I present the progress that has been made towards implementing a Square Root Information Filter (SRIF) into the asteroid-modelling software SHAPE. I compare SRIF’s performance with the current fitting algorithm, with the conclusion that SRIF has the potential to perform substantially better than its predecessor. I show the results of SRIF operating on previously collected delay-doppler data for the asteroid 2000 ET70. I also discuss potential future changes to improve shape’s fitting speed and accuracy.