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 Institute of Space Sciences is interested in all the aspects of Gravitational Wave Astronomy: Instrumental Hardware & Software; Data Analysis Developments; and Science Exploitation (including GW source simulations to assists the Data Analysis).
Regarding the contribution of our group to LISA, we expect to lead the Spanish contribution, to be funded by the Spanish government, as in the case of LISA Pathfinder mission. This contribution will consists of
- Payload Control System, including the Software. The exact functions of this System in LISA are yet to be defined.
- Payload Diagnostics Package: Sensors (and also some actuators): Thermal, magnetic and radiation monitor, again as we did for the LISA Pathfinder mission.
- It is important to mention that the know-how acquired in the LISA Pathfinder mission has allow us to set up (in the optics laboratory) a high-precision laser metrology system operating at low frequencies that has a lot of potential to play an important role during the mission development, in particular to test hardware developed by other institutes in the LISA collaboration.
- Ground Segment: Data Center. The main Data Center will located in France (in Paris). The ICE will have another one that will enable local analysis of the real data. Other similar Data Centers will located in Germany, UK, and Italy. This Center will be an improvement of the current operations room for LISA Pathfinder that we have at the ICE premises.
The eLISA Consortium that submitted the white paper The Gravitational Universe has been rebuilt into the LISA Consortium to accommodate the NASA participation and other new countries. Carlos F. Sopuerta is part of the consortium board and chair of the Working Group on Extreme-Mass-Ratio Inspirals. On the other hand, Carlos F. Sopuerta has been part of the Gravitational Wave Working Group (GW-WG) set up by ESA to identify the potential contributions of the different member states and the USA to the L3 mission. Three meetings took place in ESTEC (2) and in NIKHEF (1).
Most of the team activity has been devoted to LISA Pathfinder during 2016. However, there have been some activities related to technology developments towards LISA.
On Aug 15th 2016 the CubeCat-2 was launched from the Jiuquan base in China. Among other payloads, this CubeSat was carrying a prototype magnetometer based on anistropic magnetoresistors that we have been developing as a candidate for the LISA magnetic diagnostics subsystem. This prototype is much more compact and reduces the magnetic back-action when compared with the magnetometers used in LISA Pathfinder, i.e. fluxgate magnetometers.
In terms of temperature diagnostics, during 2016 the group has done an important hardware investment in order to push forward a novel technique to develop a compact, ultra-stable temperature sensor based on optoresonators. This is the main objective of the ComFuturo grant from M. Nofrarias. In brief, this requires locking a frequency-stabilized laser to the high purity resonance of the resonator. This research uses cutting-edge technology currently developed in experimental labs with wide applicability to any precision measurement, including astrophysical instrumentation.
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