What's up in the solar system, October 2016 edition: ExoMars arrives!

My apologies for the late post this month. I blame the end of the Rosetta mission. So sorry to take its paragraph out of my monthly roundup! But hopefully this month will see another ESA mission begin its science operations phase: ExoMars Trace Gas Orbiter arrives on October 19, and it will deliver the Schiaparelli lander to its brief life on the Martian surface. Other milestones this month: Juno will shorten its long initial Jupiter orbit to its much shorter, two-week-long science orbit. Cassini will spiral through four, count them, four orbits of Saturn. ISRO's Mars Orbiter Mission has issued its first science data release. And New Horizons is going to finish downlinking all its Pluto data.

Here's Olaf Frohn's chart of active space missions.

Earth Launches and Landings (contributed by Jason Davis)

The International Space Station will remain at half-capacity throughout October. It is operating under Expedition 49, with Russian commander Anatoly Ivanishin, NASA's Kate Rubins, and JAXA's Takuya Onishi. Back on September 7, Jeff Williams, Alexey Ovchinin and Oleg Skripochka returned to Earth, with the expectation that NASA's Shane Kimbrough and cosmonauts Sergey Ryzhikov and Andrey Borisenko would launch on September 23. But a short circuit was discovered during testing of the new crew trio's Soyuz MS-02 spacecraft, which pushed the launch date back to November 15. Two ISS cargo launches are possible this month: an Orbital ATK Cygnus craft between October 9 and 13, and a Progress resupply vessel on October 25. The Cygnus cargo run will also serve as the return-to-flight mission for Orbital ATK's Antares rocket.

In other human spaceflight news, China is expected to send a pair of astronauts to visit its Tiangong 2 space station this month. Tiangong 2, which launched in September, is a small-scale complex that will also be used to carry out an automated cargo ship docking test.

On October 5, a pair of communications satellites launch on an Ariane 5 rocket in French Guiana. United Launch Alliance has not set a new date for its WorldView 4 mission from Vandenberg Air Force Base, which was delayed last month due to a wildfire. Finally, Spaceflight Now reports an October 31 launch date for Europe's Sentinel 5p Earth-observing spacecraft.

Inner Solar System

I don't have any news on Akatsuki since August, but it's always worth checking in on the mission's Twitter feed and website with help from an online translation tool.

Earth's Neighborhood

This month, new moon was on October 1 and there'll be a second new moon on October 30. Full Moon will be on October 15.

Lunar Reconnaissance Orbiter continues its "Cornerstone Mission" extension, producing great images and also having a little fun. They just released this video, a collaboration with singer/songwriters Matt Cusson and Javier Colon. I love the generational inspirational story played out in the video.

I don't have an updates on ARTEMIS since August. There has been some news on Chang'e 3: the lander survived the four-hour duration of the lunar eclipse in September, using the opportunity to perform observations with its one remaining functional instrument, its ultraviolet telescope. Meanwhile, I don't know whether Yutu is alive or not, and I haven't had any information on the status of Chang'e 5 T1 for a long time.

OSIRIS-REx has successfully checked out all its science instruments and is now in its Outbound Cruise phase. Today it is 12.38 million kilometers from Earth. Its next major event is an Earth flyby on September 23, 2017. Keep up with the mission via Twitter.

Near-Earth Asteroids

Hayabusa2 is now 135 million kilometers from Earth and 53 million kilometers from Ryugu. It's on track for a July 2018 arrival at the asteroid.

Mars

It's now nearly summer solstice in the southern hemisphere landing sites of the two Mars rovers, the hottest part of the year, when warmer nighttime temperatures mean less motor preheating and more active days for the rovers. Mars will be at perihelion on October 29, and the solstice is on November 28. Perihelion is also when we can start expecting dust storms, and indeed the skies are getting more opaque now.

This is the month of ExoMars Trace Gas Orbiter's Mars arrival. Schiaparelli will separate from the orbiter on October 16 at 14:42 UT. Entry into Mars' atmosphere is expected exactly 3 days later. For the orbiter, the Mars orbit insertion burn will begin on October 19 at 13:09 UTC and will last about 134 minutes. Confirmation of a successful orbit entry will come from radio tracking of the spacecraft's changing velocity by ESA and NASA ground stations at 15:23 UTC. Here's more detail about what to expect on arrival day. I had to choose between covering Rosetta and ExoMars from Germany, so I'll be watching this one from home. I've asked Irish space blogger Ruth McAvinia to be The Planetary Society's on-the-ground reporter for this event, so look forward to her posts!

Mars Express Mars Webcam recent images and Mars Odyssey THEMIS image releases continue to include enjoyable views of the defrosting south polar ice cap, nearly at solstice. I thought this one from Odyssey was particularly nice:

It's now Opportunity sol 4513. This month Opportunity left Marathon Valley behind, crossing Lewis and Clark Gap into Bitterroot Valley and driving east toward a landmark now named Spirit Mound. Unfortunately, dustier skies have led to a sharp drop in available power, down to 474 watt-hours in the most recent update.

On the other side of Mars, Curiosity has passed beyond the Murray buttes, drilling one more time at a site called Quela. I am overdue for writing a Curiosity update! In fact, I may not get that update written before Curiosity drills at yet another location, possibly as early as this weekend, according to this USGS update. They're now drilling at regular intervals to explore how the Murray formation changes as the rover crosses it. The nearby landscape has gotten a bit rougher, so the rover's recent several drives have been on the short side, under 20 meters.

Mars Reconnaissance Orbiter reports quite a bit of local dust and water ice cloud activity across the planet in the most recent MARCI weather report, but still storm-free skies over both rovers. (Rover imaging shows that both are seeing lots of dust kicked up by storms elsewhere, though.) Last month, Mars Reconnaissance Orbiter's HiRISE camera celebrated 10 years of operation at Mars, looking back at their very first high-resolution image. Elsewhere in their image releases, I found this stunning view of a streamlined crater, about which HiRise team members Henrik Hargitai and Ginny Gulick wrote: "This single image...contains features formed by periglacial, volcanic, fluvial, impact, aeolian and mass wasting processes, all in one place."

MAVEN celebrated one Mars year of its science mission yesterday. In the announcement, they quoted MAVEN principal investigator Bruce Jakosky as saying " "Taken together, the MAVEN results tell us that loss of gas from the atmosphere to space has been the major force behind the climate having changed from a warm, wet environment to the cold, dry one that we see today."

Finally, Mars Orbiter Mission is going into its third year of operations and still going strong. Last week, they finally began releasing data to a data archive. I am, of course, downloading all the data and beginning to get a handle on it. Look for a couple of articles on those images in the days to come. Here's a teaser.

Beyond Mars

Last month, the Dawn team published six papers in Science magazine, including one that suggests that Ahuna Mons is an ice-mud cryovolcano. The papers are all behind a paywall, but you can read the abstracts here. As always, check the Photojournal for the latest images!

Juno went through solar conjunction from September 23-30. I have heard no news about the mission recently, but I'm going to assume that no news is good news. Conjunction paused the collection of Marble Movie data for that week, but Juno should now be photographing Jupiter again, through October 18. The next big event for the mission is Perijove 2 on October 19, during which it will be performing a large rocket burn in order to reduce its orbit period from 53.5 days to only 14 days. A rocket burn means no science data for the 48 hours around closest approach to Jupiter. That's the bad news. The good news is that this should be the last big burn, and we can look forward to the science mission and high-resolution images every other week beginning in early November.

Cassini is in the middle of a phase of very short, 10-day orbits right now; it began Rev 244 on September 29, begins Rev 245 on October 8, Rev 245 on October 18, and Rev 247 on October 27. Short orbits necessarily mean close-in orbits; its apoapsis is barely beyond the orbit of Titan, while its periapsis is between Dione and Tethys, within the diffuse E ring. Cassini's orbit is highly tilted right now at 58 degrees, so its observations largely focus on polar processes (Saturn aurora, Titan polar clouds) and on features in the rings, of which Cassini is getting a wide-open view. The next targeted flyby of Titan is on November 14; the encounter will set it up for its big leap on November 29, when its periapsis will be moved dramatically closer to Saturn, just outside the F ring.

New Horizons is now 36.6 AU from the Sun and 3.6 AU beyond Pluto. It now takes more than 10 hours for signals to go out there and back. There weren't any team blogs this month, but there were two news stories out of the mission: one explaining Charon's red north  pole, and the other on Chandra X-Ray telescope observations of Pluto that coincided with the 2015 flyby. In other news, the team now expects that they'll complete downlinking all the Pluto flyby data from New Horizons this month, according to Alan Stern.

Finally, the Voyagers are still going, going, going. Voyager 1 is at 136.4 AU from the Sun, and Voyager 2 is at 112.3 AU.