Log Book for January 8, 2011
Science Report 3
Lucinda Land Reporting
Day two of testing Sandstorm's range was a success. Yesterday we lost touch with Sandstorm at 193.12 meters outside of the Hab with the router inside the lab area. We were testing the range of the router signal while inside the Hab with the rover. Sandstorm went an additional 16.09 meters today to make her total distance with the router inside the Hab 209.21 meters.
We put fresh batteries in Sandstorm and then took her out to the same place yesterday where she stopped. We wanted to confirm if it was the range of the signal or dead batteries for the reason that she no longer responded. Once the XO and the rover finished pressurization in the airlock he hand carried her to the GPS location he logged yesterday as her stopping point. We still had connection to Sandstorm at that point and drove her a further 16 meters. The obvious issues with long range driving of the rover was video confirmation as the image on the laptop screen would freeze. All the software that drives the rover is created by our NorCal Mars Society team and one idea that came forward in today's test was to have a refresh button built into the rover software to refresh her camera to hopefully unfreeze transmission when operating. Reducing frames per second (fps) to her lowest setting didn't make any significant changes with video feed.
Another issue with wi-fi signal to connect with Sandstorm was line of site and the presence of hilly terrain. Sandstorm had a bit of trouble traversing deep snow and steeper mounds. We tried to keep her on as flat a surface as possible. She could however make it through small dips and bumps in the road with an increase of the throttle. Larger rocks would often impede her movement but the Marsonauts would aid her in maneuvering around it.
One example of better maneuvering technique with the aid of a Marsonaut was when the Crew Engineer was visible in her forward camera view. This way Sandstorm was able to follow in a relatively clear path. This was most helpful when Sandstorm experienced very rocky terrain and Crew Engineer Wong walked in front of Sandstorm to lead her through without incident This will be a future technique to use when taking her out on another remote exploration.
There was a change of batteries made during her nearly two hour EVA with the XO later joined by the Crew Engineer. Since Sandstorm's batteries only last an hour, we had to change them out for her to continue her tests. This was done with the use of the Hab's ATV pressurized garage. During the second half of her EVA, Sandstorm's router was moved outside the Hab to test her range. Sandstorm logged 128.74 meters with the router outside the Hab. Her batteries died prematurely and she was rendered temporarily inoperable. We made sure to determine that her batteries were dead by removing any other possible variables such as hilly terrain and distance. The XO brought her back into the router's line of sight and on flatter terrain where operation of her was still not possible.
We will start Sandstorm up again tomorrow and give her fresh batteries. So far so good on getting her started up and in motion. We have been quite successful with getting her going. We just wish she could go longer and that the signal strength was strong enough to deliver adequate video feed to confirm her placement and direction of movement. Using her in conjunction with Marsonauts proved helpful when we couldn't rely on her camera for confirmation of placement, direction, or terrain.
Tomorrow we will take her outside for a second test with the router outside and using fresh batteries. We will measure a second distance and see if we can beat the 128.74 meters she logged in this configuration. My hypothesis was that she would go for a longer distance with the router outside the Hab than inside. However, our two days of testing with the router inside proved that she can go a distance of at least 209.21 meters. Now we need to prove whether she gets more distance or not with the router outside the Hab.
In her near future we will continue tests with the use of her Gigapan camera and GPS logging systems.