Category Archives: The Moon

Update on Chang’e 3 mission and Yutu rover

Here’s a summary at The Planetary Society of the Chinese Chang’e 3 lander and Yutu rover mission accomplishments and status: Yutu Update – The Planetary Society.

But the rover did not arrive at the crater, or even reach the lander. It stopped as it was getting close to the lander, apparently because the electronics associated with moving its wheels and solar panels, so probably an important central control unit, failed at that point. I don’t know when it stopped, but the map shown at LPSC is instructive. It shows the daily stops between drives (the rover was only operated when in direct contact with China, for at most half a day at a time), and counting them suggests the fault occurred in the middle part of the day, possibly due to excessive heating which might have been exacerbated by dust buildup on the rover body. But this is conjecture, as I don’t know that each stop occupied only one day.

At any rate, it soon became apparent that the rover could neither move nor fold itself up to protect against the cold of the night. Enormous efforts were made to overcome this, to no avail. As night approached the problem was made public, most memorably by the rover’s Twitter alter-ego itself. Meanwhile the lander continued operating, and I’ll come back to that later. Sunset, and possibly the end of Yutu’s short life, came on 25 January. After a seemingly interminable wait the sun rose again, and a few days later on 12 February both lander and rover woke up. Yutu was more robust than expected. All its instruments, even the fragile cameras, were fine, but it couldn’t move. I don’t know if the lack of movement extends to the robotic arm with the APXS. The instruments may work, but future science would be very limited if the NIR spectrometer and the ground-penetrating radar are limited to always making the same observation.

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Video: What if the Moon was a Disco Ball?

A reader points me to this fun video showing variations of the answer to the important question:  What if the Moon was a Disco Ball?

Science misc: Moon mantle puzzles, Space colonizing diversity, Sky falls more often, Deflating the inflation model

A selection of science related links of intrest that I’ve come across recently:

The Moon’s structure and composition are not as well understood as one might think : The Moon’s Mantle Muddle: Maybe we’ve been looking for the wrong minerals, or maybe our models are wrong – Daily Planet/Air & Space Magazine

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How many people do you need in your exoplanet colonization caravan to insure a healthy diversity of genes? How Many People Does It Take to Colonize Another Star System? – Popular Mechanics

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A nuclear detection sensor system detects more asteroids hitting the earth than thought: Blast Sensors Detect More Asteroid Strikes Than Expected – NBC News.com

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Theoretical physicist Sir Roger Penrose is skeptical that the recent measurements of variations in the cosmic radiation background necessarily validate the Inflation Model as the explanation of the early universe: Sir Roger Penrose: Cosmic Inflation Is ‘Fantasy’ – Science Friday

NASA’s ‘Take the Plunge’ Challenge: Guess when LADEE hits the Moon

NASA invites you to make a guess as to when the LADEE spacecraft will smack the Moon:

Take the Plunge: LADEE Impact Challenge

 NASA’s Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft is gradually lowering its orbital altitude over the moon. LADEE will continue to make important science observations before its planned impact into the lunar surface later this month.

When will it impact the lunar surface? NASA wants to hear your best guess!

Take the Plunge LADEE Impact Challenge

LADEE mission managers expect the spacecraft will impact the moon’s surface on or before April 21. On April 11, ground controllers at NASA’s Ames Research Center in Moffett Field, Calif., will command LADEE to perform its final orbital maintenance maneuver prior to a total lunar eclipse on April 15, when Earth’s shadow passes over the moon. This eclipse, which will last approximately four hours, exposes the spacecraft to conditions just on the edge of what it was designed to survive.

This final maneuver will ensure that LADEE’s trajectory will impact the far side of the moon, which is not in view of Earth and away from any previous lunar mission landings. There are no plans to target a particular impact location on the lunar surface, and the exact date and time depends on several factors.

“The moon’s gravity field is so lumpy, and the terrain is so highly variable with crater ridges and valleys that frequent maneuvers are required or the LADEE spacecraft will impact the moon’s surface,” said Butler Hine, LADEE project manager at Ames. “Even if we perform all maneuvers perfectly, there’s still a chance LADEE could impact the moon sometime before April 21, which is when we expect LADEE’s orbit to naturally decay after using all the fuel onboard.”

Anyone is eligible to enter the “Take the Plunge: LADEE Impact Challenge.” Winners will be announced after impact and will be e-mailed a commemorative, personalized certificate from the LADEE program. The submissions deadline is 3 p.m. PDT Friday, April 11.

For more information about the challenge and to enter, visit: http://socialforms.nasa.gov/ladee

“We want to thank all those that watched LADEE launch and have followed the mission these past months,” said Jim Green, NASA’s Director for Planetary Science at NASA Headquarters in Washington. “Our Moon holds a special place in so many cultures, and because of LADEE, we’ll know more than ever before about our nearest neighbor.”

LADEE’s mission marked several firsts. It was the first demonstration of Optical Laser Communications from space (sent data six times faster than radio), and the first deep space spacecraft designed and built “in house” at NASA’s Ames Research Center.  It was also the first payload to launch on a U.S. Air Force Minotaur V rocket integrated by Orbital Sciences Corp., Va., and was the first deep space mission to launch from NASA’s Goddard Space Flight Center’s Wallops Flight Facility on Wallops Island, Va., when millions watched the night launch on Sept. 6, 2013.

The vending-machine size spacecraft has been orbiting the moon since Oct. 6. On Nov. 10, LADEE began gathering science data, and on Nov. 20, the spacecraft entered its science orbit around the moon’s equator. LADEE has been in extended mission operations following a highly successful 100-day prime science phase.

LADEE’s three science payload instruments have been working to unravel the mysteries of the lunar atmosphere and dust environment acquiring to date more than 700,000 measurements. In its previous orbit, LADEE’s closest approach to the moon’s surface was between 20 and 50 km, and its farthest point was between 75 and 150 km – a unique position that allows the spacecraft to frequently pass from lunar day to lunar night, approximately every two hours. This vantage provides data about the full scope of changes and processes occurring within the moon’s tenuous atmosphere.

Scientists hope to address a long-standing question: Was lunar dust, electrically charged by sunlight, responsible for the pre-sunrise glow detected during several Apollo missions above the lunar horizon? LADEE also is gathering detailed information about the structure and composition of the thin lunar atmosphere.

A thorough understanding of these characteristics of our nearest celestial neighbor will help researchers understand other bodies in the solar system, such as large asteroids, Mercury, and the moons of outer planets.

Update on the Chinese Yutu lunar rover and Chang’e 3 lander

Leonard David obtains some details on the problems with the Chinese Yutu rover from  Yong-Chun Zheng, an associate researcher at the National Astronomical Observatories, Chinese Academy of Sciences : China’s Moon Landing Mission: A Status Check – Inside Outer Space

The primary failure is in the “driving electronics section”:

“The rover cannot move again,” Yong-Chun said. In addition to that, the solar wings of the Yutu rover cannot be folded to keep the inside of the robot warm during lunar night. All other functions of the rover are working properly, he said.

Yong-Chun said that the Yutu rover has experienced very low temperatures during the last three lunar nights. According the designed procedures, the rover has entered into the mode of long-term management.

Meanwhile, Yutu’s panoramic camera and its ground penetrating radar “are working normally,” Yong-Chun reported.