Magnetic sensors for space flight are highly sensitive inductive sensors but they are cumbersome and heavy (150g/axis) which impacts the launching cost. Since many years, research has been performed in order to reduce the sensor size and mass. However no further progress is expected on this line without a definite change of paradigm. The solution could be spintronic devices provided they could present the proper sensitivity. Our aim is therefore to develop a magnetic sensor which will combine an innovative architecture with a low-noise magnetoresistive element based on a phenomenon we recently discovered. The experimental work will be : i)the microfabrication of the device; ii) measurement of the electrical noise. The device composition will be optimized depending on the obtained results.