The MUlti-slit Solar Explorer (MUSE) is a NASA medium-class explorer mission that is currently in phase B and scheduled for launch no earlier than 2027. The MUSE science investigation aims to use high-resolution and high-cadence spectroscopic and imaging EUV observations of the solar atmosphere to understand the multi-scale physical processes that heat the multi-million-degree solar corona, drive the source of the solar wind, and cause solar activity (flares and coronal mass ejections) that lead to space weather that impacts Earth. MUSE will consist of an EUV context imager and an EUV spectrograph, both requiring normal incidence mirrors with a very high level of polishing and figuring, in order to allow high-resolution imaging and spectroscopy. The mission is led by Lockheed Martin Solar and Astrophysics Laboratory (LMSAL). The payload is being developed by LMSAL and the Center for Astrophysics (CfA) at the Harvard Smithsonian Astrophysical Observatory, while INAF-OAB will produce the focusing mirrors with the financial support of the Italian Space Agency (ASI). In this paper, we describe the first steps that are being taken in the procurement of the focusing mirrors in Zerodur, the work plan with the ion beam figuring and the pitch tool aimed at bringing the surface defects within the specification. Additionally, we describe the metrology system that we are setting up to detect the residual deviation to the final shape.
Solar-C (EUVST) is the next Japanese solar physics mission to be developed with significant contributions from US and European countries. The mission carries an EUV imaging spectrometer with slit-jaw imaging system called EUVST (EUV High-Throughput Spectroscopic Telescope) as the mission payload, to take a fundamental step towards answering how the plasma universe is created and evolves and how the Sun influences the Earth and other planets in our solar system. In April 2020, ISAS (Institute of Space and Astronautical Science) of JAXA (Japan Aerospace Exploration Agency) has made the final down-selection for this mission as the 4th in the series of competitively chosen M-class mission to be launched with an Epsilon launch vehicle in mid 2020s. NASA (National Aeronautics and Space Administration) has selected this mission concept for Phase A concept study in September 2019 and is in the process leading to final selection. For European countries, the team has (or is in the process of confirming) confirmed endorsement for hardware contributions to the EUVST from the national agencies. A recent update to the mission instrumentation is to add a UV spectral irradiance monitor capability for EUVST calibration and scientific purpose. This presentation provides the latest status of the mission with an overall description of the mission concept emphasizing on key roles of the mission in heliophysics research from mid 2020s.
Experimental multilayer reflectance data on flight mirrors and witnesses for three extreme ultraviolet (EUV) channels of
the Atmospheric Imaging Assembly (AIA) instrument aboard NASA’s Solar Dynamics Observatory are presented and
compared to theoretical models. The relevance of these results to the performance of the AIA instrument is discussed.
We will discuss the design, specification, construction, and assembly of the 4 mirror systems that make up the Solar
Dynamics Observatory (SDO) Atmospheric Imaging Array (AIA). We will include the extensive imaging performance
measurements made on the mirror throughout the post-polishing mirror processing period.
The High-resolution Lightweight Telescope for the EUV (HiLiTE) is a Cassegrain telescope that will be made entirely of
Silicon Carbide (SiC), optical substrates and metering structure alike. Using multilayer coatings, this instrument will be
tuned to operate at the 465 Å Ne VII emission line, formed in solar transition region plasma at ~500,000 K. HiLiTE will
have an aperture of 30 cm, angular resolution of ~0.2 arc seconds and operate at a cadence of ~5 seconds or less, having
a mass that is about 1/4 that of one of the 20 cm aperture telescopes on the Atmospheric Imaging Assembly (AIA)
instrument aboard NASA's Solar Dynamics Observatory (SDO). This new instrument technology thus serves as a path
finder to a post-AIA, Explorer-class missions.
We are developing a new sounding rocket payload, the Advanced Technology Solar Spectroscopic Imager (ATSSI), that will use an 8 X 8 array of transition edge sensors (TES) to obtain true spectroheliograms in a spectral bandpass spanning approximately 50 eV to approximately 3 keV. The TES array will be flown at the focus of a Wolter I telescope, where it will image as 3 arc-min by 3 arc-min field of view with a pixel resolution of approximately 6 arc-sec. In this way, it will obtain approximately 1000 individual spectra with an expected average energy resolution of approximately 3 eV FWHM. In addition to the TES array, the ATSSI will employ six multilayer telescopes with bandpasses centered on atomic lines at 17.1 angstrom (Fe XVII), 195.1 angstrom (Fe XII), 171.1 angstrom (Fe IX), 57.9 angstrom (Mg X), 98.3 angstrom (Ne VIII), and 150.1 angstrom (O VI). Two additional telescopes with bandpasses centered at 1550 angstrom (C IV) and 1216 angstrom (H I) will also be used. The eight narrowband telescopes will provide high spatial resolution (<EQ 1 arc- sec), full-disk solar images and will be complemented by two grating slit spectroheliographs. One grating will obtain high resolution spectroheliograms between 2750 angstrom and 2850 angstrom (for Mg II h- and k-line studies), and the other will be multilayer-based and will probe the Fe IX/X - O V/VI complex around 171 Angstrom (73 eV). With this set of instruments, we expect to explore more fully the nature of the energy flow between small-scale coronal, chromospheric and transition region structures, as well as to address the issue of what mechanisms are responsible for heating the quiescent solar atmosphere.
The Multi-Spectral Solar Telescope Array (MSSTA) is a sounding rocket-borne observatory composed of a set of normal-incidence multilayer-coated telescopes that obtained selected bandpass spectroheliograms of the Solar atmosphere. These spectroheliograms were recorded on specially fabricated XUV and FUV 70mm Kodak film. Rocket launches of this instrument payload took place in 1991 and 1994 at the White Sands Missile Test Range in New Mexico, sponsored by the NASA sounding rocket experiment program. Immediately prior to the 1994 launch, visible light focusing test of each telescope were performed in-situ using a 1951 Standard Air Force High Resolution Test-target, to measure optical resolution performance. We determined that the MSSTA II telescopes performed at diffraction-limited resolutions down to 0.70 arc-second at visible wavelengths. Based on these measurements, we calculated an upper-bound to the focusing errors that incorporate the sum of all uncorrelated system resolution errors that affect resolution performance. Coupling these upper-bound estimates with the in-band diffraction limits, surface scattering errors and payload pointing jitter, we demonstrate that eleven of nineteen MSSTA II telescopes - having negligible figures of focus errors in comparison to the corresponding visible diffraction limits - performed at sub arc-second resolution at their operation FUV/EUV/XUV wavelengths during flight. We estimate the in-band performance down to 0.14 +/- 0.08 second of arc.
We describe a new payload, the Chromospheric/Coronal Spectroheliograph (CCS), that is optimized for the study of the chromospheric/coronal interface and the search for the sources of energy that sustain the quiescent solar atmosphere. We will utilize the existing optical bench, electronics, and some imaging system from the inventory of multilayer telescopes built up in our previous successful rocket flights of the Multi-Spectral Telescope Array. We will develop several new optical systems to explore more fully the thermal structure of the transition region and introduce a multilayer grating spectroheliograph to permit a more precise determination of the temperature of the structures that control the flow of energy between the chromosphere and the corona.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.