Dnepr (R-36M2)

National Space Agency of Ukraine * KB Yushnoye * ISC KOSMOTRAS

Die Dnepr  (R-36M2) ist verwandt mit der Zyklon-2 (R-36) aber weist deutliche Unterschiede auf. Sie ist wie diese zweistufig, aber mit einer zusätzlichen, in den erweiterten Fairing  integrierten Oberstufe (PBV) aufgerüstet. Im Unterschied zur Zyklon fehlen bei der Dnepr in beiden Stufen die charakteristischen externen Steuertriebwerke. Das Triebwerk der ersten Stufe bündelt vier einzelne RD-263 und RD-264 Triebwerke, die zweite Stufe hat ein einzelnes Triebwerk RD-0256 mit 4 internen Steuerdüsen RD-0257 (Kombination = RD-0255).
Die Dnepr wird von NPO Yushnoye/PO Yuzhmash (Ukraine) entwickelt und von ISC KOSMOTRAS (Rußland/Ukraine) vermarktet. Die Dnepr wird in 3 Varianten geplant. Dnepr-1 wird die genannte dreistufige Version genannt. Bei der Dnepr-M wird das Antriebssystem der dritten Stufe modifiziert sein. Die Dnepr-3 wird vierstufig (+ Space Tug) und in der Lage sein, auch geostationäre Satelliten zu platzieren.
Der erste Start einer Dnepr-1 erfolgte am 21.04.1999 mit dem  0,325 t schweren Satelliten UOSAT 12 von Tyuratam (Kasakstan) aus einem unterirdischen Silo.

The Dnepr space launcher is a converted R-36M2 ICBM. "Kosmotras", an international company which includes the "Yuzhnoye" design bureau the constructor of the missile, is marketing the vehicle. "Kosmotras" was given the rights by the Russian Government to convert and launch over 150 missiles as "Dnepr" launch vehicles. The Dnepr built by OKB "Yuzhnoye" at Dnepropetrovsk (Ukraine) and is 34.3 m high 3.0 m diameter and weighed 210 metric tons. The Dnepr uses liquid propellant (N2O4 and UDMH). The first stage has a RD-264 Glushko motor (NPO Energomash) with integrated flux and 4 combustion chambers. It features 4160 kN thrust and 293 s Isp at ground level (4520 kN and 318 s in vacuum). The second stage propulsion block consists of a mono-chamber motor surrounded by a set of 4 vernier motors designed by Kosberg (KB Kimautomatiki). The RD-0228 of the initial versions were replaced by RD-0255. This provides 755 kN thrust to the second stage. The Dnepr is equipped with an additional missile post-boost stage. It has a Yangel (KB Yuzhnoye) RD-864 (later RD-869). The thrusters of this system point forward instead of aft. To be used for orbit injection, the stage must flip around to point its thrusters (and payload) backward.
Dnepr payloads are contained in a Space Head Module, which comprises by the payload fairing, a nonseparating intermediate section, a payload adapter with a protective membrane, a Gas Dynamic Shield (GDS) or Encapsulated Payload Module (EPM), and the spacecraft.
The Dnepr payload fairing is the same design used on the R-36M2 ICBM. It is shaped in four conical sections, with a longitudinal joint held together by 28 pyrotechnic devices that can split the fairing into two sections. The sections are mounted to a fixed cylindrical skirt by 8 more pyrotechnic devices. When the devices are activated, the halves are pushed apart by 4 springs on each half, and rotate before being released at a predetermined angle. The intermediate section is a fixed cylindrical spacer that provides additional payload volume. It is typically 2080 mm (81.9 in.) long, but larger units up to 4080 mm (160.6 in) long can be used for larger payloads.
The payload adapter mounts to the bottom ring frame of the intermediate section, and interfaces directly to one or more spacecraft. A protective membran at the top of the adapter isolates the spacecraft from the third stage avionics compartment. To protect the spacecraft from ground contamination and the exhaust of the forward-pointing third stage thrusters, either a GDS or an EPM is used. The GDS is a thin sheet mounted to the forward end of the intermediate skirt. The EPM is a two-piece shell that is mounted inside the Space Head Module. The GDS or the forward section of the EPM is separated in before spacecraft deployment.
The Dnepr launch vehicie does not have the capability to deploy payloads directiy into GTO. However, Kosmotras has studied a technique to deliver small spacecraft to GEO using the gravity of the Moon to provide the plane change and perigee raising. In this scenario, the spacecraft is attached to Star 48A and Star 27 solid motors, supplied separately by ATK Thiokol. The Star48A would send the spacecraft to the Moon, where a gravity slingshot maneuver would lower the transfer orbit inclination from 50.5 deg to 0 deg, and raise the orbit perigee to geostationary altitude. When the spacecraft reaches perigee of the new transfer orbit, the Star 27 motor would fire to circularize the orbit at GEO. Using this method, a 500 kg (1100 lbm) spacecraft could be delivered to GEO.

MKK Kosmotras and the Strategic Rocket Forces of Russia (RVSN) are negotiating with the administration of the Orenburg oblast, in southern Russia, to conduct orbital launches with its Dnepr vehicles from the Dombarovski strategic missiles base (50°45'N, 59°30'E), some 15 km from the Kazakhstan border.