Parasol 8th birthday

Launched on December 18, 2004, Parasol, second CNES mission integrated on the Myriade microsatellite platform, has just celebrated its eighth year in space.
Parasol is a technical and scientific success. Thanks to the experience acquired by CNES engineers, both on the platform and the Polder instrument, the design and realisation of the mission took less than 5 years, which is a particularly short delay for a space experiment

Moreover, despite problems with the star tracker, the mission has now an availability near 90%.
It enabled the acquisition of coincident data with other instruments of the A-Train constellation during nearly 5 years

The scientific objectives of the mission -the characterisation of the radiative and microphysical properties of the clouds and aerosols- have been fullfilled and in some instances exceeded.
Thanks to the quality of the measurements and to new sophisticated inversion methods, it is possible for example to get the size of the droplets at the top of the clouds or to get information on aerosols even over bright surfaces.
By analyzing the complementarity of the polarimeter with other instruments of the constellation such as the lidar and/or the radar, new parameters, not envisonned at first, are now extracted.
One can mention some macro-physical properties of clouds (altitude and geometrical thickness) or the presence and the quantization of aerosol plumes over cloudy areas.

Illustration of PARASOL capability to detect and quantify the presence of a layer of aerosols above cloudy areas. Case of the aerosol plume emitted by the Eyjafjallajokull volcano on May 8, 2010. The color scale represents the optical thickness at 550nm related to the particles concentration. © F.Waquet, Laboratoire d'Optique Atmosphérique

This anniversary is a little peculiar because it will probably be the last one. Indeed, due to insufficient ergols, the satellite will be desorbited during the autumn 2013.
Its orbit drifting will be to high to ensure the continuation of the mission.

Despite this very positive assessment, only one regret: next september, we will need to wait at least for 7 years until the 3MI mission on board EPS-SG takes over acquisition of new directional polarized measurements from space.

The Parasol project team informs the scientific community and in particular, the users of Parasol data, that the mission local time (1:30 pm at the beginning and approximately up to end of 2009) is drifting. As the mission has gone on well beyond its expected duration, the inclination of the spacecraft is not maintained from years and now the drift is increasing rapidly into the afternoon. Parasol is currently crossing the equator at approximately 3:00 pm local time. See below a figure that shows the evolution of the local time over the mission duration. This drift does not significantly affect the quality of the products, but leads to a sensitive modification on solar geometries during acquisitions.
Furthermore, we remind that since February, 2012 there is no more overlapping at the equator with the other sensors of the A-Train constellation.

PARASOL celebrated its 7 years in orbit and is still functioning perfectly.

PARASOL orbit lowering and mission continuity

The 2 orbit lowering maneuvers realized by the CNES operational teams allowed to reach an orbit 9.5 km under the A-Train. The measurements continuity is scheduled until the end of September 2013.

Positive response of the LOS bureau for PARASOL mission extension

The LOS bureau emitted a positive response to Parasol mission extension taking into account the orbit lowering scheduled in November 2011.

A-TRAIN operational coordination meeting (MOWG) in Biarritz, France.

This year, CNES hosted the A-Train constellation MOWG meeting. During this MOWG, CNES presented to its A-Train partners the selected strategy for Parasol mission extension as well as the characteristics and schedule of the new orbit lowering. These operations are scheduled in November 2011 and will be realized in order to respect the LOS bureau recommandations.

6th PARASOL exploitation Review at CNES Toulouse

This 6th REVEX allowed to note the very good functioning of the satellite and the Ground Segment as well as to note the exploitation extension until the end of 2013 (end of life operations included).

CNES is now in charge of the PARASOL "Ocean" and "Land Surface" data production

Following a change concerning the exploitation responsability on "Ocean" and "Land Surface" Parasol level 2 and 3 data, the CPP team of the CNES (Polder/Parasol production center) is now responsible for the production of these level 2 and 3 data. Previously the production was done by the company Hygeos.
At CNES, the exploitation of these data began from April 14th for "Ocean" data and from June 1st for "Land Surface" data.

The distribution of these products, previously done by the company Hygeos, is now provided:

on Postel server for "Land Surface" Level 3 data
and on request only (email address: cpp at cnes.fr) for the "Ocean" data.

An archive of all these level 2 and 3 data, "Ocean" and "Land Surface", will soon be available at CNES.

Mission Extension Review Steering Committee (REDEM).

The REDEM Steering Committee gave a favourable answer to the PARASOL mission extension and recommands an extension of the mission until the end of September 2013 followed by the realization of the end of life operatins by the end of 2013. To follow the LOS bureau recommandations, the REDEM Steering Committee asked the project group to prepare a new lowering of PARASOL orbit before the end of 2011. The new selected altitude is 10 km under the satellites of the A-Train constellation. A new position of the LOS bureau is expected to ratify this extension.

Mission Extension Review (REDEM).

End 2010, the scientific community asked for an extension of PARASOL mission. CNES instructed this request and presented the results during the REDEM on April 4, 2011. Since the application of the "Loi d'Opérations Spatiales" (LOS: Space Operations Law) in December 2010, a mission exploitation extension must respect as much as possible the criteria defined by the new law and the advices emitted by the LOS bureau.

NASA'S Glory Satellite Fails To Reach Orbit.

NASA's Glory Earth-observation science satellite, which launch was postponed to March 4th, failled to reach its orbit due to the failure of the rocket's fairing to separate.

More information...

French scientists all set for U.S. Glory mission.

NASA's Glory Earth-observation science satellite launch set on February 23 is postponed. French scientists are taking part in this adventure with support from CNES.

More information...

PARASOL celebrated 6 years in orbit, on December 18, 2010.

Since already 1 year Parasol left its position in the A-Train constellation but continues to provide its unique observations of the directional signatures of clouds and aerosols.

According to the mission extension review held in 2010, the continuity of measurements is forseen until the end of 2011. During the first quarter of 2011, CNES will answer to a new mission extension request submitted by the scientific community.

More information...

International Symposium on the A-Train Satellite Constellation 2010, New Orleans, USA

The International Symposium on the A-Train Satellite Constellation 2010 follows and expands on the first A-Train Symposium held in Lille, France in 2007. It aims to provide a forum to exchange information on the latest scientific advancements using multisensor measurements from the A-Train. An additional objective of the Symposium is to better inform new and present users on recent enhancements to A-Train data sets and subtleties related to their use. Because the instruments employ different measurement techniques, fusing the observations and/or data products is often challenging. Consequently, another important objective is to highlight key issues and strategies for combining the diverse measurements.

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PARASOL gets off the train

After collecting observations synchronous with the other satellites from the A-Train for almost 5 years, PARASOL was moved to a lower orbit (3.9 km beneath) at 12:48 UT on December 2, 2009. The maneuver was performed by the CNES flight operations teams. The microsatellite PARASOL had joined the A-Train constellation in early February 2005.

PARASOL orbit tracks have been slowly drifting eastward these past few months, due to insufficient fuel supplies that prevented PARASOL to be part of the last inclination maneuver performed by the other A-Train satellites in Spring 2009. However, observations were still in phase with the other sensors. On the new orbit, observations from PARASOL will no longer be simultaneous with the other sensors, except for only a few days at regular intervals.

CNES's decision to position PARASOL to a lower orbit was motivated by safety reasons to minimize the risk of collision, should PARASOL begin to fail. While the expected duration of the PARASOL mission was 2 years, it will reach 5 years in March 2010.

On December 18, 2009, PARASOL will celebrate its 5th anniversary in orbit, alone, yet pursuing its mission of observation of clouds and aerosols.

An "A-Train Lille Symposium 2007" was held in Lille - Grand-Palais - from October 22 to 25, 2007.
The goal of this international meeting was: "Bringing together A-train observations and modelling to understand aerosols and clouds"

PARASOL level-1 Archive (Version 3) reprocessing completed. The reprocessing of the 18-months level-1 data archive is now complete. More information about improvements from Version 2 to Version 3 can be found on http://parasol-polder.cnes.fr.

Products level 1C, corresponding to level 1 extracts over CALIPSO track are also available from June 2006. See example here.

PARASOL Scientific Products are available to users

PARASOL Validation Review was held on May 18th, hosted by the Laboratoire d'Optique Atmosphérique in Lille.
The assessment of the various aerosol and cloud parameters was successfull and the distribution of the data to the users has been authorized by D.Tanré, PI of the mission.

1st PARASOL REVEX (EXploitation REView): the space segment part was held on May 2006, 11th and the products part was held on the 12th.

During this REVEX, one could note the good course of the exploitation since the in flight commissioning and the satisfaction shown by scientific teams about Parasol products quality. It was thus decided to carry on the exploitation as long as the system can supply good quality data. The propellent budget enables to envision to maintain Parsol in the A-train constellation until spring 2009, even if no guaranty can be given on the duration of the operations after the "nominal" lifespan of the satellite.

CNES technical teams managed to solve the few problems at the beginning of operations, and to obtain a mission availability hugely higher than the objective (availability of 95 % for an objective of 75 %). The efficiency of the operational teams largely contributes to the success of the mission.