DubaiSat-2

DubaiSat-2

An artist rendering of DubaiSat-2
Mission type Remote sensing
Operator EIAST
COSPAR ID 2013-066D
SATCAT № 39419
Mission duration 5 years
Spacecraft properties
Bus SI-300
Manufacturer Satrec Initiative
Launch mass ~300 kilograms (660 lb)
Dimensions 1,500 by 1,950 millimetres (59 by 77 in)[1]
Start of mission
Launch date 21 November 2013, 07:10:16 (2013-11-21UTC07:10:16Z) UTC[2]
Rocket Dnepr
Launch site Dombarovsky 370/13
Contractor ISC Kosmotras
Orbital parameters
Reference system Geocentric
Regime Low Earth
Perigee 600 kilometres (370 mi)[3]
Apogee 600 kilometres (370 mi)[3]
Inclination 97.8 degrees
Epoch Planned
Main camera
Name HiRAIS
Resolution 1 metre (3 ft 3 in)

DubaiSat-2 is an electro-optical Earth observation satellite built by the Emirates Institution for Advanced Science and Technology under an agreement with Satrec Initiative, a satellite manufacturing company in South Korea.[4][5][6] EIAST’s objective with DubaiSat-2 is to provide electro-optical images, that can be commercialized, for users within the United Arab Emirates and beyond and to develop and implement new technologies not used in DubaiSat-1.[7] EIAST also intends to continue manpower training for the UAE’s space program.[8] 16 UAE engineers have been working on the design, development, testing and manufacturing of the satellite. The participation of the UAE engineers, who are currently working in South Korea, has increased by 100 per cent from the DubaiSat-1 project and it is hoped that this will take EIAST to the next level in satellite development.[5][9][10]

Overview

The space segment consists of a spacecraft bus and an electro-optical payload. The electro-optical payload is a push-broom camera with Time Delay Integration (TDI) sensors (1 panchromatic and 4 multi-spectral bands). DubaiSat-2 is designed for a sun-synchronous orbit of 600 km, with a spatial resolution of 1m PAN and 4m Multispectral (MS), and a Swath of 12.2 km.[8][11]

The modules in the satellite use two CAN Bus networks to communicate with each other and it has the capacity to store approximately 17,000 km2 of image data. It also includes an experimental propulsion system for orbit correction and maintenance. The satellite’s expected lifetime is at least five years.[12][13][14]

Space segment

DubaiSat-2 has a hexagonal shape. The mechanical bus consists of 2 decks and an upper sun shield to protect the cold propellants from solar and Earth radiation. The electronics are distributed on the decks and on the side panels. Four solar panels are attached to the sides of the satellite. Longerons and rails make up the bus structure frame. On the top, carbon-fiber-reinforced polymer (CFRP) struts hold the Sun shield at the baffle of the High Resolution Advanced Imaging System (HiRAIS). The High-Resolution Imaging System is attached to the bus at the internal deck. The mechanical configuration of the satellite is less than 2000 mm in height and less than 1500 mm in diameter. The total mass of the satellite is less than 300 kg.[15]

The power system supplies and controls the required voltage levels and current essential for satellite operation during its mission. The power system uses a rechargeable Li-ion battery to provide power for the satellite’s payload and other subsystems. The system is divided into two stages, first is the charging stage and the second is the discharging stage. The charging stage is made of a solar power generator and power regulator. DubaiSat-2 generates more than 450W of power using four solar panels. Each solar panel contains 6 arrays and each array consists of 26 cells. The solar panels charge the batteries. The battery charging process is handled and regulated by the Battery Charging Regulators modules. DubaiSat-2 has three battery charging regulators with hot redundancy configuration which seamlessly take over if the primary battery charging regulator fails. The spacecraft can function normally with only two battery charging regulators.[15][16][17]

Mission payload

The High-Resolution Advanced Imaging System (HiRAIS) is the primary payload of Dubaisat-2. It is an advanced Earth observation Camera which captures high resolution images and is capable of other functions such as high-speed data transmission. The HiRAIS is a compact and light weight instrument; and is built from a composite material to obtain high strength while keeping its weight down. The camera is based on a Korsch optical design which uses a three-mirror configuration to reduce optical irregularities and provides a wide field of view.[18][19]

The HiRAIS consists of three main units: the Electro-Optical Subsystem, the Solid-State Recorder Unit, and the Image Transmission Unit. The Electro-Optical Subsystem is composed of the telescope, an auxiliary camera module, and a Focal Plane Assembly which are all integrated into one system. It is a pushbroom type camera with a 1 meter Ground Sampling Distance (GSD) for panchromatic imagery and 4 meter GSD in four multispectral bands.[13][15][16]

The Solid-State Recorder Unit handles the processing, storage and maintenance of image data and is capable of storing image data received from the Focal Plane Assembly during the imaging mode. It is also responsible for image data compressing, encrypting and encoding before sending it to the Image Transmission Unit during downloading mode. The unit has a storage capacity of 256 Gbit arranged in 4 identical storage boards.[15][16]

The Image Transmission Unit provides transmission of X-band data at a rate of 160 Mbit/s. It is divided into two main components: X-band Transmitter Unit and a high gain X-band Antenna.[15][16][20]

Propulsion system

DubaiSat-2 is propelled by a propulsion system called The Hall Effect Propulsion System. It is an electrical propulsion system with Xenon gas fuel and microwave cathode. The system will be used for the satellite's orbit correction and maintenance.[21][22]

Ground segment

DubaiSat-2 ground system consists of the Main Mission Control Station, the Subsidiary Mission Control Station, the Main Image Receiving and Processing Station, Customer Image Receiving and Processing Station, and the Antenna system.

The ground station monitors and controls the satellite. From there satellite operation planning is conducted, which includes imaging and download scenarios, mission timelines, orbit maintenance operation, and image downloads. The ground station is located at EIAST’s premises in Dubai, United Arab Emirates.[23]

Launch

DubaiSat-2 was successfully launched by a Dnepr rocket operated by Kosmotras of the Russian Federation.[24][25][26] It has been placed into a polar Sun Synchronous Orbit at an altitude of 600 km and local UAE time of descending node of 10:30 am.[27][28][29] Initially set for the last quarter of 2012, the launch took place at 07:10:16 UTC on 21 November 2013. Thirty one other satellites were deployed by the rocekt, with an additional payload remaining attached to the upper stage.[2][30][31] The revisit time for a ground location will be 8 days maximum. The tilting capability of DubaiSat-2 can go up to ±45° roll tilt, ±30° pitch tilt.

Future plans

By 2015, DubaiSat-2 and its predecessor, DubaiSat-1, will be joined and will work together with UAE's third satellite, Khalifa Sat.[32][33]

See also

References

  1. ↑ "DubaiSat-2" (in Korean). Sactrec Initiative. Retrieved November 27, 2012.
  2. 1 2 Graham, William (21 November 2013). "Russian Dnepr conducts record breaking 32 satellite haul". NASASpaceflight.com. Retrieved 21 November 2013.
  3. 1 2 "EIAST engineers reveal specifications of DubaiSat-2". Arabian Aerospace. May 26, 2011. Retrieved December 8, 2012.
  4. ↑ "DubaiSat-2 launch on track: Eiast". European Association of Remote Sensing Companies. April 15, 2011. Retrieved December 8, 2012.
  5. 1 2 "DubaiSat-2 project ready for operation after passing key software tests". AME Info. August 16, 2012. Retrieved November 18, 2012.
  6. ↑ "DubaiSat-2". Satrec Initiative. Retrieved November 18, 2012.
  7. ↑ "EIAST engineers reveal design details and specifications of DubaiSat-2". Al Bawaba. May 26, 2012. Retrieved November 27, 2012.
  8. 1 2 "DubaiSat-2 Introduction". Emirates Institution for Advanced Science and Technology. Retrieved November 18, 2012.
  9. ↑ "DubaiSat-2". Gunter Dirk Krebs. Retrieved December 7, 2012.
  10. ↑ "UAE needs talent to drive space sector: EAIST". Emirates 24/7. April 22, 2012. Retrieved December 8, 2012.
  11. ↑ "DubaiSat-2 imaging satellite ready for blast off". The National. February 17, 2011. Retrieved December 8, 2012.
  12. ↑ "DubaiSat-2 to Be an Improvement on Predecessor". The National. United Nations Platform for Space-based Information for Disaster Management and Emergency Response. May 26, 2011. Retrieved December 8, 2012.
  13. 1 2 Conroy, Erin (May 26, 2011). "DubaiSat-2 to be an improvement on predecessor". The National. Retrieved November 18, 2012.
  14. ↑ "DubaiSat-2 project ready after passing key tests". Emirates 24/7. August 12, 2012. Retrieved December 8, 2012.
  15. 1 2 3 4 5 "DubaiSat-2". eoPortal Directory. Retrieved November 18, 2012.
  16. 1 2 3 4 "DubaiSat-2 Space Segment". Emirates Institution for Advanced Science and Technology. Retrieved November 18, 2012.
  17. ↑ "EIAST launches logo competition for DubaiSat-2 project". AME Info. November 17, 2012. Retrieved December 8, 2012.
  18. ↑ "DubaiSat-2 mission payload – HiRAIS". Emirates Institution for Advanced Science and Technology. November 26, 2012. Retrieved December 7, 2012.
  19. ↑ "EIAST uses International Astronautical Congress platform to highlight achievements". AME Info. October 23, 2012. Retrieved December 7, 2012.
  20. ↑ "EIAST engineers reveal design details and specifications of DubaiSat-2". Emirates News Agency. May 25, 2011. Retrieved December 8, 2012.
  21. ↑ "DubaiSat-2 Space Segment". Emirates Institution for Advanced Science and Technology. Retrieved December 8, 2012.
  22. ↑ Tajmar, Martin; et al. (September 11, 2011). "Simulation of the Spacecraft Electric Propulsion Interaction on DubaiSat-2 using SPIS" (PDF). National Space Grant Foundation. Retrieved December 8, 2012.
  23. ↑ "DubaiSat-2 Ground Segment". Emirates Institution for Advanced Science and Technology. Retrieved December 8, 2012.
  24. ↑ "EIAST signs contract for DubaiSat-2 with Russia's ISCK". Indo-Asian News Service. Yahoo! News. February 16, 2011. Retrieved December 8, 2012.
  25. ↑ "EIAST, Russian company to launch DubaiSat-2 satellite". Middle East North Africa Financial Network. February 17, 2011. Retrieved December 8, 2012.
  26. ↑ "EIAST signs contract for launch of DubaiSat-2". Arabian Aerospace. February 17, 2011. Retrieved December 8, 2012.
  27. ↑ "DubaiSat-2 to be launched in 2013". Emirates 24/7. February 16, 2011. Retrieved December 8, 2012.
  28. ↑ "DubaiSat-2 project passes key tests to ensure it withstands rigours of space". Zawya. February 1, 2012. Retrieved November 18, 2012.
  29. ↑ "DubaiSat-2 design finalised". Khaleej Times. February 1, 2012. Retrieved December 8, 2012.
  30. ↑ "DubaiSat 2/: STSat 3/: Brite-PL 1/: WNISAT-1 Dnepr 1 Launch". Zapaday. November 16, 2012. Retrieved November 27, 2012.
  31. ↑ Shahbandari,Shafaat (December 19, 2012). "DubaiSat-2 to be launched mid-2013". Gulf News. Retrieved December 21, 2012.
  32. ↑ "Latest UAE satellite to launch soon". Digital Production Middle East. August 13, 2012. Retrieved December 8, 2012.
  33. ↑ "Latest UAE satellite set to be launched in next few months". Emirates News Agency. Retrieved December 8, 2012.
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