Failure Prone Zenit Launch Vehicle Successfully Returns to Flight

Land Launch Zenit booster

The problem-plagued Zenit launch vehicle returned to flight on Saturday with the successful launch of the Israeli Amos-4 communications satellite from the Baikonur Cosmodrome in Kazakhstan. The 3.5-ton satellite, which was built by Israel Aerospace Industries for Israeli operator Spacecom, will deliver Ka- and Ka-band communications to the portions of the Middle East, Russia and south and east Asia.

This is the first successful flight of the rocket since the failure of a Sea Launch Zenit-3SL on Feb. 1. The launch vehicle crashed into the Pacific Ocean shortly after take-off when its first stage failed, taking the Intelsat 27 satellite down with it.

The Zenit launch vehicle, which has a success rate of just over 85 percent, was originally intended for multiple uses. Four Zenits were attached to the core of the giant Energia launch system designed to lift the Buran space shuttle into orbit. Zenits were also designed to fly separately as a replacement for the Soyuz booster for manned flights and as a satellite launcher.

However, the Soviet government retired the Energia launch system after only two flights.  Following the collapse of the Soviet Union in 1991, Zenit production ended up under the control of the newly independent Ukrainian government. Russia subsequently abandoned the idea using the rocket to replace the Soyuz booster for human spaceflight.

Zenits, which come in two- and three-stage configurations, are primarily used to launch single communications satellites. They are launched from two locations: the Baikonur Cosmodrome in Kazakhstan, and an ocean-going platform towed from the United States to an equatorial location. Sea Launch handles the ocean launches and also provides flights from Baikonur through Land Launch.

The rocket has had a troubled history since its introduction in 1985. A total of 81 Zenits have been launched, with 69 successes, 9 failures and three partial failures. The complete success rate is only 85.2 percent.

The multi-national Sea Launch consortium was formed in 1995 to launch Zenit rockets from a platform in the Pacific Ocean. The partners included Boeing of the United States, Energia of Russia, SDO Yuzhnoye/PO Yuzhmash of Ukraine, and Aker Solutions of Norway.

Sea Launch has 35 flights under its belt since 1999, with 31 successes, 3 failures and 1 partial failure, for a success rate of 88.6 percent.

Sea Launch’s history has been as troubled as its launches. A spectacular January 2007 failure in which the Zenit exploded on the launch pad set off a series of delays, financial obligations and customer defections that destabilized the company’s finances. Sea Launch filed for bankruptcy in June 2009.

In late October 2010, the company re-emerged from bankruptcy with an Energia subsidiary upping its share of the partnership from 25 percent to 95 percent. Boeing and Aker, now known as Kvaerner Moss Technology, split the remaining 5 percent.

The first four launches conducted under the new arranged succeeded. However, problems re-emerged in February when the Zenit launch vehicle failed shortly after lift-off and nose-dived into the sea.

Later that same month, Boeing sue Sea Launch, saying it is owed $350 million as a result of the bankruptcy. The lawsuit claims that the partners agreed to reimburse Boeing for investments the company made in Sea Launch if the venture failed. The legal action targets the Energia subsidiary that now runs Sea Launch. That subsidiary is owned by Energia and SDO Yuzhnoye/PO Yuzhmash.