Preserving humanity’s achievements allows us to document our existence and our quest to explore the vast unknown. The Endeavour space shuttle orbiter, which completed 25 missions from 1992 to 2011, stands as one of these monumental achievements. In 2012, the shuttle was brought to the California Science Center, where it would spend its retirement on public display. For nearly 12 years, the 178,000-pound orbiter rested horizontally in the Samuel Oschin Pavilion, displaying its impressive 122-foot-long body and 78-foot wingspan. However, in January 2024, the Endeavour's position was changed — it was raised upright.

Now, the orbiter, along with two aft skirts, two solid rocket boosters, and an external tank, stands vertically in a ready-to-launch position at the Science Center’s new Samuel Oschin Air and Space Center. The move involved two years of pre-construction and lift planning as part of the “Go for Stack” process, which began in July 2023. After the installation of the aft skirts, boosters, and tank, the final step was to position the shuttle. But how do you move a 178,000-pound spacecraft and place it precisely in launch position?

Bragg Companies, a crane service based in Long Beach, California, was hired for the job, using five cranes for each lift. The Liebherr LR 1750/2 hydraulic crawler crane was stationed on-site full-time, working in tandem with various hydraulic truck cranes throughout the project. The Liebherr LR 1750 crawler crane was equipped with 1,466,000 pounds of counterweight, a tip height of approximately 395 feet, and a maximum radius of about 151 feet.

“The Liebherr LR 1750’s ability to electronically limit hoist and swing speeds was crucial to the success of the lifts, especially given the tight tolerances in the pit and the variable wind conditions at the tip height,” said Justin Lambert, general manager of Bragg Crane & Rigging, in a press release.

Crawler cranes, which move on tracks (or crawlers) instead of wheels, provide stability and the ability to operate on soft ground and uneven terrain. These cranes are commonly used in industries such as wind energy, oil rigs, airports, dams, shipbuilding, and many other applications. Though hydraulic crawler cranes are known for their heavy lifting capabilities, wind remains their primary challenge. Wind can affect load stability and crane performance, increasing safety risks and complicating lifts.

Throughout the project at the Science Center, high winds and rain presented challenges when lifting and setting the shuttle components inside the new building. Given their massive size and large surface areas, all lifts had to be performed in minimal wind conditions, which were typically found during early morning hours.

To begin the stacking process, Bragg transported the aft skirts from Mojave, California, to Los Angeles and used a Liebherr LR 1750 crawler crane to lift and position them. The team then utilized both the crawler crane and a Liebherr LTM 1160 mobile crane to lift, upend, and position the solid rocket motors and external tank.

The most complex lift involved the Endeavour orbiter itself. After a challenging transport process, a Liebherr LR 1750 hydraulic crawler crane, supported by Liebherr LTM 1400 and LTM 1160 mobile cranes, successfully lifted, upended, and positioned the orbiter inside the new Samuel Oschin Air and Space Center building.

The most difficult part of the operation was attaching the external tank to the Endeavour. The tank had to be carefully lowered through scaffolding without its outer foam layer making contact with anything. The tight fit between the external tank and the solid rocket boosters added to the complexity. After nearly 14 hours of careful work, on January 31, 2024, the Endeavour was fully detached from the crane and sling, and the final connection of the shuttle to the external tank and boosters was completed.

“With the successful lift and mating of Endeavour, we have achieved the final space shuttle stack. This is the culmination of more than thirty years of work and a feat that has never been accomplished outside of a NASA or Air Force facility,” said Jeffrey Rudolph, president and CEO of the California Science Center, in a press release.

Liebherr is not only focused on preserving history but also on shaping the future, with a clear emphasis on sustainability and net-zero goals. In recent years, the company has unveiled several “unplugged” machines, such as crawler cranes and drilling and piling rigs. These unplugged crawler cranes are equipped with electro-hydraulic drives that offer performance equal to their conventional counterparts. They feature lithium-ion batteries capable of powering the cranes for up to 4 hours of lifting, with recharging times of 4.5 hours. Performance can be enhanced by adding extra batteries, and these unplugged models also reduce noise levels when idling.

The company continues to develop advanced versions of its hydraulic machinery to improve transport and lifting efficiency. Earlier this year, Liebherr introduced the LTR 1150, a new 60-tonne telescopic crawler crane with a 150-tonne lifting capacity and a transport width of 3.5 meters. This is the first telescopic crawler crane to be equipped with the Liebherr VarioBase, which automatically calculates the optimum load capacity in real-time based on the fixed track width and adjustable rotation angle. Additionally, Liebherr has introduced “WindSpeed Load Charts” for the LTR 1150, allowing operators to safely and flexibly work in wind speeds up to 15.6 m/sec, even with the crane's full load capacity in many boom positions.