You can control the drawing order and presence of layers in the map by using the Manage Layers dialog box. The dialog box shows a list of those layers and group layers that are visible in the ArcGIS Explorer map as well as layers that provide height information to other layers. The former set of layers are referred to as Draped layers; these layers are placed on top of the latter set of layers, the map's Elevation layers, obtaining their z-values (height values) from them.
Here is an example of the dialog box showing several layers:
To move the display position of a layer
Select the layer in the treeview and click either the Move Up or Move Down buttons to move the layer in the corresponding direction or you can also drag and drop the layer to the position you want.
To move layers or layer packages that are group layers or contain group layers
You can move layers or layer packages that are group layers or that contain group layers like any other layers; however you cannot change the order of the layers within the group layer. Note that group layers are not supported directly in ArcGIS Explorer; however layers and layer packages that contain them are.
To remove a layer from the current map
Select the layer and click the Remove button at the right of the dialog box.
To remove a layer's cache
Select the layer and click the Clear Cache button at the right of the dialog box. This has the effect of fetching the most recent data of the service related to the layer.
Learn more about managing cache