ESA Science & Technology - Publication Archive

Reference: ESA-LOFT-RP-0006, Issue 1, Revision 3.

LOFT, a Large Observatory for X-ray Timing, is one of five candidate missions for the M3 launch opportunity. A Preliminary Requirements Review (PRR) of all candidate missions has been performed to review their status in support of the M3 selection. This document reports the results of the technical and programmatic review for the LOFT mission candidate.

This is the Assessment Study Report (also known as the Yellow Book) for LOFT - a candidate mission for the M3 launch opportunity in Cosmic Vision.

LOFT is an M-class mission candidate for the M3 slot within the Cosmic Vision programme, for a planned launch between 2022 and 2024. LOFT, with 3 other science missions, was recommended by the Space Science Advisory Committee (SSAC) to enter an assessment study (Phase 0), starting by an ESA internal study followed by parallel industrial study activities.

Within the M3 boundary conditions, the readiness for launch by end 2022/2024 is a severe requirement which in practice requires designing the space segment without major technology developments and with minimum developments risks. Therefore, only technologies with estimated Technology Readiness Levels (TRL) of at least 5 by the end of the Phase A (estimated at the end of 2014) may be used.

This document aims at providing a complete and comprehensive list of all high level mission requirements (including S/C and payload, launcher, ground segment and operations) necessary to achieve the science goals detailed in [LOFT Science Requirements Document (SciRD), SRE-SA/LOFT/2011-001, Issue 1, Rev. 7]. Accordingly it is an applicable document that shall be complied with for all mission design activities. The MRD will be further reviewed matching the results of future study phases (e.g. definition phase) to finally evolve into the System Requirements Document at the start of the implementation phase.

This Payload Definition Document describes the consolidated instrument designs of the Large Area Detector (LAD) and the Wide Field Monitor (WFM) proposed for LOFT. The current issue (2.0) describes the status of the instruments at the time of the Mid-Term Review (MTR) of the LOFT mission study phase.

Made available online before print publication

High-time-resolution X-ray observations of compact objects provide direct access to strong-field gravity, to the equation of state of ultradense matter and to black hole masses and spins. A 10 m²-class instrument in combination with good spectral resolution is required to exploit the relevant diagnostics and answer two of the fundamental questions of the European Space Agency (ESA) Cosmic Vision Theme "Matter under extreme conditions", namely: does matter orbiting close to the event horizon follow the predictions of general relativity? What is the equation of state of matter in neutron stars? The Large Observatory For X-ray Timing (LOFT), selected by ESA as one of the four Cosmic Vision M3 candidate missions to undergo an assessment phase, will revolutionise the study of collapsed objects in our galaxy and of the brightest supermassive black holes in active galactic nuclei. Thanks to an innovative design and the development of large-area monolithic silicon drift detectors, the Large Area Detector (LAD) on board LOFT will achieve an effective area of ~12 m² (more than an order of magnitude larger than any spaceborne predecessor) in the 2-30 keV range (up to 50 keV in expanded mode), yet still fits a conventional platform and small/medium-class launcher. With this large area and a spectral resolution of <260 eV, LOFT will yield unprecedented information on strongly curved spacetimes and matter under extreme conditions of pressure and magnetic field strength.

This document records the scientific requirements for the Large Observatory for X-ray Timing (LOFT). These are the reference requirements through which the Mission Requirements Document will be derived.

Summary of the study performed at ESA's Concurrent Design Facility (CDF) into the M-class mission Large Observatory for X-ray Timing (LOFT).

Contents of the presentation:

• Introduction
• Study logic
• Requirements
• Baseline design for a launch with Vega
  1. Main trade-offs
  2. System and subsystem overview
  3. System budgets
  4. Risk, cost, and programmatics
• Design assessment for a launch with Soyuz
• Payload aspects
• Conclusions
• Open issues