SPICA (spacecraft)


The Space Infrared Telescope for Cosmology and Astrophysics, is a proposed infrared space telescope, follow-on to the successful Akari space observatory. It is a collaboration between European and Japanese scientists, which was selected in May 2018 by the European Space Agency as a finalist for the next Medium class Mission 5 of the Cosmic Vision programme. The other 2 finalists are: THESEUS and EnVision. SPICA will improve over the spectral line sensitivity of previous missions, Spitzer and Herschel space telescopes, between 30 and 230 µm by a factor of 50—100.

History

In Japan, SPICA was first proposed in 2007, initially called HII-L2 after the launch vehicle and orbit, as a large Strategic L-class mission, and in Europe it was proposed to ESA's Cosmic Vision programme, but an internal review at ESA at the end of 2009 suggested that the technology readiness for the mission was not adequate.
In May 2018, it was selected as one of three finalists for the Cosmic Vision Medium Class Mission 5 for a proposed launch date of 2032. Within ESA, SPICA is part of the Medium Class-5 mission competition, with a cost cap of 550M Euros.

Overview

The concept is a collaboration between the European Space Agency and the Japan Aerospace Exploration Agency. If funded, the telescope would be launched on JAXA's H3 launch vehicle.
The Ritchey–Chrétien telescope's 2.5-metre mirror would be made of silicon carbide, possibly by ESA given their experience with the Herschel telescope. The main mission of the spacecraft would be the study of star and planetary formation. It would be able to detect stellar nurseries in galaxies, protoplanetary discs around young stars, and exoplanets, helped by its own coronograph for the latter two types of objects.

Description

The observatory would feature a far-infrared spectrometer and is proposed to be deployed in a halo orbit around the L2 point. The design proposes to use V-groove radiators and mechanical cryocoolers rather than liquid helium to cool the mirror to below which provides substantially greater sensitivity in the 10–100 μm infrared band ; the telescope is intended to observe in longer wavelength infrared than the James Webb Space Telescope. Its sensitivity would be more than two orders of magnitude over both Spitzer and Herschel space telescopes.
;Large-aperture Cryogenic Telescope
SPICA would employ a 2.5 m diameter Ritchey–Chrétien telescope with a field of view of 30 arc minutes.
;Focal-Plane Instruments
As in the name, the main objective is to make advancement in the research of cosmology and astrophysics. Specific research fields include: