SWARM mission news archive
5th meeting of the QWG (Quality Working Group) at IPGP, Paris
Validation of ASM data from Swarm C during the Potsdam conference
Swarm is a Mission of ESA's Earth Explorer programme, which main objective is to study the spatial and temporal variations of the magnetic field, as well as the ionospheric environment of the Earth. The mission is monitored by the scientific teams of the Denmark Technical University (DTU, Copenhague), the Institut de Physique du Globe (IPGP, Paris) and the German Research Centre for Geosciences (GFZ, Potsdam). It operates a constellation of three identical satellites, launch in 2013, each one carrying two magnetometers: one vectorial magnetometer (VFM) coupled to a star tracker (STR), both designed by the DTU, which give the direction of the magnetic field in space, and one redundant absolute scalar magnetometer (ASM), which measures its intensity. This ASM was designed by CEA-Leti, Grenoble, with CNES technical and financial support and the IPGP scientific support. The ASM also takes vectorial measurements which makes it the first autonomous absolute vectorial magnetometer in space. These experimental vectorial data are jointly validated by the CEA-Leti and the IPGP.
Since November 2014 Swarm-C satellite doesn't have any more an ASM instrument and cannot supply scalar measurements. Nonetheless the impacts on the mission are minimized because Swarm-C is positioned in tandem with Swarm A, in low orbit (1,4° in longitude from the equator). The first models of the magnetic field created from the mission's data enabled to show that the systematic bias between the ASM instruments on board Swarm A and Swarm C is of about 0.12 nT (Olsen et al., 2015), much lower than the specification of the absolute precision of 0.3 nT at 2. Thus, with an adaptation of the modelling methods and calibration, the VFM instrument on board Swarm C can be calibrated thanks to the ASM on board Swarm A with acceptable mission performances.
The simultaneous production of scalar and vectorial data by the tree ASM for one year enabled the IPGP to build a very high quality autonomous model of magnetic field (Hulot et al., 2015). During the 4th workshop on Swarm data quality which took place in Potsdam at the beginning of December 2014, the scientific validity of the ASM data and model was recognised by the scientific community, which expressed the wish to participate to the exploitation of the scalar and vectorial experimental data generated by the IPGP and the LETI. The usefulness of the ASM vectorial mode in orbit is thus demonstrated which makes it the first autonomous absolute magnetometer validated in orbit.
Unavailability of ASM measurements on Swarm C since 05/11/14 at 19:37:27 UTC
A major anomaly occurred on the ASM on Swarm C, which delivers no more telemetry since 05/11/14 at 19:37:27 UTC. This loss of telemetry came with a decrease of the instrument's power consumption, that led the instrument to be switched off by the platform. Several attempts to restart it were done since then but were unfortunately unsuccessful. The root cause of the anomaly is being investigated.
On that satellite, the ASM redundant model was already lost at launch. No absolute scalar measurement is therefore available on Swarm C since this failure. Since the main role of the ASM on each satellite is to allow the regular calibration of the VFM data, this loss is a serious concern. The possibility of such an incident was however considered, that led to select Swarm C as one of the 2 satellites in lower orbit, in tandem with Swarm A (1,4° longitude separation at equator). It seems that this choice was appropriate.
Indeed, the ASM on Swarm A and B remain fully operational. The first magnetic field models established from Swarm data after only one year in orbit present a performance which is similar to models produced after several years using data from CHAMP, the previous mission. Last but not least, those models also revealed that during the first year, when the ASM on Swarm C was providing data, the systematic bias observed after modellisation between this instrument and the ASM on Swarm A was only around 0.12 nT. This excellent agreement shows that, provided an adaptation of the modellisation and calibration methods, it may be possible in the future to calibrate the VFM instrument on Swarm C from the ASM on Swarm A, with a limited impact on the mission's performance.
It should also be remembered that the ASM has been operated in vector mode on the 3 satellites right from the beginning of the mission, thus delivering simultaneous scalar and vector data. This capability was used by IPGP to build a magnetic field model regardless of VFM data. The quality of this model is very good, compared with the one of models using VFM data. The scientific merit of ASM experimental vector data was acknowledged by the scientific community, who now wishes to be associated to the data exploitation. Terms of such collaborations are being discussed. So this vector experiment is a real success.
First Level 2 Swarm data products available
Starting from 21 May 2014, the first Level 2 data products have been made available to the Swarm User community.
More information on ESA's website.
ESA makes first Swarm datasets available
The European Space Agency is pleased to announce the release of the first set of products based on the Swarm satellites.
More information on ESA's website.
Swarm's precise sense of magnetism
Although they were launched only five months ago, ESA's trio of Swarm satellites are already delivering results with a precision that took earlier missions 10 years to achieve.
Engineers have spent the last five months commissioning the identical satellites and carefully guiding them into their orbits to provide the crucial measurements that will unravel the mysteries of Earth's magnetic field.
Over the coming years, this innovative mission will provide new insight into many natural processes, from those occurring deep inside the planet to weather in space caused by solar activity.
The first results and status of the mission will be presented at a Swarm science meeting on 19-20 June in Denmark.
Read the complete news on ESA's website.
ASM first results
The first operations of the absolute scalar magnetometers (ASM) started on the 26/11/13. The instruments were switched on on the 3 satellites on the 26/11/13. Some health check were first performed thanks to the diagnoses modes available onboard. The instruments were then switched to measurements modes:
then they achieved scalar measurements of the magnetic field at 250 Hz over 3 orbits (ASM in burst mode), to analyse the spectral content of the magnetic field above 1 Hz, about which little is currently known,
they were finally switched to vector mode, which is the nominal measurement mode for the ASM on Swarm, to produce simultaneous scalar and vector measurements at the same location at 1 Hz.
All functional verifications were successful.
The scalar performances were assessed from the first measurements and showed to be excellent : the resolution is better than 1 pT/Hz on the 3 instruments and does not depend on the field modulus, as shown on the plots below. Compared to the performance of the scalar magnetometers on the Ørsted and CHAMP satellites, this represents an improvement by a factor of 4 to 50 depending on the value of the ambient field, as on those satellites the performances were dependent on the magnetic field modulus.
Besides, the ASM precision is better than 65 pT in the worst case (performance demonstrated on ground) and independent on the field modulus, which represents an improvement by a factor 5 if compared with the scalar magnetometers on Ørsted and CHAMP.
The vector performances of the ASM are promising. Indeed, a rough preliminary calibration was done using the measurements from the first orbits, that already allowed to achieve scalar residual around 1 nT, which was our target. Below is an example of the measurements obtained with the ASM in vector mode on the 3 satellites, in the ASM reference frame, at ASM time. Note that given the scale of the plot, the curves obtained from the 3 ASM instruments measurements are superimposed and merged, because the 3 satellites are currently still very close from each others (76 to 211 km).
Successful Swarm launch, the satellites trio is in orbit!
The 3 Swarm satellites were successfully launched on Friday the 22nd of November, 2013 at 12:02 UTC (13:02 CET), by a Russian Rockot launcher, from the Plesetsk cosmodrome. They were injected simultaneously, on a near polar orbit, at an altitude of 490 km. Several orbital manoeuvres will be done in the coming weeks, in order to reach the operational constellation, with a side-by-side flying lower pair of satellites (Swarm A and B) at an initial altitude of about 460 km and a single higher satellite (Swarm C) at about 530 km. This configuration will be achieved 4 months after launch.
The 3 first days in orbit were dedicated to the Launch and Early Orbit Phase (LEOP), which is critical. During this phase, the satellite booms were deployed, the vital platform equipments were activated, configured and verified. This includes the S-band communication subsystem, the electrical power subsystem, the thermal control subsystem, the attitude and orbit control system, the cold gas propulsion subsystem, and the data handling system. The star tracker assembly was switched-on to achieve the fine pointing mode. The GPS Receiver was switched on to allow the on-board time synchronisation and the GPS navigation solution usage in fine pointing mode.
This LEOP phase was successfully completed, the 3 satellites are now in a safe and stable in-orbit configuration, with the booms deployed, the attitude and orbit control system in fine pointing mode and the main platform equipments and subsystems switched ON and verified. The constellation is ready to start the first nominal orbit acquisition manoeuvres and commissioning phase activities, which will last 3 months.
Next step is to switch on and verify the scientific payload. The Absolute Scalar Magnetometers (ASM), provided by CNES, are going to be switched on at D+4.
It was confirmed that Swarm will be launched on 22/11/2013 at 12:02 UTC.
The launch the 3 swarm satellites from Plesetsk, Russia, originally scheduled for 14 November 2013, has been postponed by at least one week.
This delay is due to the decision to replace a unit in the Breeze upper stage of the Rockot launcher. The new launch date should be announced shortly.
Swarm launch campaign blog: http://blogs.esa.int/eolaunches/
The satellites' functional tests are completed
The six absolute scalar magnetometers were successfully verified. The preparations for launch are progressing on schedule.
Visit ESA's blog for more details on the Swarm launch campaign.
Swarm launch campaign continues in Plessetsk.
All proceeds normally and in accordance with the schedule. A CNES/LETI team ensures a permanence for all the tests involving the ASM, in order to verify their proper course. The FM1 satellite functional tests (Abbreviated Functional Test / AFT) took place on the nominal side on 02/10/13. The ASM telemetry is fully consistent with the expected.
In addition to the satellite AFT tests, ASM good health tests are scheduled in Plessetsk to verify the ASM good operation in a more detailled way. They were successfully realized on the ASM FM2A and FM2B on 30/09/13.
The FM3 satellite fuelling is completed. EADS will now proceeds to the FM2 fuelling.
The launch is still scheduled for the 14/11/2013.
A 1st CNES / LETI team arrived on site on 27/09/13, in order to verify the proper functioning of the different tests involving the ASM.
FM3 satellite functional tests (Abbreviated Functional Test / AFT) were performed on tuesday 24/09 on the nominal side and on wednesday 25/09 on the redundant side. In the same way, the FM2 satellite tests were performed on friday 27/09/13 on the nominal side and on saturday 28/09/13 on the redundant side. The ASM telemetry verification shows that the functioning is perfectly nominal.
Visit ESA's blog to follow the Swarm launch campaign
The launch campaign has begun, the 1st satellite was transported from Ottobrunn to Plessetsk on the 17/09
Succesful Rokot launch last night
Three Gonets-M communications satellites were sucessfully launched last night, from the Plesetsk space center in northern Russia, by a Russian Rokot launcher. The launch, which took place at 23:23 UTC on wednesday (03:23 Moscow time on thursday), marked Rokot's return to flight after a nine-month suspension. Flights were suspended since January 2013, after the rocket's Briz-KM booster failed to deliver three military satellites into their designated orbits, resulting in the loss of one of the satellites.
Good news for the Swarm mission, which should be the next to be launched by this rocket, on the 14th of Novembre 2013.
Swarm launch scheduled for November 14th, 2013
ESA confirmed the 14/11/13 date for the launch of the 3 Swarm satellites from Plessetsk base (subjected to the success of upcoming Rockot launch scheduled on the 12/09/13). The launch campaign will thus soon begin. The 3 satellites are in their containers, ready for expedition, they will be transported to Plessetsk by plane respectively on the 17, 19 and 21/09.
Swarm launch expected mid November 2013
The next Rockot launch is now scheduled on the 10th of Septembre 2013. The Swarm launch would then be scheduled in November 2013, the 17th being the provisional date.
Swarm launch foreseen in October 2013
Khrunichev completed the investigation related to the launcher's anomaly observed on the 15/01/13. The next rockot launch is scheduled at the end of June 2013. The Swarm launch could then be scheduled in October 2013.
Swarm launch is postponed until August - September at the earliest
Following the launcher's anomaly which occured on the 15/01/13, Khrunichev needs to pursue the investigations at least until the end of March 2013. The next rockot launch would then be planned not earlier than the end of May. This would delay the Swarm launch until August - September at the earliest.
Swarm launch delayed to mid year at the earliest
On January 15, 2013 a Rockot launch vehicle using a Breeze-KM upper stage successfully placed three Russian military communication satellites into orbit. However, after releasing the satellites into their correct orbit, the Breeze-KM post-deployment maneuver failed. An inquiry is in progress in Russia, which may further delay the Swarm launch to mid-year at the earliest. One more Russian government launch is due before Swarm.
Swarm launch date is now uncertain (April 2013 at the earliest)
The ASM sensors and interface bracket anisotropy re-characterisation is now completed, the flight hardware was sent back to EADS. The 3 satellites will be stowed in their transport containers again before the end of the year.
The next Rockot launch which was expected in November was postponed again until next year. Then, on the 09/12/2012, the Proton launcher encountered a new failure which may have an impact also on the next rockot launch due to similarities between Proton/Briz-M and Rockot/Briz-KM motors. Moreover another rockot launch is to be scheduled before Swarm. The Swarm launch date is now uncertain, it is foreseen during the second quarter of 2013 at the earliest.
SWARM launch postponed until April 2013
At present two Rockot launches are foreseen at Plesetsk in November 2012 and January 2013, prior to the Swarm launch. The Swarm launch is now scheduled in April 2013, but the date is likely to be consolidated after the November launch.
Taking advantage of the launch delay to April 2013, it was decided to carry out some additional work on the satellites, which were stored in their transport containers since the 10th of July. The ASM sensors and the interface bracket were dismounted and sent back to CEA-LETI for anisotropy re-characterisation.
SWARM launch postponed
The 3 Swarm satellites are stored at IABG in Ottobrunn (Germany) in their containers filled with nitrogen since mid-July, waiting for their transfer to Plesetsk.
A Rockot launch was successful on the 28/07/12, it marked the return to flight of Rockot after the failure of February 2011. Another Rockot launch should take place before Swarm, it was scheduled for mid-September 2012, but was postponed to November after the failure of Proton/Briz-M on 06/08/12, due to similarities between Proton/Briz-M and Rockot/Briz-KM motors. Due to this new reschedule, the Swarm campaign cannot begin before mid-December 2012, which will lead to Swarm launch mid-March 2013 at the earliest.
Some news from SWARM: the AIT test of the 2nd satellite ended in December, the 3rd satellite will be tested during the 1st quater of 2012. Everything is nominal about the ASM. The launch is still scheduled for the autumn 2012.
The first Swarm satellite (FM2) is currently installed in the IABG Magnetic Field Simulation Facility located at Ottobrunn in Germany. The magnetic tests are in progress (see pictures). The environment tests of the second Swarm satellite (FM1) have started early Septembre. The integration of the third Swarm satellite (FM3) is being pursued at EADS Friedrichshafen.
Swarm on display at Le Bourget
After the delivery acceptance of the 6 ASM flight models, supplementary tests were carried out by CEA/LETI in order to characterize the magnetic signature of the ASM sensors mounted on the satellite's titanium bracket. Following these measurements, the instruments were shipped to EADS at Friedrichshafen for integration into the Swarm satellites; the FM2 were handed over on the 10/02/11, the FM1 and FM3 on the 16/03/11.
CNES and CEA/LETI delivered to ESA the third and last pair of the absolute scalar magnetometer (ASM) flight models. These two instruments, one nominal model and one redundant, will equip the third Swarm satellite. The 6 flight models have thus been delivered to ESA in 2 months and offer excellent performances, with a remarquable repeatability.
Only one month after the delivery of the first pair of the absolute scalar magnetometer ASM / Swarm flight models, CNES and CEA/LETI delivered to ESA the 2nd pair of flight models, constituted of a nominal and a redundant models. These instruments will equip the 2nd Swarm satellite of the ESA. The delivery review took place on 17/01/2011 at LETI. The delivery has been accepted, with again test results deemed excellent.
CNES and LETI delivered the 2 first ASM flight models to ESA and EADS (flight model N°1, nominal and redundant). The delivery review board was held on the 14/12/2010 at LETI. The delivery was accepted, the results were considered excellent. The hardware was then delivered to EADS at Friedrichshafen on the 16/12/2010, the handover meeting was held on the 17/12/2010.
CEA-Leti said that a prototype of the new-generation scalar magnetometer, which it designed and developed in partnership with CNES, has passed the qualification step en route to being deployed in the SWARM space mission.
Read the complete press release
|19/08/2010||Swarm, Toulouse experts and the PWM autopsy (in French)|
|09/03/2010||CNES and CEA/LETI participate to Jean-Louis Etienne's next polar mission|
|4-5/03/2010||PFM DPU vibration and shock tests|
|09/11-08/12/2009||PFM and FM sensors and harnesses vibration and shock tests|
|24/09/2009||ASM PFM Test Readiness Review (TRR)|
|24-26/06/2009||2nd SWARM international science meeting at GFZ in Potsdam|
|04/06/2009||ASM CDR Board meeting: green light for phase D|
|24/04/2009||CDR SWARM CDR Board meeting at ESTEC|
|31/03/2009||ASM Critical Design Review (CDR) at CNES|
|20/03/2009||1st meeting of the French SWARM scientific community in Paris|
|27/02/2009||SWARM project Critical Design Review (CDR) at ESTEC|
|13/02/2007||Presentation of the SWARM Preliminary Design Review at ESTEC|
|12/12/2006||ASM PDR Board meeting: green light for phase C|
|10/11/2006||Presentation of the ASM Preliminary Design Review|
|03-05/05/2006||1st SWARM international science meeting at Nantes University|
|01/11/2005||Beginning of ASM B Phase at CNES|
|06/10/2005||Programme decision by CNES Board of Directors: go-ahead for phases B/C/D/E (CNES Press Release)|