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| DARWIN Mission Summary Status |
| Darwin is one of the most challenging space projects ever considered by the European Space Agency. Its principal objectives are to detect Earth-like planets around nearby stars, to analyze the composition of their atmospheres and to assess their ability to sustain life as we know it. The Darwin mission is conceived as a nulling interferometer operating in L2 which makes use of on-axis destructive interferences to extinguish the stellar light while keeping the off-axis signal of the orbiting planet.
The objective of this document is to summarize the status of the activities related to Darwin that have been recently completed by ESA. Most activities have been performed under ESA contracts in European Industries and Scientific Institutes. These activities cover the development of core technologies, the design and manufacture of critical payload subsystems, tests of technology demonstration breadboards, the development of software simulators, studies of candidate Darwin payload and spacecraft architectures, and definitions of guidance, navigation and control systems for multi-spacecraft missions. |
| Publication date: 19 Feb 2007 |
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| DARWIN System Assessment Study - Alcatel Summary Report |
This report is the summary of the work done in the DARWIN System Assessment Study and presents its main results: selected concept and architecture, preliminary design, main performance at functional and interface levels.
This study has spanned around 12 months, featuring:
- a Phase 1 devoted to requirements review and architecture trade-of: it has led to the selection
of the non planar arrangement
- a Phase 2 devoted to preliminary design: together with the consolidation of the selected
arrangement, it has produced the payload and spacecraft preliminary design, including
performance budgets
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| Publication date: 15 Feb 2007 |
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| DARWIN System Assessment Study - Alcatel Summary Report |
This report is the summary of the work done in the DARWIN System Assessment Study and presents its main results: selected concept and architecture, preliminary design, main performance at functional and interface levels.
This study has spanned around 12 months, featuring:
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a Phase 1 devoted to requirements review and architecture trade-of: it has led to the selection of the non planar arrangement
- a Phase 2 devoted to preliminary design: together with the consolidation of the selected arrangement, it has produced the payload and spacecraft preliminary design, including performance budgets
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| Publication date: 15 Feb 2007 |
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| Recurring Service Modules for Future Science Missions |
| Over the last few years, due to a diminishing purchasing power and difficulties in increasing the available budget, cost effectiveness has become a great concern within ESA. Indeed, missions cost have noticeably increased (especially for science missions) and many initiatives have been undertaken to control and limit the expenditure by streamlining processes and resources, especially in order to implement a mission within a more restrictive budget. In addition, the scientific community requirements are more and more challenging: demanding mission objectives lead to more complex mission concepts. Moreover, a quicker response time from approval to launch would be desirable, whilst keeping a very high overall level of reliability. The main objective of this study is to review the application of recurring service modules as a potential answer to the challenges listed above. |
| Publication date: 19 Jan 2007 |
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| DARWIN System Assessment Study - Astrium Summary Report |
| The objective of the DARWIN System Assessment Study is the definition of the overall architecture and the preliminary design of the DARWIN mission. This includes an operational orbit at the Second Lagrange Point of the Sun-Earth system (L2), a launch and transfer scenario, and a spacecraft and payload design which ensure that the mission requirements can be fulfilled. The specifications of the subsystems have to be derived, critical items and drivers have to be identified, and required technology development activities have to be proposed in order to allow for establishing a roadmap towards the verification of the science performance feasibility.
The DARWIN System Assessment Study is divided into two phases. Phase 1 is concerned with a review and trade-off of different concepts concerning the payload, the space segment, and the mission. Phase 2 is devoted to a detailed design of the payload and the space segment, as well with a consolidated mission design. A third phase is foreseen for design consolidation. |
| Publication date: 12 Dec 2006 |
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| DARWIN System Assessment Study - Astrium Summary Report |
| The objective of the DARWIN System Assessment Study is the definition of the overall architecture and the preliminary design of the DARWIN mission. This includes an operational orbit at the Second Lagrange Point of the Sun-Earth system (L2), a launch and transfer scenario, and a spacecraft and payload design which ensure that the mission requirements can be fulfilled. The specifications of the subsystems have to be derived, critical items and drivers have to be identified, and required technology development activities have to be proposed in order to allow for establishing a roadmap towards the verification of the science performance feasibility.
The DARWIN System Assessment Study is divided into two phases. Phase 1 is concerned with a review and trade-off of different concepts concerning the payload, the space segment, and the mission. Phase 2 is devoted to a detailed design of the payload and the space segment, as well with a consolidated mission design. A third phase is foreseen for design consolidation. |
| Publication date: 12 Dec 2006 |
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| Development of compound semiconductor detectors at ESA |
| Some examples of space-borne applications that require improvements in detector technology compared with conventional Si and Ge designs are described. Properties of compound semiconductors are noted, and a range of different detector developments are briefly reviewed. Material fabrication improvements for several compound semiconductors have resulted in near Fano-limited performance. |
| Publication date: 30 Nov 2006 |
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| X-Ray Observatory Study preparation activities - Status Report #2 |
| The X-Ray Observatory (XRO), also known as XEUS (X-Ray Evolving-Universe Spectroscopy), is one of the potential future missions identified in the framework of the ESA Call for Themes issued in April 2004 [RD-CV1525].
A summary of the study evolution has been provided in the previous XRO status report [RSStRep] issued at the end of March 2006. The work of ESA and JAXA on the revised mission scenario has progressed further over the past 6 months, including internal as well as industrial activities and dedicated technology developments. |
| Publication date: 02 Nov 2006 |
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| HICoPS Executive Summary |
| Purpose of the HICoPS paper study, described in this summary, is a combination of a miniature rover and a set of miniaturised scientific experiments for planetary research. The instrumentation allows to analyse a planet with a broad spectrum of very efficient techniques. The rover Nanokhod, based on a proposal by Dr. Rudolf Rieder (MPCh Mainz) and vH&S, has undergone several evolutionary design steps in the past 10 years. This rover has the ability to carry a full set of miniaturised scientific instruments inside a levered rotationally mounted miniature compartment (Payload Cab). Prior to HICoPS, there were mainly two precursing studies: GIPF and MRP. The rover has been completely redesigned by vH&S within theMRP (Mercury Robotic Payload) study contract. GIPF (Geochemistry Intrument Package Facility) describes a full set of scientific instrumentation for remote geochemistry analysis in planetary research. GIPF and MRP developments have been performed in parallel, with the final integration in mind, which is now commenced by the HICoPS activity. |
| Publication date: 26 Oct 2006 |
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| CDF Study Report for WFI - A Wide Field Imager for Supernovae Surveys and Dark Energy Characterisation |
| CDF Study Report: CDF-46(A)
The ESA Concurrent Design Facility (CDF) was requested and financed by ESA/ESTEC/SCIAM to carry out a feasibility study for an optical-near-infrared wide field imager (WFI). Such a mission would search for Type Ia supernovae over a given redshift range with optical and near infrared wavelength coverage.
The overall aim of the mission would be to use supernova observations to model the changing rate of expansion of the universe and to determine the contributions of decelerating and accelerating energies such as the mass density and dark energy density. This model could be constructed using a Hubble diagram (redshift vs. magnitude) populated with supernovae measurements.
This study is the first step in the feasibility assessment of a technology reference mission and a follow-on phase-A industrial study is foreseen for the payload, where most of the technology development is needed. |
| Publication date: 15 Oct 2006 |
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| Far Infrared Interferometer Technology Reference Study |
| Paper IAC-06-A3.1.05, 57th International Astronautical Congress, Valencia, Spain, 2-6 October 2006.
In response to ESA's call for space science themes in the frame of Cosmic Vision 2015-2025, the scientific community identified a Far Infrared mission with very high spatial resolution as a potential future science mission for Europe. A future far infrared mission would typically work at wavelengths between 25-300 microns and combine high sensitivity with an angular resolution better than 1 arcsecond at the shortest wavelengths. Such requirements would call for very large telescope diameters or for an interferometer based design.
To investigate the feasibility of this potential future mission the Science Payload & Advanced Concepts Office (SCI-A) at ESA initiated a Far Infrared Interferometer (FIRI) Technology Reference Study (TRS). The selected baseline concept for this study is a single spacecraft Michelson interferometer (i.e. pupil plane recombination) with two light collecting telescopes and a central hub beam combiner, all cryogenically cooled. To enable such a mission concept many innovative design solutions and technology developments would be required in the area of cryogenics, mechanisms and optics.
In this paper an overview of the result of the internal feasibility study of the FIRI concept will be provided. Specific emphasis is on critical subsystems and on required future technology development activities. |
| Publication date: 06 Oct 2006 |
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| Wide Field Imager Technology Reference Study |
| Paper IAC-06-A3.1.04, 57th International Astronautical Congress, Valencia, Spain, 2-6 October 2006. In response to ESA's call for space science themes in the frame of Cosmic Vision 2015-2025, the scientific community identified a Wide-Field Optical and Near Infrared Imager as a potential future science mission for Europe. Such a mission would search for Type Ia supernovae at low redshift in the optical and near infrared part of the spectrum with the aim to measure the changing rate of expansion of the universe and to determine the contributions of decelerating and accelerating energies such as the mass density, the vacuum energy density and other yet to be studied dark energies. To investigate the feasibility of this potential future mission the Science Payload & Advanced Concepts Office (SCI-A) at ESA initiated the Wide Field Imager (WFI) Technology Reference Study (TRS). The WFI would have a 2 m class telescope, a 1 square degree field of view imaging camera and a low-resolution integral field spectrometer. This paper summarizes the results of this ESA internal feasibility study of the WFI. The paper focuses on the spacecraft design and the critical subsystems and provides an overview of required technology development activities for such a mission. |
| Publication date: 06 Oct 2006 |
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| ESA Study of a Wide Field Imager for Supernovae Surveys and Dark Energy Characterization |
| In the proceedings of the 6th International Conference on Space Optics
This paper summarizes the results of an ESA feasibility study of a Wide-Field Optical Infrared Imager (WFI) that would search for Type Ia supernovae at low redshift with the aim to measure the changing rate of expansion of the universe. WFI multi-spectral images of the deep universe could also benefit to many other research area in astrophysics. The WFI payload includes a 2 m class telescope, a 1 square degree field of view imaging camera and a low-resolution integral field spectrometer. A mission concept was identified that consists of a 2000 kg spacecraft launched by a Soyuz-Fregat into a L2 halo orbit. The WFI mission could benefit from the technology developed for the ESA Herschel and Gaia missions and for the NIRSpec ESA instrument. A fully European WFI mission would require improvement of existing European detector and on-board processor technology as well as some effort to support the utilization of the 26 GHz Ka band. |
| Publication date: 13 Jul 2006 |
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| Sample return from Mercury and other Terrestrial Planets using Solar Sail Propulsion |
| A conventional Mercury sample return mission requires significant outbound and return trips, and the large mass of a planetary lander and ascent vehicle. In this paper, it is shown that solar sailing can be used to reduce lander mass allocation by delivering the lander to a low, thermally safe orbit close to the planetary terminator. In addition, the ascending node of the solar sail parking orbit plane can be artificially forced to avoid out-of-plane manoeuvres during ascent from the planetary surface. Propellant mass is not an issue for solar sails, so a sample can be returned relatively easily, without resorting to lengthy, multiple gravity assists. A 275 m square solar sail with a sail assembly loading of 5.9 g m-2 is used to deliver a lander, cruise stage and science payload to a forced Sun-synchronous orbit at Mercury in 2.85 years. The lander acquires samples, and conducts limited surface exploration. An ascent vehicle delivers a small cold gas rendezvous vehicle containing the samples for transfer to the solar sail. The solar sail then spirals back to Earth in one year. The total mission launch mass is 2353 kg, on an H2A202-4S class launch vehicle (C3=0). Extensive launch date scans have revealed an optimal launch date in April 2014 with sample return to Earth 4.4 years later. Solar sailing reduces launch mass by 60% and trip time by 40%, relative to conventional mission concepts. In comparison, mission analysis has demonstrated that solar sail Mars and Venus sample return appears to have only modest benefit in terms of reduced launch mass, at the expense of longer mission durations than conventional propulsion systems. |
| Publication date: 01 Jul 2006 |
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| Far Infrared Interferometer - CDF Study Report |
The ESA Concurrent Design Facility (CDF) was requested and financed by ESA/ESTEC/SCIAM to carry out the assessment study of a Far-InfraRed Interferometer Technology Reference Study (FIRI). The main science objective is to perform measurements at significantly improved angular resolution obtainable with today's IR telescopes (i.e. sub-arcsec resolution) by using space Interferometry. The overall mission goals were to study the following:
- Formation and evolution of stars
- Formation of planetary systems and planet detection
- Formation and evolution of galaxies
The objectives of the study were to assess the feasibility of a Far-InfraRed Michelson Interferometer mission and the identification of the critical technology in order to define a Technology Development Plan with particular emphasis on the following:
- To assess the feasibility of a far-infrared Michelson interferometer based on a single spacecraft
- To design the mission
- To identify the critical technologies and define their development plan
- To make cost, risk and programmatics analysis for the mission and for the technology development plan
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| Publication date: 15 Jun 2006 |
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| Assessment of a Luminescence Dating (LD) Technique in Martian Surface exploration |
Chronology is the key to understanding climatically and tectonically driven changes on Mars. The objective of the present proposal was to assess the potential of in-situ Martian sediment dating using luminescence techniques. The work was divided into two parts:
a) Work package 1 : Review and optimisation of appropriate techniques and instrumentation
b) Work package 2 : Laboratory measurements and proposals for instrumentation. |
| Publication date: 01 Jun 2006 |
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| Cross-Scale TRS: Mission Objectives |
| The Cross-scale TRS is one of ESA's Technology Reference Studies. The purpose of the TRSs is to provide a focus for the development of strategically important technologies that are of likely relevance for future scientific missions. This is accomplished through the study of several technologically demanding and scientifically interesting missions, which are not part of the ESA science programme. The TRSs subsequently act as a reference for possible future technology development activities. The TRSs will not interfere with (or replace) the standard ESA mission selection process. |
| Publication date: 21 Apr 2006 |
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| Imaging spectroscopy with Ta/Al DROIDs, performance for different Al trapping layer thicknessess |
| To overcome the limited field of view which can be achieved with single STJ arrays, DROIDs (Distributed Read Out Imaging Devices) are being developed. DROIDs consist of a superconducting absorber strip with proximized STJs on either end. The ratio of the two signals from the STJs provides information on the absorption position and the sum signal is a measure for the energy of the absorbed photon. In our devices the absorber is an epitaxial Ta strip that extends underneath the Ta/Al read-out STJs. Thus, the bottom electrode of the STJs is an integral part of the absorber. Due to the proximity effect, the STJs have a lower energy gap than the absorber, causing trapping of quasiparticles in the STJs. The trapping will change with thicker Al layers because the energy gap of the devices will decrease. A series of 50x200µm and 20x200µm absorbers (including 50x50µm STJs) and different Al trapping layer thicknesses, ranging from 65 to 130nm, have been tested. The devices have been illuminated with 6 keV 55Fe photons. The position resolution is found to improve with increasing Al thickness. It is found that the current model needs to be adapted for DROIDs to account for different injection of quasiparticles into the STJ and extra losses to the absorber. |
| Publication date: 15 Apr 2006 |
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| Imaging spectroscopy with Ta/Al DROIDs, performance for different absorber lengths |
| To overcome the limited field of view that can be achieved with single STJ arrays, DROIDS (Distributed Read Out Imaging Devices) are being developed. DROIDs consist of a superconducting absorber strip with proximized STJs on either end. The ratio of the two signals from the STJs provides information on the absorption position and the sum signal is a measure for the energy of the absorbed photon. To produce a large field of view with the least number of connection wires possible, the size of the DROID is an important parameter. A set of devices with different lengths, ranging from 200 to 700µm, has been tested at optical wavelengths. The widths of the DROIDs are 30µm with 30x30µm STJs Ta/Al STJs on either side. With 30nm layer thickness of Al the trapping of quasiparticles in the STJ is not optimal, but the devices can comfortably be operated at 300mK. All devices have been processed on a single wafer and are located on the same chip. Thus the STJs are all identical and any variation in response can be attributed to a difference in geometry. The position resolution is found to be degraded for shorter absorbers due to cross talk between the two STJs. The charge output of the different devices decreases with length due to reduced tunnel probability and losses in the absorber. |
| Publication date: 15 Apr 2006 |
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| S-Cam 3, optical astronomy with a STJ-based imaging spectro-photometer |
| S-Cam 3 is the 3rd generation of a cryogenic camera, based on superconducting tunnel junctions (STJs), for ground-based optical astronomy, deployed at the 4.2m William Herschel Telescope (WHT) at La Palma (Spain). It exploits a 10x12 pixel array of Ta/Al STJs, covering a field of view of ~9°x11° on the sky. The wavelength band extends from 330-750nm, with a wavelength resolving power of ~10 at 500nm. The detectors are operated at ~285mK, achieved with a double stage 4He-³He sorption cooler. Each pixel has its own electronic readout chain at room temperature, with a JFET-based charge sensitive preamplifier. The instrument has undergone extensive testing and calibration, followed by the first observation campaign at La Palma in July 2004. This campaign has focused on point sources with time variability, exploiting the instrument's unique combination of spectro-photometry with high time resolution.
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| Publication date: 15 Apr 2006 |
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