A retry to launch the Express 6-A spacecraft on Saturday (Sunday, GMT), if successful, will put Russia on track for a major revamping of its satellite communications assets.
Everything stands ready for the March 11 launch of the communications satellite on a Proton rocket from Baikonur Cosmodrome in Kazakstan. The Express 6-A replaces a similar satellite destroyed in October during the post-launch explosion of the Proton rocket carrying it.
At least, two more Russian "satcoms" operated by the Russian Satellite Communications Company (RSCC), are due to go up this year to meet growing demand for communications channels in the former Soviet Union.
Representatives for Khrunichev Enterprise, Proton's manufacturer; RSCC, which owns the Express spacecraft and Intersputnik, the largest user of the satellite system, all confirmed Thursday that the preparation for the launch is on schedule.
Earlier reports by wire services erroneously announced that the launch has been delayed until March 29.
The State Commission overseeing the Express 6-A launch is expected to arrive at Baikonur Cosmodrome on March 7 to review the final processing and give the final go-ahead for the launch, planned for around 11 p.m. Eastern Standard Time on Saturday (Sunday, 4:00 GMT). The Proton'sBlock DM upper stage will perform two burns to send the 2.6-ton (2,642-kilogram) spacecraft toward its geostationary orbit 80 degrees east longitude over the equator.
Resettlement in the sky
If successful, the Express 6-A launch will have a positive effect on the existing Russian communications satellites in geostationary orbit. (Geostationary is a high-altitude orbit that allows satellites to "park" over certain regions of Earth, remaining overhead because at that altitude their orbital velocity matches that of the planet's rotation.)
The launch is aimed at preserving those satellites' orbital positions, which Russia registered in previous years, but which might expire unless an actual spacecraft is placed there.
The reshuffle would also allow older spacecraft with diminished capabilities to be replaced with newer, more powerful hardware. RSCC officials said last week that the older Express 6 (number 12) spacecraft currently hovering over 80 degrees east longitude will be moved farther east to the orbital position of 140 degrees east longitude. Express 6-A has 12 Alcatel-built transponders, while Express 6 (number 12) has 10 C-band operational transponders.
In turn, the Gorizont 33 (Statsionar 7) spacecraft, which currently occupies the position of 140 degrees east longitude, has only five C-band transponders that are operational.
In the meantime, French aerospace giant Alcatel has just delivered a communications payload with 12 transponders for another Express A spacecraft. The Express 3-A satellite is set for launch in June into orbital position 11 degrees west latitude, where it will replace Gorizont 37 (Statsionar 11), which has only 7 working C-band transponders.
Beyond the horizon
RSCC also plans to launch a new 2.1-ton (2,134-kilogram) Gorizont (which is Russian for "horizon") in April into the orbital position 145 degrees east longitude, previously occupied by the Gorizont 32 spacecraft.
Then, sometime during the third quarter of this year, the old Gorizont 40 (Statsionar 6), with seven C-band transponders will be moved from orbital position 90 degrees east longitude into a dormant 96.5 degrees east longitude position. The 90-degree position will be taken by the Yamal spacecraft, which was launched in September of last year and belongs to Russian company Gazkom.
RSCC may also use an older generation Ekran spacecraft to fill its dormant positions in the geostationary orbital slots. According to information from the Russian Aviation and Space Agency , Rosaviacosmos, the 1.9-ton (1,930-kilogram) Ekran might ride one of the first Proton rockets with upgraded engines -- the same kind that will ultimately be used to lift the Zvezda service module for the International Space Station.
Rosaviacosmos announced earlier that upgraded engines should be test-flown on at least two Proton rockets, before it allows Zvezda go up in July.
Alexander Martinov, who is managing satellite communications programs at the Russian space agency, told SPACE.com Friday that two Ekran spacecraft are available: one is fully assembled and already in Baikonur, while the other is at NPO PM, the satellite manufacturer in the Siberian town of Zheleznogorsk.
An Altair data relay satellite is another potential payload for one of the upgraded Proton launches, which would precede the Zvezda launch.
Rosaviacosmos wanted to have the 2.2-ton (2,235-kilogram) spacecraft in orbit to facilitate docking between Zvezda and the ISS. Altair had been assembled by NPO PM months ago, however, the space agency lacked funds to finance the launch until very recently.
Martinov said that the contract to refurbish and complete Altair has finally been placed and the spacecraft might realistically be ready for shipping to Baikonur around May. The launch could take place in June.
Geostationary communications satellites managed by RSCC (listed West to East)
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