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Examining the Martian Environment
Thoth Technologies & York University

The Northern Light mission will deploy a complete entry, descent and landing system equipped with sophisticated scientific instruments and experiments on the surface of Mars. This Canadian Mars lander and rover system will provide extensive new scientific information on the Martian surface, subsurface and atmosphere.

Lander instrumentation includes a wide angle, stereo-camera system for rover navigation and landing-site imaging, a telephoto camera system for high-resolution colour imaging of the Martian horizon, and a sky camera to investigate atmosphere and to detect air glow. An Argus atmospheric spectrometer will measure solar absorption and derive atmospheric composition and a radiation budget. An active vibrator and receiver will conduct an acoustic study of the Martian subsurface, using short, sub-millisecond pulses.

The Argus 4000 Spectrometer
The Argus 4000 spectrometer is the primary science instrument for the Northern Light lander. This Mars instrument is an adaptation of our terrestrial Argus 1000 spectrometer that measures greenhouse gases from space, launched in 2008 on India’s PSLV as part of the Canadian CanX-2 mission and currently in Low Earth Orbit.

Argus 4000 Spectrometer

The Argus 4000 has many innovative design features. The instrument structure is assembled from pinned and glued sheet metal, making it extremely small, light, and robust. The instrument has no moving parts, making it ideal for operation in the harsh Martian environment. The linear diode detector is randomly addressable; consequently, integration times can be varied across the array on a pixel-by-pixel basis, giving excellent noise performance.

We include up to four independent spectrometer elements in our baseline for Northern Light. We will develop front-end optics to interface the spectrometers and to separate the diffuse and direct radiation components of the Martian atmosphere. Spectroscopy is a Canadian technological strength. Thoth’s Northern Light team includes the technical and scientific leads responsible for previous Canadian instrument developments, including instruments developed for the NASA’s ER-2 research plane, for shuttle missions STS-41G and STS-52, and for the Canadian MANTRA, Stratoprobe, and SCISAT-1 missions.

The Aurora Spectrometer
The Aurora spectrometer is a small, geological spectrometer optimized for the surface exploration of Mars. Mounted on the microrover or miniarm and combined with a microscope unit, the instrument will have a wide wavelength coverage (625 nm to 2500 nm) to assess surface geological conditions and to investigate surface boulders. With the aid of the grinder, the spectrometer will also examine the underlying structure of geological material. In addition to geological exploration, the Aurora spectrometer will be used to analyse the angular dependency of radiation flux in the Martian atmosphere. Building on heritage Argus technology and optimized for exploration in extreme environments, the Aurora spsectrometer has no moving parts, and spectral orders will be separated using a silicon/InGaAs sandwich detector. The pointing direction of the instrument is adjustable; light is fed from the front optics via fibre feed to the main spectrometer unit.

The Camera Systems
The Northern Light lander will be equipped with a camera system capable of narrow and wide field surveys. The narrow field survey will provide a very high resolution, panoramic view of the landing site. Colour filters will perform spectral mapping and mineral identification; the camera will also perform limited atmospheric and astronomical observations. The Earth as seen from Mars will be between 7 and 50 arc-seconds in size; it will therefore be possible to capture an ‘Earth rise.’

The wide field survey will provide an overall colour view of the lander’s surroundings. This view will be used for a ‘first look’ at the landing site and will help to plan rover deployment and route planning. This survey will open the first Canadian window on Mars, which should be of great interest to the media and the public.

The MASSur Seismic Sensors
Development of the Mars Active Seismic Surveyor (MASSur) is being led by Robert Stewart (GENNIX Technology Corp. and University of Calgary) with support from Henry Bland, Eric Gallant (GENNIX Technology Corp.) and Malcolm Bertram (University of Calgary). Professor Stewart and his team have provided an instrumentation description and requirements specification for the MASSur Seismic Sensor.

The Mars seismic surveying instruments are designed to provide shallow images (depth profiles) of the Martian near surface as well as its rock properties. A prime objective of this surveying is to reveal the elastic and mechanical properties of the Mars surficial material. The use of compressional (P) and shear (S) waves will give compressibility and rigidity estimates of the near surface as well as its structure. Analysis of the P- and S-wave data promises to indicate the rock type and saturant. Sediments, permafrost, and water may all have distinct signatures. This seismic system proposes to use a vibrational source and elastic-wave receivers (accelerometers) on both the Mars lander and the associated rover. The rover will have a vibratory source (piezoelectric/magnetostrictive) on its underbody and a receiver deployed on the rover’s arm. The lander will also have a seismic source apparatus and seismic motion sensor. The redundancy of lander and rover apparatus provides economy and ensures that primary science objectives can be met without rover deployment.

The Environmental Sensors
UV SensorNorthern Light will be equipped with seven environmental sensors to monitor landing-site conditions. The development of these sensors is being led by Mark Sims (Open University, UK), who has provided detailed instrument descriptions.

The environmental sensors will measure UV (see Figure 11), oxidizing substances, air temperature (-120 oC to +30 oC), air pressure (accuracy 0.1 mBar/Resolution 0.01 mBar), wind speed, dust impact (Aeolian transported dust particles, with maximum impact rate 4 Hz and momentum in the range 10-7 kgm-1 to 10-11 kgm-1 ) and vibration. These sensors will have a combined mass of 130 g. Flight models were developed for Britain’s Beagle 2 lander.

The Ground-Penetrating Radar (GPR)
Ground-penetrating radar and seismic instruments will be complementary and may share power, recording, and transmission systems. The purpose of the GPR is to provide fine-scale, sub-surface imaging to a depth of 20 m on loose aggregate and up to 100 m on permafrost or ice. We believe that it should be possible to accommodate a 200 MHz radar system comprising two 50 cm flexible dipole antennas mounted on opposing sides of the microrover.

Sensors & Software Ltd. has conducted an extensive feasibility study on space-qualified GPR for the CSA and will supply specialist radar consultancy support for Northern Light’s GPR.

Point Spectrometer

The TC Corer
The TC Corer will be supplied by Holinser and the Hong Kong Polytechnic University. Holinser is an established supplier of heritage space components. The company will supply a corer (mass approximately 400g) capable of boring up to 1 cm into surface rocks. This tool will be used in conjunction with the Aurora spectrometer and microscope to examine the near-surface composition and to look for signs of near-surface life.

Mars Capsule
Northern Light will carry a Mars capsule to the surface of Mars. The capsule will be a lightweight, hermetically sealed package containing standard data DVDs. The capsule will carry uncensored letters from Canadians, offering all Canadians direct access to the Northern Light mission.