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
Sol (day on Mars) Mars Sol Date is defined mathematically as MSD = (Julian Date using International Atomic Time - 2451549.5 + "k")/1.02749125 + 44796.0, where "k" is a small correction of approximately 0.00014 d (or 12 s) due to uncertainty in the exact geographical position of the prime meridian at Airy-0 crater. The word "yestersol" was coined by the NASA Mars operations team early during the MER mission to refer to the previous sol (the Mars version of "yesterday"), and came into fairly wide use within that organization during the Mars Exploration Rover Mission of 2003. It was eventually picked up and used