Zarya and Unity modules of ISS orbiting Earth. Photo: NASA

Flight controllers for the International Space Station this week turned their attention to tests to verify the readiness of the complex to support docking by Space Shuttle Atlantis next month and the arrival of the next pressurized module - Zvezda - in July.

A docking attitude test was performed Tuesday to verify the operation of the motion control system aboard Zarya - the electronics associated with commanding maneuvers of the ISS for rendezvous and docking operations.

In addition to verifying the attitude in which the Station will be placed prior to Atlantis' arrival, the teams also performed an additional test with the onboard automatic docking system, called Kurs, that will allow the ISS to rendezvous with the nearby Zvezda for docking of the Station's living quarters. Though data are still being evaluated, all indications are that the system is healthy and ready to support the arrival of the ISS' newest module.

Zvezda remains scheduled for launch between July 8-14 atop a Proton launch vehicle. An actual launch date within that window will be selected about a month prior to launch.

All other operations aboard the ISS are normal, with battery cycling continuing to ensure a healthy electrical power system in preparation for Atlantis' mission to replace and repair some batteries and their associated components. The STS-101 mission remains scheduled for a mid-April launch to deliver supplies and restore full redundancy to the Station's power system.

Processing of Atlantis has been completed and the orbiter should be in the Vehicle Assembly Building tonight for mating to its solid rocket booster/external tank stack. Plans are for the Shuttle to be moved to its sea-side launch pad next week leading toward April's launch to the ISS.

The International Space Station is in an orbit of 232 by 223 statute miles. Since the launch of Zarya in November 1998, the ISS has completed more than 7,555 orbits.