Mobile Launcher’s Crew Access Arm Successfully Tested

Crew Access Arm Testing
Technicians and engineers in Exploration Ground Systems at the NASA’s Kennedy Space Center in Florida recently tested the Crew Access Arm (CAA) that was added on the mobile launcher being prepared to support the agency’s Orion spacecraft and Space Launch System rocket.
Photo credit: NASA/Kim Shiflett

As astronauts prepare for trips to destinations beyond low-Earth orbit, their last steps before boarding an Orion spacecraft will be across the Crew Access Arm (CAA) on the mobile launcher.

Earlier this year, the CAA was added to the mobile launcher being prepared to support NASA’s Orion spacecraft and Space Launch System (SLS) rocket, the largest in the world. Technicians and engineers in Exploration Ground Systems at the agency’s Kennedy Space Center recently tested the crucial arm, confirming it worked as designed.

The test was designed to determine the functionality and integrity of the CAA and supporting mobile launcher systems.

“This was the first functional swing testing for the Crew Access Arm,” said Cliff Lanham, Mobile Launcher Project Manager at Kennedy. “Prior to testing, we checked the mechanical attachment, hydraulics and cabling to make sure we had confidence it would work properly.”

380-foot-tall mobile launcher tower
The crew access arm is located at the 274-foot level on the 380-foot-tall mobile launcher tower. The CAA will rotate from its retracted position and interface with the Space Launch System rocket at the Orion crew hatch location to provide entry in and exit from the spacecraft.
Photo credit: NASA/Kim Shiflett

The CAA is designed to rotate from its retracted position and line up with Orion’s crew hatch. The arm will provide entry and emergency egress for astronauts and technicians into and out of the Orion spacecraft.

In advance of those missions, the Exploration Ground Systems team at Kennedy has been overseeing testing of umbilicals and other launch accessories on the 380-foot-tall mobile launcher in preparation for stacking the first launch of the SLS rocket with Orion.
During the test, there were several moves of the arm controlled by systems on the mobile launcher. The test also was important because of the upcoming move of the mobile launcher from its park site to the Vehicle Assembly Building (VAB).

“The CAA will be extended when it goes inside the VAB,” Lanham said. “We cannot rotate the arm once in the VAB due to space constraints.”

Testing inside the VAB is designed to ensure all systems work properly in connection with the building prior to stacking the first SLS and Orion for Exploration Mission-1. EM-1 will be the first unpiloted flight of the new NASA spacecraft traveling 280,000 miles from Earth well beyond the Moon.

Engineers Mark Completion of Umbilical Testing at Launch Equipment Test Facility

A banner signing event was held at the Launch Equipment Test Facility.
A banner signing event was held at the Launch Equipment Test Facility at NASA’s Kennedy Space Center in Florida to mark completion of umbilical testing. Photo credit: NASA/Kim Shiflett

The team that tested the umbilical lines and launch accessories that will connect from the mobile launcher (ML) to NASA’s Space Launch System (SLS) rocket and Orion spacecraft for Exploration Mission-1 celebrated their achievement during a banner signing at the Launch Equipment Test Facility (LETF) at the agency’s Kennedy Space Center in Florida.

Engineers and technicians in the Engineering Directorate and the Exploration Ground Systems Program, along with contractor support, began the tests at the LETF about 2.5 years ago. The first to be tested was one of two aft skirt electrical umbilicals. Testing of the final umbilical, the second of two tail service mast umbilicals, was completed on June 27.

“The team of NASA test engineers and test managers, and contractor engineers and technicians, worked tirelessly six days a week, 10 hours a day, in order to meet the highly aggressive schedule and deliver the hardware to the mobile launcher for installation,” said Jeff Crisafulli, Test and Design branch chief in the Engineering Directorate.

In all, 21 umbilicals and launch accessories were tested on various simulators at the LETF that mimicked conditions during launch to ensure they are functioning properly and ready for installation on the ML. Most have been delivered and installed on the ML tower. These include the Orion service module umbilical, interim cryogenic propulsion stage umbilical, core stage forward skirt umbilical and core stage inter-tank umbilical. Two aft skirt electrical umbilicals, two aft skirt purge umbilicals, a vehicle stabilizer system, eight vehicle support posts and two tail service mast umbilicals were installed on the 0-level deck of the ML.

Before launch, the umbilical lines will provide power, communications, coolant and fuel to the rocket and spacecraft. Additional accessories will provide access and stabilization. During launch, each umbilical and accessory will release from its connection point, allowing the SLS and Orion to lift off safely from the launch pad.

“Design, fabrication and testing of the new mobile launcher’s umbilicals and launch accessories is a once-in-a-lifetime opportunity that I am proud to have been part of,” Crisafulli said.