S. Korea begins transporting country's 1st lunar orbiter to U.S. for Aug. launch
SEOUL, (Yonhap) -- South Korea on Tuesday started transporting the country's first lunar orbiter to the United States ahead of next month's launch using a SpaceX rocket, officials said.
South Korea plans to launch the Korea Pathfinder Lunar Orbiter, also known as Danuri, aboard the SpaceX Falcon 9 rocket from Cape Canaveral Space Force Station in Florida at 8:24 a.m. on Aug. 3 (Korean Time).
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.
Danuri will begin circling around the moon in December and conduct a yearlong mission to observe it using an array of instruments, including cameras and magnetometers. It will also identify potential landing sites for future lunar missions.
Last month, South Korea successfully launched its first homegrown space rocket, Nuri, also known as KSLV-II, from the country's southern coastal village of Goheung in a major milestone in the nation's space program.
South Korea launched a preliminary feasibility study for the successor to the Nuri rocket, with the goal of sending a lunar landing module to the moon in 2031.
South Korean spacecraft fueled for ride from Cape Canaveral to the moon
A South Korean spacecraft set for launch to the moon next week from Cape Canaveral has been loaded with the fuel it needs to maneuver into a low-altitude lunar orbit for image-taking and scientific observations.
The Korea Pathfinder Lunar Orbiter, or KPLO, spacecraft is set for launch at 7:08 p.m. EDT (2308 GMT) next Thursday, Aug. 4, aboard a SpaceX Falcon 9 rocket from Cape Canaveral Space Force Station. Mission managers said earlier this week the launch was delayed two days to allow time for SpaceX to complete additional work on the Falcon 9 rocket.
Technicians and engineers working inside SpaceX’s payload processing facility recently completed fueling of the Korean lunar probe, following the spacecraft’s delivery to Cape Canaveral from South Korea on July 6.
The spacecraft was loaded with hydrazine fuel inside the SpaceX clean room. South Korean engineers who traveled to the launch base with the KPLO spacecraft also completed final tests on the probe, South Korea’s first mission to the moon and first venture in deep space exploration.
The 1,495-pound (678-kilogram) spacecraft was expected to be encapsulated inside the Falcon 9 rocket’s payload fairing after fueling. The aeroshell will protect the spacecraft during the final phase of launch preparations, and during the first few minutes of the launch itself.
Then SpaceX will transport the payload module from the processing facility to the Falcon 9 rocket’s hangar a couple miles away, where ground teams will connect the spacecraft inside the rocket’s nose cone to the Falcon 9’s upper stage.
The entire rocket will then roll out and will be raised vertical on pad 40 at Cape Canaveral. The KPLO mission is one of two launches currently scheduled next Thursday at the Florida spaceport. A United Launch Alliance Atlas 5 rocket with a U.S. military satellite is set to lift off about 12-and-a-half hours before the Falcon 9 rocket on the KPLO mission.
Part of the KPLO mission’s purpose is in its name. The mission is a pathfinder, or precursor, for South Korea’s future ambitions in space exploration, which include a robotic landing on the moon in the early 2030s. South Korea has also signed up to join the NASA-led Artemis Accords, and could contribute to the U.S. space agency’s human lunar exploration program.
The KPLO mission is also named Danuri, a combination of the words “dal” and “nurida” in Korean, meaning “enjoy the moon.”
“The basic idea of this mission is technological development and demonstration,” said Eunhyeuk Kim from the Korea Aerospace Research Institute. “Also, using the science instruments, we are hoping to get some useful data on the lunar surface.”
The mission carries six science instruments and technology demonstration payloads.
KPLO will test a new South Korean spacecraft platform designed for deep space operations, along with new communication, control, and navigation capabilities, including the validation of an “interplanetary internet” connection using a disruption tolerant network.
The mission’s scientific objectives include mapping the lunar surface to help select future landing sites, surveying resources like water ice on the moon, and probing the radiation environment near the moon.
The $180 million (233.3 billion won) mission will launch toward the moon on a low-energy, fuel-efficient ballistic lunar transfer trajectory, a path being pioneered by NASA’s small CAPSTONE spacecraft, a tech demo mission that launched last month on a Rocket Lab mission and is scheduled to slip into orbit around the moon in November.
If KPLO launches in the first week of August, its arrival date at the moon is fixed on Dec. 16. The Falcon 9 will propel the spacecraft on a trajectory that will take it close to the L1 Lagrange point, a gravitationally-stable location nearly a million miles (1.5 million kilometers) from the daytime side of the Earth, some four times farther than the moon.
Gravitational forces will naturally pull the spacecraft back toward the Earth and the moon, where the Korean probe will be captured in orbit Dec. 16. A series of propulsive maneuvers with the spacecraft’s thrusters will steer KPLO into a circular low-altitude orbit about 60 miles (100 kilometers) from the lunar surface by New Year’s Eve.
After a month of commissioning and tests, the spacecraft’s year-long primary science mission should begin around Feb. 1. If the orbiter has enough fuel, mission managers could consider an extended mission beginning in 2024, Kim said.
One of the payloads on the KPLO, or Danuri, mission is a U.S.-built instrument named ShadowCam.
Derived from the main camera on NASA’s Lunar Reconnaissance Orbiter, ShadowCam will peer inside dark craters near the moons poles, where previous missions detected evidence of water ice deposits. The NASA-funded ShadowCam instrument is hundreds of times more sensitive than LRO’s camera, allowing it to collect high-resolution, high signal-to-noise imagery of the insides of always-dark craters using reflected light.
NASA is also providing tracking and communications support for the KPLO mission through its Deep Space Network antennas in California, Spain, and Australia. KARI, South Korea’s space agency, also has its own deep space communications antenna, but it doesn’t offer the continuous coverage of NASA’s worldwide network.
South Korea began developing the KPLO mission in 2016 for a planned launch in 2020, but officials delayed the mission due after the spacecraft grew above its original launch weight, and engineers needed more time to complete detailed design work.
Start von SpaceX Falcon9 mit Korea Pathfinder Lunar Orbiter Danuri
South Korean lunar orbiter succeeds in critical trajectory correction maneuver
SEOUL, South Korea — South Korea’s first robotic lunar orbiter is looping back to the moon from the L1 Lagrange point after successfully conducting a critical trajectory correction maneuver Sept. 2, a milestone in its voyage toward 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.
“The maneuver was a critical step for Danuri to make fuel-efficient travel to the moon and reach the moon’s orbit on time,” the ministry said in the statement.
The orbiter, launched Aug. 5 on a SpaceX Falcon 9 rocket from Cape Canaveral Space Force Station, Florida, is on a ballistic lunar transfer trajectory — which takes the spacecraft toward the sun before looping back to arrive at the moon’s orbit in December. The route, while much longer than traveling directly toward the moon, allows more fuel efficiency as it leverages the sun’s gravity for travel.
The orbiter — if everything goes as planned — will be captured in lunar orbit on Dec. 16. A series of propulsive maneuvers with the spacecraft’s thrusters will steer it into a circular, low-altitude orbit about 100 kilometers from the lunar surface by Dec. 31. After a brief period of commissioning and tests, the spacecraft’s yearlong mission is expected to begin in January.
Roh Hyung-il, a KARI spokesman, told SpaceNews there would be another major trajectory correction maneuver in November. Once captured in lunar orbit on Dec. 16, he added, the spacecraft will conduct five more maneuvers between Dec. 17 and Dec. 31 to get to its final orbit 100 kilometers from the lunar surface.
Starting in January, Danuri — also known as the Korea Pathfinder Lunar Orbiter — will measure terrains, magnetic strengths, gamma rays and other traits of the lunar surface using six onboard instruments, including a NASA-funded hypersensitive optical camera called ShadowCam, during its yearlong mission. The orbiter will also identify potential landing sites for future lunar missions.
South Korea’s Danuri orbiter demonstrates ‘space internet’ en route to moon
These 15 images, taken Sept. 24 by Danuri, shows the moon in different positions relative to Earth at 10-minute intervals. Credit: Korea Aerospace Research Institute
SEOUL, South Korea — South Korea’s robotic lunar orbiter Danuri successfully demonstrated “space internet” on its way to the moon by sending video and photo files, including a popular Korean band’s music video, at a distance of more than 1.2 million kilometers to Earth, said Korea Aerospace Research Institute (KARI), the spacecraft’s operator, Nov. 7.
The demonstration was conducted twice — Aug. 25 and Oct. 28 — using a space internet demonstrator developed by the Electronics and Telecommunications Research Institute (ETRI) here, validating an interplanetary internet connection using delay-disruption tolerant networking. The device was designed to test the data transmission capability in a space environment where disconnection of telecommunications frequently occurs. The tests were supervised by KARI, ETRI, and NASA Jet Propulsion Laboratory, according to KARI. While the first demonstration was conducted with the orbiter located about 1.21 million kilometers away from Earth, Danuri was 1.28 million kilometers from Earth for the second demo, according to KARI.
“The performance verification test is significant in that they were conducted at distances of about three times the communication distance of about 380,000 kilometers, which was the mission given to Danuri before launch,” the institute said in a Nov. 7 statement.
KARI also unveiled photos of the Earth and the moon’s orbit taken by the orbiter. Using a built-in high-resolution camera developed by KARI, the orbiter took photos at a distance of between 1.46 million kilometers and 1.548 million kilometers for a month from Sept. 15 to Oct. 15. The spacecraft took fifteen photos Sept. 24 from a distance of 1.544 million kilometers as the moon orbited Earth.
“These photos are meaningful in that the Danuri captured the process of the moon orbiting and passing the Earth,” KARI said in the statement.
Launched Aug. 4 on a SpaceX Falcon 9 rocket from Cape Canaveral Space Force Station, the orbiter is traveling toward the moon at a speed of 0.54 kilometers per second to reach the moon’s orbit by Dec. 17, according to KARI. A series of propulsive maneuvers with the spacecraft’s thrusters will steer it into a circular, low-altitude orbit about 100 kilometers from the lunar surface by Dec. 31. After a brief period of commissioning and tests, the spacecraft’s yearlong mission is expected to begin in January.
Danuri enters moon's orbit
This photo taken by the Danuri lunar orbiter shows the earth and the moon on Nov. 28. The Ministry of Science and ICT said Thursday that the Danuri took the photo when the earth and the moon looked similar in size when viewed from the lunar orbiter. Courtesy of Ministry of Science and ICT
The Danuri lunar orbiter began entering the moon's orbit on Saturday, 135 days after Korea's domestically developed space vehicle was launched on Aug. 5, according to the Korea Aerospace Research Institute (KARI), Saturday.
The KARI said that the Danuri performed its first of five lunar orbit insertion (LOI) maneuvers at 2:45 a.m. on Saturday. The maneuver involved the process of reducing its speed so that the Danuri could be stably captured by the moon's gravity.
During the process of slowing down, the Danuri operated thrusters for around 13 minutes to decelerate its speed from about 8,000 kilometers per hour to 7,500 kilometers per hour to reach its target position.
The KARI said the LOI process is a challenging task because the Danuri, which moves faster than a bullet, must enter the lunar orbit, which itself moves at about 3,600 kilometers per hour.
Whether the first maneuver was successfully performed or not will be announced by the KARI and the Ministry of Science and ICT on Monday. The Danuri is scheduled to slow down its speed four more times until Dec. 28. The second slowdown will be conducted on Dec. 21.
"The LOI process was carried out by automatically executing the commands sent to the Danuri in advance at a set time. But every situation before and after the LOI was monitored in real-time on the ground," the KARI said.
Carried by SpaceX's Falcon 9 rocket, the unmanned space vehicle, the Danuri, was launched from Cape Canaveral Space Force Station in Florida on Aug. 5.
After going through a total of five lunar orbit entry maneuvers, until Dec. 28, the Danuri is scheduled to settle into the moon's orbit, which is 100 kilometers above the moon.
If it is confirmed to have successfully entered the moon's orbit, the Danuri will carry out scientific missions for a year from January. Its missions include finding a spacecraft moon landing site, measuring the magnetic field and gamma rays and testing space-based internet communication.
The Danuri is seen as Korea's first step toward space. The country recently announced its ambitious space development projects including a moon landing by 2032 and Mars by 2045.
During its four-month voyage, Danuri has achieved meaningful results for Korea's space program. It took photos of the earth and the moon with a high-resolution camera on Aug. 26 and 29, sending the first photo taken outside the earth's gravitational zone by domestically developed Korean technology. On August 25 and October 28, the Danuri succeeded in communicating by sending data such as images, photos and text messages from space back to Earth.
Quelle: The Korea Times