By the end of the Cold War in 1991, the UR-100N missile developed by the collective of Vladimir Chelomei had been the most numerous strategic weapon in the Soviet nuclear fleet. Capable of carrying up to six warheads, the UR-100NU started flying in 1977, and some 360 missiles, known in the West as SS-19, had been manufactured by the Khrunichev plant in Moscow, by the time their production stopped in 1991.

Technical description

With the end of the Cold War, the Khrunichev enterprise in Moscow, which used to manufacture the UR-100N-type missiles, started converting the weapon into the Rockot space booster. At the same time, NPO Mashinostroenia, which originally developed the UR-100 family of missiles, proposed its own conversion project dubbed "Strela" (Arrow).

Unlike Rockot, which incorporated a brand-new Breeze upper stage to make a space launcher, the Strela would require only minor modifications on the original missile. The UR-100NU was equipped with the so-called, APB (Agregatno-Priborny Otsek), which was essentially a maneuverable platform designed to deliver multiple warheads to their targets. In the Strela project, engineers reprogrammed the APB to work as the third stage pushing its payload into orbit. A special avionics section with the diameter 2.4 meters and length of 800 millimeters was fitted on top of the third stage. It would contain guidance and flight control hardware:

• Trajectory measuring equipment;
• The system for relaying telemetry to the ground control;
• System for the emergency cutoff of the engines on the first and second stages of the rocket;
• Additional stabilization system, which would stabilize the rocket during coastal phase of flight, when main engines are not firing;

The payload would be attached to the interface located on top of the avionics section. The spacecraft would be protected in flight either by standard warhead firing from the UR-100NU rocket or by a "stretched and narrow" fairing, which was tested with the latest reincarnations of the missile. The payload sections were designated KGCh-1 and KGCh-2 respectively.

In a typical launch, the first stage of the rocket separates at the altitude of about 70 kilometers, which is followed by the separation of the payload fairing at the altitude of 114 kilometers during the burn of the second stage. The second stage separates upon reaching the altitude of around 200 kilometers and the third stage with the payload then coasts passively before its own small thrusters fire to complete the orbital insertion.

Technical specifications of the Strela launcher:

Payload capacity

For its initial test flights, the Strela launcher would utilize the existing launch silos of the UR-100NU rocket in Baikonur Cosmodrome and then fly operational missions from the silos at the retired ICBM base in Svobodny in the Russian Far East. The facilities would require only minimal modifications.

From Baikonur, the Strela would be able to enter the orbit with the inclination 62.8 degrees toward the Equator delivering around 1,400 kilograms of payload to the altitude of about 200 kilometers. Around 500 kilograms could be boosted to the altitude of 1,800 kilometers with the same inclination.

When flying from Svobodny, the Strela would be able to access a wide range of orbits with the inclinations from around 52 to 61 degrees and near-polar orbits from 90 to 97 degrees toward the Equator. Under 1,600 kilograms could be inserted into a 200-kilometer orbit with the inclination 51.8 degrees and 1,110 kilograms could be boosted to the Sun-synchronous orbit, overflying North and South poles of Earth. (190)

Development

While Khrunichev enterprise used its established marketing muscle to market Rockot booster internationally, NPO Mash was "selling" the Strela to the Russian government along with a family of its semi-military satellites, among them remote sensing Condor-E spacecraft, carrying radar and optical payloads. Not surprisingly, it took much longer for the Strela to reach the launch pad, then for the Rockot backed by foreign investors.

As of 2001, the first test launch of the Strela booster from Baikonur was expected in the second or third quarter of 2002, however lack of funding kept delaying the mission.

The first Strela was reportedly lowered into the silo at Site 132 around February 2003, however the launch did not take place until December of that year.

The first test flight

2003 Dec. 5: After years of delays, the Strela booster flew its first orbital mission from Baikonur Cosmodrome. The vehicle blasted off from the underground silo facility at Site 132 at 09:00 Moscow Time on December 5, 2003. The rocket then successfully delivered its payload into a 404 by 465-kilometer orbit with the inclination 67 degrees. However, the press service of the Russian strategic missile forces mistakenly identified the mission as a sub-orbital training launch of the 25-year-old ballistic missile and the official Russian media blindly disseminated the report.

UR-100N UTTKh family tech dossier:

An experimental launch of the UR-100NU missile with the "stretched" payload firing adopted for the Strela project and designated KGCh-2 from Baikonur. (Photo was taken sometimes before August 2001) (Note lighting tower of the Proton launch complex at Site 200 on the background.) Credit: NPO Mash

Main elements of the Strela launcher. Credit: NPO Mash

The payload section of the Strela booster designated KGCh-2. Copyright: © 2001 by Anatoly Zak

The payload section of the Strela booster with the mockup of the Condor spacecraft, carrying optical remote-sensing payload. Copyright: © 2002 by Anatoly Zak

The Condor-E spacecraft with the radar payload was considered a main payload for the Strela launcher. Copyright: © 2002 by Anatoly Zak