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ICPS umbilical installed on SLS mobile launcher

The ICPS umbilical is installed on NASA's SLS mobile launcher. Photo Credit: Ben Smegelsky / NASA

The ICPS umbilical is installed on NASA’s SLS mobile launcher. Photo Credit: Ben Smegelsky / NASA

The road to the first flight of the Space Launch System (SLS) took another step forward March 21, 2018, when one of the last of the big swing arms was installed on the mobile launcher at Kennedy Space Center, Florida.

Construction workers with JP Donovan attached the swing arm—the interim cryogenic propulsion stage (ICPS) umbilical—to a crane using rigging lines. The crane then lifted the it to a height of 240 feet (73 meters) where it was bolted to the tower. The process took four hours, according to NASA.

SLS Block-1 on launchpad at night

Artist’s impression of an SLS Block 1 rocket on the launch pad at night. Image Credit: NASA

Now that the umbilical is installed, the next step is to incorporate additional equipment equipment, including electrical wiring, environmental control system tubing, and hydraulics, to name a few. After that, the arm will be tested as part of a validation and verification process.

The mobile launcher, which closely resembles the orange towers of the Apollo era, will support assembly, testing, check-out, and servicing of the SLS, and will be rolled out to the pad on the Crawler Transporter, just as the Space Shuttle and Saturn V were. It will serve as the launch pad for Orion/SLS launches.

The new swing arm will supply propellant, environmental control systems, pneumatics, and electrical connections to the ICPS on SLS rocket, which will be used to boost the Orion spacecraft beyond low-Earth orbit toward the Moon. The umbilical will also detect hazardous gas leaks.

Comparable to the S-IV-B of the Apollo program’s Saturn V, the ICPS is the upper stage of the Block 1 version of the SLS.

The mobile launcher is being prepared for the first integrated test flight, called Exploration Mission-1. NASA’s Exploration Ground Systems team is installing the umbilicals. The ICPS swing arm is one of twenty umbilicals that will service the SLS.

Other launch accessories are the Crew Access Arm, which the astronauts will use to board the spacecraft; the Vehicle Stabilizer System, which reduces swaying during rollout and during high winds; and Vehicle Support Posts, which support the twin Solid Rocket Boosters and measure strain and loads during stacking, integration, rollout, and launch.

No crewed spacecraft has launched from the United States since 2011. Exploration Mission-1 will be uncrewed and is currently planned for its debut in 2020, but Exploration Mission-2 is expected to be the first crewed launch of the SLS, and is scheduled for no early than 2023. It will be the first human flight beyond low-Earth orbit since 1972, and will fly a crew around the Moon.

Video courtesy of NASA



Collin R. Skocik has been captivated by space flight since the maiden flight of space shuttle Columbia in April of 1981. He frequently attends events hosted by the Astronaut Scholarship Foundation, and has met many astronauts in his experiences at Kennedy Space Center. He is a prolific author of science fiction as well as science and space-related articles. In addition to the Voyage Into the Unknown series, he has also written the short story collection The Future Lives!, the science fiction novel Dreams of the Stars, and the disaster novel The Sunburst Fire. His first print sale was Asteroid Eternia in Encounters magazine. When he is not writing, he provides closed-captioning for the hearing impaired. He lives in Atlantic Beach, Florida.

Reader Comments

Do you expect me to believe the projected launch dates that NASA posts. Space.X will have made many flights to Mars by the time NASA ever gets a human in space. Give up on NASA.

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