Land surface imagery
Surface Water Extent
|Mission status||Mission complete|
|End of life date||14-04-2015|
|Measurement domain||Ocean, Land|
|Measurement category||Multi-purpose imagery (ocean), Multi-purpose imagery (land)|
|Measurement detailed||Land surface imagery, Surface Water Extent, Mineral Type|
|Instrument type||High resolution optical imagers|
Overview Spacecraft Launch Mission Status Sensor Complement References
EgyptSat-2, also called MisrSat-2, is Egypt's second Earth observation satellite. It was built by RSC Energia for operation by the NARSS (National Authority for Remote Sensing and Space Sciences) of Kairo, Egypt. In 2009, Egypt awarded a contract to Russia for the development of a high-resolution imaging satellite.
The goal of the mission is to collect high-resolution imagery of the Egyptian territory and surrounding regions for digital mapping, assessments of mineral, water and other resources, environmental monitoring, vegetation monitoring, studies of the headwaters of the Nile, and disaster management.
The project builds on the success of the EgyptSat-1 spacecraft launched atop a Dnepr rocket in 2007. EgyptSat-1 was capable of providing imagery with a ground resolution of 7.8 m operating from a Sun Synchronous Orbit at 660 km. Contact with the spacecraft was lost in 2010, but the mission demonstrated the benefits of the operation of an Earth observation satellite, providing detailed data for digital mapping purposes and various scientific studies.
EgyptSat-2 was designed and built by RSC (Rocket and Space Corporation) Energia and uses a variation of Energia's USP (Universal Satellite Platform) known as 559 GK bus (previously used on the Yamal-100 spacecraft series). The spacecraft has a launch mass of 1050 kg and utilizes a hexagonal satellite body that uses a modular design approach to allow the platform and payload to be manufactured separately for integration ahead of satellite testing. The spacecraft structure consists of low-mass composite materials with internal and external panels providing installation locations for satellite equipment. 1)
The spacecraft is 3-axis stabilized and very agile (the re-aiming speed is 2º/s). Attitude sensing is provided by high-precision star trackers and an IMU (Inertial Measurement Unit). Reaction wheels are used for attitude control achieving a high pointing accuracy to allow the acquisition of images of target areas.
Three deployable solar panels are used for power generation with a nominal power supply of up to 3 kW. The arrays are fixed and do not provide sun-tracking functions. Power is stored in Nickel-hydrogen batteries, a PCDU (Power Conditioning and Distribution Unit) provides a regulated 28.5 V power bus to all satellite subsystems. Thermal control is accomplished by using heat pipes and radiators to dissipate excess heat into space while insulation and heaters are used to keep equipment at stable temperatures.
The spacecraft uses a chemical propulsion system for orbit adjustments and maintenance. The USP bus also includes an optional electrical propulsion system, but it has not been specified whether EgyptSat-2 is utilizing such a system.
RF communications: An X-band system is used for payload data downlinks at rates of 300 to 600 Mbit/s to ground stations near Cairo and Aswan in southern Egypt. Telemetry data downlink and command uplink is accomplished via S-band.
The design life of EgyptSat-2 is 11 years.
Launch: EgyptSat-2 was launched on April 16, 2014 (UTC 16:20) on a Soyuz-U vehicle from the Cosmodrome in Baikonur, Kazakhstan. About 9 minutes after liftoff, the third stage shut down followed by the separation of the EgyptSat-2 spacecraft a few seconds later. 2) 3)
Orbit: Non-sun-synchronous orbit of 685 km x 710 km, inclination = 51.6º. The lower inclination allows the satellite to pass over Egypt more often than a satellite in a polar orbit.
• June 9, 2015: Egypt has lost control of the remote sensing EgyptSat-2 orbital satellite and is considering purchasing Russian satellite images of Earth, the Russian Kommersant daily reports. 4)
- In January 2015, control over the satellite was handed over to Egyptian specialists at NARSS (National Authority for Remote Sensing and Space Sciences). According to Kommersant, the satellite started to experience malfunctions in May. "The device can be considered lost: its on-board computer has frozen, the device is not responding to a single command from Earth and it was impossible to revive it. Most likely, the satellite cannot be restored," a space industry source told the newspaper on June 5, 2015.
- Egyptian and Russian experts have been working together to restore communication with the satellite since April 14, 2015.
- The Russian side cannot be blamed for the malfunction, as EgyptSat-2 started experiencing technical problems after it was put under full control of Egyptian specialists, Kommersant said, adding that Egypt is now eying the use of Russian commercial Earth observation satellite Resurs-P and the Kanopus-V1 (Canopus-B) satellite.
• Starting on May 1, 2014, the satellite started slowly raising its orbital altitude (perigee) with the help of an electric propulsion system.
• On April 30, 2014, EgyptSat-2 acquired its first images that were released in early May by RSC Energia showing Taylor Bay and Melbourne, Australia. The panchromatic images of Taylor Bay show boats on the piers of Lake Eildon and some clouds above the area. 5)
• Teams at RSC Energia began commissioning activities. By April 22, 2014, initial electrical testing and checks of the propulsion system had been completed with nominal results showing that the satellite was charging its batteries and distributing power to all subsystems.
• EgyptSat-2 was released into its orbit at ~ 10 minutes after liftoff. It then deployed its three solar panels for power generation, established a stable three-axis orientation and started communicating with ground stations.
MSI (Multispectral Imager)
RSC Energia sub-contracted the development of the satellite's imager and its data downlink system to OAO Peleng and NIRUP Geoinformatsionnye Sistemy in Belarus. The European consortium EADS Astrium (now Airbus Defence and Space) was also involved in the payload development (Ref. 2).
MSI uses a folded-optics design to achieve the required focal length. The imager covers the visible spectral band as well as infrared radiation using CCD detectors, focal plane electronics and analog/digital converters to generate its images. The payload supports multispectral and panchromatic imaging covering a FOR (Field of Regard) of up to 1,400 km, depending on the imaging mode and the required resolution.
In multispectral mode, the instrument acquires full color images at a resolution of 4 m. Panchromatic images achieve a resolution of 1 m. The optical imager supports various modes of operation including single-scene imaging, route imaging, mapping and stereo imagery acquisition.
1) Patrick Blau, "Soyuz-U Rocket successfully launches EgyptSat-2 Earth Observation Satellite," Spaceflight 101, April 16, 2014, URL: http://www.spaceflight101.com/soyuz-u---egyptsat-2-launch-updates.html
2) Anatoly Zak, "Russia launches spy satellite for Egypt," URL: http://www.russianspaceweb.com/egyptsat2.html
3) "EgyptSat-2 (MisrSat-2) spacecraft launch," URL: https://web.archive.org/web/20140416231526/http://www.tsenki.com/en/launch_services/help_information/launch/2014/?EID=108885
4) "Egypt Mulls Buying Russian Satellite Images After EgyptSat 2 Loss," Space Daily, June 9, 2015, URL: http://www.spacedaily.com/reports/Egypt_Mulls_Buying_Russian_Satellite
5) Patrick Blau, "EgyptSat-2 Satellite collects first Images of Earth," Spaceflight 101, May 5, 2014, URL: http://www.spaceflight101.com/soyuz-u---egyptsat-2-launch-updates.html
The information compiled and edited in this article was provided by Herbert J. Kramer from his documentation of: "Observation of the Earth and Its Environment: Survey of Missions and Sensors" (Springer Verlag) as well as many other sources after the publication of the 4th edition in 2002. - Comments and corrections to this article are always welcome for further updates (firstname.lastname@example.org).
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