Adjective
TSTO (not comparable)
(astronautics, space flight, aerospace) Initialism of two-stage to orbit.
This growth factor sensitivity is shown parametrically for both SSTO and two-stage-to-orbit (TSTO) vehicles for a standard LEO mission. Source: Internet
The structural coefficient is defined as: Comparison of growth factor sensitivity for Single-Stage-to-Orbit (SSTO) and restricted stage Two-Stage-to-Orbit (TSTO) vehicles. Source: Internet