Dispatch from Mars Society Arctic Expedition – Robert Zubrin July 12, 2001
We held a morning meeting after breakfast and then set things in motion for a very involved three person EVA.
Crew morning briefing.
The plan was to deploy Vladimirs’ geophone flute on Haynes Ridge under Mars mission EVA constraints and then fire it up to engage in subsurface seismic exploration. The team would be Vladimir, Katy, and I; the same group that had trained with the instrument while we were out of the simulation two days ago. The EVA would be quite complex because the geophone flute consists of 24 sensors and a trigger placed into the ground at 4 meter intervals along a 100 meter line (it is this row of holes in a line that has given the system the “flute” name). All this would be wired together along with a computerized data acquisition system that needs to be programmed in the field. Collectively the apparatus weighs over 300 lbs.
It took us about 40 minutes to get suited up and out of the airlock. Then we loaded the equipment into an ATV trailer and trundled off across Haynes Ridge. The weather was cold with a light drizzle that wetted the outside of our helmets and impaired visibility somewhat. Fortunately we had taken care to soap the inside of our helmets, and so avoided fogging. Upon reaching the selected site, we first laid out a 100 meter tape measure in a roughly north-south direction. Then we scraped away rocks to push each of the 24 sensors about 6 inches into the ground. Following that, we unspooled heavy wire cables 50 meters in each direction from the center, after which we hooked up all the sensors using a series of connectors. The trigger was then enplaced, and all the wires rigged up to a battery and computer data system located near the sensor array midpoint. Then we turned the computer on. The power indicator glowed but no display showed.
This was a real problem. The geophone flute must be programmed with certain initial conditions each time it is set up, and it is also necessary for the computer operator to use data generated in real time to interact with the person causing the seismic signals if useful results are to be obtained. Neither of these essentials would be possible if the data display could not be read in the field. Peering at the display very closely I realized that the screen actually was turned on, but was too faint to be read in outdoor light, especially given the added visual degradation caused by our wet helmets and the presence of rain water on the computer screen. There was a brightness control in the computer, but it was digital, not analog. In order to be able to brighten the screen you had to be able to read the screen. Catch 22.
I had some unprintable thoughts about engineers who design systems this way, and I believe my compatriots spent a moment in similar reflection. Then we set about finding a solution.
We returned from a sucessful 5 hour EVA deploying and using Vladmir’s geophone flute on Haynes Ridge about 45 minutes ago.
The answer we hit one was to pull the large foam panels out of the geophone’s storage box and create a dark enclosure around Vladimir and the computer. Under these conditions he was able to make out the pale letters on the scrreen and increase the brightness and contrast to program the thing and proceed with the experiment.
Then we wired in the trigger phone, put a steel plate nearby, and stood back as Katy blasted it with the sldegehammer ten times. A beautiful pyramidal array of graphical data appear on the screen, with sonic echoes from as deep as550 meters!
We then moved the trigger and hammer plate 50 meters to the north end of the array, unspooled some wire to connect them to the data system, and repeated the experiment. Again we obtained good data. So we did it again at the south end of the string and were successful again. Then we pulled out all the sensors, disconnected everything, spooled in the wires and cables, stowed it all back in the boxes, loaded the trailer, and returned to Flashline Station. The total EVA time was approximately 4 hours.
Back in the hab, Vladimir analyzed the data. It showed no subsurface water or ice, which would be key targets for seismic searches on Mars. Instead, the seismic data supported the conjecture that the ridge is mostly simple dolomite rocks. But that’s okay; a geophone can’t put water where there isn’t any.
Three points, however, were forcefully driven home by the exercise. First, as the reader will surmise from the above paragraphs, serious planetary research requires field operations that are far outside the existing or prospective range of capabilities of robotic rovers. No robot, or group of robots, could have done what we did today. Second, humans, even when impaired by spacesuit simulators, lack of tools compatible with spacesuits, bad weather, and a poorly engineered computer display system, can do whatever is required not merely to do very complex operations, but make them succeed. Finally, a thing that was made clear to all the EVA’s participants in a really sensuous way is that exploration is a very physical activity. The equipment we used was heavy, and it had to be lifted and carried significant distances over rough ground. At the end of 4 hours doing this kind of work in spacesuit simulators, all three of us were feeling pretty tuckered out.
This underlines an important point. The amount of exploration, both in quantity, quality, and variety, that a human crew will be able to accomplish on Mars will be directly proportional to their physical condition upon arrival. In my view, this means that we do not fly the crew to Mars in zero gravity. Whether using chemical or nuclear propulsion, the outbound trip to Mars will take approximately six months. (In a properly planned Mars mission, nuclear propulsion either adds payload or saves launch mass relative to what can be achieved using chemical rockets, but does not reduce transit time significantly.) Even with a stringent exercise rigidly enforced (which has not proved feasible on most long duration space missions to date) any zero gravity crew would undergo significant deconditioning on their way to Mars.
Therefore, instead of going to Mars in zero gravity, artificial gravity (obtainable through rotating the spacecraft) should be employed. Unfortunately, the NASA space medicine hierarchy has for the past 40 years been totally dominated by zero-gravity health-effects researchers and they have channeled all research resources in that direction. It is a scandal that today, almost 44 years into the space age, the United States has not flown a single space flight experiment involving either humans or higher animals in artificial gravity. Going to Mars in zero gravity is a bad idea. Going beyond Mars in zero gravity is impossible. NASA needs to broaden its view.
