What's up in solar system exploration: March 2016 edition
Welcome to my monthly inventory of the 20-plus spacecraft actively exploring our solar system. Beyond the "routine" of mission operations scattered across planets, highlights of this month include the impending launch of the ExoMars Trace Gas Orbiter and Schiaparelli lander, currently planned for March 14, and the resumption of regular VMC Mars images by Mars Express. Also, expect plenty of planetary science news coming out of the Lunar and Planetary Science Conference running from March 21 to 25 (of which I'll be attending the first three days). Before I run down all the missions, here's Olaf Frohn's summary diagram:
Earth Launches and Landings (contributed by Jason Davis)
Some time between March 14 and 25, ExoMars Trace Gas Orbiter will blast off for Mars from Kazakhstan. The Schiaparelli lander was united to the orbiter on February 16, and ExoMars has now been fueled. The first launch opportunity is at 09:31 UT / 05:31 EDT / 02:31 PDT. (Americans, take note that Daylight Saving Time begins the day before the launch, so set your alarm clocks appropriately; European daylight time does not start until March 27.)
Inner Solar System
Updates on JAXA's Akatsuki have been limited. If I'm interpreting the Google translations of their official Twitter account correctly, they have spent the last month working with the spacecraft's ultrastable oscillator, part of its radio science experiment. According to the final paragraph of this update, Akatsuki will begin science observations in April.
Last month, Lunar Reconnaissance Orbiter performed some radar experiments using its Mini-RF instrument to receive transmissions broadcast from the Goldstone Deep Space Network station and bounced off the Moon. "These types of measurements will help scientists better understand where ice may be buried near the lunar poles," they said via Twitter. Here on Earth there's a new exhibit of huge Lunar Reconnaissance Orbiter prints up at the National Air and Space Museum in Washington, DC; you can view an online version of the exhibit here, but there's nothing quite like seeing these enormous photos printed and displayed as the museum-quality photographs that they are.
I had begun to think that the life of the Yutu rover was over, but amateur deep space radio enthusiast UHF Satcom said on February 22 that "Yutu Lunar Rover is back in town! A massive signal on 8462.053MHz complete with sidebands, maybe low-rate data." The latest word from Chang'e 3 is that it was awake and talking to Earth on February 18. Lunar mapper Phil Stooke noticed that a photo included in that Chang'e 3 news update appears to have been taken by Yutu in March 2014 from its final parking spot, and he had not seen it published before.
According to an email from scientist Jasper Halekas, the ARTEMIS probes are currently in good health and operating as planned in very stable, highly elliptical orbits; "we should be able to keep them there for years to come." They are focused on heliophysics, working cooperatively with the other THEMIS probes, the Van Allen Probes, and the Magnetospheric Multiscale (MMS) mission, but by virtue of their location in space they study the interaction of the solar wind with the Moon as well.
I don't have any updates on the status of the other active Chang'e spacecraft or of Hayabusa2. Hayabusa2 has a long cruise ahead of it, planned to reach asteroid Ryugu in mid-2018.
I don't yet have any updates on Odyssey in its new 06:45 sun-synchronous orbit -- maybe next month.
Mars Express has been quiet because it was in "eclipse season," a period when its orbit takes it behind Mars as seen from the Sun for up to 40 minutes per orbit, forcing the spacecraft to rely on batteries. This particular eclipse season happened when Mars was near aphelion, when it doesn't generate as much power even when it is seeing sunlight. That impacts data return (because the radio transmitter consumes a lot of power). One consequence of being in eclipse season is that the VMC (the Mars Webcam) has been off for several months, but it should be back on as of today! All this is explained in a lengthy and informative ESA blog post by Simon Wood.
Just today, the MAVEN orbiter released this really cool image of Phobos, captured in two distinct ultraviolet wavelengths. According to a feature on the MAVEN website, the mission made several close approaches to Phobos in November and early December of last year, approaching to within 500 kilometers of the moon. MAVEN is the only NASA orbiter that can approach Phobos so closely; Mars Express is also doing regular Phobos observations. MAVEN's next two deep-dip campaigns have now been planned for early June and late July of this year.
It's midwinter for Opportunity so there has not been much driving, but it's enjoying spectacular views from a perch that hopefully looks more precarious than it actually is, on the side of Knudsen Ridge, in Marathon Valley. These images aren't just for their scenery, of course; they are guiding the choices of science targets for the MI and APXS instruments, work that Opportunity began last week. Total odometry for Opportunity is now 42.66 kilometers. Keep up with Opportunity at the mission's official status update site.
On the other side of Mars, Curiosity has left Namib Dune behind and is getting ready to drive up and on to the Naukluft plateau. Once atop the plateau Curiosity should soon get the first clear view of the Murray buttes and the passage through the gap in the sand dunes. There is no news about the status of the anomaly with the CHIMRA mechanism in the robotic arm turret, which is responsible for sieving, portioning, and delivering samples to the analytical instruments. Fortunately the priority for Curiosity at the moment is to drive, drive, drive.
Comet activity at Churyumov-Gerasimenko is quieting down as the comet recedes from the Sun. That means that Rosetta has been able to approach the comet more closely than in recent months, and is mapping the southern hemisphere from a distance of 35 kilometers. According to an update on the ESA blog, the comet morphology mappers have named three more regions on 67P in the south pole: Bes, Geb, and Neith. They are finding the southern hemisphere to be less dusty than the north, making it easy to see structural detail on the comet.
Dawn is now orbiting Ceres at the lowest altitude it'll ever achieve: an average 385 kilometers. Check the Photojournal for the latest images, I am particularly taken by this oblique view across Ceres' limb. Dawn is so close to Ceres that we can begin to feel like we're getting a view out the airplane window!
New Horizons continues to downlink data from its July flyby. Last week saw the completion of the downlink of the highest-resolution images that New Horizons took of Pluto. The next target they plan to observe is 1994 JR1, in April. They continue to release captioned images every Thursday. The most recent few images include geologic maps; I will write more about their mapping work and scientific interpretation from the Lunar and Planetary Science Conference toward the end of this month.
Finally, the Voyagers are still going, going, going. Voyager 1 is at 134.2 AU from the Sun, and Voyager 2 is at 110.5 AU.
That's it for March. Stay tuned for another roundup of deep-space exploration in April!