EVA Report – May 14th

Crew 212 Rover test EVA report 14-MAY-2019

Engineering EVA

Author: Paolo Guardabasso
Purpose of EVA: Drive test of Opportunity, Spirit, Curiosity.
Start time: 10:45
End time: 12:15

Narrative: this EVA was performed to test the three rovers in similar conditions, to verify their status; it was chosen to perform the EVA in the late morning so that temperatures simulated an EVA worst case scenario. Three crew members (the Crew Engineer Paolo, the Spacesuit engineer Camilo and the Executive Officer Vittorio) drove on Cow Dung Road 0110 about one mile north from the Hab (arriving close to the crossing with Galileo Road) and then performed a U-turn and drove south. Around 0.3 miles after, Opportunity turned off becausethe battery overheated. The driver of Opportunity mounted on Curiosity and the EVA crew proceeded south and passed the Hab, driving one more mile south. Then, they performed a U-turn and drove back to the Hab. Battery levels were verified after 1 mile, at the failure point of Opportunity (1.3 miles), after 2 and 3 miles and at the Hab. A detailed GPS map is attached.

Results:

· Opportunity: the rover stopped because of the battery overheated after about 1.3 miles. It was recovered in the late afternoon (6:30pm)

· Spirit: the rover battery dropped to 65% after only 4 miles (declared autonomy is 50 miles).

· Curiosity: the rover performed nominally throughout the mission.

A graph of the battery levels for each rover over the distance is attached.

Recommendations

· Opportunity should not be used, or only be used during early morning or late day EVAs, when the temperature is low, and never without a backup rover.

· Spirit can only be used on a maximum range of 3 miles, otherwise the battery might not be enough for the way back.

· For all the rovers, a check of radiator water levels should be run as soon as possible, to verify that the tank is filled as per the manual.