Since the end of 2012, Korea Astronomy and Space Science Institute (KASI) has been developed the Near-infrared
Imaging Spectrometer for Star formation history (NISS), which is a payload of the Korean next small satellite 1
(NEXTSat-1) and will be launched in 2017. NISS has a cryogenic system, which will be cooled down to around 200K by
a radiation cooling in space. NISS is an off-axis catadioptric telescope with 150mm aperture diameter and F-number 3.5,
which covers the observation wavelengths from 0.95-3.8μm by using the linear variable filter (LVF) for the near infrared
spectroscopy. The entire field of view is 2deg x 2deg with 7arcsec pixel scale. Optics consists of two parabolic primary
and secondary mirrors and re-imaging lenses having 8 elements. The main requirement for the optical performance is
that the RMS spot diameters for whole fields are smaller than the detector pixel, 18μm. Two LVFs will be used for 0.9-
1.9μm and 1.9-3.8μm, whose FWHM is more than 2%. We will use the gold-coated aluminum mirrors and employ the
HgCdTe 1024x1024 detector made by Teledyne. This paper presents the conceptual opto-mechanical design of NISS.
The FPC (Fine-guiding and astroPhysics Camera) consists of two NIR (Near Infrared) cameras as focal plane
instruments of the SPICA (Space Infrared Telescope for Cosmology and Astrophysics). The FPC-G (FPC-Guidance) is
for fine guiding with an accuracy of less than 0.036" at 0.5 Hz, and the FPC-S (FPC-Science) is for a back-up of the
FPC-G as well as for scientific observations with 10 filters - including 3 LVFs (Linear Variable Filter) - in NIR (0.8 -
5.2µm) imaging and spectroscopy. As one of the international consortium member of the SPICA project, KASI (Korea
Astronomy and Space science Institute) is leading the conceptual design and the scientific cases of the FPC with
Multi-purpose Infra-Red Imaging System (MIRIS) is a near-infrared camera onboard on the Korea Science and
Technology Satellite 3 (STSAT-3). The MIRIS is a wide-field (3.67° × 3.67°) infrared imaging system which employs a
fast (F/2) refractive optics with 80 mm diameter aperture. The MIRIS optics consists of five lenses, among which the
rear surface of the fifth lens is aspheric. By passive cooling on a Sun-synchronous orbit, the telescope will be cooled
down below 200 K in order to deliver the designed performance. As the fabrication and assembly should be carried out
at room temperature, however, we convert all the lens data of cold temperature to that of room temperature. The
sophisticated opto-mechanical design accommodates the effects of thermal contraction after the launch, and the optical
elements are protected by flexure structures from the shock (10 G) during the launch. The MIRIS incorporates the wide-band
filters, I (1.05 μm) and H (1.6 μm), for the Cosmic Infrared Background observations, and also the narrow-band
filters, Paα (1.876 μm) and a specially designed dual-band continuum, for the emission line mapping of the Galactic
interstellar medium. We present the optical design, fabrication of components, assembly procedure, and the performance
test results of the qualification model of MIRIS near-infrared camera.
MIRIS is a compact near-infrared camera with a wide field of view of 3.67°×3.67° in the Korea Science and
Technology Satellite 3 (STSAT-3). MIRIS will be launched warm and cool the telescope optics below 200K by pointing
to the deep space on Sun-synchronous orbit. In order to realize the passive cooling, the mechanical structure was
designed to consider thermal analysis results on orbit. Structural analysis was also conducted to ensure safety and
stability in launching environments. To achieve structural and thermal requirements, we fabricated the thermal shielding
parts such as Glass Fiber Reinforced Plastic (GFRP) pipe supports, a Winston cone baffle, aluminum-shield plates, a
sunshade, a radiator and 30 layers of Multi Layer Insulation (MLI). These structures prevent the heat load from the
spacecraft and the earth effectively, and maintain the temperature of the telescope optics within operating range. A micro
cooler was installed in a cold box including a PICNIC detector and a filter-wheel, and cooled the detector down to a
operating temperature range. We tested the passive cooling in the simulated space environment and confirmed that the
required temperature of telescope can be achieved. Driving mechanism of the filter-wheel and the cold box structure
were also developed for the compact space IR camera. Finally, we present the assembly procedures and the test result for
the mechanical parts of MIRIS.
Multi-purpose Infra-Red Imaging System (MIRIS) is the main payload of the Korea Science and Technology Satellite-3
(STSAT-3), which is being developed by Korea Astronomy & Space Science Institute (KASI). MIRIS is a small space
telescope mainly for astronomical survey observations in the near infrared wavelengths of 0.9~2 μm. A compact wide
field (3.67 x 3.67 degree) optical design has been studied using a 256 x 256 Teledyne PICNIC FPA IR sensor with a
pixel scale of 51.6 arcsec. The passive cooling technique is applied to maintain telescope temperature below 200 K with
a cold shutter in the filter wheel for accurate dark calibration and to reach required sensitivity, and a micro stirling cooler
is employed to cool down the IR detector array below 100K in a cold box. The science mission of the MIRIS is to
survey the Galactic plane in the emission line of Paschen-α (Paα, 1.88 μ;m) and to detect the cosmic infrared background
(CIB) radiation. Comparing the Paα map with the Hα data from ground-based surveys, we can probe the origin of the
warm-ionized medium (WIM) of the Galaxy. The CIB is being suspected to be originated from the first generation stars
of the Universe and we will test this hypothesis by comparing the fluctuations in I (0.9~1.2 um) and H (1.2~2.0 um)
bands to search the red shifted Lyman cutoff signature. Recent progress of the MIRIS imaging system design will be
STSAT-3, a ~150kg micro satellite, is the third experimental microsatellite of the STSAT series designated in the Long-
Term Plan for Korea's Space Development by the Ministry of Science and Technology of Korea. The STSAT-3 satellite
was initiated in October 2006 and will be launched into a lower sun-synchronous earth orbit (~ 700km) in 2010. This
paper presents a brief introduction of STSAT-3 and also introduces its secondary payload, i.e. COMIS, a compact
imaging spectrometer, which was inspired by the success of CHRIS, a previous PROBA payload. COMIS takes hyperspectral
images of 30m/60m ground sampling distance over a 30km swath width. The number of bands is selectable
among 18 or 62. COMIS takes hyper-spectral images in two different modes: a) Pushbroom and b) multi-directional
observation. The payload will be used for environmental monitoring, such as in-land water quality monitoring of Paldang
Lake located next to Seoul, the capital of South Korea.
Korea Astronomy and Space Science Institute (KASI) is developing the KASI Near Infrared Camera System (KASINICS) which will be installed on the 61 cm telescope at the Sobaeksan Optical Astronomy Observatory (SOAO) in Korea. KASINICS is equipped with a ALADDIN III Quadrant (512×512 InSb array, manufactured by Raytheon). For this instrument, we make a new IR array control electronics system. The controller consists of DSP, Bias, Clock, and Video boards which are installed on a VME bus system. The DSP board includes TMS320C6713, FPGA, and 384MB SDRAM. Clock patterns are downloaded from a PC and stored on the FPGA. USB 2.0 is used for the communication with the PC and UART for the serial communication with peripherals. Each of two video boards has 4 video channels. The Bias board provides 16 voltage sources and the Clock board has 15 clock channels. Our goal of readout speed is 10 frames sec-1. We have successfully finished operational tests of the controller using a 256×256 ROIC (CRC744). We are now upgrading the system for the ALADDIN III array. We plan to operate KASINICS by the end of 2006.
The evolution of hot interstellar medium (ISM) in galaxies is fundamental to the evolution of our cosmos. The Spectroscopy of Plasma Evolution from Astrophysical Radiation (SPEAR) mission will study the hot ISM, providing pointed observations and the first all-sky spectral maps in the Far (FUV) Ultraviolet. The FUV bandpass contains the primary cooling lines of abundant elements in a variety of ionization states. SPEAR's broad bandpass (λλ 900 - 1750 Å), spectral resolution (λ/δλ ~ 700) and imaging resolution (5' - 10') has been chosen to determine independently the quantity, temperature, depletion, and ionization of hot galactic gas. These SPEAR data will allow us to study the hot ISM on both large and small scales and to discriminate among models of the large-scale creation, distribution, and evolution of hot gas in the Galactic disk and halo.
The SPEAR (Spectroscopy of Plasma Evolution from Astrophysical Radiation) mission to map the far ultraviolet sky uses micro-channel plate (MCP) detectors with a crossed delay line anode to record photon arrival events. SPEAR has two MCP detectors, each with a ~25mm x 25 mm active area. The unconventional anode design allows for the use of a single set of position encoding electronics for both detector fields. The centroid position of the charge cloud, generated by the photon-stimulated MCP, is determined by measuring the arrival times at both ends of the anode following amplification and external delay. The temporal response of the detector electronics system determines the readout's positional resolution for the charge centroid. High temporal resolution (< 35ps x 75ps FWHM) and low power consumption (<6W) are required for the SPEAR detector electronics system. We describe the development and performance of the detector electronics system for the SPEAR mission.
The SPEAR micro-satellite payload consists of dual imaging spectrographs optimized for detection of the faint, diffuse FUV (900-1750 Å) radiation emitted from interstellar gas. The instrument provides spectral resolution, R~750, and long slit imaging of <10' over a large (8°x5') field of view. We enhance the sensitivity by using shutters and filters for removal of background noise. Each spectrograph channel uses identically figured optics: a parabolic-cylinder entrance mirror and a constant-ruled ellipsoidal grating. Two microchannel plate photon-counting detectors share a single delay-line encoding system. A payload electronics system conditions data and controls the instrument. We will describe the design and predicted performance of the SPEAR instrument system and its elements.
We describe the development of optics for the SPEAR space-mission
to map the far ultraviolet (900-1750 Å) sky. The SPEAR
spectrometers contain unusual reflective optics to optimize
sensitivity to diffuse emission. We describe the manufacture, test
and performance of the collecting mirrors: Pyrex parabolic
cylinders with a 90 degree off-axis angle. We also describe the
development of the diffraction gratings: ellipses of rotation that
are holographically-ruled with constant spacing and blazed with
Far-ultraviolet IMaging Spectrograph (FIMS) is a far ultraviolet diffuse imaging spectrometer which will be launched in 2002 as the main payload of KAISTSAT-4. We have designed the optics for observing diffuse emission sources by employing an off-axis parabolic cylinder mirror in front of a slit which guides lights to a diffraction grating. The reflective diffraction grating is an ellipse of rotation providing angular resolution. We describe our plan to measure the off-axis parabolic mirror and our initial experiments to establish the measurement technique. To assist manufacture of the off-axis parabolic cylinder, a cylindrical wavefront generated using computer generated hologram (CGH) will be used during the polishing to check errors in surface profile using the Fizeau interferometer.
Current astronomical CCDs (Charge-coupled devices) are limited in size. However, there are increasing demands for larger devices for spectroscopic and direct imaging use. A comparison of the areas of a direct Schmidt-survey plate, and the largest CCD likely to be available in the foreseeable future, serves to illustrate limitations of current electronic technology. Similarly, modern spectrographs can serve either high spectral resolution or multi-object capability, but not both. One could conceive of an updated analogue of a classical coude spectrograph, which would provide both simultaneously, were the enormous detector areas required available. It is with these two long-term applications in view that we consider the prospects for large-scale CCD mosaics. Spectroscopy in particular would benefit from mixed devices in the same mosaic e.g. blue and red- optimised, IR devices etc. We address how optimally to provide the drive waveforms with (1) minimum interconnections and complexity, (2) the ability to mix CCDs, (3) the ability to tune the individual CCD waveforms for optimum low-light level performance, and (4) to conceive an architecture which is indefinitely expansible. Our solution is to multiplex the drive waveforms to the CCDs as well as the signals from them. Minimum chip-count in the sequencing electronics is ensured by using high-density PLD technology (Programmable Logic Device), which enables a module of sixteen or more CCDs to be sequenced from one PLD plus memory. We describe a laboratory prototype, and describe how this could be developed into a system with all the drive electronics for large numbers of CCDs immediately behind the focal plane array. We also summarize our software system for efficiently generating and editing the bitmaps which define the CCD waveforms.