Status of the James Webb Space Telescope integrated science instrument module system

Greenhouse, Matthew A.; Balzano, V.; Davila, Pamela S.; Drury, Michael P.; Dunn, J.; Glazer, Stuart D.; Greville, Ed; Henegar, Gregory; Johnson, Eric L.; Lundquist, Ray; McCloskey, John C.; Ohl, Raymond G.; Rashford, Robert; Voyton, Mark F.

doi:10.1117/12.895228

Cited by 11 publications

(7 citation statements)

References 9 publications

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“…There has been no indication of any degradation in MIRI's detectors. We refer the interested reader to Gardner 2 and Greenhouse et al 3 for more information about the JWST mission and its science instruments.…”

Section: Introductionmentioning

confidence: 99%

Commentary: JWST near-infrared detector degradation— finding the problem, fixing the problem, and moving forward

et al. 2012

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The James Webb Space Telescope (JWST) is the successor to the Hubble Space Telescope. JWST will be an infrared-optimized telescope, with an approximately 6.5 m diameter primary mirror, that is located at the Sun-Earth L2 Lagrange point. Three of JWST’s four science instruments use Teledyne HgCdTe HAWAII-2RG (H2RG) near infrared detector arrays. During 2010, the JWST Project noticed that a few of its 5 μm cutoff H2RG detectors were degrading during room temperature storage, and NASA chartered a “Detector Degradation Failure Review Board” (DD-FRB) to investigate. The DD-FRB determined that the root cause was a design flaw that allowed indium to interdiffuse with the gold contacts and migrate into the HgCdTe detector layer. Fortunately, Teledyne already had an improved design that eliminated this degradation mechanism. During early 2012, the improved H2RG design was qualified for flight and JWST began making additional H2RGs. In this article, we present the two public DD-FRB “Executive Summaries” that: (1) determined the root cause of the detector degradation and (2) defined tests to determine whether the existing detectors are qualified for flight. We supplement these with a brief introduction to H2RG detector arrays, some recent measurements showing that the performance of the improved design meets JWST requirements, and a discussion of how the JWST Project is using cryogenic storage to retard the degradation rate of the existing flight spare H2RGs.

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Section: Introductionmentioning

confidence: 99%

Commentary: JWST near-infrared detector degradation— finding the problem, fixing the problem, and moving forward

et al. 2012

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“…The JWST Observatory architecture includes the Optical Telescope Element (OTE) and the Integrated Science Instrument Module (ISIM) element. ISIM contains four science instruments (SI) and a Guider mounted to a composite metering structure [2]. We performed extensive STOP modeling in support of all phases of ISIM development.…”

Section: Introductionmentioning

confidence: 99%

Structural, thermal, and optical performance (STOP) modeling and results for the James Webb Space Telescope integrated science instrument module

et al. 2016

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The James Webb Space Telescope includes the Integrated Science Instrument Module (ISIM) element that contains four science instruments (SI) including a Guider. We performed extensive structural, thermal, and optical performance (STOP) modeling in support of all phases of ISIM development. In this paper, we focus on modeling and results associated with test and verification. ISIM's test program is bound by ground environments, mostly notably the 1g and test chamber thermal environments. This paper describes STOP modeling used to predict ISIM system performance in 0g and at various on-orbit temperature environments. The predictions are used to project results obtained during testing to on-orbit performance.

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“…For that reason, the L2 point was selected as the operational location for many astronomical missions such as Planck, Herschel Space Observatory, JWST, and SPICA. 1,2) The change of the resultant gravitational potential energy caused by the Sun and Earth are gentle around the L2 point. Therefore, the orbit of a spacecraft can be changed using slight applications of force such as solar radiation pressure.…”

Section: Introductionmentioning

confidence: 99%

Artificial Lagrange Points for Spacecraft with a Tethered Anchor

Ishimura

Kawachi

Tanaka

et al. 2016

AEROSPACE TECHNOLOGY JAPAN

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New artificial Lagrange points for spacecraft with a tethered anchor are presented in this paper. The positions of conventional artificial Lagrange points generated by solar radiation pressure are restricted depending on the sail lightness number. Using a tethered anchor, that restriction can be relaxed. Around the L2 point, the new artificial Lagrange points for spacecraft with a tethered anchor are derived based on the circular restricted three-body problem. The dependence of the position of the new artificial Lagrange point on the parameters such as mass ratio and tether's length is investigated for spacecraft with a tethered anchor. The trajectories of spacecraft with and without tethered anchors are calculated numerically. Results show that the tethered anchor can halve the offset of artificial Lagrange points. The effect of tethered anchor on the shift of artificial Lagrange point increases if a tether is long and the mass ratio

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Status of the James Webb Space Telescope integrated science instrument module system

Cited by 11 publications

References 9 publications

Commentary: JWST near-infrared detector degradation— finding the problem, fixing the problem, and moving forward

Commentary: JWST near-infrared detector degradation— finding the problem, fixing the problem, and moving forward

Structural, thermal, and optical performance (STOP) modeling and results for the James Webb Space Telescope integrated science instrument module

Artificial Lagrange Points for Spacecraft with a Tethered Anchor

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