The INTEGRAL mass model - TIMM

The task of The INTEGRAL Mass Model project is to build an independent geom etry model of the entire INTEGRAL payload and spacecraft. Such a model can then be used to provide independent and uniform background and performance evaluation of all instruments. It will also be used for post-launch diagnos is and for validation of payload system configuration changes. This is of s pecial importance to the INTEGRAL mission, as it will have no flight spare and a computer based mass model will represent the only means of testing an y perplexing post launch scenarios. In this paper the current plan and stat us of this project is presented as well as some results of Monte Carlo simu lations based on the mass model.