The Viking missions cost $1.06 billion, which, when adjusted for inflation, remain NASA's most expensive robotic planetary science mission of all time. Of this total, more than half ($610 million) was for lander development, $217 million was
for the orbiters, and $104 million spent on mission operations through 1982.
Viking costs per fiscal year. The two spacecraft launched in 1975 and began Mars surface operations in the summer of 1976. The chart does not include the costs associated with the 1976 transition quarter, a product of a one-time restructuring of the U.S. budgeting process. Source: Planetary Science Budget Dataset, compiled by Casey Dreier for The Planetary Society (accessible on Google Sheets or downloadable as an Excel file).
|Launch Services (Titan IIIE)||$79 million|
|Mission Operations||$104 million|
Detailed expenditures available in the Planetary Exploration Budget Dataset.