Tag: Moon

Chinese lunar rover and lander enter their third lunar night

9:21 am

The Chinese lunar rover Yutu-2 and its lander Chang’e-4 have gone into hibernation as they enter their third lunar night on the far side of the Moon.

According to Chinese news reports, both spacecraft have now exceeded their nominal lifespan.

With all systems and payloads operating well, the Yutu-2 team will continue roving and science data collection on lunar day 4 of the Chang’e-4 mission, according to a [Chinese] announcement.

Yutu-2 added 43 meters to its overall drive distance in its third day of activities, continuing a path to the northwest of the landing site, which was recently named ‘Statio Tianhe’ by the International Astronomical Union. The rover just covered seven meters between waking for lunar day 3 on Feb. 28 and Mar. 3, during which time it navigated carefully toward a 20 centimeter diameter rock in order to analyze the specimen with an infrared and visible light spectrometer to determine its origin.

I am struck by how tentative the Chinese and their rover appear. The first Russian lunar rover, Luna 17, traveled 6.5 miles in eleven months. The second, Luna 21, traveled 23 miles in four months. At the pace Yutu-2 is setting, it will not come close to these mileages. Moreover, my impression of Chinese space technology in the past decade has been that it is quite robust. This tentativeness thus surprises me. Maybe because this is a government project they are simply covering their butts should something go wrong, and thus making believe the rover is more delicate than it really is.

As Scotty on Star Trek once said, “Always under predict, then over perform.” We might be seeing that pattern here.

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The travels of Moon’s scarce surface water

9:19 am

An analysis of data from one of Lunar Reconnaissance Orbiter’s (LRO) instruments have allowed scientists to map the movements of the scarce water on the lunar surface.

Up until the last decade or so, scientists thought the Moon was arid, with any water existing mainly as pockets of ice in permanently shaded craters near the poles. More recently, scientists have identified surface water in sparse populations of molecules bound to the lunar soil, or regolith. The amount and locations vary based on the time of day. This water is more common at higher latitudes and tends to hop around as the surface heats up.

…Water molecules remain tightly bound to the regolith until surface temperatures peak near lunar noon. Then, molecules thermally desorb and can bounce to a nearby location that is cold enough for the molecule to stick or populate the Moon’s extremely tenuous atmosphere, or “exosphere”, until temperatures drop and the molecules return to the surface.

The quantities we are talking about here are very tiny. This will not be the water that future settlers will depend on. Instead, it will be those pockets of ice in the permanently shaded craters.

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Beresheet sends back first pictures

7:35 am

The privately-built Israeli lunar lander Beresheet has sent back its first pictures, taken on its way to the moon.

The picture, taken 37,600 km from Earth, shows the Israeli flag and the inscription with “Am Yisrael Hai” (the People of Israel Live) in Hebrew and the inscription “Small Country, Big Dreams” in English. The spacecraft was snapped as it passed over Australia, and the photograph was taken during a very slow rotation by Beresheet. The Israeli spacecraft, built in an IAI factory, is in an elliptical orbit around Earth – its greatest distance from Earth (the apogee) at this stage is some 131,000 kilometers.

While the press wants to trivialize this image by calling it a selfie, it was taken for very important engineering reasons. It demonstrates that the camera and the spacecraft’s pointing systems are working, exactly as planned.

Beresheet will continue to raise the apogee of its orbit until it enters the Moon’s gravitational sphere of influence, when it will then shift into lunar orbit.

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Beresheet successfully completes engine burn

8:39 am

After a computer issue prevented its last course correction, Beresheet, the Israeli private lunar probe, successfully completed that engine burn yesterday, raising its Earth orbit’s apogee to 81,000 miles, almost a third of the way to the Moon.

The Beresheet team has not explained exactly what went wrong with the computer earlier this week, or what they have done to fix the problem. All they said is that they have figured it out and worked around it.

The next engine burn to raise the orbit further will occur in about a week.

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Beresheet’s second engine burn stopped by computer reset

8:40 am

It appears that the second engine burn to raise the orbit of Israel’s privately built lunar lander, Beresheet, did not happen as planned because of an unexpected computer reboot.

In a statement Tuesday morning, SpaceIL and Israel Aerospace Industries (IAI) engineers said they were investigating the malfunction, but said that other than a known problem with the navigation system’s star tracker, the Beresheet’s systems were all functioning properly.

The maneuver was scheduled to take place Monday night, as the spacecraft passed near the Earth in an area where the Ramat Gan-based SpaceIL ground crew would not be in direct communication with the craft.

During the pre-maneuver phase, the spacecraft computer reset unexpectedly, and the maneuver was automatically cancelled.

The question that immediately comes to mind: Did they purchase a space-hardened computer? Cosmic rays can wreck havoc on computer memory, causing just this type of unexpected reset, so computers in space need to be much better shielded than on Earth.

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SpaceX successfully launches three satellites

7:02 pm

Capitalism in space: SpaceX tonight used its Falcon 9 rocket, including a first stage that had already flown twice before, to launch an Indonesian communications satellite, an Air Force smallsat, and most importantly, the Israeli-built Beresheet lunar lander, the first planetary mission entirely funded from private sources.

You can get some details about Beresheet here. If all goes as planned, it will land on the Moon on April 11 and operate for two Earth days on the surface.

SpaceX was also able to successfully land that first stage, which I think is the first time they have successfully used and recovered a first stage three times. Look for this first stage to fly a fourth time.

The 2019 launch race:

2 China
2 SpaceX
1 ULA
1 Japan
1 India
1 Europe
1 Russia

The U.S. now leads China in the national rankings, 3-2.

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NASA selects experiments it wants to put on commercial lunar spacecraft

4:51 pm

Capitalism in space: NASA has selected a dozen experiments/instruments it wants to put on private commercial lunar spacecraft, either landers or rovers.

According to the press release, some of these could fly as early as before the end of this year. If so, I suspect they will go on one of the finalists for the Google Lunar X-prize, some of whom are planning to fly this year.

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New LRO image of Chang’e-4 and Yutu-2

10:05 am

Chang'e-4 and Yutu-2

The Lunar Reconnaissance Orbiter (LRO) science team has released its third and best image of the Chinese Chang’e-4 lander and Yutu-2 rover. The image on the right is a full resolution cropped section, with the lander on the bottom and the rover above and to the left.

Just after midnight (UTC) on 1 February 2019 LRO passed nearly overhead the Chang’e 4 landing site. From an altitude of 82 kilometers the LROC Narrow Angle Camera pixel scale was 0.85 meters (33 inches), allowing a sharper view of the lander and Yutu-2 rover. At the time the rover was 29 meters northwest of the lander, but the rover has likely moved since the image was acquired. This view has close to the smallest pixel size possible in the current LRO orbit. In the future however, LROC will continue to image the site as the lighting changes and the rover roves!

These future LRO images will allow us to track Yutu-2 and get an idea of its research, even if the Chinese do not release any information.

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NASA to put humans on the Moon soon!

3:11 pm

Wanna bet? According to NASA officials, the agency is accelerating its manned effort and expects to return to the Moon with humans by 2028 at the latest!

Jim Bridenstine, NASA’s administrator, told reporters Thursday that the agency plans to speed up plans backed by President Donald Trump to return to the moon, using private companies.

“It’s important that we get back to the moon as fast as possible,” said Bridenstine in a meeting at NASA’s Washington headquarters, adding he hoped to have astronauts back there by 2028.

“This time, when we go to the Moon, we’re actually going to stay. We’re not going to leave flags and footprints and then come home to not go back for another 50 years” he said.

Why does this announcement remind me of similar enthusiastic predictions made by Russia’s space agency, Roscosmos, all of which have never come true? In fact, why does Bridenstine’s prediction remind me of many past NASA predictions since the 1980s, all of which either never happened, or happened decades behind schedule and in a manner that was far from grand?

If NASA is the agency to run this program, this prediction will not happen, period. For NASA to get back to the Moon by 2028 would require them to somehow build Gateway (which Bridenstine labels as a key component in this program) while also accelerating the launch schedule of SLS, a rocket NASA has spent fifteen years building that it doesn’t expect to launch for at least two more years, and will not put humans on it until 2024, at the earliest.

Gateway has not even been funded. It provides no way to get to the lunar surface. If it is funded it will cost billions, and likely take as long to build as SLS. SLS itself is expensive, unwieldy, and incapable of providing launch services for such an ambitious program.

Bridenstine’s announcement though did contain a ray of hope. He and his associates made a big deal about how they wish to hire many different private companies to achieve their goals. If the agency gets out of the way and lets free Americans do the job, then maybe it will happen.

We shall see. NASA’s track record when it comes to letting privately-built manned commercial spacecraft do the job is dismal, and that’s being kind.

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IAU approves China’s proposed names for Chang’e-4 landing site

10:07 am

That was fast! The International Astronomical Union (IAU) has approved all of the proposed names that China submitted for the features at or near Chang’e-4 landing site.

The IAU Working Group for Planetary System Nomenclature has approved the name Statio Tianhe for the landing site where the Chinese spacecraft Chang’e-4 touched down on 3 January this year, in the first-ever landing on the far side of the Moon. The name Tianhe originates from the ancient Chinese name for the Milky Way, which was the sky river that separated Niulang and Zhinyu in the folk tale “The Cowherd and the Weaver Girl”.

Four other names for features near the landing site have also been approved. In keeping with the theme of the above-mentioned folk tale, three small craters that form a triangle around the landing site have been named Zhinyu, Hegu, and Tianjin, which correspond to characters in the tale. They are also names of ancient Chinese constellations from the time of the Han dynasty. The fifth approved name is Mons Tai, assigned to the central peak of the crater Von Kármán, in which the landing occurred. Mons Tai is named for Mount Tai, a mountain in Shandong, China, and is about 46 km to the northwest of the Chang’e-4 landing site.

Compare this fast action with the IAU’s approval process for the names the New Horizons team picked for both Pluto and Ultima Thule. It took the IAU more than two years to approve the Pluto names, and almost three years to approve the Charon names. It is now almost two months after New Horizons’ fly-by of Ultima Thule, and the IAU has not yet approved the team’s picks for that body.

Yet it is able to get China’s picks approved in less than a month? Though it is obviously possible that there is a simple and innocent explanation for the differences here, I think this illustrates well the biases of the IAU. Its membership does not like the United States, and works to stymie our achievements if it can. This factor played a part in the Pluto/planet fiasco. It played a part in its decision to rename Hubble’s Law. And according to my sources, it was part of the background negotiations in the naming of some lunar craters last year to honor the Apollo 8 astronauts.

The bottom line remains: The IAU has continually tried to expand its naming authority, when all it was originally asked to do was to coordinate the naming of distant astronomical objects. Now it claims it has the right to approve the naming of every boulder and rock anywhere in the universe. At some point the actual explorers are going to have to tell this organization to go jump in a lake.

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Chang’e-4 & Yutu-2 enter sleep mode for second lunar night

9:40 am

The Chinese lunar lander Chang’e-4 and its rover Yutu-2 have both gone into hibernation as part of their preparation for surviving their second night on the Moon’s surface.

The Yutu-2 rover and lander will resume science and exploration activities on Feb. 28 and March 1, respectively, according to the release, with the rover needing to unfold solar panels and dissipate heat.

The previous lunar night saw the Chang’e-4 lander record a temperature low of -190 degrees Celsius (-310 Fahrenheit), with measurements made possible by a Russian-developed radioisotope thermoelectric generator which also acts as a prototype for future deep-space exploration.

Official updates on the progress of the mission had been sparse during the second lunar day of operations, though some new images and footage were released ahead of the Chinese New Year holiday, which ran from Feb. 4 to Feb. 10.

Yutu-2 has traveled about 400 feet so far.

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