Mariner 5 Key Dates & Status:
- 06.14.67: Mariner 5 Launch
- 10.19.67: Mariner 5 Arrival at Venus
- Status: Mariner 5 Mission Complete
Mariner 5 - Overview: Mariner 5 was originally built to be the backup for Mariner 4 to Mars, but was never needed for that purpose.
Thus, Mariner 5 was refurbished and modified to go to Venus instead. Mariner 5 flew by Venus at a distance of 3,990 kilometers (2,480 miles), and with its more sensitive instruments than aboard Mariner 2, revealed new information about Venus' atmosphere, including its composition of 85-99% carbon dioxide. Mariner 5 also studied the interplanetary space in the vicinity of Venus and furthered the art and science of building and operating interplanetary spacecraft.