The Earth Remote Observation System-A (EROS-A or EROS-A1) was part of the

EROS In Greek mythology, Eros (, ; grc, Ἔρως, Érōs, Love, Desire) is the Greek god of love and sex. His Roman counterpart was Cupid ("desire").''Larousse Desk Reference Encyclopedia'', The Book People, Haydock, 1995, p. 215. In the ear ...

family of Israeli commercial Earth observation satellites, designed and manufactured by

Israel Aircraft Industries Israel Aerospace Industries (Hebrew: התעשייה האווירית לישראל ''ha-ta'asiya ha-avirit le-yisra'el'') or IAI (תע"א) is Israel's major aerospace and aviation manufacturer, producing aerial and astronautic systems for both mi ...

(IAI). This was the first satellite in the series. The satellite was owned and operated by

ImageSat International Earth Resources Observation Satellite (EROS) is a series of Israeli commercial Earth observation satellites, designed and manufactured by Israel Aircraft Industries (IAI), with optical payload supplied by El-Op. The satellites are owned and operat ...

, ImageSat International N.V. (ISI) headquartered at

Limassol Limassol (; el, Λεμεσός, Lemesós ; tr, Limasol or ) is a city on the southern coast of Cyprus and capital of the district with the same name. Limassol is the second largest urban area in Cyprus after Nicosia, with an urban population ...

Cyprus Cyprus ; tr, Kıbrıs (), officially the Republic of Cyprus,, , lit: Republic of Cyprus is an island country located south of the Anatolian Peninsula in the eastern Mediterranean Sea. Its continental position is disputed; while it is ge ...

, and incorporated in the Netherlands Antilles, Cayman Islands.

Launch

The EROS A was launched on 5 December 2000, at 12:32 UTC, from Svobodny Cosmodrome, Launch Complex-5 in

eastern Siberia Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part of ...

Satellite description

The satellite was 1.2 m in diameter, 2.3 m in height. It weighed 260 kg at launch. The design was based on the military reconnaissance satellite Ofeq-3, which was previously built, also by

Israel Aerospace Industries Israel Aerospace Industries (Hebrew: התעשייה האווירית לישראל ''ha-ta'asiya ha-avirit le-yisra'el'') or IAI (תע"א) is Israel's major aerospace and aviation manufacturer, producing aerial and astronautic systems for both mi ...

(IAI) for Israeli government use.

Control systems

The satellite was equipped with a

three-axis stabilized Spacecraft attitude control is the process of controlling the orientation of a spacecraft (vehicle/satellite) with respect to an inertial frame of reference or another entity such as the celestial sphere, certain fields, and nearby objects, et ...

and a four

reaction wheels A reaction wheel (RW) is used primarily by spacecraft for three-axis attitude control, and does not require rockets or external applicators of torque. They provide a high pointing accuracy, and are particularly useful when the spacecraft must be ...

actuator. The satellite is also equipped with horizon sensors, sun sensors, gyroscopes and magnetometer for altitude determination.

Ground communication systems

The satellite is equipped with a 70

Mbit/s In telecommunications, data-transfer rate is the average number of bits ( bitrate), characters or symbols ( baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are mu ...

imagery link, a 15

kbit/s In telecommunications, data-transfer rate is the average number of bits (bitrate), characters or symbols (baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are multi ...

maintenance downlink, and a 15 kbit/s command uplink.

Mission

The satellite always crosses the equator at 10:00 am local time. Future satellites were planned to extend the time dimension to vary the crossing time between mid-morning and mid after. This will allow it to compensate for poor visibility conditions arising from clouds at different altitudes. While the satellite's primary purpose is

agricultural engineers Agricultural engineering, also known as agricultural and biosystems engineering, is the field of study and application of engineering science and designs principles for agriculture purposes, combining the various disciplines of mechanical, civil ...

, planners and other professionals who need detailed pictures of different places in the world, it can also be used for various other applications. The satellite provides commercial images with an optical resolution of 1.8 metres using. It has optical resolution capabilities of up to 1.2 meters. The satellite can be temporarily controlled by a customer when it passes over the areas of interest. This is used to allow the client privacy without the operator knowing what's being looked at. This capability, however, is not allowed over the State of Israel by the Israeli government. Following its launch, the first customer announced was the Ministry of Defense of Israel, which paid about $15 million for the exclusive rights to receive all images of Israel's territory and an area within a radius of about 2,000 km. The need for the satellite's capabilities was due to the failure of the launch of the Ofek-4 satellite, two years earlier and the decay of Ofek-3. Other customers of the satellite were the Taiwan Defense Ministry,

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

, and media organizations that purchased footage from the battlefield at the start of the Afghan war, footage that competitor "Space Imaging" (Owner of Ikonos) was banned from selling by the US government. Additionally, a database was established with photographs of the satellite that were sold to companies around the world on demand. The satellite increased its orbital altitude for the last time on 24 April 2012 and reentered on 7 July 2016.

References