October 4, 1990 – the 14th launch of the new booster "Zenith" (production designation 11K77).

The "Zenith" booster is considered to be the best Russian booster of the "middle class" with a capacity to deliver to low orbit (200 kilometers) a 13.8-ton payload. Considered best because it had two main differences with all other boosters:

It used oxygen-hydrogen fuel and thus is a very "clean" booster, it's installation on the launch pad was practically automatic and did not require a "service team" which was very convenient for military purposes.

Another "specialty" of the booster was that it's production facilities were mainly in the Ukraine – at Science Production Union "Southern" – formerly Yangel's Design Bureau.

The decision to design this booster was approved in 1976, in conjunction with the decision regarding the heavy booster "Energiya". Zenith was part of the "Energiya" booster (side booster), but designed before the main booster as a separate booster of multipurpose usage.

The "story" of Zenith was rather difficult. It's first test launch was conducted on March 13, 1985. Despite the fact that 2 of 13 test launches ended with explosions – there was a lot of pressure from the political top – to approve the booster as the "standard" for the Army (as heavy ICBM and as Space booster).

There were a number of reasons for that "pressure".

First – political – because of relations with the Ukraine. Though it was still the Soviet Union there was a growing desire on the part of regional politicians for "freedom" from Central Power. Note – that later "Zenith" became even more important for relations between Russia and the Ukraine – because the Director of "Southern" Design Bureau Leonid Kuchma became the President of the Ukraine.

Second – the Military insisted on a new heavy booster, because all other boosters were rather old (the latest was "Molniya" – approved as "standard" in 1977, but a variation of the same R-7 of 1957).

Third – approval of Zenith – would give another argument to the designers of "Energiya" – and thus better financing.

With those presures, Zenith was formally approved as the "standard" booster in 1989 – but for the first time – with a "separate opinion" written by the Baikonur Commander-in-Chief. The Science-Technical Commission of Baikonur made a negative conclusion re: the results of test launches and insisted on further research and testing, before approving the booster as "standard". But the decision was made nonetheless.

October 4, 1990 was the 14th launch of "Zenith" – and the first "exploitation" launch of the "standard" booster – with an electronic spy satellite "Tselina-2" aboard.

At the 3rd second of the flight (70 meters above the pad) the tubes of one of the engines burned through, and the booster fell onto the launch pad and exploded. The launch "table" was actually lifted 20 meters high and then fell back. The entire lunch pad was completely destroyed. (No casualties).

It took two more years to fix the problems with different booster systems, two other tests launches – also had accidents. Finally, in November 1992 they managed to have a successful launch. Since that time there have been 11 launches of the booster (mainly – military satellites) – all were successful, except for 1 accident in 1998 (the booster fell and exploded around 500 meters from the launch pad).

There is only one launch pad for Zenith – in Baikonur and it is a second one. The first was destroyed in 1990. A launch pad at the Plesetsk space range was supposed to be the main Zenith launch facility but has been under construction for 6 years and due to lack of funds, will possibly never be finished.