Construction of SLC-41’s new Crew Access Tower continues
CAPE CANAVERAL, Fla. — It took engineers a little more than a month to get the Crew Access Tower to its current state of completion. Located at Cape Canaveral Air Force Station’s Space Launch Complex 41 in Florida, the new structure is being constructed to allow astronauts to board Boeing’s CST-100 Starliner spacecraft, which will be sent aloft atop a United Launch Alliance (ULA) Atlas V 401 rocket to the International Space Station.
“We spent a lot of time with conceptual designs and with the human elements, which is very important for a project of this nature,” said Howard Biegler, ULA’s Launch Operations lead for Human Launch Services in an article published by NASA. “Building a structure is one thing, but building it so that it’s useful, that it provides a safe environment for the people who are going to be called to use this system is the hard part.”
Standing some 200 feet (61 meters) in height, the Crew Access Tower is more spacious and has more open areas than similar structures that NASA has used in the past. This change has been made to ensure the comfort of astronauts who will be in their bulky ACES flight suits waiting to board the Starliner. Crew comfort and safety are some of the key considerations managers are focusing on as they prepare the boosters, rockets, and support systems needed to launch astronauts into orbit.
“It takes a lot of people working hard together to get any spacecraft into orbit successfully, and that’s doubly true for a new spacecraft being built for humans,” said Mike Burghardt, director of Launch Segment Integration for Boeing’s Commercial Crew Program. “The Starliner will feature modern, high-reliability components to significantly increase crew safety and we back that up with robust launch system, including this Crew Access Tower.”
Late last month (October) the crew access arm – the element of the tower that will extend from the structure to the rocket and spacecraft – was connected to the White Room. Prior to their attachment to the Crew Access Tower next summer, these two components will undergo extensive checks.
One of the tower’s more interesting features is that, in the event of an emergency, astronauts would walk through “walls of water” brought into existence by the structure’s fire suppression system.
Meanwhile, flight crews and ground support teams would evacuate the area via an escape system that has yet to be added to the tower. An article discussing the Crew Access Tower that was produced by NASA noted that this system should allow these personnel to clear the tower within “less than a minute” to the safety of the evacuation vehicle.
“We have certainly changed the landscape out here,” Biegler said. “The day the first tier physically made contact with the concrete and was bolted up brought a new level of reality to the project.”
In a way, this tower represents a “return to the beginning” for NASA. Since the flight of Apollo 8 in 1968, excluding missions lifting off from the Baikonur Cosmodrome in Russia, astronauts have flown out of Kennedy Space Center’s Launch Complex 39 A and B.
Construction crews began assembling the tower in September with the first seven metal tiers being assembled four miles away from SLC-41. It was built on top of a strengthened concrete foundation at the launch pad.
Stairways, trays for cables and the prerequisite shielding were included in the structure when it was built – with each level of the tower made to fit one on top of the other. This method kept the amount of construction required at SLC-41 itself to a minimum; this is important as SLC-41 is currently the most active launch pad at Cape Canaveral with seven launches already taking place this year from the historic site and one more still scheduled to take place.
There is still quite a bit more to do before the structure is deemed “finished”. Elevators, data lines and other critical components of the tower remain to be installed. When all is said and done – it is estimated that the Crew Access Tower will weigh an imposing 966,000 lbs (438,170 kg). Current estimates place its completion in fall of 2016.
Boeing hopes that the tower will be used for its intended purpose as soon as 2017, when a United Launch Alliance Atlas V 401 booster, capped with a Starliner spacecraft will lift off with a crew on board – bound for the International Space Station.
NASA is currently working under a two-tiered strategy, with companies such as Boeing, Orbital ATK, SpaceX, and ULA providing commercial crew and cargo delivery services to the orbiting laboratory. Meanwhile, the agency prepares the Orion spacecraft and super heavy lift Space Launch System duo to send astronauts to much more distant locations.
Jason Rhian spent several years honing his skills with internships at NASA, the National Space Society and other organizations. He has provided content for outlets such as: Aviation Week & Space Technology, Space.com, The Mars Society and Universe Today.