China’s Mars orbiter and rover in trouble

Yesterday we reported a tweet from Scott Tilley that suggested engineers were having trouble establishing a communications link with China’s Mars orbiter Tienwen-1.

Today it appears that communications with China’s rover Zhurong have also not resumed following its winter hibernation from May until December.

The Post independently confirmed with two sources on Thursday that the rover should have resumed running by now, but no contact has been established.

Though Zhurong’s solar panels can be tilted to kick dust from them, during hibernation this is apparently not possible. Because the winter dust season this year was especially bad (killing InSight for example), it is possible that Zhurong experienced the same fate.

Zhurong had a 90 day mission, and instead lasted a year. Moreover, tt was never expected to survive a Martian winter. The achievement thus remains grand.

As for the Tienwen-1 orbiter, it would be a much bigger failure if communications cannot be re-established. China without question expected this orbiter to operate for years, even functioning as a communications link for later landers/rovers. Its loss will force a revision of later plans.

Tianwen-1 enters parking orbit around Mars

The new colonial movement: According to the Chinese state-run press, the Tianwen-1 orbiter has entered the parking orbit around Mars that it will use for the next three months to conduct reconnaissance of its lander/rover’s landing site.

At 6:29 a.m. (Beijing Time), Tianwen-1 entered the parking orbit, with its closest point to the planet at 280 km and the farthest point at 59,000 km. It will take Tianwen-1 about two Martian days to complete a circle (a Martian day is approximately 40 minutes longer than a day on Earth), the CNSA said.

Tianwen-1, including an orbiter, a lander and a rover, will run in the orbit for about three months.

The CNSA added that payloads on the orbiter will all be switched on for scientific exploration. The medium-resolution camera, high-resolution camera and spectrometer will carry out a detailed investigation on the topography and dusty weather of the pre-selected landing area in preparation for a landing.

China has also begun prepping the rocket that will launch Tianhe, the first module in its space station, sometime this spring. A total of eleven launches are planned over the next two years to assemble the station.

Is this the planned landing site of China’s Mars rover?

The prime landing site for China's Mars rover?

According to this Space News article, a report in the Chinese press, since revised to remove the information, had provided precise coordinates on Mars for the prime candidate landing site for China’s Tianwen-1 rover.

[I]nformation published in an article (in Chinese) in the official China Space News publication following launch in July provides a specific primary landing site. The article reported landing coordinates of 110.318 degrees east longitude and 24.748 degrees north latitude, within the southern portion of Utopia Planitia. Online versions of the article have since been edited to remove the coordinates; however, these remain published by sources citing the article.

The mosaic on the right, made up of two images taken by Mars Reconnaissance Orbiter’s (MRO) context camera (found here and here) shows this location with the white cross. The white box is the area covered by the only image taken of this area by MRO’s high resolution camera.

As these photos show, this location, in a part of Mars’ northern lowland plains dubbed Utopia Planitia, is generally smooth and flat, making for a relatively safe landing site. At the same time, it has craters and some ridges and hills that could pose issues.

That the coordinates were removed from the Chinese press story suggests that this might be the prime site, but until Tianwen-1 gets into Mars orbit and begins scouting the site with its own high resolution images, they want to reserve judgement. The spacecraft arrives in orbit in February ’21, and they presently plan to land the rover in May. That gives them three months to scout this location as well as a secondary landing site on the other side of Mars, in the Chryse Planitia northern lowlands [pdf], the same region where Viking 1 and Mars Pathfinder landed.

Once they have done this they will be able to refine the location more precisely.

Tianwen-1 successfully launched, on its way to Mars

UPDATE: According to news reports, China tonight successfully launched Tianwen-1 towards Mars, with arrival expected in February 2021.

Below the fold is a live stream of the launch of the Long March 5 rocket. It is not in English, and since it was not linked to China’s mission control, it only covers the first two minutes or so, after which the rocket went out of sight.

The leaders in the 2020 launch race:

17 China
11 SpaceX
7 Russia
3 Japan

The U.S. still leads China 18 to 17 in the national rankings.
» Read more

Tianwen-1 launch set for July 23rd

China has rolled out its Long March 5 rocket and is now preparing to launch its Tianwen-1 orbiter/lander/rover to Mars this coming Thursday, July 23rd, some time between 12 am and 3 am (Eastern).

A Long March 5 rocket is set for liftoff with China’s Tianwen 1 mission some time between 12 a.m. and 3 a.m. EDT (0400-0700 GMT) Thursday, according to public notices warning ships to steer clear of downrange drop zones along the launcher’s flight path.

Chinese officials have not officially publicized the launch date. Chinese state media outlets have only reported the launch is scheduled for late July or early August, and officials have not confirmed whether the launch will be broadcast live on state television.

This will be the first operational launch of the Long March 5, which has had three previous test launches, with the first two failing. The success of the December launch, as well as the May success of the related Long March 5B, made this Mars mission possible.

After achieving orbit in February 2021 and spending two months scouting the landing site, the lander will descend to the surface, bringing the rover with it. The prime landing site is Utopia Planitia, in the northern lowland plains.

Utopia Planitia, the prime landing site for China’s Tianwen-1 Mars rover

More blobs in Utopia Planitia
Click for full image.

Today’s cool image is not only cool, it gives a nice feel for the likely shallow ice table that is probably found close to the surface throughout the lowland northern plains of Utopia Planitia, which is also the prime landing site for China’s Taenwen-1 Mars lander/rover, scheduled for launch sometime in the next four days. [Update: there are now indications the launch will not occur until early August.]

The photo to the right, rotated, cropped, and reduced to post here, was taken on May 9, 2020 and shows a nice collection of strange land forms on the western edge of Utopia Planitia. In this one picture we can see large mounds that might be evidence of cryovolcanic activity (mud volcanoes), strings of small mounds that might be the same but that also suggest underground faults and voids, and distorted and eroded craters that could have buried glacial material in the interiors.

The largest crater in the upper left looks like it is actually filled with ice that has also spilled over to fill the adjacent and linked depression.

This location is quite typical of Utopia Planitia. See for example this post from May 13, 2020: The blobby wettish flows of Mars. In the mid-latitudes here we find ample evidence that buried very close to the surface is an ice table that when hit by an impact melts to form these strangely shaped craters.

China’s actual target landing area is far to the east of today’s cool image, in an area that is appears far less rough. » Read more

Launch update on Mars missions

The launch status of the three missions to Mars:

First, the launch of UAE’s Hope orbiter by Mitsubishi’s H-2A rocket has been pushed back to July 20th due to bad weather. Their launch window extends to August 3rd, so they still have two weeks before it closes.

Second, China has rolled to the launchpad the Long March 5 rocket, with the Tienwen-1 orbiter/lander/rover. Though they have only said that the launch will occur between July 20th and July 25th, based on past operations, they usually launch six days after roll-out, putting the launch date as July 23.

China has also provided some clarity as to Tienwen-1’s landing site on Mars. According to this Nature Astronomy paper [pdf], published on July 13th, their primary landing site is in the northern lowland plains of Utopia Planitia. The Tienwen-1 science team has also considered [pdf] the northern lowland plains in Chryse Planitia, on the other side of Mars.

Since they will spend two to three months in Mars orbit before sending the lander and rover to the surface, it could very well be that they won’t make a final decision until they get into orbit.

Finally, on July 7th Perseverance was mounted on top of its Atlas-5 rocket for its July 30th launch. Its launch window closes on August 15.