Final answer:
Landsat 8 and Landsat 9 are the two most recent satellites in the Landsat program. The Landsat record goes back approximately five decades.
Step-by-step explanation:
The two most recent Landsat satellites are Landsat 8 and Landsat 9. Landsat 8 was launched in 2013 and is currently operational, while Landsat 9 is scheduled to be launched in 2021. The Landsat program has been continuously collecting satellite imagery since 1972, so the Landsat record goes back approximately five decades.