NASA launched the Mars Science Laboratory rover successfully towards Mars on 26 November. The spacecraft is carrying instruments made by the Finnish Meteorological Institute for measuring pressure and humidity in the Martian atmosphere.
Photo: Harri Haukka
NASA’s Mars Science Laboratory (MSL), also known as the Curiosity rover, began its voyage to Mars on the second day of the launch window, on 26 November at 17:02 Finnish time. The rover is the size of a car and weighs about 900 kilograms. It will arrive at Mars after a journey of nearly nine months, in August 2012. The rover will land in Gale crater near the equator of Mars. There it is expected to move and explore the area for at least one Mars year, or about 680 Earth days. At the same time, the rover will make observations, for instance, about the geology of the area, the structure of the surface layer, and environmental conditions. If the rover works without problems, its operating lifespan can even be extended.
The Finnish Meteorological Institute has provided the MSL rover with instruments for pressure and humidity measurements (REMS-P and REMS-H) in the Martian atmosphere. The instruments are part of the REMS instrument package for environmental monitoring, supplied for the rover by INTA-CAB of Spain. The biggest advantage of the REMS-P and REMS-H instruments is their excellent accuracy and small size, as they weigh only 15 grams (REMS-H) and 35 grams (REMS-P).
The Meteorological Institute has built similar devices for several interplanetary spacecraft, such as the Huygens probe (ESA/NASA), which landed successfully on Titan, a moon of Saturn, in January 2005. Corresponding equipment was also involved in NASA’s Mars Phoenix spacecraft in 2008.
Consisting of carbon dioxide, the Martian atmosphere is dry and cold and has a density of about one hundredth of that of the Earth atmosphere. Since the axial tilt and the length of the solar day are almost the same on Mars and on Earth, the Martian and Earth atmospheres behave in the same way. The similar features of the Martian and Earth atmospheres give rise to comparative planetary research: by exploring Mars, we can also learn something new about Earth and its atmosphere, which is why this is an important object of study for the Meteorological Institute. The similarity of the atmospheres has made it possible for the Meteorological Institute and the University of Helsinki to simulate the behaviour of the Martian atmosphere by means of the weather forecast model (HIRLAM), used for instance in the Nordic countries.
The Meteorological Institute’s REMS-H and REMS-P instruments will give accurate readings of pressure and humidity in the Martian atmosphere. The intention is to compile time series on pressure and humidity for the duration of the entire MSL programme (one Mars year). After the Viking landers (1976–1982), this would be the second measurement series covering a full Mars year. The observations help explore the behaviour of the Martian atmosphere over a wide scale: from seconds to seasonal variation. The fact that the laboratory will move during the research programme will introduce local variation and may take the rover to areas showing variation in the water content of the ground and the humidity of the atmosphere.
The MSL will also look for residues and evidence of water that may have filled Gale crater in the past. The MSL will not try to find life on Mars, but it may well show whether Mars has sometimes had conditions favourable to life.
The pressure and humidity instruments delivered by the Meteorological Institute instruments are based on sensor technology developed by Vaisala Corporation. The following Finnish companies have also participated in the project: Selmic Oy, Micro Analog Systems Oy, Optomekaniikka Oy and Ideal Engineering Oy.
Ari-Matti Harri, Head of Group, tel. 050 337 5623, email@example.com (Cape Canaveral, MSL launch site, 22–27 November).
Maria Genzer, Senior Research Scientist, tel. (09) 1929 4724, firstname.lastname@example.org
Jouni Polkko, Senior Research Scientist, tel. (09) 1929 4653/ 050 5266661, email@example.com
Henrik Kahanpää, Research Scientist, tel. (09) 1929 4723/ 050 5713746, firstname.lastname@example.org
Harri Haukka, Research Scientist, tel. 044 3406510, Harri.Haukka@fmi.fi.