Rubins, of NASA, and Noguchi, of the Japanese Space Agency, will spend about 6 1/2 hours outside the orbiting space station starting about 7 a.m. EST.

They will perform such maintenance as venting ammonia from an external fixture and installing a device on an airlock cover to prevent it from blowing out when the hatch is opened.

Rubins will continue the work she and NASA astronaut Victor Glover started on the airlock cover Sunday. Rubins and Glover also installed hardware required to begin upgrades later this year on solar arrays that are more than 20 years old.

The spacewalk will be fourth for both Rubins and Noguchi. Rubins was launched from Kazakhstan on a Russian Soyuz rocket on Oct. 14, while Noguchi was launched on a SpaceX mission from Florida on Nov. 15.

The orbiting research complex, which spans the length of a football field, is equivalent to a five-bedroom home with a gym, two bathrooms and a 360-degree bay window -- the cupola -- that allows views of Earth.

Large arrays of solar panels power its systems, while liquid propellant rocket engines keep it from losing altitude.

The space station, which cost more than $150 billion to build and costs NASA over $3 billion annually, flies at more than 250 miles above the Earth at greater than 17,000 mph.