A Spaceborne Vacuum Ultraviolet (VUV) Fourier Transform Spectrometer (FTS)

Fourier transform spectroscopy is a powerful technique yielding unparalleled resolution at visible and Infrared (IR) wavelengths. Traditionally, a Fourier Transform Spectrometer (FTS) is based on a Michelson Interferometer, which utilizes transmissive beam splitters to separate incoming light for interferometry. This has limited FTSs to wavelengths above ~140 nm because transmissive optics become increasingly inefficient below this wavelength. Recently, a new all-reflective FTS was developed at the SOLEIL Synchrotron (hereafter called the SOLEIL-FTS; De Oliveira et al., 2009; 2011). This spectrometer is broad-band, and capable of measuring down to 40 nm with a resolving power of 10^6 (e.g. 40 femtometers at 40 nm). The SOLEIL-FTS has been routinely used for over a decade for laboratory-based absorption spectroscopy, and its 2011 Nature-Photonics instrument paper has received 139 citations in the 12 years since its publication demonstrating its significant impact on Vacuum Ultraviolet (VUV) spectroscopy. This proposed project to the Instrument Technology Development (ITD) sub-element of the Heliophysics Technology and Instrument Development for Science (H-TIDS) funding opportunity aims to ruggedize critical components of the revolutionary SOLEIL-FTS. The SOLEIL-FTS is comprised of six subsystems all with approximate Technology Readiness Levels (TRL) ranging from 3 to 9. This proposal will advance the critical subsystems of the FTS to TRL 6. While a spaceborne VUV FTS can address many current problems in heliophysics, our science goal is to quantify the velocity distribution of H in Earth's exosphere. The motivation behind selecting this goal is two-fold. First, the energetics of H in the exosphere are poorly understood and difficult to measure, yet have important implications for both atmospheric evolution and radiation belt dynamics. Second, our approach is to transition this new technology to spaceflight using an application as similar as possible to its current application in a ground-based laboratory. The SOLEIL-FTS is intended for absorption spectroscopy with a bright source, which is very similar to our intended application of measuring the H absorption line using solar occultations (i.e. absorption spectroscopy) at the bright H I Lyman-α emission at 121.6 nm. Our science goal will ultimately be met through a future sounding rocket flight. This proposed project will make progress towards that goal by meeting the following objectives: 1. Develop the core components of a VUV FTS for a sounding rocket instrument. 2. Ensure that the core components of the VUV FTS survive flight conditions as demonstrated through environmental testing. 3. Reduce the optical bench size of a VUV FTS from the SOLEIL-FTS design size of 80 cm. The development of the proposed spaceborne broadband VUV FTS will be a transformative technology for observational heliophysics and space science in general. This instrument would enable measurements at unprecedented resolution (resolving power of 10^6) with broadband capability (capable of measuring >10 nm bandwidth simultaneously). Further, a key feature of the proposed VUV FTS design is its inherent compactness, with the existing design having an 0.8 m optical bench with the driving factor simply being convenience for lab integration. This resolving power and size should be compared with those of the Solar Ultraviolet Measurements of the Emitted Radiation (SUMER) instrument on the Solar and Heliospheric Observatory (SOHO), which had a resolving power of 5X10^4 and an optical bench of ~3 m; or the Space Telescope Imaging Spectrograph (STIS) onboard the Hubble Space Telescope, with a resolving power of 2X10^5, and a 2.2 m (long dimension) instrument size.

Support NASA's Heliophysics strategic science objectives to understand the Sun and its interactions with Earth and the solar system, including space weather. This will be achieved by developing/demonstrating instrumentation technology necessary to address the following science goals: Explore the physical processes in the space environment from the Sun to the Earth and throughout the solar system; Advance our understanding of the connections that link the Sun, the Earth, planetary space environments, and the outer reaches of our solar system; Develop the knowledge and capability to detect and predict extreme conditions in space to protect life and society and to safeguard human and robotic explorers beyond Earth.

This is a mature technology (TRL 7+) — the realistic path in is usually NASA's Technology Transfer Program: licensing an existing NASA patent, or a Space Act Agreement to use NASA facilities/expertise directly. NASA also runs a startup licensing program with no upfront fee for companies formed to commercialize a specific NASA technology.

None of these are guaranteed paths for this specific project — TechPort itself doesn't have an "apply" button. Reaching out to the contact(s) above with a specific question is usually the fastest way to find out what's actually open.