/F strongly constrain the design of spacecraft (drag free, microperturbation and stability). The functional chains of the satellite are presented in detail with an emphasis on mechanical and thermal architecture, Acceleration and Attitude Control System (AACS) and Cold Gas Propulsion System (CGPS). It is shown how the design of the satellite is optimized, melting new advanced technology (Payload, AACS, CGPS) and low cost, well proven methods and equipment of Myriade family