steve@eos.UUCP (Steve Philipson) (08/24/89)
There has been considerable discussion in this group concerning the
jet engines used in the Soviet space shuttle program. The July 24
issue of Aviation Week contained some information on this. Excerpts
are included below. Please accept my apologies if this has already
been posted -- I've been off the net for a few weeks and thus would
have missed it.
Soviet designers originally had planned to equip their
space shuttle orbiters with two jet engines that would have
been used, if necessary, to modify the spacecraft's flight
path in the atmosphere prior to its runway landing. The two
Lyulka nonafterburning engines were to have been installed on
the aft fuselage, positioned on each side of the vertical
stabilizer. Their nacelles were to have been covered with
thermal protection for the orbital portion of the mission,
and their inlets blocked by covers that remained in the
closed position until atmospheric reentry.
"Our designers originally thought the two engines might
be need to make corrections on the glideslope during final
approach," he said. "However, approach and landing tests
performed with the atmospheric test vehicle showed that
control was sufficient without these engines."
The jet engines were similar to those used on Sukhoi
Su-27s, and would have provided sufficient thrust only
for flight path modifications on final approach, he said.
They would not have permitted the spacecraft to maintain
horizontal flight, nor make a go-around for another landing.
A decision not to use the engines was made about 1.5
years ago, and the orbiter Buran was therefore not equipped
with the powerplants when launched on its unmanned test
mission last November. The spacecraft made an accurate
approach and touchdown on the Baikonur Cosmodrome despite
heavy winds.
The engines were installed, however, on a full-scale
non-spaceflight orbiter vehicle that was used for
atmospheric flight testing. Two more Lyulka engines --
these equipped with afterburners -- were installed on the
sides of the atmospheric test orbiter as well, and the
combined thrust was sufficient to power the vehicle on
takeoff from a runway, through a climb-out to the holding
altitude, and on the return to landing.
--
Steve
(the certified flying fanatic)
steve@eos.arc.nasa.gov