MIRASET (Mid-IR Array Spectrometer demonstration for Exoplanet Transits) is an ultra-stable laboratory spectrometer. Its purpose is to demonstrate a novel approach for isolating mid-infrared spectral lines detected in the atmospheres of transiting planets orbiting M-stars. Certain combinations of these spectral lines could potentially indicate the existence of life on these planets. To achieve this objective, we employ a black body source as a calibration standard, which also mimics the emission of an M-star in our lab setup. The power range of the black body emission can be adjusted to emit the same power on the detectors as would be observed from Proxima Cen B and Trappist-1 if they were observed using space-based observatories like ORIGINS or specialized MIR exoplanet missions like MIRECLE. All major elements in the experiment at all relevant stages can be temperature controlled, from the detector package, spectrometer, to the photo diode that monitors the output of the black body source in the visible, thereby measuring the temperature on the Wien side of the BB curve, which yields a higher temperature to emission ratio than in the MIR, which is on the Rayleigh Jeans part of the curve. With this experimental setup we have demonstrated the ability to monitor the black body emission over about an hour with a photometric precision of about 2 ppm in the MIR. Over more than 6 hours of integration, the noise floor still remains well below 5 ppm, which is the requirement for the detection of important atmospheric lines from earth-like planets around M-stars (~5 ppm).
The Pandora SmallSat is a NASA flight project designed to study the atmospheres of exoplanets. Transmission spectroscopy of transiting exoplanets provides our best opportunity to identify the makeup of planetary atmospheres in the coming decade, and is a key science driver for HST and JWST. Stellar photospheric inhomogeneity due to star spots, however, has been shown to contaminate the observed spectra in these high-precision measurements. Pandora will address the problem of stellar contamination by collecting long-duration photometric observations sampled over a stellar rotation period with a visible-light channel and simultaneous spectra with a near-IR channel. These simultaneous multiwavelength observations will constrain star spot covering fractions of exoplanet host stars, enabling star and planet signals to be disentangled in transmission spectra to then reliably determine exoplanet atmosphere compositions. Pandora will observe exoplanets with sizes ranging from Earthsize to Jupiter-size and host stars spanning mid-K to late-M spectral types. Pandora was selected in early 2021 as part of NASA’s inaugural Astrophysics Pioneers Program. Herein, we present an overview of the mission, including the science objectives, operations, the observatory, science planning, and upcoming milestones as we prepare for launch readiness in 2025.
UV-SCOPE is a mission concept to determine the causes of atmospheric mass loss in exoplanets, investigate the mechanisms driving aerosol formation in hot Jupiters, and study the influence of the stellar environment on atmospheric evolution and habitability. As part of these investigations, the mission will generate a broad-purpose legacy database of time-domain ultraviolet (UV) spectra for nearly 200 stars and planets. The observatory consists of a 60 cm, f/10 telescope paired to a long-slit spectrograph, yielding simultaneous, almost continuous coverage between 1203 Å and 4000 Å, with resolutions ranging from 6000 to 240. The efficient instrument provides throughputs < 4% (far-UV; FUV) and < 15% (near-UV; NUV), comparable to HST/COS and much better than HST/STIS, over the same spectral range. A key design feature is the LiF prism, which serves as a dispersive element and provides high throughput even after accounting for radiation degradation. The use of two delta-doped Electron-Multiplying CCD detectors with UV-optimized, single-layer anti-reflection coatings provides high quantum efficiency and low detector noise. From the Earth-Sun second Lagrangian point, UV-SCOPE will continuously observe planetary transits and stellar variability in the full FUV-to-NUV range, with negligible astrophysical background. All these features make UV-SCOPE the ideal instrument to study exoplanetary atmospheres and the impact of host stars on their planets. UV-SCOPE was proposed to NASA as a Medium Explorer (MidEx) mission for the 2021 Announcement of Opportunity. If approved, the observatory will be developed over a 5-year period. Its primary science mission takes 34 months to complete. The spacecraft carries enough fuel for 6 years of operations.
KEYWORDS: James Webb Space Telescope, Near infrared, Atmospheric modeling, Point spread functions, Stars, Planets, Exoplanets, Atmospheric sciences, Sensors, Spectroscopy, Modeling and simulation
Pandora is a SmallSat mission, designed to study the atmospheres of exoplanets using transmission spectroscopy and to investigate the impact that stellar contamination and variability has on observing the spectra of these worlds. Pandora’s initial science operation lifetime is one year, so optimizing the science return is critical. Here we present two tools created to assist in the design process. The first is a 2-D spectrum simulator being developed to help refine target selection, optimize observation strategies, and assist in the creation of a data reduction pipeline. The second is a pseudo-retrieval framework that provides a quantifiable method for comparing potential targets against a handful of exoplanetary atmospheric parameters important to the Pandora mission. Preliminary results show Pandora will place tighter constraints on atmospheric properties like water abundance compared to HST and answering its mission objectives will help to inform targets for missions like JWST.
We have built an ultra-stable laboratory spectrometer, called MIRASET (Mid-IR Array Spectrometer demonstration for Exoplanet Transits), that will demonstrate a new method to extract mid-infrared spectral lines observed in the atmospheres of transiting planets around M-stars. Those lines potentially indicate the presence of life on the planet. This goal is achieved by using a black body source as a calibration reference, which in the laboratory experiment also simulates the emission of the M-star. The black body emission source will be tuned to dissipate the equivalent power on the detectors that would be observed from Proxima Cen B and Trappist-1 if they were observed with a space-based observatory such as ORIGINS or a dedicated MIR exoplanet mission such as MIRECLE. Furthermore, we use a laser that simulates a spectral line from the planet. We constantly monitor the temperature of the black body with high precision by using a photodiode measuring the black body in the visible. We will demonstrate the ability to monitor the black body emission over a several hour period, superimposed with a laser-generated spectral line, down to a photometric precision of 5ppm, while demonstrating the spectral stability of the spectrometer. This precision constitutes the requirement for the detection of important atmospheric lines from earth-like planets around M-stars.
Pandora is a low-cost space telescope designed to measure the composition of distant transiting planets. The Pandora observatory is designed with the capability of measuring precision photometry simultaneously with nearinfrared spectroscopy, enabling scientists to disentangle stellar activity from the subtle signature of a planetary atmosphere. The broad-wavelength coverage will provide constraints on the spot and faculae covering fractions of low-mass exoplanet host stars and the impact of these active regions on exoplanetary transmission spectra. Pandora will subsequently identify exoplanets with hydrogen- or water-dominated atmospheres, and robustly determine which planets are covered by clouds and hazes. Pandora observations will also contribute to the study of transit timing variations and phase curve photometry. With a launch readiness date of early-2025, the Pandora mission represents a new class of low-cost space missions that will achieve out-of-this-world science.
KEYWORDS: Space telescopes, Telescopes, James Webb Space Telescope, Mirrors, Optical instrument design, Astronomy, Space operations, Cryogenics, Aerospace engineering, Cryocoolers
The Origins Space Telescope will trace the history of our origins from the time dust and heavy elements permanently altered the cosmic landscape to present-day life. How did galaxies evolve from the earliest galactic systems to those found in the universe today? How do habitable planets form? How common are life-bearing worlds? We describe how Origins was designed to answer these alluring questions. We discuss the key decisions taken by the Origins mission concept study team, the rationale for those choices, and how they led through an exploratory design process to the Origins baseline mission concept. To understand the concept solution space, we studied two distinct mission concepts and descoped the second concept, aiming to maximize science per dollar and hit a self-imposed cost target. We report on the study approach and describe the concept evolution. The resulting baseline design includes a 5.9-m diameter telescope cryocooled to 4.5 K and equipped with three scientific instruments. The chosen architecture is similar to that of the Spitzer Space Telescope and requires very few deployments after launch. The cryo-thermal system design leverages James Webb Space Telescope technology and experience.
The Origins Space Telescope (Origins) concept is designed to investigate the creation and dispersal of elements essential to life, the formation of planetary systems, and the transport of water to habitable worlds and the atmospheres of exoplanets around nearby K- and M-dwarfs to identify potentially habitable—and even inhabited—worlds. These science priorities are aligned with NASA’s three major astrophysics science goals: How does the Universe work? How did we get here? and Are we alone? We briefly describe the science case that arose from the astronomical community and the science traceability matrix for Origins. The science traceability matrix prescribes the design of Origins and demonstrates that it will address the key science questions motivated by the science case.
The Origins Space Telescope will trace the history of our origins from the time dust and heavy elements permanently altered the cosmic landscape to present-day life. How did galaxies evolve from the earliest galactic systems to those found in the Universe today? How do habitable planets form? How common are life-bearing worlds? To answer these alluring questions, Origins will operate at mid- and far-infrared (IR) wavelengths and offer powerful spectroscopic instruments and sensitivity three orders of magnitude better than that of the Herschel Space Observatory, the largest telescope flown in space to date. We describe the baseline concept for Origins recommended to the 2020 US Decadal Survey in Astronomy and Astrophysics. The baseline design includes a 5.9-m diameter telescope cryocooled to 4.5 K and equipped with three scientific instruments. A mid-infrared instrument (Mid-Infrared Spectrometer and Camera Transit spectrometer) will measure the spectra of transiting exoplanets in the 2.8 to 20 μm wavelength range and offer unprecedented spectrophotometric precision, enabling definitive exoplanet biosignature detections. The far-IR imager polarimeter will be able to survey thousands of square degrees with broadband imaging at 50 and 250 μm. The Origins Survey Spectrometer will cover wavelengths from 25 to 588 μm, making wide-area and deep spectroscopic surveys with spectral resolving power R ∼ 300, and pointed observations at R ∼ 40,000 and 300,000 with selectable instrument modes. Origins was designed to minimize complexity. The architecture is similar to that of the Spitzer Space Telescope and requires very few deployments after launch, while the cryothermal system design leverages James Webb Space Telescope technology and experience. A combination of current-state-of-the-art cryocoolers and next-generation detector technology will enable Origins’ natural background-limited sensitivity.
The Origins Space Telescope will trace the history of our origins from the time dust and heavy elements permanently altered the cosmic landscape to present-day life. How did galaxies evolve from the earliest galactic systems to those found in the universe today? How do habitable planets form? How common are life-bearing worlds? To answer these alluring questions, Origins will operate at mid- and far-infrared wavelengths and offer powerful spectroscopic instruments and sensitivity three orders of magnitude better than that of Herschel, the largest telescope flown in space to date. After a 3 ½ year study, the Origins Science and Technology Definition Team will recommend to the Decadal Survey a concept for Origins with a 5.9-m diameter telescope cryocooled to 4.5 K and equipped with three scientific instruments. A mid-infrared instrument (MISC-T) will measure the spectra of transiting exoplanets in the 2.8 – 20 μm wavelength range and offer unprecedented sensitivity, enabling definitive biosignature detections. The Far-IR Imager Polarimeter (FIP) will be able to survey thousands of square degrees with broadband imaging at 50 and 250 μm. The Origins Survey Spectrometer (OSS) will cover wavelengths from 25 – 588 μm, make wide-area and deep spectroscopic surveys with spectral resolving power R ~ 300, and pointed observations at R ~ 40,000 and 300,000 with selectable instrument modes. Origins was designed to minimize complexity. The telescope has a Spitzer-like architecture and requires very few deployments after launch. The cryo-thermal system design leverages JWST technology and experience. A combination of current-state-of-the-art cryocoolers and next-generation detector technology will enable Origins’ natural backgroundlimited sensitivity.
The Origins Space Telescope (OST) will trace the history of our origins from the time dust and heavy elements permanently altered the cosmic landscape to present-day life. How did the universe evolve in response to its changing ingredients? How common are life-bearing planets? To accomplish its scientific objectives, OST will operate at mid- and far-infrared wavelengths and offer superlative sensitivity and new spectroscopic capabilities. The OST study team will present a scientifically compelling, executable mission concept to the 2020 Decadal Survey in Astrophysics. To understand the concept solution space, our team studied two alternative mission concepts. We report on the study approach and describe both of these concepts, give the rationale for major design decisions, and briefly describe the mission-enabling technology.
The Origins Space Telescope (OST) mission concept study is the subject of one of the four science and technology definition studies supported by NASA Headquarters to prepare for the 2020 Astronomy and Astrophysics Decadal Survey. OST will survey the most distant galaxies to discern the rise of metals and dust and to unveil the co-evolution of galaxy and blackhole formation, study the Milky Way to follow the path of water from the interstellar medium to habitable worlds in planetary systems, and measure biosignatures from exoplanets. This paper describes the science drivers and how they drove key requirements for OST Mission Concept 2, which will operate between ~5 and ~600 microns with a JWST sized telescope. Mission Concept 2 for the OST study optimizes the engineering for the key science cases into a powerful and more economical observatory compared to Mission Concept 1.
KEYWORDS: James Webb Space Telescope, Sensors, Exoplanets, Calibration, Imaging spectroscopy, Lawrencium, Spectroscopy, Imaging systems, Mid-IR, Signal to noise ratio
Time-variable phenomena such as transiting exoplanets will be a major science theme for the James Webb Space Telescope (JWST). For Guaranteed Time and Early Release Science Observations, over 500 hours of JWST time have been allocated to time series observations (TSOs) of transiting exoplanets. Several dedicated observing modes are available in the instrument suite, whose operations are specifically tailored to these challenging ob- servations. MIRI, the only JWST instrument covering the wavelength range longwards of 5 µm on JWST, will offer TSOs in two of its modes: the low resolution spectrometer, and the imager. In this paper we will describe these modes for MIRI, and discuss how they differ operationally from regular (non-TSO) observations. We will show performance estimates based on ground testing and modeling, discuss the most relevant detector effects for high precision (spectro-)photometry, and provide some guidelines for planning MIRI TSOs.
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