By the 2006 expedition, the priority for AMASE trips shifted towards testing new instruments in the field prior to their being selected for space flight on upcoming Mars missions. In a proposal to the Astrobiology Science and Technology for Exploring Planets programme, we asked the following questions:
1. How do we access suitable samples?
2. How do we identify, sample and detect molecules of interest at suitable spatial and detection sensitivity scales?
3. How do we ensure sample integrity and control for cross- contamination by organic, biogenic and inorganic molecules? 4. How do measurements from laboratory and field instrumentation
compare in terms of analysing terrestrial samples from a Mars rele- vant environment?
Each year we worked with a JPL crew that brought along a sophisticated rover that was put to the test on slopes and terrains similar to those found on Mars. JPL scientists Terry Huntsberger, Ashely Stroupe, Paulo Younse, and Michael Garrett took turns operating the Cliff-Bot rover. This team was given 2-3 days of special time to test their rover. Many of us envisioned the rover swiftly covering the landscape in a matter of minutes, reaching out its robotic arm, scooping up sediment and returning faithfully to its base. Unfortunately, sending a rover over a complex landscape, as though it were on a remote planetary body, was a much slower, hour-by-hour and inch-by-inch process that tested the patience of many a crew member.
The project now included two potential instruments that were ultimately chosen to fly on Mars Curiosity: CheMin and SAM (Sample Analysis on Mars). CheMin’s instrument PI is David Blake, a scientist at NASA Ames. Blake, a US Navy veteran and an expert in designing and testing field X-ray miner- alogy instruments, is also quite a character. Dave sang navy songs laced with profanity, told jokes and funny stories of all types, and laughed with a distinct
pirate-like “Har har”. To say he brought some “colour” to the expeditions is
from NASA Goddard including Pamela Conrad, Jennifer Eigenbrode, and Inge Loes ten Kate. SAM is a combination gas chromatograph-mass spectrometer (GC-MS) equipped with the capability of high temperature pyrolysis GC-MS and a tunable diode laser for measuring methane and its isotopic composition. CheMin was fully portable and field deployable; SAM was not.
In addition to instrument teams, Steven Squyres, the PI of the Mars Exploration Rover mission with Opportunity and Spirit, was invited to observe sampling in the field and to conduct mock Mars sampling exercises (Science Operations Working Group: SOWG – pronounced “Sahg”) based on his expe- rience “roving Mars” from Earth. The exercises were designed so that scientists and engineers, required to work together in teams during real missions, would learn as a group how to answer the four technical questions posed above. The question of how to access suitable samples had to be tackled separately with specialised practice with the rover team. Our second question – how to iden- tify, sample and detect molecules of interest at suitable spatial and detection sensitivity scales? – took up most of our time.
For many of the last AMASE expeditions, about three SOWG exercises were held each year. Travelling with AMASE was a German camera crew led by Nicole Schmitz, who was testing a camera that she hoped would fly on a future Mars mission. She joined AMASE expedition photographer Kjell Ove Storvik, Steele, and Amundsen, who chose an outcrop for investigation. The two photog- raphers then provided PanCam like photos that were sent back to the team “on Earth” – meaning inside a room on the ship – for them to analyse. Photos were in black and white and then pieced together to form a mosaic of the outcrop. The CheMin, SAM, UV fluorescence, and Life Marker Chip instrument teams were assigned an energy budget. For each measurement requested, the team needed to use up one or more of its energy allotments to “pay” for the analyses. After the teams finished arguing about where on the outcrop the samples should be taken and how they would use their precious energy resources, the crew on land sampled the outcrop with hammers and delivered the samples to the instruments. CheMin, UV fluorescence, and the Life Marker Chip instru- ments were deployed in the field; SAM on board ship. When the analyses were completed, data were “downlinked” from “Mars” to “Earth” for inspection and analysis. At this point, teams argued as to whether they were able to detect mole- cules of life on “Mars”. The discussion then shifted to whether or not a sample should be cached for future return to Earth for more sophisticated sampling.
These exercises were intense: periods of high drama and discussion, followed by periods of restless inactivity, cooped up on the ship or lounging on a rock outcrop. All samples were brought back to the ship and analysed by the full AMASE crew with a summary report for each SOWG exercise. For a flavour of this process, detailed steps are presented in Text Box 11.1.
Text Box 11.1 – The SOWG Exercise