A small but important change from the original Destiny is that Guardians will no longer be required to return to orbit when they want to switch activities in Destiny 2. This means that the amount of loading time players will have to endure while waiting to move on to their next challenge is greatly reduced. Now missions, patrols, public events, and more will all be available without having to load back to Orbit and fly into the level. But while players can seamlessly jump between exploration and other activities from their landing zone, you may want to use it while you wait for friends to join your Fireteam.
In order to do this, press the touchpad (PS4) / Menu button (Xbox One), then press Triangle (PS4) / Y (Xbox One). You will then be prompted to hold the button again to enter orbit. The screen will then fade to black and you will immediately return to your ship.
Note that unless you are a group leader, inputting this command will also make you leave the Fireteam. Conversely, Fireteam leaders will not be able to input the command and leave without relinquishing the position to another Guardian.
That is all you need to know to go into orbit in Destiny 2. For more information and guides about the game, check out our Destiny 2 wiki.