Mars Exploration Program various components of the EDL systems on Earth-based testing. However, the costs of reproducing environments in which this data would be relevant in terms of Mars' environment are considerably high, resulting in testing being purely ground-based or simulating results of tests involving technologies derived from past missions. InSight, launched from Earth May 5, 2018, the lander touched down on Mars November 26, 2018 on Elysium Planitia. Mars exploration missions, as do most NASA missions, can be fairly costly. For example, NASA's "Curiosity" rover (landed on Mars in Aug 2012) has a budget exceeding $2.5 billion. NASA also has goals of
Crewed Mars rover rovers, because they need to know at least roughly where they are and where they are going to get to a destination. Dead reckoning was the method used by the Mars Pathfinder rover "Sojourner" for navigation. A GPS satellite network for Mars would mean a constellation of satellites in Mars orbit, but one alternative would be a surface based pseudo-satellites array. These devices would have to be emplaced with high precision, unless they were self-calibrating. An example of criteria for humaned Mars surface rover was expressed by NASA in the surface variant of the aforementioned SEV, in development in during