24 research outputs found
The 10m AEI prototype facility A brief overview
The AEI 10 m prototype interferometer facility is currently being constructed
at the Albert Einstein Institute in Hannover, Germany. It aims to perform
experiments for future gravitational wave detectors using advanced techniques.
Seismically isolated benches are planned to be interferometrically
interconnected and stabilized, forming a low-noise testbed inside a 100 m^3
ultra-high vacuum system. A well-stabilized high power laser will perform
differential position readout of 100 g test masses in a 10 m suspended
arm-cavity enhanced Michelson interferometer at the crossover of measurement
(shot) noise and backaction (quantum radiation pressure) noise, the so-called
Standard Quantum Limit (SQL). Such a sensitivity enables experiments in the
highly topical field of macroscopic quantum mechanics. In this article we
introduce the experimental facility and describe the methods employed,
technical details of subsystems will be covered in future papers
Laser-interferometric dilatometry
Highly dimensionally stable materials and structures are particularly needed in optical systems such as ultra precise optical clocks, as well as materials with excellent dimensional stability and light weight properties for space applications such as telescopes, optical benches, and optical resonators. Also, the dimensional stability of mounting technologies of materials with different properties is of high interest for such applications. Glass ceramics and composite materials can be tuned to reach a very low coefficient of thermal expansion (CTE) at different temperatures, enabling best stability in the operating temperature for certain applications. In order to determine the CTE of such highly stable materials, very accurate set-ups are needed. In this thesis, metrology set-ups to measure the CTE of a large variety of material samples are designed, realized and verified, measuring dimensionally stable glass ceramics. The set-ups are able to characterize tube shaped samples at a temperature range of 140 K to 333 K. Due to our unique mirror mount design all kind of materials can be characterized. The optical dilatometer set-ups are based on a heterodyne interferometer with a displacement sensitivity at the sub-nanometer level. This instrument is used to measure the expansion of a sample when applying controlled small amplitude temperature signals. A carbon fiber reinforced polymer (CFRP) sample was characterized where CTE levels of 10 -8 K -1 from 140 K to 250 K were measured and a detailed uncertainty analysis was performed. The verified metrology set-up for tube shaped samples was adapted for CTE measurements of larger structures. Therefore, a large thermal chamber was set up and a 0.5 m CFRP spacer with Zerodur endfittings as a representative joint technology demonstrator for the GRACE Follow-On space mission at 302 K was investigated
Technology Development Roadmap: A Technology Development Roadmap for a Future Gravitational Wave Mission
Humankind will detect the first gravitational wave (GW) signals from the Universe in the current decade using ground-based detectors. But the richest trove of astrophysical information lies at lower frequencies in the spectrum only accessible from space. Signals are expected from merging massive black holes throughout cosmic history, from compact stellar remnants orbiting central galactic engines from thousands of close contact binary systems in the Milky Way, and possibly from exotic sources, some not yet imagined. These signals carry essential information not available from electromagnetic observations, and which can be extracted with extraordinary accuracy. For 20 years, NASA, the European Space Agency (ESA), and an international research community have put considerable effort into developing concepts and technologies for a GW mission. Both the 2000 and 2010 decadal surveys endorsed the science and mission concept of the Laser Interferometer Space Antenna (LISA). A partnership of the two agencies defined and analyzed the concept for a decade. The agencies partnered on LISA Pathfinder (LPF), and ESA-led technology demonstration mission, now preparing for a 2015 launch. Extensive technology development has been carried out on the ground. Currently, the evolved Laser Interferometer Space Antenna (eLISA) concept, a LISA-like concept with only two measurement arms, is competing for ESA's L2 opportunity. NASA's Astrophysics Division seeks to be a junior partner if eLISA is selected. If eLISA is not selected, then a LISA-like mission will be a strong contender in the 2020 decadal survey. This Technology Development Roadmap (TDR) builds on the LISA concept development, the LPF technology development, and the U.S. and European ground-based technology development. The eLISA architecture and the architecture of the Mid-sized Space-based Gravitational-wave Observatory (SGO Mid)-a competitive design with three measurement arms from the recent design study for a NASA-led mission after 2020-both use the same technologies. Further, NASA participation in an ESA-led mission would likely augment the eLISA architecture with a third arm to become the SGO Mid architecture. For these reasons, this TDR for a future GW mission applies to both designs and both programmatic paths forward. It is adaptable to the different timelines and roles for an ESA-led or a NASA-led mission, and it is adaptable to available resources. Based on a mature understanding of the interaction between technology and risk, the authors of this TDR have chosen a set of objectives that are more expansive than is usual. The objectives for this roadmap are: (1) reduce technical and development risks and costs; (2) understand and, where possible, relieve system requirements and consequences; (3) increase technical insight into critical technologies; and (4) validate the design at the subsystem level. The emphasis on these objectives, particularly the latter two, is driven by outstanding programmatic decisions, namely whether a future GW mission is ESA-led or NASA-led, and availability of resources. The relative emphasis is best understood in the context of prioritization
Scientific applications of frequency-stabilized laser technology in space
A synoptic investigation of the uses of frequency-stabilized lasers for scientific applications in space is presented. It begins by summarizing properties of lasers, characterizing their frequency stability, and describing limitations and techniques to achieve certain levels of frequency stability. Limits to precision set by laser frequency stability for various kinds of measurements are investigated and compared with other sources of error. These other sources include photon-counting statistics, scattered laser light, fluctuations in laser power, and intensity distribution across the beam, propagation effects, mechanical and thermal noise, and radiation pressure. Methods are explored to improve the sensitivity of laser-based interferometric and range-rate measurements. Several specific types of science experiments that rely on highly precise measurements made with lasers are analyzed, and anticipated errors and overall performance are discussed. Qualitative descriptions are given of a number of other possible science applications involving frequency-stabilized lasers and related laser technology in space. These applications will warrant more careful analysis as technology develops
SSTAC/ARTS review of the draft Integrated Technology Plan (ITP). Volume 1: Plenary Session
Briefings from the plenary session of the conference on SSTAC/ARTS Review of the Draft Integrated Technology Plan (ITP) held on 24-28 Jun. 1991 are included. Viewgraphs from the presentations are included
Technology for large space systems: A bibliography with indexes (supplement 17)
This bibliography lists 512 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1, 1987 and June 30, 1987. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems
Space station systems: A bibliography with indexes
This bibliography lists 967 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1, 1987 and June 30, 1987. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems. The coverage includes documents that define major systems and subsystems, servicing and support requirements, procedures and operations, and missions for the current and future space station
International VLBI Service for Geodesy and Astrometry 2014 Annual Report
IVS is an international collaboration of organizations which operate or support Very Long Baseline Interferometry (VLBI) components. The goals are: 1. To provide a service to support geodetic, geophysical and astrometric research and operational activities. 2. To promote research and development activities in all aspects of the geodetic and astrometric VLBI technique. 3. To interact with the community of users of VLBI products and to integrate VLBI into a global Earth observing system