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.
The lander instrumentation will include 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 Aurora 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 Aurora Spectrometer
The Aurora spectrometer will be integrated with the MARES camera and will comprise the primary science instrument for the Northern Light lander. The Aurora spectrometer will measure the Martian radiative environment and the gaseous composition of the atmosphere; it will also characterize Martian aerosol. This instrument has been under continuous development by the Meteorological Service of Canada over the last decade. Early instrument derivatives were developed for the NASA ER-2 research plane; instruments flew on shuttle missions STS-41G and STS-52, and it has also been adapted for use on the ground and on stratospheric balloon flights. A double-spectrometer design was developed and flown on the Canadian MANTRA 2002 balloon mission, and a space-instrument derivative was recently launched on the Canadian science-satellite initiative, SCISAT?1. The Aurora spectrometer for the Northern Light lander will be a new instrument derivative.
The instrument has many innovative design features. We propose to include four independent spectrometer elements in our baseline for Northern Light. The new derivative will include front-end optics to interface the four spectrometers and to separate the diffuse and direct radiation components of the Martian atmosphere.
The MARES Camera
The MARES camera is a zenith sky-imaging system that monitors wave activity in the Martian atmosphere from the ground. Gravity waves are buoyancy waves caused by the gravitational restoring force on a parcel of air displaced from its equilibrium position. They are mainly generated in the lower atmosphere either by winds blowing over surface features or as a result of convective activities. Gravity waves act as a coupling mechanism, transporting energy and momentum from the lower to the upper atmosphere, and are significant in atmospheric dynamics.
MARES will acquire monochromatic images of selected airglow features in the horizontal wavelength range of 5 to 150 km, with wave amplitudes of 5% (or better) of the mean emission intensity. Each airglow feature will require a background subtraction. The imaging processing and extraction of wave parameters from the acquired imagers will use well established techniques for imaging enhancement and wave-parameter extraction. A typical sky image, detecting air glow at 557.7 nm in the Earth’s atmosphere, is shown in Fig 1.
Fig 1: Image of Airglow in Earth’s Atmosphere,
Prof. Michael J. Taylor, Utah State University.
The Camera Systems
The narrow field survey camera on the Northern Light lander 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’ with the narrow field survey camera.
The wide field camera 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 camera will open the first Canadian window on Mars.
The MASSur Seismic Sensors
The Mars Active Seismic Surveyor (MASSur) is 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 Martian surficial material. The instrument will measure compressibility and rigidity of the near surface as well as its structure. Analysis of data promises to indicate 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 lander and rover. The Beaver 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. This duplication of lander and rover apparatus provides economy and instrument-level redundancy.
The Environmental Sensors
Northern Light will be equipped with seven environmental sensors to monitor landing-site conditions. The environmental sensors will measure UV (see Fig 2), oxidizing substances, air temperature (?120 to +30ºC), air pressure, wind speed, dust impact, and vibration. These sensors will have a combined mass of 130 g. Flight models have been developed already for Beagle 2.
