Ofeq
ManufacturerIsrael Aerospace Industries
Country of originIsrael
OperatorIsraeli Ministry of Defence / Tsahal
ApplicationsReconnaissance
Specifications
RegimeLow Earth orbit
Production
StatusActive
Built13
Launched13
Maiden launch19 September 1988 (Ofeq-1)
Last launch29 March 2023 (Ofeq-13)

Ofeq, also spelled Offek or Ofek (Hebrew: אופק, lit. Horizon) is the designation of a series of Israeli reconnaissance satellites first launched in 1988. Most Ofeq satellites have been carried on top of Shavit launch vehicles from Palmachim Airbase in Israel, on the Mediterranean coast. The low Earth orbit satellites complete one Earth orbit every 90 minutes.

The satellite launches made Israel the eighth nation to gain an indigenous launch capability. Both the satellites and the launchers were designed and manufactured by Israel Aerospace Industries (IAI) with Elbit Systems' El-Op division supplying the optical payload.

Description

While exact technical details and capabilities are classified, it is assumed that the Ofeq satellites have an effective operational lifespan of 1–3 years and ultraviolet and visible imaging sensors, except Ofeq-8 and -10 which utilize synthetic-aperture radar (SAR) for all-weather and nighttime reconnaissance. Some reports place the imaging resolution at 80 cm for Ofeq-5.[citation needed]

Most satellites are launched eastward to gain a boost from the Earth's rotational speed. However, Ofeq satellites are launched westward, in retrograde orbits, over the Mediterranean to avoid flying over, and dropping spent rocket stages over, populated land areas. Other Israeli satellites, such as the AMOS series, are launched from locations in other countries.[1]

Orbital characteristics

Ofeq's east-to-west orbit of 143.0° orbital inclination is phased to give good daylight coverage of the Middle East.[2] Some American and Russian observation satellites have near-polar orbits and make between 14 and 16 orbits per day, but pass over Israel on fewer orbits. Spacecraft need to reach roughly 27,000 km/h (7,500 m/s) to achieve low Earth orbit.

At 31.88°N, the latitude of Palmachim Airbase, where the angular velocity of the Earth is around 1,420 km/h (390 m/s) to the east, westward launched Ofeq satellites must use more fuel to counter starting going 1,420 km/h the opposite direction. Many other observation satellites with prograde orbits have the same maximum latitude and cover the same areas of the Earth. However the retrograde orbit of Ofeq increases the relative speed to the surface of the Earth and thusly increases the average number of times they pass over Israel on each revolution.

Ofeq satellites make a half-dozen or so daylight passes per day over Israel and the surrounding countries, whereas non-Israeli observation satellites in Sun-synchronous orbits get one or two passes per day from their lower inclination orbits.

Since its launch in 2002, Ofeq-5's orbital inclination of 143.4 has been the most-inclined orbit of all of Earth's artificial satellites.[3]

Launch history

References

  1. ^ "AMOS-1 → Intelsat 24". space.skyrocket.de. 18 November 2019. Retrieved 8 May 2021.
  2. ^ a b Stephen Clark (10 April 2014). "All-weather surveillance satellite put in orbit by Israel". Spaceflight Now. Retrieved 12 April 2014.
  3. ^ "UCS Satellite Database - Union of Concerned Scientists". Union of Concerned Scientists. Retrieved 23 May 2022.
  4. ^ Shavit Archived 9 April 2016 at the Wayback Machine Federation of American Scientists
  5. ^ "Israel successfully launches Ofeq-7 satellite". Israel Ministry of Foreign Affairs.
  6. ^ a b Opall-Rome, Barbara (22 June 2010). "Israel Launches Ofeq-9 Satellite". Defense News. Archived from the original on 7 September 2012. Retrieved 22 June 2010.
  7. ^ Greenberg, Hanan (23 June 2010). "Israel launches spy satellite". Ynetnews. Retrieved 6 July 2020.
  8. ^ "Israel Launches New Spy Satellite, Ofeq-11". Haaretz.
  9. ^ Anna Ahronheim (6 July 2020). "Israel successfully launches Ofek 16 spy satellite into space". The Jerusalem Post. Retrieved 6 July 2020.
  10. ^ @Israel_MOD (28 March 2023). "The Israel Ministry of Defense, IAI & IDF successfully launched the "Ofek 13" satellite at 02:10 IST today (Wednesday). The satellite entered orbit, has begun transmitting data, and completed an initial series of inspections in accordance with original launch plans" (Tweet). Retrieved 29 March 2023 – via Twitter.