It seems like we’ve been preparing for the Phoenix mission for such a long time – and now it’s finally close to landing day! T-6 days according to our countdown clock! Things are getting pretty crazy here, and I thought a little overview of how the HiRISE team is supporting the Phoenix mission would be useful.

We’ve been imaging the northern plains for Phoenix since we started our mission (here’s a bunch of reconnaissance images on our website). The first images we got back showed lots of scary boulders (a close-up of one of our Transition images shown to the right), so we sampled other areas and searched for a relatively boulder-free landing spot. The area the Phoenix team finally chose is being called the “Green Valley“, not because of the “green light = safe to go” connotation, but rather because some geological maps made of the area happened to use green as the color for the valley. Perhaps coincidentally, Green Valley is also a town near Tucson, where both Phoenix and HiRISE are based. Whatever the reason, I like that the name has a lovely calm, comforting feel.

Once the Phoenix team picked out their landing site, we worked on a high-resolution mosaic of the entire 3-sigma landing ellipse (”3-sigma” means there is a 99% probability it will land within this area; see this great blog entry on landing ellipses at the Planetary Society). The Phoenix landing ellipse is shown to the left, along with the footprints of a number of HiRISE images. (This was before we were quite done with the mosaic.) These images have helped the Phoenix team characterize the regional geology and assess the safety of the landing site.

In addition to scouting landing sites, we’re also going to be involved with Phoenix during its prime mission on the ground. We’ve been planning and practicing several different ways of cooperating:

• Early Imaging: We are going to attempt to take observations of Phoenix on the ground several times in the first week of the mission. There are three images planned, two on the first day and one on “sol 5″. (The Pheonix mission will be counting time in Mars days, or “sols.”) Since the first two images are so early, there’s a good chance we won’t know quite where it landed yet, so the chances of seeing it are slim. The sol 5 image should be really good, though – we’ll know the exact landing spot by then, plus the image will have ideal lighting conditions and the highest resolution we can get.
• Relay: The Electra instrument on MRO will relay commands from Earth to the Phoenix lander, and it will relay data from Phoenix back to Earth. This affects HiRISE only indirectly – we’ll be planning our science imaging around the times Electra needs to be communicating with Phoenix.
• Cooperative Science: Phoenix and MRO have been planning coordinated science observations using different instruments on both missions. For example, when Phoenix takes a measurement of the amount of ice on the ground, they might want an image from HiRISE at the same time, to see how much frost is visible in the surrounding area.

Landing will be just the beginning of all these exciting activities. Come join us for a public celebration on landing day, May 25th! There are all sorts of events planned: