Long Wall

Long Wall, previously known as ABL Space Systems, is an American aerospace and defense company building deployable missile defense and hypersonic flight-test systems for the U.S. military. Founded in 2017 in El Segundo, California by Harry O'Hanley and Dan Piemont — former SpaceX and Morgan Stanley employees — the company originally set out to make small-satellite launch more flexible, reliable, and affordable, offering a containerized, rapidly deployable launch vehicle (RS1) and ground system.

After a series of technical setbacks including two failed orbital launches in 2023 and 2024, and facing intense competition from SpaceX and Rocket Lab, the company announced in November 2024 that it was exiting the commercial launch market and pivoting to defense applications. In February 2025, CEO Dan Piemont announced the rebrand to Long Wall — a name inspired by the Long Walls that protected ancient Athens — to reflect its sharpened focus on national defense.

Today Long Wall repurposes its launch heritage for the U.S. Department of Defense. Its RS1 rocket has evolved into the RSX vehicle, used as a hypersonic flight-test bed and a 'threat replicator' target to test missile-defense systems, while its GS0 containerized ground system has been rebranded as Ironwood for responsive, deployable launch. In December 2025 the company unveiled Cyclops, a surface-launched, exoatmospheric interceptor designed to defeat missiles in the midcourse phase of flight at a fraction of the cost of legacy interceptors such as the Navy's SM-3.

Long Wall remains committed to U.S.-made manufacturing and to serving government and defense customers, positioning itself within a broader wave of space startups shifting toward defense amid rising geopolitical tensions and growing Pentagon interest in hypersonic and missile-defense capabilities.