Shuttle Atlantis Poised for Thursday Launch

All seven astronauts are at Cape Canaveral in Florida reviewing procedures and awaiting their construction mission to the International Space Station.

Commander Stephen Frick said to a press gathering, "We're really excited to be here in Florida today, obviously on a tremendous day, and we hope that it stays like this all week long, to have our chance to launch in Atlantis on Thursday and bring the Columbus module up to the International Space Station. Obviously it has been a real long training flow for us, a long time building to this moment, and so we are just absolutely ready to go."

The primary goal of this mission is to install a European-built space laboratory called Columbus. The module is seven meters long and more than four and half meters in diameter. A Japanese laboratory is scheduled for delivery to the space station next year.

NASA's shuttle Atlantis and a massive European laboratory are on track for their planned Thursday launch toward the International Space Station (ISS).

Atlantis' seven-astronaut crew is slated to liftoff from a seaside launch pad here at NASA's Kennedy Space Center (KSC) spaceport at 4:31 p.m. EST (2131 GMT), with a 90 percent chance of pristine weather conditions.

"The vehicle is looking good and the weather is looking good, too," said shuttle weather officer Kathy Winters, of the U.S. Air Force's 45th Weather Squadron, in a morning briefing.

Commanded by veteran shuttle astronaut Stephen Frick, Atlantis' STS-122 crew will haul the European Space Agency's (ESA) 13-ton Columbus lab to the ISS during a planned 11-day mission. Three spacewalks are on tap for the spaceflight, but NASA may extend the mission by two days to add fourth excursion to inspect a balky ISS solar array joint.

NASA test director Jeff Spaulding said shuttle workers detected a small leak in ground equipment late Wednesday after loading super-chilled liquid hydrogen into Atlantis' tanks, but the glitch is not expected to hinder plans for tomorrow's launch.

"It's on the ground side only," Spaulding told reporters. "It is not a vehicle issue at all."

NASA space shuttles use liquid hydrogen and liquid oxygen reactants to power their three fuel cells during orbital flight.

Spaulding said engineers will spend the bulk of today testing Atlantis' communication systems and loading the final pieces of cargo into the shuttle's middeck. A pair of experiments and some last-minute food items are on that list, he said.

Frick and his STS-122 crew, meanwhile, plan to visit Atlantis at the pad today as part of the prelaunch preparations, NASA officials said.

At 8:00 p.m. EST (0100 Dec. 6 GMT) tonight, pad workers are expected to retract the shroud-like Rotating Service Structure that protects Atlantis from weather at its Pad 39A launch site.

NASA has a slim window that closes on Dec. 13 in order to launch Atlantis to the ISS while the angles between the station's solar arrays and the sun are favorable for docked operations. If weather foils Thursday's launch attempt, NASA could try again as early as Friday at 4:09 p.m. EST (2109 GMT).

Winters said the weather outlook offers an 80 percent change of favorable launch conditions on Friday, but will dip to about 60 percent on Saturday.

Atlantis' STS-122 mission will mark NASA's fourth shuttle flight of the year and the second to deliver a new pressurized module to the ISS.

NASA will broadcast Atlantis' STS-122 mission live on NASA TV. Click here for SPACE.com's shuttle mission coverage and NASA TV feed.



Alan Poindexter
Atlantis pilot Alan Poindexter explains. "Columbus is the main contribution of the European Space Agency and it is the first pressurized module that is non-U.S. or non-Russian, and it adds a lot of laboratory space as well as interior volume to the space station."

The European Space Agency's Daniele Laurini takes us inside witha virtual trip. "I have a short animation. We are flying to the station. We are slowly entering into Columbus, and we zoom into the facilities that we have installed for launch. We have four major facilities dedicated to research in physiology, biology and material sciences, and in general experimentation. We slowly go back to node two and magically, through the laptop display, we go to the outside."

Atlantis astronauts plan three space walks to install the Columbus laboratory.

NASA managers say the weather looks good for Thursday's launch. If all goes as planned, Atlantis will return to the Kennedy Space Center on December 17th, wrapping up the fourth and final shuttle flight of the year.

Saturn's moon Titan contains chemicals that on Earth can serve as building blocks for complex organic molecules.

The atmosphere of Saturn's moon Titan, seen here, contains hydrocarbons that could be the starting point for microbial life .

Saturn moon home to life's building blocks

Scientists don't know how it happened, but the oxygen-starved atmosphere of Saturn's moon Titan contains chemicals that on Earth can serve as building blocks for complex organic molecules.

Scientists used an instrument on the Saturn-orbiting Cassini spacecraft and found heavy negatively charged ions in Titan's upper atmosphere, despite the absence of oxygen.

On Earth, oxygen is needed to ionise molecules in the lower ionosphere.

Titan's atmosphere is mostly nitrogen and methane, a combination that is leaving scientists wondering how the negative ions, which have 10,000 times the mass of hydrogen, formed.

Cassini collected the data during 16 different encounters of Titan.

"Their existence poses questions about the processes involved in atmospheric chemistry and aerosol formation," says Dr Andrew Coates, with University College London's Mullard Space Science Laboratory.

The molecules have additional rings of carbon and can become what are called polycyclic aromatic hydrocarbons.

Scientists believe these polycyclic molecules can serve as a starting point for simple microbial life.

The research, reported in the journal Geophysical Research Letters, builds on an earlier discovery of smaller complex molecules called tholins above Titan's surface.

Tholins, which have up to about 8000 times the mass of hydrogen, are believed include some chemical precursors to life.

"Understanding how they form could provide valuable insight into the origin of life in the solar system," says planetary scientist Dr Hunter Waite, with the Southwest Research Institute in San Antonio, Texas.


Murky brown mist
Scientists suspect organic solids from the murky brown mist that surrounds Titan have been raining down on its surface for billions of years.

The late Professor Carl Sagan coined the term tholins from the Greek word tholos, or mud. Scientists believe Titan's natural tholins could be part of the chemistry needed for life.

Titan is the second largest moon in the solar system and the only one with a dense atmosphere.

It is believed to resemble primordial Earth and scientists are studying it to try to understand how life evolved here.

Cassini, a joint mission of NASA and the European Space Agency, has been circling Saturn and its eclectic collection of moons and rings since 2004.

Its next pass by Titan is scheduled for later this week, when the probe's infrared camera will attempt to image what may be a large lake of hydrocarbons on the moon's southern hemisphere.