Last night, just after midnight, the last recovery command was sent to Spirit. It would be an understatement to say that this was a significant moment. Since the last communication from Spirit on March 22, 2010 (Sol 2210), as she entered her fourth Martian winter, nothing has been heard from her. There is a continued silence from the Gusev site on Mars.
We must remember that we are at this point because we did what we said we would do, to wear the rovers out exploring. For Spirit, we have done that, and then some.
Spirit was designed as a 3-month mission with a kilometer of traverse capability. The rover lasted over 6 years and drove over 7.7 kilometers [4.8 miles] and returned over 124,000 images. Importantly, it is not how long the rover lasted, but how much exploration and discovery Spirit has done.
This was the first panoramic image Spirit took on the surface of Mars more than seven years ago:
Meanwhile, the rover Opportunity trundles along toward the Endeavour crater:
Opportunity continues the trek towards Endeavour crater, now less than 4 kilometers (2.5 miles) away. The rover drove on four of the last six sols.
On Sol 2595 (May 13, 2011), Opportunity headed southeast with a drive of over 91 meters (300 feet). On the next sol, the rover drove further southeast achieving over 140 meters (460 feet). On Sol 2599 (May 17, 2011), Opportunity headed first southeast then east totaling over 86 meters (282 feet) of distance. On the next sol, the rover drove over 112 meters (367 feet) with a dog-leg maneuver mid-drive so close-up imaging of a crater could be done. The plan ahead is more diving.
As of Sol 2600 (May 18, 2011), solar array energy production was 406 watt-hours with an atmospheric opacity (Tau) of 0.806 and a solar array dust factor of 0.528.
Total odometry is 29,709.29 meters (29.71 kilometers, or 18.46 miles).