Arctic Preparations for Mars
Science Operations Work Group: How to do science with a rover on Mars
August 22, 2009
Driving a rover on Mars and obtaining useful scientific information is something you don't learn from one day to another. You need a lot of training and you need to be able to work with people who have different scientific backgrounds. One way to learn it is by carrying out the Science Operation Work Group (SOWG) during the AMASE expedition. The 2009 AMASE SOWG was a combined NASA/ESA effort aimed at learning how to prepare for running future missions that will search for life on Mars.Imagine that a rover has landed on Mars, like Spirit, Opportunity, or the future Mars Science Laboratory or ExoMars missions. The first pictures that the rover sent back show an area covered by small rocks and a couple of outcrops about ten metres away. This is, so far, the only information you have: you don't know what the chemical and mineralogical composition of these rocks are, or if the area could have harboured life. Your rover has several instruments that can give you plenty of information, but it is not so easy as that: the amount of energy is limited, you can drive a maximum distance of 100 metres each day, you cannot use different instruments at the same time, and some of them may take a long time, and/or a lot of energy, to obtain the measurements we need.
Moreover, there are plenty of other possibilities: you can study the rocky material that is very close to the rover by using different analytical techniques, you can take high-resolution panoramic images with filters at different wavelengths, you can drive, select a rock, drill, or obtain microscopic images. But all these operations take time and cost energy. Your rover has limited mobility, navigational errors, limited bandwidth to connect with the Earth and not all the energy you would like it to. Moreover, you have quite limited time to choose what to do, because of the length of the Martian day and also the availability of the orbiters that are used to establish connection between the rover and the deep space tracking stations.
This is exactly what we have been doing during the last two days on AMASE 2009. We are obviously not using information from the robotic explorers that are studying Mars at present. However, because Svalbard is the perfect terrestrial Martian analog on Earth, the Science Operation Work Group (SOWG) on AMASE can simulate a rover mission to Mars. So how do we do that? In a simpe way: one group of people is in the field obtaining the data (they are our rover) and another group is on the ship receiving it, discussing the possibilities and science questions/tasks we have set out to answer. All the people onboard ship are "blind" in the sense that they have not seen the actual site except via the "eyes" of the "rover". The SOWG group can not talk or connect with the people/rover in the field; they are only allowed to send them a file with the detailed instructions for the rover and that's it.
This year the task we were set as the AMASE 2009 SOWG was related to a Mars Sample Return mission and the mission scenario was the following: "a successful landing took place in a large impact crater considered to have sedimentary deposits. During the first 100 sols (Martian days) the rover travelled through a mixed sedimentary scree considered to be primarily impact ejecta. Using orbital images, the mission scientist identified probable bedrocks, so the rover took all that time to travel there. Today, at the end of sol 99, the rover position was at only 50 metres of the outcrops and commanded to move to a distance of 10 metres from them". Our mission: to decide what areas to study, where to go and what analyses to do in order to take one sample of astrobiological interest to return to the Earth.
Knowing the mission scenario, we did as many uplinks and downlink cycles as we could, having a maximum time of two hours to prepare every uplink. The main task was to prepare a time-ordered sequence of activities, with all necessary documentation (annotated images of drive targets, remote sensing targets, etc.) and to interpret the data acquired by the rover.
And there is some fun, of course! During the SOWG exercise we were quite comfortable in the meeting room of the Lance, the ship that we use for AMASE expeditions, but people in the field had an awful weather, with temperatures close to 0°C and lots of rain, waiting hours and hours for our instructions and keeping the instruments safe. It was very funny to see a couple of pictures from the Microscopic imager that showed a wet surface -- rain on Mars?! They also had to drill a small core in one of the rocks, a task that would have been pretty difficult for a rover because three people were needed for it as the rock was really hard. Also when the SOWG group were starting to focus on their work, Steve came and said: 'I am afraid that I have to give you bad news: the Cassini spacecraft has entered into safe mode and you will have to plan the next three sols in a couple of hours'... a task that was finished barely 30 seconds before the deadline.
Testing rovers for future Mars exploration: the goddess Athena drives in Svalbard
August 23, 2009
During the last decade of Martian exploration the research focus has primarily been on the search for past liquid water, using both orbiters (Mars Global Surveyor, Mars Odyssey, Mars Express and Mars Reconnaissance Orbiter) and landers (Mars Pathfinder, Mars Exploration Rovers and the Phoenix lander). Obviously no liquid water can be found today on the Red Planet because the pressure of the Martian atmosphere is too low to permit water to exist on its surface. But from all the information sent from these orbiters and landers we know that liquid water existed on Mars millions of years ago.
The next rovers that will be sent to Mars will not look only for signs of liquid water. They also will have to accomplish a very complicated task: the search for past (or present) microbial life. Several very interesting candidate areas have been identified using orbiters that acquired spectroscopic signatures of carbonates and other minerals (clays, sulphates, etc.) that indicated that water must have been present during their formation. However, we don't know at all if microbial life developed in these regions or even if it could exist nowadays on the Red Planet. If we want to answer these questions we will need rovers that are able to drive long distances, analyze samples remotely and in situ, drill to take cores and, of course, obtain high-resolution pictures at different scales of the rocks, soils and sediments.
For AMASE 2009, various tests and activities have been performed in Ny-Alesund and the Bockfjorden areas where basalts, carbonates and clays are present, which are all good analogues of possible Martian landing sites that future rovers will explore. This work has been carried out by Paulo Younse (Mechanical Engineer), Mike Garrett (Electrical Engineer), Joseph Carsten (Software Engineer) and Pan Conrad (Team Leader), all of them from JPL and also supported by a large group of the AMASE 2009 science team.
All these tests with Athena as an advanced mobility platform during the 2009 AMASE expedition were especially important because it is essential to test and develop technology that will eventually fly in future Mars missions. The next decade of Martian exploration is going to be very interesting but also very challenging, as the objectives that we are trying to achieve have profound implications towards our vision of life in the Universe. Developing and testing the appropriate tools to accomplish these objectives will be an obligatory prerequisite if we want to drive the road of success.