LISA is a mission concept proposed by the LISA Consortium on January 13th, 2017 following the call for the L3 mission of the European Space Agency. The goal of LISA is to fulfill the science presented in the white paper The Gravitational Universe, approved by ESA on 2013, consisting in low-frequency gravitational-wave astronomy. In March 7th, 2017, ESA started the phase 0 to assess the technological and economical viability of LISA. In May 2017 it is expected that ESA will make public the main conclusions of this study. It is also expected that the Phase A of LISA will start on June 2017.
LISA is an all-sky monitor and will offer a wide view of a dynamic cosmos using Gravitational Waves as new and unique messengers to unveil The Gravitational Universe. It provides the closest ever view of the infant Universe at TeV energy scales, has known sources in the form of verification binaries in the Milky Way, and can probe the entire Universe, from its smallest scales near the horizons of black holes, all the way to cosmological scales. The LISA mission will scan the entire sky as it follows behind the Earth in its orbit, obtaining both polarisations of the Gravitational Waves simultaneously, and will measure source parameters with astrophysically relevant sensitivity in a band from below 1E-4 Hz to above 1 Hz.
Aim of our participation
The ICE leads the Spanish contribution to the mission through the Gravitational Astronomy – LISA group. Spain is one of the eight signatories of the Multilateral Agreement (MLA) between ESA and Germany, Italy, United Kingdom, Spain, France, the Netherlands and Switzerland. The Spanish contribution started on 2004, led by Prof. Alberto Lobo, and consists in the Data and Diagnostics Subsystem (DDS), which include the payload control computer, also known as the Data Management Unit (DMU) and a set of high-precision and high-estability sensors and actuators to monitor the environment of the test masses in LISA Pathfinder, the Diagnostic Items (ITs).
The DMU is the main computer of the LTP (a mission critical component) which interfaces with the On Board Computer (OBC), the LPF master computer which communicates with the ground stations and distributes tasks to the various subsystems of both the satellite and the payload. The DMU also controls the diagnostic subsystem. The DMU contains fully duplicated hardware (redundancy). The Boot (BSW) and Application software (ASW) for the DMU have also been the responsability of the Spanish group.
The DIs consist of: (i.1) Thermal Diagnostics that use 24 precision thermometers and 14 precision heaters. (i.2) Magnetic diagnostics that use 4 sensitive 3-axes magnetometers (fluxgate class) and 2 precision induction coils. (i.3) Charged particle counting and spectroscopy by means of a Radiation Monitor.
The group has contributed also some parts of the LISA Technology Package Data Analysis (LTPDA) tools, a MATLAB tool developed for the analysis of the LISA Pathfinder data.
After the LISA Pathfinder launch, the scientific operations started officially on March 1st, 2016. During the operations several members of the group have travelled to the European Space Operations Center (ESOC) in Darmstadt (Germany) to participate in the operations and in particular in the data analysis, leading several times the team on duty. Our team has been in charge of the definition of several experiments on-board involving heat injections in highly sensitive locations and application of controlled magnetic fields to the free-falling test masses. We are also hosting and maintaining the web service with the different instrument daily reports. We are responsible, as hardware providers, of the monthly reporting of the Data and Diagnostics Subsystem to ESA. In addition, members of the group have made important contributions to the data analysis pipelines used in LISA Pathfinder.
M. Armano et al (LISA Pathfinder collaboration; 99 authors): Constraints on LISA Pathfinder’s self-gravity: design requirements, estimates and testing procedures, Classical and Quantum Gravity, 33, 235015 (2016)
M. Armano et al (LISA Pathfinder collaboration; 119 authors): Sub-Femto-g Free Fall for Space-Based Gravitational Wave Observatories: LISA Pathfinder Results, Physical Review Letters, 116, 231101 (2016)
M. Nofrarias, N. Karnesis, F. Gibert et al (22 authors): Optimal design of calibration signals in space borne gravitational wave detectors, Physical Review D, 93, 102004 (2016)
Senior Institute members involved
, LL. Gesa, J. Isern, I. LLoro, M. Nofrarías