Israel launched its Shavit rocket for the first time since 2014 on Tuesday, carrying an Ofek reconnaissance satellite into low Earth orbit. However, while Israel confirmed the satellite has reached orbit, officials soon cited unspecified problems with the spacecraft during the checkout period post-launch.
Ofek, also transliterated Ofeq – from the Hebrew word for Horizon – is aside from its first two members a series of reconnaissance satellites operated by Israel’s Ministry of Defence. In contrast, the first two spacecraft were used for research and technology demonstration.
Tuesday’s launch, which appears to have carried an optical imaging satellite, took place at 16:38 local time (14:38 UTC) from the Palmachim airbase on Israel’s Mediterranean coast following a 24-hour delay due to adverse weather.
Israel did not announce the launch until the spacecraft was already in orbit.
Reports shortly after the launch suggested that the satellite had experienced some form of problem during its early phases of operation.
Amnon Harari, the head of the Space department within Israel’s Ministry of Defence, informed reporters of “indications of some things that aren’t working as we expected”, and that work would be ongoing to “stabilise” the spacecraft over the next few days.
The first Ofek satellite, Ofek-1, was Israel’s first satellite and was placed into orbit on the Shavit rocket’s maiden flight in September 1988, making Israel the eighth country to develop an indigenous orbital launch capability. A second satellite, Ofek-2, followed eighteen and a half months later in April 1990.
Since these two early launches, the Ofek name has been used for military satellites.
Israel has continued to launch its Ofek satellites using its own vehicles – with the exception of Ofek-8 – while relying upon foreign commercial launches for is other payloads including the Earth Resources Observation Systems (EROS) civilian imaging satellites and Amos communications satellites.
Tuesday’s launch comes less than a fortnight after the Amos-6 satellite was lost when the Falcon 9 rocket that was to have carried it to orbit exploded during fuelling for a static fire test two days ahead of its planned launch.
With the Shavit its only orbit-going rocket and Ofek the only series of satellites launching atop it, Israel’s launch frequency is lower than most other spacefaring nations. The country has never attempted more than one orbital launch in a calendar year – the shortest time between two Shavit launches was the eighteen-and-a-half months between the rocket’s first and second launches.
Occurring six days short of the twenty-eighth anniversary of Israel’s first orbital launch, Tuesday’s is the country’s tenth known orbital launch attempt and the eighth to achieve orbit.
The Ofek-11 satellite which was launched Tuesday is believed to be an optical imaging satellite, like the majority of the Ofek series. The first such spacecraft, Ofek-3 was deployed in April 1995 and was followed by Ofek-4 in January 1998, Ofek-5 in May 2002, Ofek-6 in September 2004, Ofek-7 in June 2007 and Ofek-9 in June 2010.
The Ofek-4 and Ofek-6 satellites were both lost in launch failures, which are the only known failures for Israel and its Shavit rocket.
The Ofek-8 designation was assigned to the TecSAR or Polaris radar imaging satellite, launched aboard an Indian Polar Satellite Launch Vehicle (PSLV) in January 2008 as part of a cooperation between Israel and the Indian Space Research Organisation (ISRO) which also saw India purchase an Israeli radar imaging payload to fly aboard its RISAT-2 spacecraft, launched the following year.
Ofek-10 was a followup mission which was launched by Shavit in April 2014.
Ofek spacecraft are manufactured by Israel Aerospace Industries (IAI), Israel’s state-owned aerospace manufacturing corporation.
Optical imaging satellites launched to date have been based upon the OPSAT-2000 bus, also used for the civilian EROS satellites, with Ofek-3 and 4 first-generation satellites and the subsequent missions introducing improved capabilities.
The most recently-launched spacecraft, Ofek-9, was estimated to have a mass at launch of around 300 kilograms (660 lb) and a design life of five years. It has been in orbit for six and a quarter years.
It is currently unclear whether Ofek-11 is a further second-generation spacecraft or the beginning of a third generation of optical satellite.
Prior to the inclusion of the radar imaging satellites in the Ofek series, the spacecraft then known as Ofek-8 (which launched as Ofek-9) was to have been the last based on the OPSAT-2000 bus, with a spacecraft then known as Ofek-9 being the first of a new third generation based upon the OPSAT-3000 platform.
In 2009 reports suggested that the third-generation satellite was on hold while Israel sought international partners for its development.
Israel’s Shavit rocket is based on the Jericho II missile that was developed in the 1980s, itself an improved version of the original Jericho which was initially developed in conjunction with French aerospace manufacturer Dassault and which became operational in the early 1970s.
A solid-fuelled three-stage vehicle, three versions of Shavit have flown to date. The first two launches used ATSM-9 motors – also used on the Jericho II – as first and second stages, with an AUS-51 motor serving as the third stage.
The second configuration, known as the Shavit-1, used a stretched ATSM-13 motor as the first stage, while retaining the ATSM-9 as the second stage. The third, Shavit-2, replaced both ATSM-9 motors with ATSM-13s. The AUS-51 motor remains unchanged across the three versions.
The Shavit-1 was used for four launches, Ofek-3 to 6, between 1995 and 2004. Since 2007 all launches have used the Shavit-2, and images of Tuesday’s launch indicate that this configuration has again been used in the launch of Ofek-11.
Shavit launches take place from the Palmachim airbase, on Israel’s west coast, which has been the site for all of Israel’s orbital launches and has also been used for missile tests. T
o avoid overflying Israel’s Arab neighbours, all launches from Palmachim must fly west over the Mediterranean, as a result of which Ofek satellites operate in retrograde orbits.
Launching westwards also decreases the Shavit’s payload capacity as it is flying against the direction of Earth’s rotation, requiring more thrust to place the same amount of payload into orbit compared to if it were able to fly eastwards.