 The GDL was formed in 1928, initially focusing primarily on the development of solid-fuel rockets for military use, such as anti-aircraft and anti-tank weapons, though it branched out into liquid-fueled rocket engines in May 1929.These rockets were developed to be used as engines for aircraft instead of for conventional artillery.It was primarily through the work of the GDL that the OR and ORM series of rocket engines were developed, which would become the backbone of early Russian jet development.