B.J. Maddison

Seeker-Autonomous Long-range Rover Navigation for Remote Exploration

Under the umbrella of the European Space Agency ESA StarTiger program, a rapid prototyping study called Seeker was initiated. A range of partners from space and nonspace sectors were brought together to develop a prototype Mars rover system capable of autonomously exploring several kilometers of highly representative Mars terrain over a three-day period. This paper reports on our approach and the final field trials that took place in the Atacama Desert, Chile. Long-range navigation and the associated remote rover field trials are a new departure for ESA, and this activity therefore represents a novel initiative in this area. The primary focus was to determine if current computer vision and artificial intelligence based software could enable such a capability on Mars, given the current limit of around 200 m per Martian day. The paper does not seek to introduce new theoretical techniques or compare various approaches, but it offers a unique perspective on their behavior in a highly representative environment. The final system autonomously navigated 5.05i¾?km in highly representative terrain during one day. This work is part of a wider effort to achieve a step change in autonomous capability for future Mars/lunar exploration rover platforms.

Characterisation of swept-charge devices for the Chandrayaan-1 x-ray spectrometer (C1XS) instrument

The Indian Space Research Organisation (ISRO) Chandrayaan-1 mission is Indias first lunar spacecraft, containing a suite of instruments to carry out high-resolution remote sensing of the Moon at visible, near infrared and X-ray wavelengths. Due for launch in early 2008, the spacecraft will carry out its two year mission in a polar orbit around the Moon at an altitude of 100 km. One of the eleven instruments in the spacecraft payload is the Chandrayaan-1 X-ray Spectrometer (C1XS), a descendant of the successful D-CIXS instrument that flew on the European Space Agency SMART-1 lunar mission launched in 2003. C1XS consists of 24 swept-charge device (SCD) silicon X-ray detectors arranged in 6 modules that will carry out high quality X-ray spectroscopic mapping of the Moon using the technique of X-ray fluorescence. This paper presents an overview of the Chandrayaan-1 mission and specifically the C1XS instrument and describes the development of an SCD test facility, proton irradiation characterisation and screening of candidate SCD devices for the mission.

Radiation Study of Swept-Charge Devices for the Chandrayaan-1 X-ray Spectrometer (C1XS) instrument

The Chandrayaan-1 X-ray Spectrometer (C1XS) will be launched as part of the Indian Space Research Organisation (ISRO) Chandrayaan-1 payload in September 2008, arriving at the Moon within 7 days to begin a two year mission in lunar orbit conducting mineralogical surface mapping over the range of 1 - 10 keV. The detector plane of the instrument consists of twenty four e2v technologies CCD54 swept-charge devices (SCDs). Such devices were first flown in the Demonstration of a Compact Imaging X-ray Spectrometer (D-CIXS) instrument onboard SMART-1 [4, 5]. The detector plane in each case provides a total X-ray collection area of 26.4 cm2. The SCD is capable of providing near Fano-limited spectroscopy at -10°C, and at -20°C, near the Chandrayaan-1 mission average temperature, it achieves a total system noise of 6.2 electrons r.m.s. and a FWHM of 134 eV at Mn-Kα. This paper presents a brief overview of the C1XS mission and a detailed study of the effects of proton irradiation on SCD operational performance.