Next week, the future inhabitants of the International Space Station (ISS) will have one last chance to peek inside the module that is to be their living quarters on the orbiting complex before it blasts off into space.

Several Russian cosmonauts and U.S. astronauts will leave Moscow for Baikonur on Monday for an inside-and-out familiarization with the module, a procedure known as the Crew Equipment Interface Test (CEIT).

The crew-quarters module, called Zvezda, is being processed in Area 254 of the Baikonur Cosmodrome in Kazakhstan. Its long-delayed launch on board a Proton rocket is currently scheduled for July 12. So far this week a number of tests on the module, including crucial checks in the vacuum chamber, have been completed.

 The group of cosmonauts and astronauts who will participate in the Baikonur training sessions represent four different crews preparing for work aboard the ISS:

• Bill Sheppard, Yuri Gidzenko and Sergei Krikalev, members of the station's first resident crew are expected to travel to the ISS on October 30.
• Vladimir Dezhurov, Mikhail Turin and Kenneth Bowersox are the backup crew for the first resident expedition to the ISS.
• Edward Lu, Daniel Burbank, Yuri Malenchenko and Boris Morukov will visit the station aboard a space shuttle during the STS 106 mission, after Zvezda docks with the ISS.
• Genadi Padalka and Nikolai Budarin, a contingency crew, sometimes referred to as the "Zero" crew, will be launched into orbit to manually dock the Zvezda module to the ISS in case the planned automatic rendezvous fails.

During two sessions planned between May 22 and 26, the astronauts and cosmonauts will familiarize themselves with both the exterior and interior of the module. Following the training, the module will go through final integration and is scheduled to be mated with its launch vehicle on July 3.

In the meantime the manufacturers of the failure-plagued Proton rocket, which had delayed the Zvezda launch, say they are up for the challenge of preparing the booster to carry the module to space on July 12.

The Proton crash last October pushed the launch of Zvezda back from the beginning of the year. Although the rocket model was returned to service in February, the Russian Aviation and Space Agency (Rosaviacosmos) decided to use modified engines on the second and third stages of the rocket that will carry Zvezda. The agency announced that two or three Protons with the modified engines carrying less important payloads should first complete successful flights before Zvezda could take off.

The first rocket with modified engines was shipped from Khrunichev's production plant in Moscow to Baikonur at the end of last month. It is currently expected to take off on June 5 carrying the Gorizont 45 communications satellite.

The second modified Proton that will take off prior to the Zvezda launch has been assembled and it will leave for Baikonur on Friday night, Yuri Gorodnichev, the chief-engineer of the Khrunichev production plant told SPACE.com.

The rocket is now scheduled to take off on June 27, carrying the Geyzer relay satellite for the Russian Ministry of Defense. The success of this launch will be viewed as a green light for Zvezda. Last month, Russian officials said they hoped to launch the second modified Proton around June 20.

Proton rocket Number 39801, which is slated to carry Zvezda, is currently going through final electrical tests at Khrunichev and is scheduled to be shipped to Baikonur on May 28.

"We will meet this deadline," Gorodnichev said.