These menus typically take you to lower-level data screens. From the data screens you can define search criteria and browse the catalog. From the top level menu, the most important menu command for most users will be , which is used to select options from the list that appears in the top window. This command allows you to move down to lower-level submenus and eventually, to the data screens. As you move into the lower-level data screens, note that the menu commands change.
Command menus vary depending on the context of the screen.
You need to traverse the menu screens to get to the data screens, which is where you will actually begin doing an archive search. Chapter 9 contains detailed descriptions of the contents of each screen. When you first get into the HST catalog, you are in the Top Level Menu. The available menu screens are listed along with a brief description of their contents. You move through the menu levels by selecting choices from the menu.