Emily Lakdawalla • Jul 23, 2008
How are we coming on Phoenix mission success?
So we're approaching the two-thirds mark on the mission, and some of you readers out there are getting a little antsy about what Phoenix has accomplished to date. The issues with TEGA have certainly slowed down the plans to examine soil samples. But TEGA's not the only instrument on the mission, and things are really going very well. Let's look at the Phoenix mission success criteria and see how the mission is doing. You can read the mission success criteria and other pre-landing plans for the mission in the thrilling document "Mission Design Overview for the Phoenix Mars Scout Mission" (thanks to James Canvin for the link).
Firstly, let's consider the minimum mission success criteria. Phoenix has successfully completed all of these.
- Land successfully on the surface of Mars and achieve a power safe state.
- Acquire a partial 120° monochromatic panorama of the landing site.
- Provide samples of the surface soil as well as samples from one depth beneath the surface to either TEGA or MECA wet chemistry.
- If TEGA, analyze at least 2 soil samples to create a profile of H2O (in the form of hydrated minerals, adsorbed water, or possibly ice at the deepest level) and mineral abundances near the surface. It shall also analyze an atmospheric sample in its mass spectrometer.
- If MECA, analyze the wet chemistry of 2 soil samples.
- Document all non-atmospheric samples and their collection locations with images.
- Land successfully on the surface of Mars and achieve a power safe state.
- Acquire a true color (RGB), 360° panorama of the landing site.
- Obtain calibrated optical spectra of at least 3 locations that include both rocks and soil.
- Provide temperature and pressure measurements throughout landed surface operations at a frequency that determines key atmospheric properties.
- Provide samples of the surface soil, and samples from two depths beneath the surface, to both TEGA and MECA.
- Use TEGA to analyze at least 3 soil samples to create a profile of H2O (in the form of hydrated minerals, adsorbed water, or possibly ice at the deepest level) and mineral abundances near the surface. It shall also analyze an atmospheric sample in its mass spectrometer.
- Use MECA to analyze the wet chemistry of at least 3 soil samples. It shall also analyze 3 additional samples in its microscopy station.
- Document all 9 non-atmospheric samples and their collection locations (before and after sampling) with images.
I'd venture a guess, though, that although NASA would be able to call Phoenix a success if that's all it completed, the scientists wouldn't be satisfied. I'm sure that in their hearts, the science team wants more: four wet chemistry lab analyses, eight TEGA samples, successful operation of the Atomic Force Microscope, and a life a lot longer than 90 sols, just to name a few. The mission success criteria also don't take into account the extensive campaign of coordinated observations they're doing with Mars Reconnaissance Orbiter. Nor do they even mention the TECP probe on the robotic arm. Nor do they include the ongoing observations of atmospheric properties and high-resolution targeted shots of various spots in the landscape with the mast-mounted camera, which are very effectively making use of lander resources that are not being taken up by the laborious process of acquiring an ice-rich soil sample for TEGA. So Phoenix has already done a lot more than its "mission success" criteria include -- yet it's also done less, where TEGA and MECA are concerned.
I do still plan to have a more detailed sol-by-sol update on Phoenix, but probably won't have it ready until at least tomorrow, so stay tuned.