The Crew Access Arm for a new generation of spacecraft was lifted into place the morning of Aug. 15 at Space Launch Complex-41 where workers are modifying the launch pad to give astronauts access to Boeing's CST-100 Starliner on launch day.

The 50-foot-long, 90,000-pound arm will form a bridge between the newly built Crew Access Tower and the hatch of the spacecraft. Astronauts will walk across the arm to climb inside the Starliner for flight. Poised to begin a mission, the Starliner will sit on top of a United Launch Alliance Atlas V rocket.

The arm also holds the White Room, an enclosed area big enough for astronauts to make final adjustments to their suits before climbing aboard the spacecraft.

Work began around 7:30 a.m. with crews attaching cables to the arm before a crane slowly hoisted itoff the launch pad surface. Another crew of workers was waiting in the tower about 160 feet above the surface as the crane maneuvered one end of the arm into a notch on the tower. They bolted and welded the apparatus to the tower to complete the process.

The addition of the arm is the latest in a rapid string of accomplishments for NASA's Commercial Crew Program and its partners. Working independently on separate contracts with NASA's program, Boeing and SpaceX are developing spacecraft and launch systems to take astronauts to the International Space Station.

The additional launch capability will allow the resident crew of the station to grow by one, effectively doubling the time astronauts have in orbit to conduct science vital to spaceflight research, as well as investigations into benefits for those on Earth.

"You have to stop and celebrate these moments in the craziness of all the things we do," said Kathy Lueders, manager of NASA's Commercial Crew Program. "It's going to be so cool when our astronauts are walking out across this access arm to get on the spacecraft and go to the space station."

The arm and tower have been constructed between Atlas V launches at SLC-41. The arm was built at a construction yard near NASA's Kennedy Space Center and trucked to the launch pad on Aug. 11. The tower was built in segments close to the launch pad and stacked together to form the nearly 200-foot-tall structure.

It is the first new crew access structure at the Florida spaceport since the space shuttle's Fixed Service Structures were put in place before Columbia's first flight in 1981. It also is the first new crew access tower at Cape Canaveral Air Force Station since the Apollo Program.

"You think about when we started building this 18 months ago and now it's one of the most visible changes to the Cape's horizon since the 1960s," said Chris Ferguson, a former shuttle commander who is now Boeing's deputy program manager for the company's Commercial Crew Program. "It's a fantastic day."

The advances reminded some of the early days of human spaceflight when the first generation Atlas rockets put astronauts into orbit.

"John Glenn was the first to fly on an Atlas, now our next leap into the future will be to have astronauts launch from here on Atlas V," said Barb Egan, program manager for Commercial Crew for ULA.

Earth is not the only place work is underway to prepare for Commercial Crew missions. Astronauts on the International Space Station will perform a spacewalk Friday to install an International Docking Adapter to a station port that will allow visiting spacecraft including those on commercial crew missions to dock with the orbiting laboratory.

Carried into orbit during the most recent cargo resupply mission, the IDA will become a doorway for astronauts as they cross from their spacecraft into the station. The adapters are outfitted with a network of sensors and fixtures that work with automated systems to dock the spacecraft to the port.