Japan's first-generation space cargo ships have just completed their mission, with the last of its cargo spacecraft sent out to its fiery retirement over the Pacific Ocean.
The ninth and final H-II Transfer Vehicle (HTV), a resupply ship to the Internation Space Station also known as "white stork" or Kountori in Japanese, burned up as planned yesterday Aug. 20.
HTV-9 detached from the ISS on Aug. 18, bringing with it approximately 7,500 lbs. of trash and used equipment. The cargo spacecraft made a loop around Earth for a spell before receiving the command from mission controllers to perform a deorbit burn, plummeting the freighter burning down over the Pacific Ocean yesterday morning.
In 2009, the HTV with solar power began operating for the ISS. Nine missions carried the spacecraft payload -- all successful.
"Over the past 11 years, the H-II Transfer Vehicle Kounotori has delivered over 40 tons of cargo, research, hardware, and equipment to the International Space Station," said Joel Montalbano, NASA's space station program manager. "I want to congratulate Japan on the HTV missions."
The death of HTV-9 will not stop the orbital lab runs of the Japanese cargo. A successor freighter known as the HTV-X, which is expected to travel to the station for the first time in 2022, was built by the Japan Aerospace Exploration Agency (JAXA).
The HTV-X can hold more freight than the old HTV, and the vehicle can also go a long way. JAXA officials have said that the HTV-X could fly supplies to NASA's proposed moon orbiting space station, known as Gateway.
Leaving the orbital scene, HTV reduces the numbers of robot resource craft operating to three: Northrop Grumman's Cygnus spacecraft, SpaceX's Dragon capsule (the uncrewed cargo version), and Russia's Progress vehicle.
This fleet should soon be strengthened, and not only by HTV-X. Dream Chaser, a Colorado-based space plane developed by Sierra Nevada Corp., is expected to fly robotic freight missions to the orbiting laboratory in 2021.
Humans have worked and lived continuously aboard the ISS for almost twenty years, testing out new technologies and advancing scientific knowledge. Astronauts in the ISS have paved the way for breakthroughs that on Earth cannot be achieved.
So far, 19 countries and 240 people have visited the ISS. The space laboratory has hosted over 3,000 scientific investigations and research in more than 100 countries. NASA considers the ISS a critical testbed to understand and overcome the challenges of long-duration spaceflight.
