in order to protect something

The Strategic Military Services better know as S.M.S is a private and special military force, they're owned and operated by Richard Bilrer (Zentraedi) and serve as a military provider to the New U.N Forces. Alto joins the S.M.S and pilots the VF-25 Messiah variable fighter right after the death of Henry Gilliam, who was killed while fighting with a Vajra. His brilliant and promising skills in that battle let him catch Ozma Lee's attention, leader of the Skull Squadron, who presented him with the opportunity to join and gave him the codename: skull 4.

The S.M.S has two important teams in the series: the Skull Team with Ozma Lee as leader (Mikhail/Luca/Alto/Canaria as subordinates) and the Pixie Team wih Klan as capitain (Nene/Raramia as subordinates). Noteworthy: All in the Skull Team are humans while all in the Pixie Team are Zentraedi. Also, an important fact is that most of the people in the organization were former N.U.N.S veterans, so they're not just talented civilians.

S.M.S had a great influence in Alto's development in the series, They gave him the opportunity to make his dreams come true, expand his world and grow as a man.

As a random note, the S.M.S actually resembles a modern form of the unit of Space War I,The Skull Squadron. They don't only share the name with this important team, but also Ozma Lee's VF-25S has the same colours as Roy Focker's Skull 1, Michael's VF-25G shares the blue colour with Maximilian Jenius's unit, Alto Saotome's VF-25F with Hikaru Ichijo's and even Klan's Queadlunn-Rea resembles in colour Milia Fallyna Jenius' fighter, who happens to be a Zentraedi too.