Joining the list of nations with ambitious plans in space, South Korea set off for the moon on Thursday.
Its first lunar spacecraft, named Danuri, was carried toward space on time at 7:08 p.m. Eastern time by a SpaceX Falcon 9 rocket, which launched from Cape Canaveral Space Force Station in Florida. After about 40 minutes and a series of engine firings, the Korean spacecraft separated from the rocket’s second stage, embarking on its journey to the moon.
When it arrives in lunar orbit, it will join spacecraft from NASA, India and China that are currently exploring Earth’s companion. Danuri’s scientific payload will study the moon’s magnetic field, measure quantities of elements and molecules like uranium, water and helium-3, and photograph the dark craters at the poles where the sun never shines.
What is Danuri, and what will it study?
Originally known as the Korea Pathfinder Lunar Orbiter, the mission has now been given the name of Danuri, a portmanteau of the Korean words for “moon” and “enjoy.” It will be South Korea’s first space mission to go beyond low-Earth orbit.
Its scientific instruments include a magnetometer, a gamma-ray spectrometer and three cameras. NASA supplied one of the cameras, ShadowCam, which is sensitive enough to pick up the few photons that bounce off the terrain into the moon’s dark, permanently shadowed craters. These craters, located at the moon’s poles, remain forever cold, below minus 300 degrees Fahrenheit, and contain water ice that has accumulated over the eons.
The ice could provide a frozen history of the 4.5 billion-year-old solar system and a bounty of resources for future visiting astronauts. Such ice can also be extracted and melted to provide water and broken apart into oxygen and hydrogen, which would provide both air to breathe for astronauts and rocket propellants for travelers looking to launch from the moon to other destinations.
What else has South Korea done in space?
South Korea is developing its own rockets. Its first design, Naro-1, successfully reached orbit on the third try, in 2013. Since then, the Korea Aerospace Research Institute — South Korea’s equivalent of NASA — has shifted its efforts to Nuri, a larger, three-stage rocket. The second Nuri flight in June successfully placed several satellites in orbit.
South Korea has several communications and earth observation satellites in low-Earth orbit. It also has an extensive military missile program.
How many countries have sent missions to the moon?
The United States and the Soviet Union sent numerous robotic spacecraft to the moon beginning in the 1960s. NASA’s Apollo program sent astronauts there from 1968 through 1972. The world then almost entirely lost interest in the moon for three decades, but a hubbub of activity has returned.
In the past few years, China has sent multiple successful robotic spacecraft, including three landers. NASA has sent several orbiters there and has enlisted commercial companies to send payloads to the lunar surface in the coming years.
Japan and the European Space Agency have launched moon missions, and India has sent two orbiters to the moon, although a lander accompanying the second orbiter crashed as it descended toward the surface in 2019.
Another mission in 2019, Beresheet, a lander built by an Israeli nonprofit, SpaceIL, also crashed as it attempted to land on the moon.
Why will it take Danuri so long to get to the moon?
The spacecraft is taking a long, energy-efficient route to the moon. It first heads toward the sun, then loops back around to be captured in lunar orbit in mid-December. This “ballistic trajectory” takes longer but does not require a large engine firing to slow the spacecraft when it gets to the moon.
Danuri will then adjust its orbit to an altitude of 62 miles above the moon’s surface. The main scientific mission is scheduled to last for one year.
What else is going to the moon this year?
A small NASA-financed spacecraft, CAPSTONE, is en route to the moon to explore a highly elliptical orbit, where NASA plans to build a lunar outpost for future astronauts. It is scheduled to arrive in lunar orbit in November.
But the big event of the year will be Artemis 1, an uncrewed test of NASA’s giant rocket and capsule that are to take astronauts back to the moon in the coming years. NASA is aiming to launch in late August or early September.
A couple of commercial companies, ispace of Japan and Intuitive Machines of Houston, are also hoping launch small robotic landers to the moon late this year.