After a week of four spacewalks to fix a creaky joint on the International Space Station’s rotating solar array arm and boost the station’s electrical power for future research, weary astronauts are finally done.

Now comes the time for a two-orbit test that will show if the repairs to the outpost’s power machinery were successful. Everyone on board will be watching when mission control sends up commands to the ISS’ starboard solar wing, which turns to face the sun perpendicularly in an effort to get maximum electrical output. Failure means less scientific productivity when the permanent crew increases from three to six in May.

"We all put our hearts into this very much because we love the space station. And so, yeah, we're standing by to see the results," outpost commander Mike Fincke said. "For six people onboard, and with all the science we're going to be doing, we're going to need every watt of that power."

The other wing, dubbed Solar Alpha Rotary Joint (SARJ), which is found on the station’s port side had been operating with little difficulty since it was installed in September 2006. Its starboard sister however has been causing problems since its delivery in June 2007. Its joint caused friction higher friction than was allowable, and has been stationary since September 2007.

Later inspections have revealed the joint hadn’t been lubricated properly, which in turn led to internal grinding on the bearings. Metal shavings from the friction clogged the joint, which threatened to crack the gear due to the friction.

Endeavour mission specialists Heidemarie “Toolbag” Stefanyshyn-Piper, Shane Kimbrough and Steve Bowen toiled for four days cleaning and lubricating the troublesome joint and replacing 11 of 12 bearings (one had been changed earlier), and the latter two finished the work on Monday.

Amid applause and thanks, Bowen’s relieved reply was "You're welcome. Any time, although never on the SARJ again, I hope."

The port side rotary joint was given a bit of maintenance attention by the spacewalkers as well. Kimbrough lubricated it with a modified caulk-gun to coat it in dark grease and prevent similar friction to its counterpart. As he did so he discovered that some wear had been going on with the joint, but certainly not on the same scale as what was seen on its starboard counterpart. He called the minor damage "a junior version of what we have on the other side."

The fix completed Monday is only temporary. For the long term a spare joint will be delivered and installed during 10 spacewalks in 2010.

Endeavour has also brought to the ISS a new toilet, two new crew quarters, a kitchen galley, an exercise machine and last but not least a urine water purifier. Unfortunately they had trouble getting the latter so their stay at the station was extended one day to look into it.

The crew will hit Terra Firma at the Kennedy Space Center at 1:18 P.M. Sunday.