The Ascent of Airware Al-Li in Space Applications

Over thirty years ago, 2195 plates were selected for the cryogenic sections of the Space Shuttle’s external tank. Alloy 2195 provided over 3000 kg in weight savings, enhanced structural integrity and payload improvements which enabled construction of the International Space Station. The material offered higher strength/modulus, improvements in stress corrosion cracking, enhanced cryogenic properties and 5% lower density when compared to legacy 2219 plate. Forty missions of the Space Shuttle utilized External Tanks built using alloy 2195 for both LOX and LH2 cryogenic tankage.

However, 2195 is qualified to a maximum thickness of 60 mm. To address the gauge limitation of 2195, Airware® alloy 2050 has joined alloy 2195 as a preferred plate material for both pressurized and non-pressurized structural components of space launchers and crew modules. The thickness range for 2050 matches the applicable gauge ranges in alloy 2219 and 7050. Drop-in replacements allow 5% weight reduction due to the lower density of 2050 when compared to 2219. It offers improvements in strength and modulus with an A rating for stress corrosion cracking.

Actual reengineered structures demonstrate up to 10% weight reduction through thinner stiffeners with wider pocket spacing. Both products are readily joined via the friction stir welding process. Mature longitudinal, radial, and mixed mode FSW joining has been fully demonstrated.

While the Space shuttle program was winding down, industry saw a dramatic increase in the pace of development of new space launch vehicles. SpaceX is leading the pack with Falcon 9 and Falcon Heavy resupplying ISS, launching thousands of communication satellites and carrying out other missions. To date, SpaceX has launched Falcons over six hundred times and developed a concept of reusability of the first (core) stage. Newer launcher systems include Blue Origin’s New Glenn, ESA’s Ariane 6 and more recently Relativity Space’s Terran R. We all witnessed two successful cislunar Artemis missions which proved that Orion Crew Module can safely orbit and return humans to Earth. Future missions will test Human Landing Systems needed for landing on the Moon in 2028. Artemis mission is based on Boeing’s Space Launch System and Lockheed Martin’s Orion Crew module. These vehicles rely heavily on both 2195 and 2050 plates for the most critical components. Current applications of 2195 and 2050 in space vehicles include: dome caps, barrel panels, stiffeners, adapters, gores/domes, and intertanks.

This presentation will provide information on the characteristics of these two products and examples of their applications.