 Artist's view of the three Swarm spacecraft | |
| Mission type | Earth's magnetic field observation |
|---|---|
| Operator | ESA |
| COSPAR ID | SWARM A: 2013-067B SWARM B: 2013-067A SWARM C: 2013-067C |
| SATCATno. | SWARM A: 39452 SWARM B: 39451 SWARM C: 39453 |
| Website | ESA Swarm homepage |
| Mission duration | 4 years (planned) 12 years, 2 days (elapsed) |
| Spacecraft properties | |
| Manufacturer | Astrium |
| Launch mass | 468 kg |
| Dry mass | 369 kg |
| Dimensions | 9.1 m × 1.5 m × 0.85 m |
| Power | 608 watts |
| Start of mission | |
| Launch date | 22 November 2013, 12:02:29UTC |
| Rocket | Rokot/Briz-KM |
| Launch site | Plesetsk,Site 133/3 |
| Contractor | Eurockot |
| Orbital parameters | |
| Reference system | Geocentric |
| Regime | Polar orbit |
| Perigee altitude | Swarm A: ≤460 kilometres (290 mi) Swarm C: ≤460 kilometres (290 mi) Swarm B: ≤530 kilometres (330 mi) |
| Apogee altitude | Swarm A: ≤460 kilometres (290 mi) Swarm C: ≤460 kilometres (290 mi) Swarm B: ≤530 kilometres (330 mi) |
| Inclination | Swarm A: 87.3°[1] Swarm C: 87.3°[2] Swarm B: 87.7°[3] |
| Mean motion | 15 |
| Transponders | |
| Band | S Band |
| Frequency | 2 GHz |
| Bandwidth | 6Mbit/s download 4 kbit/s upload |
| Instruments | |
| VFM: Vector Field Magnetometer ASM: Absolute Scalar Magnetometer EFI: Electric Field Instrument ACC: Accelerometer LRR: Laser Range Reflector | |
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Swarm is aEuropean Space Agency (ESA) mission to study theEarth's magnetic field. High-precision and high-resolution measurements of the strength, direction and variations of the Earth's magnetic field, complemented by precise navigation,accelerometer andelectric field measurements, will provide data for modelling the geomagnetic field and its interaction with other physical aspects of the Earth system. The results offer a view of the inside of the Earth from space, enabling the composition and processes of the interior to be studied in detail and increase our knowledge of atmospheric processes and ocean circulation patterns that affectclimate andweather.
The overall objective of the Swarm mission is to build on the experience from theØrsted andCHAMP missions and to provide the best ever survey of the geomagnetic field (multi-point measurements) and its temporal evolution, to gain new insights into the Earth system by improving our understanding of theEarth's interior and climate.[4]
The Swarm constellation consists of threesatellites (Alpha, Bravo and Charlie) placed in two differentpolar orbits, two flying side by side at an altitude of 450 kilometres (280 mi) and a third at an altitude of 530 kilometres (330 mi).[4][5] The launch was delayed and rescheduled to 12:02:29UTC on 22 November 2013, fromPlesetsk Cosmodrome, Russia.[6] ESA contractedAstrium to develop and build the three orbiters,[4] whileEurockot provided the launch services.[7]
Through a Canadian-European partnership, theCanadian Space Agency'sCASSIOPE satellite's e-POP instrument suite was formally integrated as the fourth satellite in the Swarm constellation in 2018, joining Alpha, Bravo, and Charlie as Echo.[8]
Primary objectives:
Secondary objectives:
The payload of the three spacecraft consists of the following instruments:[5]
The threeSwarm satellites arrived at thePlesetsk Cosmodrome in September 2013 to begin final testing before fuelling and incorporation with theRokot launch vehicle.[10]
TheSwarm constellation was successfully launched aboardRokot/Briz-KM on 22 November 2013.[11]
The constellation is controlled by theEuropean Space Operations Centre inDarmstadt, Germany. By the beginning of May 2014, Swarm had finished its in-orbit commissioning.[12] Preliminary data indicates that the constellation is performing well as data received closely matches that from a previous German mission,CHAMP.[12]
During the commissioning stage problems were discovered with the backupMagnetometer on the "Charlie" satellite, which led to "Bravo" satellite being placed in the lone high altitude orbit (510 km) and "Charlie" joining "Alpha" in the lower tandem orbit (462 km) to improve the resilience of the constellation.[12] Commissioning data also indicated greater noise in data when a satellite was in view of the sun; the current theory is this is caused by differential heating in the satellite, but this has not been confirmed.[12] Overall, the constellation is in good health and, due to accurate orbital insertion, has significant fuel reserves remaining.[12]
In September 2016, scientists published a study that revealed a direct link between GPS blackouts of low-Earth-orbiting satellites and "thunderstorms" in theionosphere. During the first two years of Swarm's operation their GPS connection was broken 166 times.[13] The high-resolution observations from the satellite helped to link these outages to ionospheric thunderstorms at altitudes of 300–600 km in the Earth's atmosphere.[14]
In December 2016, scientists announced that, by using data from the Swarm satellites, they had discovered a new feature in the Earth'souter core, ajet-stream of rapidly moving liquid iron moving at around 50 km per year.[15][16]
In April 2017, Swarm's data was used to confirm thatSTEVE was a previously unrecognized atmospheric phenomenon.[17]
In May 2020, Swarm revealed that Earth's magnetic field is gradually weakening in an area stretching fromAfrica toSouth America, which might cause technical disturbances in satellites orbiting Earth.[18]
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