FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1989
1989 - 0420.PDF
emergency landing at an alternative base. Since Challenger broke apart owing to aero dynamic stress, rather than the explosion, the Buran abort procedure would presumably be chosen at relatively low speed. An engine failure later in the launch would result in an abort-once-around, with a landing at Baikonur after one orbit. The provision of these crew safety options has resulted in a reduced Energia payload weight/lift-off mass ratio, however. Ejection seats During test flights the two-man crew will use ejection seats. These allow escape during an on-the-pad emergency and up to Mach 3 and a height of 25km during the first two minutes of launch, and below 30km at Mach 3 to landing. Ejection seats will not be fitted when there is a larger crew. The Soviets say that four cosmonaut crew men and six specialist passengers could be carried on Buran, although Volk says that the maximum crew would be seven. Cosmonaut chief Vladimir Shatalov has suggested that crews could include inter national guest cosmonauts. The largest US Shuttle crew numbered eight. During Buran's first launch the shuttle's angle of attack was about 10°, says Oberg. The strap-on boosters separated by sliding down from the booster, rather than laterally, to avoid damaging the wings. The main engines cut off at T+486 seconds, probably sequentially to reduce vehicle stress. Buran separated using its RCS thrusters and glided in a suborbital trajectory until T+36 min 19 seconds, when it performed a 67-second OMS 1 burn at an altitude of 160km. The 42-second OMS 2 burn followed at T+47min. Buran finished up in a 252-256km orbit, inclined at 51-5° The OMS 2 and the OMS 3 retrofire burn occurred over the coast of Chile, where two Soviet tracking ships, the Dobrovolsky and Nedelin, were stationed. Other ships, deployed off the coast of Africa, were the Belyayev and Volkov. Continuous commu nications with the totally automated Buran, from the Kaliningrad control centre near Moscow, were made using Molniya and Gorizont satellites, the latter equipped with Luch transponders. Successful landing The Mach 25 entry interface—an untried test of the guidance, attitude control, and thermal protection systems—occurred at a height of 122km. A 20min blackout period followed, and Buran, having demonstrated a 1,000km crossrange manoeuvre (half its capability), was "contacted" at a height of 40km, 400km from the Baikonur runway. At 20,000m its speed was 3,000km/hr and at 10,000m this had reduced to 800km/hr. The landing was made at 350km/hr, and while the shuttle rolled to a 30-second stop it was braked by the deployment of a drag 'chute, which pulled out a drogue and three cupolas with a total area of 75m2. These were ejected as Buran's speed decayed to 50km /hr. The roll-out took about 1-lkm to l-2km. The flight time was 3hr 25min. Buran's mission was the greatest Soviet triumph since Sputnik. Landing in 18m/sec crosswinds blowing about 30° across the runway, near to the limit, was "very satisfying", cosmonaut Titov tells Flight. Baikonur's shuttle runway, 12km from the launch pad, is 4,500m long and 84m wide. The base also has landing control building, incorporating communications, navigation, and telemetry computers. There are six distance-measuring stations, three at each end of the runway. One is positioned on the centreline and the others are several kilometres away. These deter mine the vehicle's position and update its guidance system during the approach, closely monitored by navigators in the control room. A microwave landing system and radar also aids the landing. Two more runways are being built, at Simferopol in Crimea and in Vladivostok. Buran could land at any of the world's airports, say the Soviets, "Provided these were equipped with the necessary navigation landing systems." Future missions The next Buran mission—possibly on Ener gia 3—will also be unmanned and will be extended, say Soviet officials at Baikonur. It will be followed by the manned mission, probably commanded by Volk and with Stankjavikus as copilot, in 1990. The second flight may now be manned, however, follow ing recent announcements by Tass that a manned shuttle will fly in 1990. As Energia can launch large unmanned spacecraft, Buran will be used for missions "requiring post-launch assembly by mechan ical devices, robots, and specialists". Such payloads will comprise new modules for Mir, large optical telescopes, radio telescopes, power stations, and antenna arrays. Buran will also be used to retrieve large space modules, such as the dormant 19-tonne+ Salyut 7 and its attached Cosmos 1686 Heavy Cosmos module (on separate flights), and modules from Mir. It will have a manually operated remote manipulator system. Military missions could include the repair of sensitive surveillance satellites. The Soviets say that Buran could also be docked to the present Mir 1 station, using a docking port which could be attached to the second of two add-on modules to be flown to the station this year. Retrieval flights would carry payloads for cost-effectiveness. "Faulty nuclear power systems", such as those on Rorsat satellites stranded in LEO, could be retrieved, the Soviets suggest. During a maximum 30-day duration flight Buran could also be used as an individual scientific research laboratory. It will fly missions lasting a maximum of seven days until declared operational, presumably after a series of manned tests. Buran has also been linked to the construction of the 450-tonne manned Mars ship that will be despatched to the planet next century. Contrary to popular belief, however, the progress of Energia and Buran in the 1990s is likely to be slow. E Another unmanned flight is planned before Buran flies with a two-man crew aboard 26 FLIGHT INTERNATIONAL, 18 February 1989
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
