"Literally this is all I've got: I've got a safety deposit box. I have a bank account because my money, my pay, has to go somewhere. And I have a post office box. And that's it. That's all I've got," Helms told SPACE.com in an interview last week.

"I'm basically living out of my car until launch," she joked.

The whole idea: To shed the psychological burdens of day-to-day life on Earth so she can concentrate on the mission at hand: Outfitting the station's newly arrived U.S. Destiny science laboratory and preparing the outpost for further assembly.

With her impending absence from the planet making news around the world, Helms doesn't want to have to worry about her home being burglarized -- something that has happened to several NASA astronauts in the past -- or whether the bills are being paid on time.

"We've had instances of people getting their credit cards stolen. We've had instances of people getting their homes broken in to, and I just don't ever have to worry about that anymore," said Helms, a veteran of four previous shuttle flights.

"I just don't want that kind of hassle. I don't want to have to worry about people writing me, telling me that a hurricane is about to wipe out my apartment, or whatever. I just don't want to deal with that. I don't want that kind of distraction."

Helms, 43, and the so-called Expedition Two crew -- which will be commanded by Russian cosmonaut Yuri Usachev and also includes NASA astronaut Jim Voss -- are scheduled to depart Kennedy Space Center at 6:42 a.m. EST (11:42 GMT) Thursday.

Four shuttle astronauts will ferry the trio up to the international station and then return to Earth March 20 with the outpost's first full-time tenants -- Bill Shepherd, Yuri Gidzenko and Sergei Krikalev.

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Helms and her station crewmates will remain aboard the outpost for at least 130 days, but chances are their stay could be extended an extra month or two.

So Helms moved swiftly to put her earthly life on temporary hold, a process that has presented all sorts of interesting challenges.

U.S. income taxes had to be filed early. Change-of-address forms had to be sent out to redirect magazine subscriptions and other mail to her post office box. And severing her connection with the phone company proved to be a severe headache.

"The phone company was the hardest one to cut loose on because they're really interested in keeping your service right now. I had to explain to them that I was going somewhere I would not even have a phone, because they were trying to get me to buy phone services in a different location," she said.

"They wanted to know where I was going, and I just said 'Somewhere where you can't reach me. Sorry.'"

Making arrangements for Mango -- a "black cat with attitude" -- was less of a problem.

"I was doing foster care with the cat, and one of the last things I did before I left my apartment for good is I moved her to her new parent," Helms said. "And it's a permanent adoption. It's not foster care. So that was one of the many, many items I had to get closure on as I was getting ready for this flight."

Closing up shop at her apartment led to a nomadic existence of sorts. Helms shuffled between the homes of various friends for a month and a half, and took a certain amount of ribbing from fellow astronauts, such as Discovery mission specialist Paul Richards.

"I've had this month of being mobile, and I'm getting jokes about shopping carts. Paul Richards, for example, told me he saw my home sitting by the side of the road. Apparently, there was some old shopping cart on the highway that he had seen."

The preparatory work by Helms, meanwhile, stands in stark contrast to that done by crewmates Usachev and Voss, both of whom are married and have families.

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Voss, for instance, spent part of the past month finishing up chores around the house and is looking forward to returning to the comforts of an established home.

"I have a completely different situation from Susan's. I've kept everything in place because I want my home, my phone, everything to be there when I come back," he said. "And when I come back, I'll ease right back into the same situation I had when I left."

The Helms approach, however, is particularly appropriate, and psychologically freeing, for a single astronaut, said Discovery mission specialist Andy Thomas, a bachelor who spent four months on Russia's Mir space station in 1998.

"Actually, when you go up there, you can cast off these burdens of paying the bills, paying the car payment, getting the dog to the vet -- all of these things which have continuous stresses on us [on Earth]," he said.

"You actually take them for granted, but they're actually a source of great stress. And when you can get away from those, if you can, and get up into that new environment, you can have really a very benign, sort of peaceful time."

Six weeks of the preflight gypsy life, however, can take its toll, and Helms is anxious to get airborne. "I'm looking forward to making [the station] a home -- getting kind of tired of that shopping cart," she said.

The transition from space back to Earth is something she'll ponder at a later date.

"There may be some psychological impacts of living in space for six months and then coming back to Earth...but I don't want to think about that right now," she said.

"I want to get in there first and do the mission, and then I'm sure it's going to be one of those situations where when it's over, you're going to think, 'Man, that went by so fast,'" she said.

"I'm sure when we look back at it, it will be (A), the experience of a lifetime, and (B) it will appear to have gone by really, really quick."