LUVOIR (Large UV Optical Infrared telescope) is a concept for a large multi-wavelength, multi-generational, serviceable observatory following the heritage of the Hubble Space Telescope. In scope with its ambitious planned design, its science goals would enable transformative advances across a broad range of astrophysics. With a proposed launch date in mid 2030s, this observatory includes upgradeable state-of-the-art instruments and would reside at Earth-Sun L2 point. LUVOIR's broad range of capabilities, including its wide UV-NIR wavelength range, will allow it to study yet-to-be-discovered phenomena and answer yet-to-be dreamed of questions we do not yet know to ask. A large fraction of LUVOIR's schedule would be open to the community through a general observing program. The LUVOIR study team is considering two architectures, one with a 15-m mirror (Architecture A), and another with a ~8-m mirror (Architecture B). Architecture A is designed for launch on NASA's planned Space Launch System (SLS), while Architecture B is being designed to launch on a heavy-lift launch vehicle with a 5-m diameter fairing, similar to those in use today.
LUVOIR Architecture A (LUVOIR-A) features a 15-m diameter primary telescope aperture and four serviceable instruments, while Architecture B (LUVOIR-B) has a ~8-m telescope aperture and 3 instruments. The primary mirror for LUVOIR-A is currently designed as a three-mirror anastigmat system (TMA), with a fourth fine steering mirror (FSM) located at the real exit pupil of the optical telescope element. The advantages of this system include a wide field-of-view that can be accessed by a number of instruments, with spherical, coma, and astigmatism aberrations corrected, and the inclusion of the FSM also allows for ultra-fine pointing stability to be achieved by all of the instruments. The design of the telescope for LUVOIR-B is still under development.
The ECLIPS (Extreme Coronagraph for Living Planetary Systems) coronagraph is a complex instrument, designed to suppress the overwhelming glare of starlight so that faint planets can be seen adjacent to their parent stars. We require a target contrast ratio of < 1010 to accomplish these observations. This instrument is split into three channels that cover the following bandpasses: UV (200 to 400 nm), optical (400 nm to 850 nm), and NIR (850 nm to 2.0 microns), with each channel equipped with two deformable mirrors for wavefront control, a suite of coronagraph masks, a low-order/out-of-band wavefront sensor, and separate science imagers and spectrographs. We are studying vector vortex and APLC coronagraph designs. ECLIPS would enable, for the first time, direct imaging and spectroscopy of Earth-sized exoplanets.
The High Definition Imager (HDI) instrument is the primary astronomical imaging instrument for observations in the near UV through the near IR. The HDI design provides a 2 x 3 arcminute field-of-view, taking full advantage of the angular resolution provided by the telescope, and consists of two channels - an ultraviolet-visible (UVIS) channel covering 200 nm - 950 nm and a near-infrared (NIR) channel covering the range 800 nm - 2500 nm. The respective focal plane detector arrays provide Nyquist sampled images at 400 nm (2.73 mas/pixel) for UVIS imaging and at 1200 nm (8.20 mas/pixel) for NIR imaging.
LUMOS (LUVOIR Ultraviolet Multi Object Spectrograph) is a multi-object spectrograph covering far-ultraviolet (100 nm) through visible (400 nm) wavelengths. LUMOS is a highly multiplexed ultraviolet spectrograph, with medium and low-resolution multi-object imaging spectroscopy and FUV imaging modes. LUMOS can be considered as a successor to the Hubble Space Telescope Imaging Spectrograph (STIS) instrument, with two orders-of-magnitude higher efficiency, multi-object capability, and a wide-field multi-band imaging channel.
POLLUX is a European contribution to the LUVOIR mission study. It is a concept for a UV spectro-polarimeter with high resolution point source capability (R =120,000) that would be complementary to the UV capability of the LUMOS instrument. It is to be defined and designed by a consortium of 10 European institutions, with leadership and support from CNES.