Up until this year, the only nation with rovers on Mars was the United States. Thanks to a decades-old program, the country has managed to advance Mars exploration to heights that will probably never be matched by any other nation. Or will they?

To date, five rovers made in America, at least partially, have been sent to the Red Planet. They are the Sojourner, Spirit, Opportunity, Curiosity, and Perseverance. Of them, only two are presently still active, the Curiosity and the recently arrived Perseverance, and they’re accompanied by a tiny helicopter called Ingenuity.

Each of the five land-based pieces of hardware sent up there by the Americans is extraordinary in one way or another. A good chunk of them far exceeded their initial life expectancy, some have made discoveri...