Russian Spacecraft Vital to Boost ISS Crew Size


A docking port at the aft of the International Space Station's Zvezda service module (far right in this depiction) is now clear after the undocking of a Russian-built Progress 19 cargo ship on March 3, 2006. The Progress 20 cargo tug (docked at Pirs compartment at mid-right) and Soyuz TMA-7 vehicle (center at Zarya module) are also shown.
Credit: NASA/JSC.

NASA and
its international partners plan to increase space station crews up to six
astronauts by no later than April 2009, banking on 16 U.S. shuttle flights and extra
Russian Soyuz and cargo ships, the agency’s station program chief said Friday.

Michael Suffredini,
NASA program manager for the International Space Station (ISS), said the U.S. agency
is drawing up plans with Russia’s Federal Space Agency for two additional Soyuz
flights – and possibly an extra unmanned Progress vehicle – per year to support
six-astronaut crews in 2009.

contract I expect to sign before the end of the year,” Suffredini said in a
teleconference with reporters. “The whole discussion of the six-person crew, now that we’ve got the
[assembly] sequence in place, became our priority.”

Thursday, NASA chief Michael Griffin and his space agency counterparts from
Russia, Europe, Canada and Japan announced plans
to complete the ISS by 2010 – when NASA three remaining space shuttles are set
to retire. That plan includes
16 ISS-bound shuttle flights and earlier launches for Europe’s Columbus
module and the Japanese
Experiment Module (JEM).

Two additional “contingency missions” padding NASA’s shuttle manifest, aimed at delivering spares and other logistics to the space station, will likely not be needed, Suffredini said.

“Today I would tell you that I have a pretty high degree of confidence that we may not need this flights,” he said, adding that they could be performed should they become necessary in the future.

Larger crews

ISS crews,
once set at three astronauts per mission pending its construction, have been
limited to two-person teams following the drop in NASA shuttle visits after the
2003 Columbia accident. The
shuttle Discovery returned to the ISS in July 2005 during NASA’s STS-114 return to flight mission.

A second
test flight, STS-121
also aboard Discovery, is slated
to launch no earlier than May 10, NASA officials have said. That flight, commanded
by astronaut veteran Steven
Lindsey, is expected to return the ISS to a three-person crew when it
ferries European astronaut Thomas
Reiter to the orbital complex.

The next
shuttle flight dedicated to ISS assembly, STS-115 carrying a new truss segment
and solar arrays to the station, is slated to launch aboard the Atlantis
orbiter no earlier than Aug. 28. However, the next Russian-built Soyuz vehicle
to ferry humans to the ISS is scheduled to launch spaceward on March 29 EST
with the station’s Expedition
13 crew.

Soyuz and Progress spacecraft have proved a vital lifeline for the ISS, ensuring
new crews and supplies reached the station as NASA recovered from the Columbia
accident. During that time, about two Soyuz vehicles ferried astronauts to the
ISS each year, with four Progress vehicles arriving with supplies.

“Prior to
Columbia, we rotated almost all the crews with the shuttle,” Suffredini said.

But the
larger, six-person expeditions will likely be a mix, with at least one U.S. or
NASA partner astronaut riding shuttles into orbit while other station members
arrive by Soyuz, he said, adding that flight schedules, the number of Russian
vehicles needed and rotation details still remain to be determined.

Last month,
NASA struck a $21.8 million-per-passenger deal with Russia’s Federal Space
Agency which secures Soyuz seats to return U.S. astronaut and ISS Expedition
12 commander Bill McArthur to Earth and launch Expedition 13 flight
engineer Jeffery Williams to the station.

said that only two future ISS-bound Soyuz flights will not have a U.S. seat
available, and that not every shuttle to the station will carry a new

rotate about one person on the average on a shuttle, and we won’t rotate on
every shuttle,” Suffredini said. “We’ll rotate as we need to to make the crews line
up right.”

  • NASA,
    Partners Set Space Station Construction Plan
  • NASA Aims at May 10 for Next Shuttle Flight
  • Return to Flight: NASA’s Road to STS-121
  • The International Space Station So Far: Five Years
    of Service, But Incomplete