Lunar Reconnaissance Orbiter snaps a smeared image of South Korea’s Danuri lunar obiter

Danuri as seen by LRO
Click for original image.

Cool image time! On March 5 to March 6, 2024, the orbits of NASA’s Lunar Reconnaissance Orbiter (LRO) and South Korea’s Danuri orbiter had three close approaches, during which LRO had a chance to snap pictures of Danuri as it zipped by in the opposite direction.

The first image is to the right, cropped but expanded to post here.

The flight paths of the two vehicles were nearly parallel but in opposite directions, resulting in extreme relative velocity. The LROC NAC exposure time was very short, only 0.338 milliseconds. But still, Danuri was smeared by a factor greater than 10x in the downtrack direction.

…On the first opportunity, LRO was slewed 43 degrees to capture Danuri from a distance of 5.0 kilometers

Of the three pictures taken, this one appears the best. In all three cases, the fast relative speed was too fast for the camera shutter, so that Danuri’s image was smeared as you see.

There likely is little or no ice in the Moon’s permanently shadowed craters

Shadowcam-LRO mosaic
The floor of Shackleton Crater showing no obvious ice deposits,
as seen by Shadowcam. The black cross marks the south pole.
Click for original image.

This week the 55th annual Lunar and Planetary Science Conference is being held in Texas. The conference was originally established in connection with the Apollo missions to allow scientists to release their Moon research results. It quickly morphed into an annual event covering research from the entire planetary research community.

I have reviewed the abstracts for this year’s meeting, and culled what I think are the most significant new results from the conference, which I will report on in the next few posts.

We begin however with possibly the most important result from the conference, given by the science team for the ShadowCam instrument on South Korea’s Danuri lunar orbiter. That low-light camera was designed to take high resolution pictures of the permanently-shadowed craters of the Moon, to see if there was any visible or obvious ice hidden there. Though the science team presented a number of papers, the summary paper [pdf] by the instrument’s principal investigator, Mark Robinson of Arizona State University, gave the bottom line:

The data so far is finding very little evidence of water ice in these dark regions.
» Read more

The scientific results from South Korea’s first lunar orbiter Danuri

floor of Shackleton Crater
The floor of Shackleton Crater at the Moon’s
south pole. Click for original image.

Link here. The article provides a good summary, with three results of significance:

  • NASA’s Shadowcam camera successfully obtained low light images of the permanently shadowed craters at the Moon’s south pole. One of those images is to the right. All images showed no obvious evidence of ice. The arrow points to the track of a boulder that rolled down the slope.
  • A gamma-ray detector, designed to map the chemcial surface of the Moon, ended up detecting many intergalactic gamma-ray bursts, including the brightest ever in October 2022 that was observed by numerous detectors.
  • Data of the Moon’s magnetic field suggested the far side was “more electrically conductive than the near side,” a result that scientists said “doesn’t make sense.”

Danuri is still functioning, long after its primary mission was completed, and could continue to operate for years yet.

South Korea’s KARI space agency releases new images taken by its Danuri lunar orbiter

To celebrate the anniversary of its launch, South Korea’s KARI space agency today released new images taken by its Danuri lunar orbiter.

Images include views of Reiner Gamma, a so-called swirl, which features a localized magnetic field and marks a bright spot within the Oceanus Procellarum region. Another shows shadows inside Amundsen Crater, close to the lunar south pole and a potential landing site for NASA’s Artemis 3 mission, which is slated to put astronauts on the moon in late 2025.

Another southern feature captured by Danuri is Drygalski Crater, showing the central peak inside the impact crater.

Shadowcam on South Korea’s Danuri lunar orbiter sees no obvious ice in the permanently shadowed interior of Spudis crater

Overview map

Using Shadowcam, a camera built by Arizona State University that is on South Korea’s Danuri lunar orbiter and is designed to see into very dark regions of little light, scientists have obtained optical images showing the permanently shadowed interior of Spudis Crater, located only about ten miles from the Moon’s south pole.

That picture is below. To the left is an annotated overview created from Lunar Reconnaissance Orbiter (LRO) high resolution images. The white box inside Spudis Crater indicates the area covered by the section of the Shadowcam image I have focused on. The red outlines indicate areas that are thought to be permanently shadowed. The relatively flat ridgeline between Shackleton and Spudis is one of the prime future landing sites for NASA’s Artemis program.
» Read more

No ice inside permanently shadowed crater near Moon’s south pole?

Marvin crater as seen by Shadowcam
Click for original image.

Overview map

Using a camera on South Korea’s lunar orbiter Danuri, dubbed Shadowcam and designed to look into the permanently shadowed craters at the Moon’s poles, scientists have taken an image that sees into the forever dark region of one such crater.

The picture to the right, released on March 13, 2023 by the Shadowcam science team, is of the crater Marvin, located about 16 miles to the east of the south pole. The pink outline indicates the area that is thought to be permanently shadowed.

The second image to the right provides a wider view of the south pole region, with the craters labeled and outlined by the green lines. The orange lines mark permanently shadowed areas. The white box indicates the approximate area covered by the Shadowcam picture. One of the candidate landing sites for Starship, as part of NASA’s Artemis program, is the eastern rim of Shackleton, essentially at the south pole itself.

Previous data suggests that ice should be found in those permanently shadowed areas, because other orbiters have detected evidence of hydrogen there. The Shadowcam picture above however shows nothing that strongly suggests the presence of ice, unless that darker flat area on the floor of the crater is ice-infused dust. If so however, it is quite ancient and solid, based on the presence of several craters within it.

The press release makes no mention of this question, probably because the scientists are still analyzing the data. This first look however suggests the ice is not there, or is in a form that is going to require a lot of processing to extract the water from it.

American camera snaps picture of shadowed floor of Shackleton crater

floor of Shackleton Crater
Click for original image.

Using ShadowCam, a NASA-funded camera designed to take high resolution images of the permanently shadowed regions on the Moon, scientists have snapped the first picture of shadowed floor of Shackleton crater.

That image, reduced to post here, is to the right. I have added some labels to clarify what we are seeing. The arrow points to a boulder track caused when the boulder rolled down the crater rim slope.

The camera will be used to image the moon’s permanently shadowed regions with a resolution of better than 6.6 feet (2 meters) per pixel

ShadowCam is one of six instruments on the South Korean lunar orbiter, Danuri, which is now in lunar orbit and beginning its science phase. This was therefore only a successful test image to make sure the camera was working as planned.

Though the area photographed was in shadow (otherwise it would have saturated ShadowCam’s sensitive camera), this first image appears to show no ice at the base of the crater. This simply could be that this part of the crater floor is not permanently shadowed, but gets illuminated enough to melt off any ice. Or it could be that no ice exists in these places. We need to wait and see.

South Korea’s Danuri orbiter enters lunar orbit

South Korea’s first lunar orbiter, dubbed Danuri, has successfully entered lunar orbit after a four-month journey designed to save fuel and weight.

The Danuri spacecraft was expected to begin entering lunar orbit at on Friday (Dec. 17) at 2:45 p.m. EST (1945 GMT, 2:45 a.m. Dec. 17 in South Korea), according to a statement (opens in new tab) from the Korea Aerospace Research Institute (KARI). The maneuver, the first of five planned engine burns through Dec. 28 to refine Danuri’s orbit around the moon, will clear the way for the probe to get started on its lunar science objectives.

Danuri, also known as the Korea Pathfinder Lunar Orbiter (KPLO), began its long and circuitous journey to the moon on Aug. 4, launching on a SpaceX Falcon 9 rocket from Florida’s Cape Canaveral Space Force Station. The moon probe has traveled over 3.3 million miles (5.4 million kilometers) on its journey so far, KARI officials have said.

Its six instruments, including one American camera designed to look into the permanently shadowed craters on the Moon, will study the Moon from a polar orbit.

South Korea’s Danuri lunar orbiter successfully makes course correction

On September 2nd engineers for South Korea’s Danuri lunar orbiter successfully completed a major course correction, firing its engines to adjust its path towards the Moon.

The science ministry announced Sept. 4 that the maneuver was so successful that the Korea Aerospace Research Institute (KARI), which controls the spacecraft called Danuri, has decided to skip an additional correction maneuver planned for Sept. 16.

It will reach lunar orbit on December 16th, then make five more orbital adjustments before reaching its science orbit in January. While the spacecraft has instruments from both South Korea and the U.S. for studying the lunar surface, its main goal is to teach South Korea engineers and scientists how to do this.

SpaceX launches South Korea’s Danuri lunar orbiter

SpaceX today successfully launched South Korea’s Danuri lunar orbiter, also called the Korea Pathfinder Lunar Orbiter.

The first stage completed its sixth flight, landing on a drone ship in the Atlantic. The fairings completed their fourth flight.

Danuri is now on its way to the Moon, with a planned arrival in lunar orbit on December 16, 2022. It carries six instruments, one of which was developed by NASA. The spacecraft, while designed to study the Moon, is primarily a technology test mission laying the groundwork for more sophisticated interplanetary South Korean missions. More information about the mission can be found here.

The leaders in the 2022 launch race:

34 SpaceX
28 China
10 Russia
6 Rocket Lab
5 ULA

The U.S. now leads China 49 to 28 in the national rankings, and the entire world combined 49 to 45. With this launch American private enterprise has now surpassed the entire launch total for all of 2021, and has the most launches for the U.S. since 1967, when it completed successfully 57 launches.

South Korea ships its first lunar orbiter to U.S. for August launch

The new colonial movement: South Korea today packed and shipped its first lunar orbiter, dubbed Danuri, to the United States for an August 3, 2022 launch on a SpaceX Falcon 9 rocket.

According to the Ministry of Science and ICT, Danuri was sent from the Korea Aerospace Research Institute in Daejeon, 160 kilometers south of Seoul, to Incheon International Airport, west of Seoul, in a specially designed container. The orbiter will be flown to Orlando International Airport and arrive at the Floridian space center Thursday. It will later undergo maintenance, assembly and other pre-launch preparations for about a month before launch.

If all goes right, Danuri will orbit the Moon for a year, both testing its own technology as well as observing the lunar surface.