Soyuz wraps up countdown exercise in French Guiana
BY STEPHEN CLARK
Posted: May 9, 2011
A Soyuz rocket successfully completed a week of launch pad fit checks and a mock liftoff at the European-run spaceport in French Guiana last week, confirming the site is ready to start launching the Russian booster by autumn.
In Thursday's exercise, engineers staffed control rooms at the spaceport, computers cycled fueling valves and activated the rocket's computers, and communications antennas and tracking cameras were called up to follow the launcher's ascent, according to Arianespace, the commercial operator of the Soyuz.
The only thing missing was the Soyuz rocket's kerosene and liquid oxygen propellants, nitrogen for the pressurization system and hydrogen peroxide for the rocket's engine pumps.
"It's a dry run," said Bruno Gerard, Arianespace's manager for the Soyuz in French Guiana. "We didn't do the filling operations, but we simulated the filling operations. It means, for example we took all the trailers from the storage to the launch pad."
Three railway trailers containing liquid propellant and gases were in place at the Soyuz launch pad for the countdown simulation.
Thursday's flight exercise targeted a simulated liftoff at 4 p.m. local time (1900 GMT) on a 30-minute mission to deploy a 5,665-pound communications satellite in a geosynchronous transfer orbit stretching more than 22,000 miles above Earth.
On Friday, controllers practiced draining the Soyuz rocket of propellant. The launcher was removed from the launch pad Saturday.
"It's great because we did this qualification planning two months ago," Gerard said. We negotiated this planning with our Russian colleagues. We are now currently exactly on point with this planning. We did not move one day late."
The week of testing came after CNES, the French space agency, relinquished management of the Soyuz launch pad in March. Arianespace will control commercial Soyuz flights from the space center, which remains under the oversight of CNES.
The spaceport lies on the northeast coast of South America near Kourou, French Guiana. It has hosted more than 200 launches of the Ariane rocket family and preceding Diamant and Europa boosters.
Two new launchers are slated to join the Ariane 5 rocket in Kourou this year.
The Russian Soyuz is expected to haul two in-orbit validation spacecraft for Europe's Galileo navigation satellite constellation as soon as October. A solid-fueled Vega launcher, developed by an Italian-led consortium of European companies, will also debut by the end of 2011.
While the Ariane 5 will continue flying dual-payload missions with large communications satellites, the Soyuz will focus on the medium-class launch market for commercial and European government spacecraft. The smaller Vega launcher will mostly conduct missions with lightweight science payloads.
With all three rockets, Arianespace will have footing in all sectors of the launch market.
After launch pad construction delays pushed back the first Soyuz launch from Kourou, the facility was finally deemed ready to receive a rocket early this year.
The launch site is a replica of the existing Soyuz pads at the Baikonur Cosmodrome in Kazakhstan, except the French Guiana facility features a 170-foot-tall mobile gantry to shield the rocket from strong thunderstorms and lightning in the South America jungle. It also allows workers to mate payloads to the rocket while the Soyuz is vertical on the launch pad.
Weather threats are not common at the arid launch site in central Asia.
After assembling the Soyuz rocket's three core stages in an integration building known as the MIK, Russian engineers rolled the launcher 2,000 feet to the pad April 29 and raised it vertically atop its concrete foundation. Later that night, cranes lifted the rocket's hydrazine-fueled Fregat upper stage and payload fairing atop the launcher.
Over the next few days, officials rolled back the movable launch pad tower and switched on the rocket's radio transmitters to check their compatibility with the space center's network of tracking stations and radars.
According to Arianespace, the Soyuz countdown started Wednesday and was halted three minutes before liftoff to practice abort procedures. Thursday's countdown continued until clocks reached zero and continued through flight, although the Soyuz engines never fired and the rocket remained firmly on Earth.
The rocket used for last week's operations was a Soyuz 2-1a launcher, one of two such vehicles delivered to French Guiana from TsSKB-Progress, the Soyuz builder in Samara, Russia.
The first launch from French Guiana will use the Soyuz 2-1b version of the venerable rocket, featuring a more efficient RD-0124 third stage engine that can help the vehicle lift more mass into orbit.
The Soyuz 2-1b rocket for the debut launch will arrive in Kourou by the end of June.
The RD-0124 engine uses helium for pressurization and a slightly different type of kerosene fuel. Ground facilities will be tested again around the end of May to ensure they can handle the new kind of kerosene, Gerard said.
The biggest factor in the schedule for the first Soyuz mission in South American is the readiness of two Galileo navigation satellites.
The first time propellant is loaded inside the Soyuz at Kourou will be on the day of the inaugural launch from South America. Because the Soyuz countdown operations are well understood in Russia, officials decided a fueling test would be unnecessary during last week's qualification.
"The process on the launcher side is already qualified in Russia," Gerard said. "It's exactly the same here. We don't need to do a wet rehearsal for the propellant."
The Soyuz and its variants have flown more than 1,700 times from Baikonur and the Plesetsk Cosmodrome in Russia.
Engineers already checked ground facilities in propellant and gas flow tests, and Arianespace is confident the Soyuz side of the fueling system will work flawlessly the first time.
The next time a Soyuz rocket stands on the Kourou launch pad will be about four days prior to the planned blastoff. In a similar process as the recent validation checks, the rocket will roll horizontally out of the MIK and be pointed toward the sky at the launch pad. The Fregat stage and two Galileo satellite payloads will next be added.
"In our qualification operation, we have the same schedule as the plan we will use in the real chronology," Gerard said.
Two Soyuz launches from the Guiana Space Center are planned this year. The second mission will likely deliver the French Pleiades 1 satellite to orbit on a national security and civil imaging mission.