cosmos.wikisort.org - Spacecraft

Sentinel-3A is a European Space Agency Earth observation satellite dedicated to oceanography which launched on 16 February 2016.[5] It was built as a part of the Copernicus Programme, and is the first of four planned Sentinel-3 satellites. Its sister satellite, Sentinel-3B, launched on 25 April 2018. After completing initial commissioning, each satellite was handed over to EUMETSAT for the routine operations phase of the mission. Two recurrent satellites - Sentinel-3C and Sentinel-3D - will follow in approximately 2024 and 2028 respectively to ensure continuity of the Sentinel-3 mission.

Sentinel-3A

Vector drawing of the Sentinel-3
Mission type	Earth observation
Operator	ESA · EUMETSAT
COSPAR ID	2016-011A
SATCAT no.	41335
Website	Sentinel-3 (ESA)
Mission duration	Planned: 7 years[1] Elapsed: 6 years, 5 months, 16 days
Spacecraft properties
Spacecraft type	Sentinel-3
Bus	Prima
Manufacturer	Thales Alenia Space[2]
Launch mass	1,250 kg (2,760 lb)[3]
Dry mass	1,150 kg (2,540 lb)[4]
Dimensions	3.9 × 2.2 × 2.2 m (12.8 × 7.2 × 7.2 ft)[3]
Power	2,300 watts[3]
Start of mission
Launch date	16 February 2016, 17:57 (2016-02-16UTC17:57) UTC[5]
Rocket	Rokot
Launch site	Plesetsk Cosmodrome, Site 133
Contractor	Eurockot Launch Services
Orbital parameters
Reference system	Geocentric
Regime	Sun-synchronous
Semi-major axis	7,182.47 km (4,462.98 mi)
Eccentricity	0.000309
Perigee altitude	802.12 km (498.41 mi)
Apogee altitude	806.56 km (501.17 mi)
Inclination	98.62°
Period	100.97 min
RAAN	117.18°
Argument of perigee	86.80°
Mean motion	14.26 rev/day
Repeat interval	27 days[6]
Epoch	17 February 2016, 18:53:04 UTC[7]
Transponders
Band	S band (TT&C support) X band (science data)
Bandwidth	S band: 64 kbps uplink, 1 Mbps downlink X band: 2 × 280 Mbps[1]
Instruments OLCI Ocean and Land Colour Instrument SLSTR Sea and Land Surface Temperature Radiometer SRAL Synthetic Aperture Radar Altimeter MWR Microwave Radiometer DORIS Doppler Orbitography and Radiopositioning Integrated by Satellite LRR Laser Retro-Reflector GNSS Global Navigation Satellite System
Sentinel-3 Sentinel-3B →

Mission history

In October 2015, the Sentinel-3A launch was planned for December 2015,[8] but delays in transportation from Cannes to the Plesetsk Cosmodrome postponed the launch to January 2016.[9] The spacecraft arrived at Talagi Airport aboard an Antonov An-124 on 28 November.[10][11] By 17 December, Sentinel-3A completed pre-launch testing and was placed into storage for the Christmas break, lasting until 11 January 2016.[12] After the break, launch was scheduled for 4 February,[13] but while the spacecraft was being fuelled for launch, Khrunichev Space Center in Moscow determined that the launch pad needed to be recertified, resulting in a further delay.[14] Launch was eventually rescheduled for 16 February.[15]

Launch

Sentinel-3A was successfully launched on 16 February 2016 at 17:57 UTC from the Plesetsk Cosmodrome aboard a Rokot launch vehicle. The Briz-KM upper stage fired twice to insert the spacecraft into its intended 815 km (506 mi) orbit, first at 5 minutes and then at 75 minutes after launch. Spacecraft separation occurred at 79 minutes after launch, and ground controllers received the first communication from the vehicle at 92 minutes.[5][16]

Operations

The first instrument switched on was OLCI. It made its first picture on 29 February 2016, capturing Svalbard island along with a part of the arctic ice pack near solar terminator.[17]

See also

• Sentinel-3#Instruments

References

External links

• Sentinel-3 program website by ESA
• Sentinel-3 website by the Copernicus Programme
• Real-time orbital tracking - uphere.space

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