DubaiSat-2 ( ar, دبي سات-2) is an electro-optical

Earth observation satellite An Earth observation satellite or Earth remote sensing satellite is a satellite used or designed for Earth observation (EO) from orbit, including spy satellites and similar ones intended for non-military uses such as environmental monitoring, ...

built by the Emirates Institution for Advanced Science and Technology under an agreement with Satrec Initiative, a satellite manufacturing company in

South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia, constituting the southern part of the Korea, Korean Peninsula and sharing a Korean Demilitarized Zone, land border with North Korea. Its western border is formed ...

. EIAST's objective with DubaiSat-2 is to provide electro-optical images, that can be commercialized, for users within the

United Arab Emirates The United Arab Emirates (UAE; ar, اَلْإِمَارَات الْعَرَبِيَة الْمُتَحِدَة ), or simply the Emirates ( ar, الِْإمَارَات ), is a country in Western Asia (Middle East, The Middle East). It is ...

and beyond and to develop and implement new technologies not used in DubaiSat-1. EIAST also intends to continue manpower training for the UAE's

space program A space program is an organized effort by a government or a company with a goal related to outer space. Lists of space programs include: * List of government space agencies * List of private spaceflight companies * List of human spaceflight prog ...

. 16 UAE

engineers Engineers, as practitioners of engineering, are professionals who invent, design, analyze, build and test machines, complex systems, structures, gadgets and materials to fulfill functional objectives and requirements while considering the li ...

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 percent from the DubaiSat-1 project.

Overview

The space segment consists of a

spacecraft bus A satellite bus (or spacecraft bus) is the main body and structural component of a satellite or spacecraft, in which the payload and all scientific instruments are held. Bus-derived satellites are opposed to specially produced satellites. Bus ...

and an

electro-optical Electro–optics is a branch of electrical engineering, electronic engineering, materials science, and material physics involving components, electronic devices such as lasers, laser diodes, LEDs, waveguides, etc. which operate by the pr ...

payload Payload is the object or the entity which is being carried by an aircraft or launch vehicle. Sometimes payload also refers to the carrying capacity of an aircraft or launch vehicle, usually measured in terms of weight. Depending on the nature of ...

. The electro-optical payload is a push-broom camera with Time Delay Integration (TDI) sensors (1

panchromatic Panchromatic emulsion is a type of black-and-white photographic emulsion that is sensitive to all wavelengths of visible light. Description A panchromatic emulsion renders a realistic reproduction of a scene as it appears to the human eye, altho ...

and 4 multi-spectral bands). DubaiSat-2 is designed for a

sun-synchronous orbit A Sun-synchronous orbit (SSO), also called a heliosynchronous orbit, is a nearly polar orbit around a planet, in which the satellite passes over any given point of the planet's surface at the same local mean solar time. More technically, it is ...

of 600 km, with a

spatial resolution In physics and geosciences, the term spatial resolution refers to distance between independent measurements, or the physical dimension that represents a pixel of the image. While in some instruments, like cameras and telescopes, spatial resolut ...

of 1m PAN and 4m Multispectral (MS), and a Swath of 12.2 km. The modules in the satellite use two

CAN Bus A Controller Area Network (CAN bus) is a robust vehicle bus standard designed to allow microcontrollers and devices to communicate with each other's applications without a host computer. It is a message-based protocol, designed originally for m ...

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 Propulsion is the generation of force by any combination of pushing or pulling to modify the translational motion of an object, which is typically a rigid body (or an articulated rigid body) but may also concern a fluid. The term is derived from ...

for orbit correction and maintenance. The satellite's expected lifetime is at least five years.

Space segment

DubaiSat-2 has a

hexagonal In geometry, a hexagon (from Greek , , meaning "six", and , , meaning "corner, angle") is a six-sided polygon. The total of the internal angles of any simple (non-self-intersecting) hexagon is 720°. Regular hexagon A '' regular hexagon'' has ...

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 In engineering, a longeron and stringer is the load-bearing component of a framework. The term is commonly used in connection with aircraft fuselages and automobile chassis. Longerons are used in conjunction with stringers to form structural ...

and rails make up the bus structure frame. On the top, carbon-fiber-reinforced polymer (CFRP)

strut A strut is a structural component commonly found in engineering, aeronautics, architecture and anatomy. Struts generally work by resisting longitudinal compression, but they may also serve in tension. Human anatomy Part of the functionality o ...

s 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. 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 A lithium-ion or Li-ion battery is a type of rechargeable battery which uses the reversible reduction of lithium ions to store energy. It is the predominant battery type used in portable consumer electronics and electric vehicles. It also see ...

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 450 W of power using four solar panels. Each solar panel contains 6 arrays and each array consists of 26

cells Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Locations * Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery w ...

. 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.

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. 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. 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. 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.

Propulsion system

DubaiSat-2 is propelled by a

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.

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 A ground station, Earth station, or Earth terminal is a terrestrial radio station designed for extraplanetary telecommunication with spacecraft (constituting part of the ground segment of the spacecraft system), or reception of radio waves f ...

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.

Launch

DubaiSat-2 was successfully launched by a

Dnepr Dnepr may refer to: *Dnieper, a river flowing through Russia, Belarus and Ukraine to the Black Sea *Dnepr (motorcycle), a Ukraininan motocycle brand *Dnepr (rocket), a 1999 space launch vehicle *Dnepr radar, Soviet space surveillance and early warn ...

rocket operated by Kosmotras of the

Russian Federation Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eig ...

. It has been placed into a polar

Sun Synchronous Orbit A Sun-synchronous orbit (SSO), also called a heliosynchronous orbit, is a nearly polar orbit around a planet, in which the satellite passes over any given point of the planet's surface at the same local mean solar time. More technically, it is ...

at an altitude of 600 km and local UAE time of descending node of 10:30 am. 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 rocket, with an additional payload remaining attached to the upper stage. 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

In 2018, DubaiSat-2 and its predecessor, DubaiSat-1, was joined and will work together with UAE's third satellite,

KhalifaSat KhalifaSat ( ar, خليفة سات), also known as DubaiSat-3 ( ar, دبي سات-3), is a remote sensing Earth observation satellite that was designed and built at the Space Technology Laboratories of the Mohammed bin Rashid Space Centre in Dub ...

References

{{DEFAULTSORT:Dubaisat-2 Spacecraft launched in 2013 Space program of the United Arab Emirates Earth imaging satellites Spacecraft launched by Dnepr rockets