Diamond turned, light weight, athermal, visible TMA telescope for the planned New Horizons mission to Pluto

Hegge, M. J.; Baer, James W.; Hardaway, Lisa; Taudien, Glenn E.; Sabatke, Derek; Shidemantle, S. R.; Santman, Jeffry J.; Comstock, Lovell E.

doi:10.1117/12.617018

Cited by 3 publications

(1 citation statement)

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“…This design was chosen as a testbed for validations of the solar cross-calibration methods as it is representative of state of the art hyperspectral imagers [9][10][11][12][13] . The performance parameters and the optical layout are shown in Table 1 and Fig.…”

Section: Optical Designmentioning

confidence: 99%

A hyperspectral imager for high radiometric accuracy Earth climate studies

et al. 2011

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We demonstrate a visible and near-infrared prototype pushbroom hyperspectral imager for Earth climate studies that is capable of using direct solar viewing for on-orbit cross calibration and degradation tracking. Direct calibration to solar spectral irradiances allow the Earth-viewing instrument to achieve required climate-driven absolute radiometric accuracies of <0.2% (1σ). A solar calibration requires viewing scenes having radiances 10 5 higher than typical Earth scenes. To facilitate this calibration, the instrument features an attenuation system that uses an optimized combination of different precision aperture sizes, neutral density filters, and variable integration timing for Earth and solar viewing. The optical system consists of a three-mirror anastigmat telescope and an Offner spectrometer. The as-built system has a 12.2° cross track field of view with 3 arcmin spatial resolution and covers a 350-1050 nm spectral range with 10 nm resolution. A polarization compensated configuration using the Offner in an out of plane alignment is demonstrated as a viable approach to minimizing polarization sensitivity. The mechanical design takes advantage of relaxed tolerances in the optical design by using rigid, non-adjustable diamond-turned tabs for optical mount locating surfaces. We show that this approach achieves the required optical performance. A prototype spaceflight unit is also demonstrated to prove the applicability of these solar cross calibration methods to on-orbit environments. This unit is evaluated for optical performance prior to and after GEVS shake, thermal vacuum, and lifecycle tests.

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Section: Optical Designmentioning

confidence: 99%

A hyperspectral imager for high radiometric accuracy Earth climate studies

et al. 2011

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A meta-analysis of coordinate systems and bibliography of their use on Pluto from Charon’s discovery to the present day

Zangari

2015

Icarus

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Design, fabrication, and testing of an all-metal ultra-compact telescope

Zhao¹,

Shen²,

Xinhua³

2022

Appl. Opt.

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The design, fabrication, and testing of an all-metal four-mirror telescope for high-resolution remote sensing is presented in this paper. The system works in the visible (VIS) band and is designed with a focal length of 1406 mm, an aperture of 200 mm, and a full field of view (FOV) of 1.32°. The mechanical structure is designed to realize the snap-together alignment. The primary mirror (M1) and tertiary mirror (M3) are designed as a co-substrate element to simplify the fabrication and alignment. The telescope’s weight is 3.5 kg, and the volume is just φ 230 × 220 m m 3 . Metallic mirrors are fabricated with single-point diamond turning, and post-polishing is used to correct the mirror’s surface form deviation and remove turning tool marks effectively. After polishing, the RMS value of the mirror surface form deviation of the final mirror can reach 0.02 λ at λ = 632.8 n m , and the surface roughness Ra value is about 1.83 nm. Benefiting from the all-metal mechanical design, the alignment process of the telescope is fast and accurate. The interferometric wavefront, modulation transfer function, and focal length of the telescope are measured, and the results demonstrated that it achieves the near-diffraction-limited imaging performance.

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Diamond turned, light weight, athermal, visible TMA telescope for the planned New Horizons mission to Pluto

Cited by 3 publications

References 1 publication

A hyperspectral imager for high radiometric accuracy Earth climate studies

A hyperspectral imager for high radiometric accuracy Earth climate studies

A meta-analysis of coordinate systems and bibliography of their use on Pluto from Charon’s discovery to the present day

Design, fabrication, and testing of an all-metal ultra-compact telescope

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