The handling cart is a structure which supports the mainframe when it is not installed or attached to the telescope. The cart also supports other systems not attached to the mainframe, including remote electronics enclosures, the slit-mask loader, spare filters, dispersers, etc. The cart has lifting points and/or wheels which are used to move the instrument on and off the Nasmyth platform. The cart includes mechanisms for transferring the mainframe supports from the cart to the telescope.