Abstract: To predict the lifetime of spacecraft electronic products, this paper proposes the accelerated life test (ALT) for those products. Firstly, the failure mode, the mechanism, and the effect analysis (FMMEA) are used to identify the major failure mode, the related mechanism and the sensitive stress. Secondly, the theoretical analysis or the enhanced reliability testing is carried out to obtain the limit of working stress for the product. Finally, the ALT scheme is designed. The spacecraft Solid State Power Amplifier (SSPA) is investigated experimentally to validate the applicability of ALT for the electronic products of spacecraft.