Auxiliary power system
During the return on earth Buran glide without engine, but in a plane the turbojets supply the energy for the on-board systems. For Buran they made an auxiliary power group (VSU) which is plug on the hydraulic system (elevons, rudder, brake system, actuators).
To guarantee the safety 3 auxiliary power groups are installed on each of 3 hydraulic canals, guaranteeing the well functioning of the actuators after 2 breakdowns.
Every VSU includes the engine, the pipe of evacuation, the arrival of fuel, the automatic system and the panel of maintenance on the ground.
Picture of a VSU, auxiliary engine РТВД-14 at OKB Archippus Cradle (now NPO "Saturn"):
VSU on the test bench:
Different stages of the assembly and the tests of the VSU:
On the following photos we see the shuttle 1.01 (it still named "Baïkal" before being renamed in "Buran") in the zone of pyrotechnic test from 15 till 25 April 1988. On the left photo the VSU is started up and we see the cloud of exhaust gases, on the right photo we see the escape of gases in normal regime.
Technical details
Characteristic |
Value |
Power, kW |
17-105 |
Revolution frequency, tr/min |
|
Turbine |
55 000 |
Axle shaft |
4 500 |
Fuel |
Hydrazine |
Temperature |
5-50 |
Functioning time, min |
75 |
Dry weight, kg |
235 |