Soyuz crew approved for fast approach to space station
BY STEPHEN CLARK
Posted: March 5, 2013
The next three residents launched to the International Space Station will reach their new home six hours after blastoff, flying an express rendezvous with the complex and reducing the crew's time in the cramped confines of the Soyuz capsule.
Liftoff of the Soyuz TMA-08M spacecraft is scheduled for 4:43 p.m. EDT (2043 GMT) March 28 from the Baikonur Cosmodrome in Kazakhstan. Docking is set for 10:31 p.m. EDT (0231 GMT) after four orbits around Earth.
The six-hour rendezvous will replicate demonstrations done by Russia's Progress resupply freighters, which accomplished the first same-day rendezvous with the International Space Station in August.
"We tried this approach on the cargo vehicles, and now we're trying to do it on the manned vehicles," said Sergei Krikalev, a veteran cosmonaut and administrator of the Gagarin Cosmonaut Training Center near Moscow.
Russian cosmonauts Pavel Vinogradov and Alexander Misurkin, along with NASA astronaut Chris Cassidy, will be aboard the Soyuz.
Engineers did not make any changes to the Soyuz capsule for the mission, but the quick flight to the space station will be a test for the crew and ground controllers.
"All the systems of the vehicle are the same, but the work is more intense," Vinogradov said Monday through a translator. "There are no new systems or modes in the vehicle, but the coordination work of the crew should be better."
The crew's activation of the Soyuz and docking preparations, typically spread out in a two-day period, must be completed in less than six hours.
"We'll scrunch that whole timeline down into about a six-hour period," Cassidy said.
Soyuz cosmonauts and astronauts sit in specially-fitted couches inside the capsule's descent module for launch and docking. The accelerated rendezvous means the crew will wear their Sokol spacesuits and be seated for up to 10 hours, from the time they are strapped in on the launch pad until after docking.
"The interesting thing from a human point-of-view is we don't have the time to take off our spacesuits, so we'll be strapped in our seats in our spacesuits for the whole duration of that six-hour period plus the pre-launch activities. So it will be a long day and a lot of time in the suits," Cassidy said.
"It's going to be a long workday for the crew," Vinogradov said. "We will have to stay up for a very long time before - getting ready for the launch - but I think it's much more efficient."
On the plus side, the crew will reach the expansive space station sooner. Larger than a three-bedroom house, the complex includes a kitchen, bathrooms and lots of open space.
"The Soyuz is a very small vehicle," Cassidy said. "It's designed with a specific purpose and that's to get crews up and down ... and it does a fantastic job. It's not the most comfortable vehicle to be in for an extended period of time. The toilet is right next to where you sleep, which is right next to your buddy and eating and all. It's like living for a day in a Smart car or a Volkswagen Beetle. It's very scrunched."
The six-hour rendezvous is a first-time experience for an International Space Station crew, but astronauts and cosmonauts have accomplished quick rendezvous profiles before.
Two-man crews flying in NASA's Gemini program docked with target vehicles a few hours after launch in the 1960s, and early Soviet-era Soyuz missions launched and rendezvoused in orbit on the same day.
Officials switched to longer two-day rendezvous profiles to give crews extra time to adapt to microgravity and conserve propellant.
"Now we have on-board new machinery and new software, so the vehicle is more autonomous," Krikalev said. "So it's possible to do a lot on-board the vehicle and to calculate the burns so they don't consume a lot of fuel."
The fast-track rendezvous reduces the workforce required to operate the Soyuz spacecraft. Instead of staffing the Soyuz control center in Russia for more than two days, a full complement Soyuz controllers will only be needed for a day.
The space station's managers in February formally approved the six-hour rendezvous plan for the March 28 launch, but the international partners have not signed off on using the template on future flights, according to Mike Suffredini, NASA's space station program manager.
Russia has requested to use the quick rendezvous on all Soyuz missions, but NASA has raised concerns over the crew's comfort and workload, along with the technical difficulty and precise orbital mechanics necessary to launch and dock on the same day.
A formal decision on whether to use the quick rendezvous scheme on the following Soyuz mission in May will come in April, according to NASA officials.