|
More
Information: |
|
|
A Proton M/Briz-M
debuted successfully launching an Ekran M-18 from Launch Complex 81,
pad 24, at Baikonur Cosmodrome at 0447 UTC (8:47 p.m. PST April 6)
on April 7. The satellite will be positioned at 99°E, replacing
Ekran M-20, which was launched in 1992, and has operated long beyond
its design life. The satellite has a launch mass of 2100 kg (4628
lbm). This flight marks the last flight of the Ekran M satellite bus
- the spacecraft carries only a single TV-relay channel, which is
small compared to modern communications satellites equipped with
dozens of transponders. One more Ekran M spacecraft remains in
inventory, but will likely be placed in a museum - there are no
plans to launch it because its storage life has expired.
The launch vehicle
was built by GKNPT Khrunichev. The modernized rocket features
improved stages with lighter structural mass and a new propellant
management system which reduces residual propellant at shutdown and
toxic fuel at stage impact points. The thrust of the six RD-253
engines powering the first stage has been increased by 7%.
Energomash increased the trust of the engine from 151 to 160 tons.
International Launch Services (ILS), a joint venture between
Lockheed Martin and Khrunichev, will market commercial launches of
the Proton M.
The Proton M flight
version arrived at Baikonur in July 2000 with its first test launch
planned for as early as August 2000. However, financial and
technical problems delayed the mission to October, then November
2000 and finally to March/April 2001. The Proton M launch became a
priority when the Ekran M-15 satellite developed problems
threatening to disrupt the transmission of television broadcasts to
Siberia and the Russian Far East. Depending on the results of the
first test launches, two or three test flights are planned before
the vehicle will be certified for routine missions. Rosaviacosmos
plans for all the test launches to fly with actual satellites. The
first commercial flight of the Proton M is expected in late 2001 to
launch the Intelsat 903 telecommunication satellite.
A Proton Briz M can
launch 3 to 3.2 metric tons (6612 to 7053 lbm) into geostationary
orbit or 5.5 metric tons (12,122 lbm) into a geostationary transfer
orbit. It can place up to 22 metric tons (48,488 lbm) in low Earth
orbit with a 51.6-degree inclination, the orbit of the International
Space Station (ISS). Pad 24 was modified for the launches of the
Proton M vehicle and currently is the only pad of four Proton launch
complexes compatible with the new vehicle.
The Briz-M
incorporates digital avionics in the upper stage. The Briz-M also
uses less volume compared to its predecessors, providing additional
volume to carry cargo. As a result, the new Proton fairing will
offer 2.5 times greater volume for satellites over the Proton K/DM
configuration. The new Briz M upper stage was first flown on a
Proton K launch vehicle in May 2000. The Briz M upper stage can also
be mated with Zenit and Ariane rockets.
KB
Salyut, Khrunichev's design bureau, is developing a cryogenic upper
stage for the Proton M. Designated KVRB, it will use liquid hydrogen
and liquid oxygen. The KVRB upper stage first flight is currently
planned for 2003, increasing Proton M’s performance to GTO to 6400
kg (14,106 lbm). The development of the cryogenic stage was begun by
Khrunichev in the 1980s, but has been stalled for years by Russia's
financial problems. KB Salyut developed the cryogenic upper stage
for India’s GSLV and plans to use this “off-the-shelf”
technology for the Proton. KB Salyut has said that the Proton's
cryogenic stage would carry 18 metric tons of propellants compared
to 12 metric tons carried by the stage developed for India.
SPACEandTECH Digest is a weekly roundup of the latest industry news of interest
to the space professional. SPACEandTECH Flash! is an internet push
service offered by Andrews Space & Technology to bring the
latest on orders, launches, and important breaking news to your
desktop. SPACEandTECH Digest and SPACEandTECH Flash! are part of
the Andrews Space & Technology www.spaceandtech.com
website, a website designed to serve the information needs of the
space industry.
If you would like to subscribe to the SPACEandTECH
Flash!
(currently a free service), contact the www.spaceandtech.com
Editor-in-Chief, Joe Hopkins, at editor@spaceandtech.com
|
