Spaceflight Now: Space Station/STS-98

Station crew faces tough schedule

Posted: January 18, 2001

An 18-day delay for the next space station assembly mission has thrown a wrench into the on-board crew's timeline, compressing an already busy schedule of work that must be completed before arrival of their replacements in early March, officials said today.

The 97-ton international space station with its solar wings spread as seen by Endeavour during undocking. Photo: NASA
Launch of the shuttle Atlantis on a long-awaited flight to deliver the $1.38 billion Destiny laboratory module has been delayed from Jan. 19 to around Feb. 6 to allow time for additional booster wiring inspections.

Assuming assembly flight 5A takes off Feb. 6 as currently planned, Atlantis's crew will dock with the station Feb. 8, attach the lab module on Feb. 9 and undock Feb. 15.

Between then and arrival of the next shuttle mission in the first week of March, the Expedition One crew - commander William Shepherd, Sergei Krikalev and Yuri Gidzenko - must move their Soyuz ferry craft to a different port; accept arrival of an unmanned Progress supply ship; and make preparations for arrival of the Expedition Two crew.

At the same time, they will be activating lab systems and stowing equipment brought up aboard Atlantis.

Expedition Two commander Yuri Usachev, James Voss and Susan Helms, the station's second full-time crew, will ride to the outpost aboard shuttle Discovery in early March. That mission is known as assembly flight 5A.1.

"The hardest part of the 5A slip is the reduced time between the 5A mission and the 5A.1 mission," said space station flight director Jeff Hanley.

"If 5A.1 were to stay where it currently is on the calendar, we'd be down to a couple of weeks between the undocking of 5A and the launch of 5A.1. In that amount of time, we have to move the Soyuz ... and that's the better part of a day, minimum. We're going to have to then launch the Progress and dock it to the service module aft port."

The current plan - and all dates are subject to change at this point - calls for moving the Soyuz from the Zvezda command module's aft port to the Zarya module's Earth-facing port on Feb. 20. The Progress vehicle would be launched three days later and dock to the vacant Zvezda port.

"We won't be all that hard pressed to offload the third Progress before 5A.1," Hanley said. "But the other things we have to do in that two-week period in addition to those things is to allow the crew time to prepare for the handover to the Expedition Two crew."

He said flight planners originally wanted "to block out at least a week" to give Shepherd and company time to prepare handover notes for the Expedition Two crew, to complete storage of supplies and equipment ferried up aboard Discovery and to pack up equipment scheduled to be sent back to Earth.

"So we're going to be challenged to fit all that in in a two-week period," Hanley said. "We'll do what we always do with prioritizing the work and setting the agenda and let the prioritization drive what gets in the plan and what doesn't."

During a weekly planning session today with flight controllers in Moscow, the Alpha astronauts voiced their concern about the compressed schedule and asked planners to at least consider launching the next Progress vehicle before Atlantis takes off.

"If Progress is launched earlier, we'll have enough time to offload and you'll remember there is a plasma crystal experiment inside the Progress vehicle we want to make sure that we don't waste our efforts," one of the crew members radioed.

"We were the only ones trained on that experiment and that was the key experiment planned towards the end of our stay here. So we want to make sure that we don't waste the resources for the experiment."

"Copy that," a Russian controller replied. "But since there is a delay of shuttle, we don't know how (that will) affect Progress vehicles and their launch dates."

"We copy that, but somebody mentioned that 5A.1 flight will stay on time," the Alpha crew said. "Therefore, it seems we will have just two weeks to offload 5A, get Progress, perform (an) experiment and get ready for 5A.1.

"So think about it, because the end of our stay here might be too overloaded with all the activities. Based on our experience before, it's hard to find time for physical exercises at the end of our stay here with all those activities and we need to get ready for the return as well."

But Hanley said it does not appear the Progress could be launched before Feb. 6 and that the Russians were merely discussing the possibility of launching before Atlantis only if the shuttle encountered an additional delay.

In the meantime, he said, "the 5A prep activities will continue."

"This crew is prepared to do what it takes to wait out any delays that we see," Hanley said. "The crew's disposition is excellent, they are incredibly productive throughout the day and they've been expending most of their calories recently working on inventorying the ship."

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