he "Zenit 2" is launched from Baikonur only now. Rocket stages arriving
from the Ukraine on railroad cars can be put in storage, or delivered directly to the
"Zenit" Assembly and Test Building. Three rail cars are used, one each for the
first stage, second stage, and fairing. All vehicle processing takes place in a horizontal
orientation. Using overhead bridge cranes, the elements of the launch vehicle are removed
from the rail shipping cars and transferred to special mating trolleys that are capable of
translating or rotating the stages to ensure proper alignment for mating. Any additional
required flight hardware is integrated onto the stages, the stages are mated together, and
the vehicle undergoes electrical and other tests. Only 76 work hours are needed to prepare
and integrate the arriving stages to the point where the spacecraft can be integrated.
Following vehicle preparation, the spacecraft is integrated onto the vehicle, electrical
connections are checked, and then the spacecraft is covered by the payload fairing. The
integrated launch vehicle can then be transferred to the transporter / erector rail cars
for transport to the launch pad. Spacecraft integration onto the launch vehicle requires
21 work hours (not counting separate spacecraft preparation activities), for a total of 91
h from arrival of the vehicle stages at the cosmodrome to the completion of vehicle
integration. Spacecraft processing may be performed in Area 31, Area 254, or at other
facilities used for commercial launch services of other launch vehicles. The facilities
include an Assembly and Test Building (ATB) for checkout operations, vacuum testing, and
antenna testing. Spacecraft fueling operations are conducted in a separate building.
"Zenit 2" launches are conducted
from Launch Complex 45, which includes two launch pads. However, Pad 45 Right suffered
heavy damage when "Zenit" Flight 15 exploded at liftoff. It has not been
repaired since, so all subsequent launches have used Pad 45 Left. Each pad is a large,
flat, concrete structure including an exhaust duct with a water noise suppression system.
The launch mount is a metal structure with four hold-down clamps, and automatic fittings
for automatic propellant filling and, if necessary, draining. The launch complex area
includes storage facilities for LOX and kerosene, as well as pressurized helium, nitrogen,
and air. Tall lightning towers protect the erected vehicle from lightning strikes.
The launch complex does not include a
traditional service tower or umbilical tower. Instead, the "Zenit" arrives in a
horizontal position on a transporter / erector system mounted on two railcars. The
transporter / erector automatically erects the vehicle into a vertical position using
large hydraulic pistons. The vehicle is supported by a simple erector structure during
this process. During the erection process the electrical, pneumatic, hydraulic, cooling,
and propellant loading connections automatically mate with the appropriate interfaces at
the base of the launch vehicle and at the top of the first stage. Once the vehicle is
fully integrated, the erector is retracted and moved away from the pad, leaving only a
small, simple tubular cable mast that carries the electrical and pneumatic connections
between the vehicle and the launch mount. There is also a movable service tower that is
capable of enclosing the upper portion of the launch vehicle. However, this was built to
support planned manned missions, and while it is available for conventional spacecraft, it
is not generally needed. |