New room extended at space station

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The US space shuttle Discovery linked up with the International Space Station (ISS) yesterday on a mission to prepare the orbital outpost for new European and Japanese laboratories.
With shuttle commander Pamela Melroy at the controls, Discovery eased up to the station and latched onto a docking port at 8.40am EDT.
Working both outside the station and within it, the astronauts moved the Harmony module, which will serve as a connection point for two new laboratories for the station, to a temporary location on the side of the station.
The space station’s robot arm, operated by Stephanie Wilson and Daniel Tani, smoothly moved the 16-ton module out of the shuttle and onto the station, where automatic bolts secured it in place in a temporary home on the left side of the station’s living quarters.

The work outside was more strenuous. Astronauts Scott E. Parazynski and Douglas Wheelock began their spacewalk shortly after 6 a.m. Eastern time. They prepared the Harmony module for its removal from the shuttle’s payload bay and performed some of the preliminary work for the other big task of the mission, moving an enormous set of solar arrays and the truss they stand on from their initial position atop the station to the permanent home on the far end of the truss on the station’s left side.

So far, technical difficulties on the mission have been minor.

So little insulating foam was shed from the shuttle’s external tank that mission managers have determined that a more focused inspection of the shuttle’s heat shield is unnecessary. When that word was passed up to the shuttle on Thursday afternoon before the crew sleep period was to begin, the shuttle commander, Pamela A. Melroy, responded enthusiastically, ”Oh, man, that is fantastic news.”

She said that it was a relief to know that tile and panel damage was not a concern and that they would be able to take the time that would have gone to inspection and use it to further prepare the Harmony module for entry. “We just can’t wait to get inside,” Ms. Melroy said.

The spacewalk, for the most part, went smoothly. The astronauts struggled occasionally with balky bolts and hose connectors, which are optimistically called “quick-disconnect” devices. They were wary of the small amounts of frozen ammonia that drifted away from some the hoses, because they could contaminate the atmosphere within the station if brought in on the space suits. The amount of ammonia, which is used as a coolant, was small.

At one point, Paolo Nespoli, the Italian astronaut who was coordinating the spacewalk from inside the station, asked his colleagues to take a small break to enjoy what might be the greatest perk of working in space: the view. He asked them to look over the starboard side as the station passed over Houston.

The two spacewalkers oohed and aahed as the familiar coastline slid by below.

“Hello, Houston!” Dr. Parazynski said.

The spacewalkers were back in the airlock before noon.

Over the communications system, Ms. Melroy congratulated Dr. Parazynski and Mr. Wheelock on the work of the entire team, which she said she watched while making lunch for the crew.

LHC( Large Hadron Collider) :ATLAS big wheel triumph

LHC ( Large Hadron Collider)
ATLAS celebrates installing the last of the eight big wheels. These wheels form the end-cap muon spectrometer of the detector.
The ATLAS end-cap muon detectors, the ‘big wheels’, have been compared to many things: flowers, orange halves, clock faces and works of art. But, more importantly, each is an incredible feat of engineering. On Friday last week the team celebrated the completion of the last wheel, and moved into the final stages of installation.

"I must admit that at the end of last year I would not have believed that we would manage to install these eight big wheels essentially on schedule," admitted Peter Jenni, ATLAS spokesperson. The first of the wheels took a long time to install, but the last one took just a couple of weeks. "This is really a great achievement."

The big wheels harbour ATLAS’s middle layer of muon chambers in the forward region and are one of the last large pieces to be installed. Each is 25m across, weighs between 40 and 50 tonnes and contains around 80 precision chambers or 200 trigger chambers. The support structure itself is just one third of the weight of the total wheel.

Because of their sheer size, each wheel had to be made in 12 pieces for the trigger planes and 16 pieces for the precision-measurement planes, or "petals", of aluminium, the last of which was installed on Friday. Each was assembled at CERN using components from all over the world before being fitted together, piece by piece like a jigsaw.

Because of the need for space for the chambers, designing a suitable structure presented a unique challenge, one that project engineers, Raphaël Vuillermet, Dimitar Mladenov and Giancarlo Spigo were happy to take on.

"The detectors themselves have been on drawings for 15 years; everyone knew where they would go but no one knew about the structure," explains Dimitar. "There were chambers everywhere so our design had to build around them and in the small spaces in between them."

The result after 3 years of calculation, design and sleepless nights was a uniquely thin and light structure that is precise to less than a millimetre.

The 100-member collaboration from Israel, Japan, the US, China, Russia, Europe and Pakistan began assembly of components in 2005 and installation in 2006. "Because the pieces are so delicate we had to be careful throughout the whole process," explains Raphaël. "I was very afraid about something happening to the chambers and also to the people, because you are working 30 metres up. But we didn’t have any problems."

The completion of the big wheels is symbolic for ATLAS because, as technical coordinator Marzio Nessi explains, "the big wheels were always seen as something we would do at the end. And now we have done them."

For Dimitar the biggest challenge was the timing. "I feel proud, but not for myself, for everyone. It was the result of hard work. The only thing that we were lucky about was the weather; if there had been a single day of heavy rain we might have been delayed. But Marzio said not to worry and to leave the weather to him, and the weather was great. I don’t know how he did it!"

Now just two smaller scale wheels and the end-wall chambers remain to be installed, and the big wheels have already begun to give read-outs as part of test runs using cosmic ray data that ATLAS performs every six weeks.

With their striking symmetry and aesthetic appeal the big wheels are likely to become icons of the experiment. But to Marzio, all pieces of ATLAS are beautiful. "This piece just happens to be 25m high."