In this Master Thesis we begin with a short analysis of the current space market, with the aim of searching solutions that allow us to implement femto-satellites (that is, satellites with a mass less than 100 grams) and mini-launchers (in this case less than 100 kilograms). New synergies will be explored in order to reduce drastically the cost of development, construction, operation and disposal of femto-satellites and mini-launchers for operations in LEO (Low Earth Orbits below 300 kilometers of altitude) and short duration, about one week. http://code.google.com/p/moon-20 Two application examples based on current technologies that are not usually space compliance will be shown. The first example pretends to fulfill the N-Prize requirements and it is called WikiSat. The second example is an Earth observation application called EPSCSat. The N-Prize is a competition that consists in putting into orbit a satellite of less than 20 grams with less than 10,000 sterling pounds of launch cost. This tiny satellite shall be tracked for at least nine turns around the Earth at a height in excess of 100 kilometers above the ground to qualify for the N-Prize. The femto-satellite design will be extended to the EPSCSat and it is presented as an additional application of this work. The EPSCSat is a satellite with a camera, an optic for Earth observation and a fast download link thanks to the use of a radio-link in the S-Band.