Abstract: Solutions for inverse problems appearing in space applications and space technology are described. The inverse problem is formulated as non-linear optimization problem. For solving the inverse problem, some additional information must be added from the previous knowledge about the physical phenomenon. In general this a priori information means smoothness, in other words, regularized solutions are searched. The methodology is applied to geophysics (magneto-telluric inversion), meteorology (temperature retrieval from satellite data), and oceanography (inverse hydrological optics), as examples of space applications. The scheme is also employed for solving inverse problem emerging from technology: inverse design (space radiator).