Picard is a microsatellite sending back data needed to improve models used for forecasting solar activity. It was designed to take simultaneous measurements of parameters such as the speed at which the Sun rotates, the radiation it emits, the presence of sunspots and its shape and diameter, to help scientists understand the relationship between them. These models also help to evaluate the influence of the Sun on the dynamic chemical processes governing balances in Earth’s atmosphere.
The Picard programme also has other objectives, namely to study the Sun’s internal structure using helioseismology techniques and to analyse the impact of solar variability on the processes governing balances in Earth’s atmosphere, notably the relationship between solar ultraviolet radiation and stratospheric ozone.
CNES was responsible for developing the Picard system, particularly the satellite, which it is also operating. The LATMOS atmospheres, environments and space observations laboratory at CNRS is prime contractor for development of the payload and specifically the SODISM instrument. The two other instruments, PREMOS and SOVAP, have been developed respectively under the responsibility of Swiss Space Office and the Belgian Federal Science Policy Office.
The science operations centre for Picard (CMS-P) is operated by the B.USOC. Its main responsibilities are to program the payload according to the scientific objectives and the operational and technical requirements, to gather and analyse the payload-related housekeeping data, to process and distribute the raw and calibrated data. At the end of the mission, after a period for massively reprocessing the data, the scientific products will be transferred to the IAS-MEDOC for long term archiving
At the beginning of 2013, the PICARD international Steering Committee ratified the recommendation of the REDEM steering committee not to extend the mission. Instead, starting in March 2013, technical experiments are conducted on different sub-systems of the satellite and instruments while allowing the continuation of scientific observations whenever possible.
The Sun and its impact on Earth’s climate is a topic of prime importance. The Picard project was first proposed in 1998 by the Aeronomy laboratory of the French national scientific research centre (SA/CNRS). On 3 December 2004, the CNES (Centre National d'Etudes Spatiales) Board of Directors decided to authorize this project frozen since 30 April 2003, in line with the recommendations of its Science Programmes Committee. It will go live in 2008.
Picard is a CNES Myriade microsatellite that will precisely measure the Sun’s diameter and its variations, as well as solar irradiance, with the twofold aim of learning more about how the Sun affects Earth’s climate and studying its physics and inner structure.
Initially scheduled for 2003, Picard has been launched 15 June 2010 at the start of the next solar cycle, on a scheduled two-year mission. The microsatellite’s payload will comprise:
The main tasks of the CMS-P are to:
The PICARD microsatellite mission will provide 3 to 4 years simultaneous measurements of the solar diameter, differential rotation and solar constant to investigate the nature of their relations and variabilities. The PICARD's systemuses most of the basic components of the CNES microsatellite product line. Except for the altitude control system, the microsatellite platform for PICARD is very similar to that of DEMETER.
The PICARD mission center is normally operated by the B-USOC and that, most probably, antennae (S band) in Toulouse and Kiruna will be used for telemetry needs (about1.5 Gbits per day). Depending on the data compression scheme selected, a higher telemetry rate (1.9 Gbits per day) could require a third antenna. The delivery key point (hand over) of PICARD CMS took place on November 23 and 24, 2010, in Brussels with representatives from CNES, which was the prime contractor for this development, from B-USOC which is its operator, from BELSPO, which funds the development and the operations and from IASB which hosts it.
After the key point, the CMS-P was accepted without reservation by its operator. The operations responsibility, conducted in coordination with the Mission Operations Preparation Group (scientific group) and its maintenance switches from CNES to B-USOC. These last delivery and responsibility change conclude the passage of PICARD system to routine operation mode.