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Huygens HASI servo accelerometer: a review and lessons learned

Hathi, B.; Ball, A. J.; Colombatti, G.; Ferri, F.; Leese, M. R.; Towner, M. C.; Withers, P.; Fulchigioni, M. and Zarnecki, J. C. (2009). Huygens HASI servo accelerometer: a review and lessons learned. Planetary and Space Science, 57(12) pp. 1321–1333.

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The Servo accelerometer constituted a vital part of the Huygens Atmospheric Structure Instrument (HASI): flown aboard the Huygens probe, it operated successfully during the probe's entry, descent, and landing on Titan, on 14th January 2005. This paper reviews the Servo accelerometer, starting from its development/assembly in the mid-1990s, to monitoring its technical performance through its seven-year long in-flight (or cruise) journey, and finally its performance in measuring acceleration (or deceleration) upon encountering Titan's atmosphere. The aim of this article is to review the design, ground tests, in-flight tests and operational performance of the Huygens Servo accelerometer. Techniques used for data analysis and lessons learned that may be useful for accelerometry payloads on future planetary missions are also addressed. The main finding of this review is that the conventional approach of having multiple channels to cover a very broad measurement range: from 10-6 g to the order of 10 g (where g = Earth's surface gravity, 9.8 m/s2), with on-board software deciding which of the channels to telemeter depending on the magnitude of the measured acceleration, works well. However, improvements in understanding the potential effects of the sensor drifts and ageing on the measurements can be achieved in future missions by monitoring the 'scale factor' – a measure of such sensors' sensitivity, along with the already implemented monitoring of the sensor's offset during the in-flight phase.

Item Type: Journal Article
Copyright Holders: 2009 Elsevier Ltd.
ISSN: 0032-0633
Keywords: accelerometry; atmospheric instrument; planetary entry probes
Academic Unit/Department: Science > Physical Sciences
Interdisciplinary Research Centre: Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR)
Item ID: 17677
Depositing User: Colin Smith
Date Deposited: 09 Jul 2009 15:20
Last Modified: 11 Jun 2014 22:08
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