Canadian Space Agency
Credit: Canadian Space Agency/SpaceQ.

The Canadian Space Agency Looks to Develop Two Priority Technologies with up to $2M in Contracts

The Canadian Space Agency (CSA) is looking to develop and advance two Priority Technologies (PT); Integral field Spectroscopy for Near Infrared (NIR) Wide Field Imaging (PT1) and Radiometric Calibration System for Large Astronomical Focal Plane (PT2), and is offering two contracts valued up to at $1.4 million for PT1 and $600,000 for PT2.

According to the CSA “priority technologies are those that have been established by the CSA as the critical technologies to be developed to meet the objectives set forth by the Canadian Space Strategy” with these two PT’s meeting the CSA priorities for astronomy missions.

The RFP is available here:

Background:

PT1: Integral field Spectroscopy for Near Infrared (NIR) Wide Field Imaging

Wide Field Imaging has become an important sub-discipline of astronomy with the proliferation of large aperture, high-resolution telescopes.

Integral field unit (IFU) spectrographs are used to speed up such observations by simultaneously obtaining the spectra of multiple objects in a 2D image at the same time.

Such spectroscopic investigations are typically carried out with single slit or slitless spectrographs, which in the case of a crowded field suffer from spectra overlapping. An IFU approach offers the advantage of clean spatial separation of individual spectra.

In IFU based on image slicer technique, an image formed by fore-optics is sliced and re-arranged such that each slice falls onto a separate slit followed by a dispersing element and then being re-imaged on a detector in a way that there is no spectra overlapping. Image slicer can be made of glass or metal with the main technological challenges being low surface roughness, low wavefront error or low cross- talk. The other technology for multi-object spectroscopy is based on the lenslet- fiber IFU combination. Its disadvantage is lower throughput due to fiber losses.

So far there is no IFU type spectrographs placed in space.

Fiber-lenslet based IFUs (all ground based)

  • SMIRFS-IFU: Prototype IFU and technology demonstrator for UKIRT, 72 elements, optimized for the near infrared
  • TEIFU: 1000-element IFU for the 4.2m William-Herschel-Telescope
  • GMOS-IFU: 2 fields of 1000 and 500 elements to enable simultaneous background subtraction. Two built for Gemini North and Gemini South
  • IMACS-IFU: 2 fields of 1000 elements each to enable background subtraction and beam switching. Located at the Magellan-1 6.5m telescope IMACS spectrograph.

Slicer-based IFUs

  • GNIRS-IFU: 21 slices, IFU for the GMOS spectrograph of GEMINI North.
  • KMOS-IFU: 24 deployable IFUs of 15 slices each, currently in construction
  • JWST NIRSpec IFU: 30 slice IFU for the James Webb Space Telescope’s NIRSpec spectrograph, currently in telescope AIT phase.

Targeted Missions

Upcoming opportunities include Canadian involvement in the next generation of “Dark Energy” missions:

  • ESA’s cosmic vision candidate science missions;
  • NASA WFIRST mission;
  • A Canadian-led mission, the Canadian Space Telescope (CST).

The WFIRST mission shall be used as a design reference mission for the development of this cross- cutting technology.

PT2: Radiometric Calibration System for Large Astronomical Focal Planes

Very large multi-detector mosaic focal planes sensitive in both visible and near infrared (NIR) wavelength regions are enabling technologies for the next generation of large-area astronomical surveys from space, such as ESA’s Euclid mission and NASA’s Wide Field Infrared Survey Telescope (WFIRST), as well as for the future ground-based instrumentation. While mixed-technology mosaic focal planes open significant surveying possibilities, accurate calibration is becoming increasingly important for the state-of-the-art mosaic focal planes and the reduction of systematic errors in the relative spectrophotometric measurements will be critical to the mission science. Through the calibration process, the system’s response to a radiometric input is quantified demonstrating that the performance of individual detectors can be as good when operating in concert with many detectors in mosaic, the interactions and dependencies between the optical and electronic components are characterized and systematic errors that may result are identified and evaluated. Calibration increases the probability of mission success by verifying that the sensor will meet mission requirements with a correct interpretation of the data to make accurate mission-specific decisions.

The goal of this technology development is to select a concept, identify the critical technologies, develop, manufacture and validate the functionality of the radiometric calibration system capable of producing highly controllable, stable and uniform illumination over large areas of the state-of-the-art mosaic focal planes together with stringent systematic error requirement of less than 1%.

Targeted Missions

The results of this technology development are highly relevant to all future astronomical instruments employing very large mosaic focal planes. Upcoming opportunities for next generation of “Dark Energy” missions include:

  • ESA’s cosmic vision candidate science missions;
  • NASA WFIRST mission;
  • Canadian-led mission, the Canadian Space Telescope (CST); and the future ground-based astronomical observatories with an extremely large telescope (ELT) such as the Thirty Meter Telescope (TMT).

For example, the WFIRST WFI will have a very large focal plane consisting of 18 H4RG-10 detectors as shown in Fig. 1. This places stringent requirements on the calibration system such as spatial uniformity over large area and more specifically on how precisely the exact calibration light spatial distribution is known (at first light) and on how stable this distribution is over time.

While the demanding requirements of the relative calibration system (RCS) of the WFIRST mission will be used as a design reference the ultimate goal is to develop the universal state-of-the-art radiometric calibration hardware and calibration methodology directly applicable to many future flagship missions.

About Marc Boucher

Boucher is an entrepreneur, writer, editor & publisher. He is the founder of SpaceQ Media Inc. and CEO and co-founder of SpaceRef Interactive LLC. Boucher has 20+ years working in various roles in the space industry and a total of 30 years as a technology entrepreneur including creating Maple Square, Canada's first internet directory and search engine.

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