NASA will shed light on plant investigations aboard the International Space Station in a briefing at noon EST, Friday, Feb. 5. The briefing from NASA's Kennedy Space Center in Florida will be broadcast live on NASA Television.

The upcoming shuttle mission, planned to launch Feb. 7, will continue assembling the space station so it can be used for continuous scientific research as a national and multinational laboratory.

Microgravity plant growth experiments conducted aboard the station will help prepare for long-duration spaceflights of the future. The use of miniaturized green fluorescent proteins, that glow in the dark, and associated compact imaging systems, may be used to help monitor crop conditions on Earth.

NASA has begun counting down toward the planned predawn launch of the space shuttle Endeavour on Sunday.

Endeavour is poised to blast off from the Kennedy Space Center in Florida on Sunday morning at 4:39 a.m. EST (0939 GMT) to deliver a brand-new room and observation portal to the International Space Station. The clocks began ticking down toward launch time early this morning.

"We're right on schedule, where we're supposed to be," said NASA test director Jeff Spaulding during a Thursday status briefing.

There is a 70 percent chance of good weather for Endeavour's launch. The potential for high winds is the only concern, shuttle weather officials said.