The surfaces and atmospheres of planets and moons can be seen in the infrared too. Also clouds of gas will be seen which will give birth to new stars, and it will see the winds that will be springing up from stars just born. The chemical elements and molecules, like H2, CO, CO2, H2O, and the more exotic molecules will be seen floating in space clumped together into clouds by gravity. Milky Way Galaxy has been forming in the past and what it will be churning-out in the future. Sometimes these clouds hide interesting objects within.
Astronomers go up into the stratosphere and make sure their instruments work right.
Hubble can only be visited each 2-3 years and at great cost. Hubble is all booked up and more. Hubble gets 10 times more requests for observing use from astronomers than it can accommodate. But this is typical for observatories. Good observatories are over-requested by factors of 2 to 10.