A spare solid state recorder was also installed to allow efficient handling of high-volume data. Prior to the second servicing mission, Hubble used three 1970s-style reel-to-reel tape recorders. During the second servicing mission, one of these mechanical recorders was replaced with a digital solid state recorder. During this mission a second mechanical recorder was replaced by a second solid state recorder. The new recorder could hold approximately 10 times as much data as the old unit (12 gigabytes instead of 1.2 gigabytes). The recorder weighs and is 12 by 9 by 7 inches in size.