The US shuttle Discovery is all set for its latest mission to the International Space Station (ISS).

美国发现号航天飞机为最近的国际空间站任务做准备。

This is the Discovery orbiter's 37th mission

The 13-day flight will deliver science equipment to the platform, including a new freezer to store biological samples and a furnace（炉子，熔炉） for baking materials.

The lab equipment was made in Europe, which is represented（表现，描绘） in Discovery's crew by Swede Christer Fuglesang.

The mission will be the 30th shuttle flight dedicated¹ to station assembly and maintenance（维护，保持）.

The current plan is for a further six sorties to be made to the ISS before America's re-useable spaceship fleet is retired² at the end of next year or early in 2011.

The lift-off from the Kennedy Space Center in Florida is timed for 0136 local time (0536 GMT) on Tuesday.

The latest mission has a strong European focus.

European Space Agency (Esa) astronaut Christer Fuglesang will conduct two of the three spacewalks planned during Discovery's stay at the ISS.

On one of these walks, the Swede will move cabling on the exterior³（外部，表面） of the station in readiness for the arrival next year of a connecting unit, called Node 3 or "Tranquility", and a huge window referred to as the Cupola.

The two modules⁵ will be Europe's final large-scale contributions to the assembly of the ISS.

Discovery's payload bay is taken up with the Italian-built Multi-Purpose Logistics Module⁴ (MPLM), which acts as a giant packing box on shuttle logistics missions.

For this flight, the MPLM contains almost seven tonnes of cargo⁶. This mass includes two more important European donations to the ISS project.

One is a Melfi (Minus Eighty Laboratory Freezer for ISS), which can store biological samples.

"This is the second such freezer," explained Martin Zell, Esa's head of ISS Utilisation.

"This first one is already up there since three years and working extremely well.

"It's the main freezer element on the station and can operate between plus-4C, at the upper temperature, down to minus-80 degrees; and even in different temperatures in its four cold volumes, or compartments," he told BBC News.

The additional Melfi will facilitate（帮助，促进） the increased science workload⁷ taking place on the station now that its resident crew has been raised from three to six.

All manner of biological samples will be stored in the new facility, including blood taken from the astronauts.

This is routinely drawn⁸ for study, to further scientists' understanding of the impacts of long-duration spaceflight on the human body.

Growing issue

The other notable European cargo item is the Materials Science Laboratory.

This contains a safe furnace (up to 1,400C) in which astronauts can first melt and then solidify⁹ a range of samples, such as metal alloys¹⁰（金属合金）.

The weightless conditions on the station mean the fine-scale structures in these cooling samples will grow in a different way from how they would at the surface of the Earth.

Scientists expect these experiments to provide novel information that can be applied¹¹ to everyday industrial manufacturing processes.

With MSL and the Melfi units, Europe is providing both the coldest and the hottest conditions for science on the station.

As well as preparing the platform for the arrival of Tranquility and the Cupola, the mission's spacewalks will replace experiments that currently live on the outside of Esa's Columbus laboratory.

They will also exchange one of the tanks for storing ammonia（氨水）, which is used to move excess heat from inside the station to the radiators¹² located outside.

Discovery will also drop off US astronaut Nicole Stott for a three-month stay on the ISS, and pick up colleague Tim Kopra for the ride home. Kopra has been living on the platform for the past five weeks.