EVA # 3
Author: Felipe Torres, Crew scientist
Purpose of EVA: Recognition of the lithology of the zone. We would recognize the area to identify the convenience of collecting geologic samples in this zone. Additionally, our crew geologist would train our other crew members so that they would also able to collect samples needed as followed by our mission plan; this in case she is not able to go out on an EVA for some reason so that she’s not the only one capable of fulfilling this activity but that any crew member could do so.
Start time: 9:30 am
End time: 11:00 am
Narrative: We got ready for our EVA by preparing the instruments we would use for collecting samples: hammer, shovel, zip-lock bags. The rovers we used were finally Spirit and Perseverance, following Atila’s recommendation after Curiosity’s battery performance wasn’t as expected.
We drove our vehicles from MDRS entrance road and turned left at Cow Dung Road heading north towards Brahe Hwy 1572. Cristian and Maria were leading the group riding Spirit rover, and Felipe was behind driving Percy. After driving for approximately 1 mile, Percy was showing a concerning decrease in its battery, reaching around 80% in this short distance, while Spirit was in around 96%. This became the main concern for the EVA as we started debating whether or not we were going to make it to our destination before 60% and we decided that at 62% we would stop and keep advancing by foot.
We arrived at the intersection between Cow Dung Road and Brahe Hwy 1572 with Spirit rover at 86% battery and with Percy at 63% battery. The original plan was to turn left at Brahe Hwy 1572 in our Rovers until the intersection between Route 1575 and 1574 and then explore the Moon Overlook area by foot. Plans had to change since we were limited by Percy’s battery; we decided to start walking, which we realized wasn’t a good option for the following reasons: it was a long distance to cover by foot and the EVA time wasn’t going to be enough to be back to the Hab at the stipulated time; there wasn’t a clear path so we were unsure about the direction we should be heading and this made us feel uncertain about our location. The reason there wasn’t a clear path was that a recent flood had erased the path and now it’s not as clear as it used to be, which we confirmed afterwards by noticing a group of rocks that were blocking the ”road” as a signal that the road wasn’t longer available.
As the main purpose of the EVA was collecting geological samples, it is to remark that we found some pieces of minerals that we believe were gypsum; we collected samples of these minerals as it was of interest for us even though our main interest was collecting clays. The reason we are interested in these clays is that normally these minerals collect water, which can be a determining factor in finding life on Mars. Current rover on Mars (Perseverance) has an instrument that allows to measure the transmittance of a certain mineral; following our mission plan, we would like to collect these clays to take them to a laboratory in Colombia with a similar instrument of that on Perseverance rover on Mars, and study different aspects of this technique.
At this point we had lost communication with the rest of the crew in our Hab and we decided to use our GPS to confirm our location and we concluded that we were right where we thought we were. We weren’t able to keep advancing by foot due to the road conditions and EVA time available, so we decided that Cristian and Paula would keep advancing in Spirit through Cow Dung Road to explore the different exits at Cow Dung to verify that we were in the right one, while Felipe stayed at the same location waiting for them as Percy had battery issues (63%). Cristian and Maria advanced around half a mile to Cow Dung at Gateway to Lith and came back for Felipe to return to the Hab together.
At this point we were discussing probable causes of Percy’s battery issue and we decided that Cristian would return to Hab by himself riding Percy, and Felipe and Maria would follow riding Spirit, this was to see if the issue was the way Percy was being driven.
We arrived back at Hab with Spirit at 68% and Percy at 50% and concluded that the best way to drive the rovers is slow, not overworking them by accelerating fully, even if we drive at M speed we should not press the accelerator fully but only partially, as it is not necessary to go fast anyways. This way we’ll be able to save batteries and we’ll be able to cover larger distances.
For the next EVA to this destination, the best option will be to only have two crew members driving Spirit, as it’s the one with the most reliable battery condition. Yet it is still to be determined if we will reconsider an EVA at this same location.
To conclude, we weren’t able to accomplish the scientific purpose of this EVA, as we couldn’t reach the desired destination and hence, the geologist couldn’t show the rest of the crew how to collect these clay samples and what clays exactly were of interest. Nevertheless, the EVA was useful to identify some flaws or issues that we may encounter when doing long EVA’s.
Destination: Moon Overlook
Coordinates (use UTM NAD27 CONUS): 517631, 4254439
Participants: Cristian Acosta, Maria Bustos, Felipe Torres
Road(s) and routes per MDRS Map: MDRS entrance road, Cow Dung Road, Brahe Hwy 1572
Mode of travel: Rover (Spirit, Perseverance)