China has made progress in scientific data simulation for the Chinese Space Station Telescope (CSST), also known as the Xuntian Space Telescope, marking a crucial step in preparing for the country's flagship space astronomy facility.
A collaborative Chinese research team built an end-to-end observation simulation suite for both the telescope's main optical system and various observation terminals.
The suite achieved high-quality, pixel-level simulation of observation data, which will be used for the comprehensive evaluation of the telescope's overall performance.
The research was published online Wednesday in a special issue of the journal Research in Astronomy and Astrophysics, and is expected to lay the foundation for high-yield original scientific output after the telescope is launched.
The CSST is a major space astronomy facility planned as part of China's manned space program. Equipped with a 2-meter-aperture primary mirror, the telescope features a large field of view, high image quality and wide waveband coverage.
It is expected to facilitate major scientific discoveries across various astrophysical fields, including cosmology, the study of galaxies, the Milky Way, stars and planets, according to the National Astronomical Observatories under the Chinese Academy of Sciences (NAOC), which led the study.
Scientific simulation is an indispensable procedure prior to the launch. It acts as a "digital rehearsal" for the mission, generating mock data to validate the process flow and optimize observation strategies before the launch.
The CSST is an important component of China's space station. After launch, it will fly independently in the same orbit as the space station and can dock with the station for supply, maintenance and upgrades.
Key breakthrough achieved in data simulation for China's Space Telescope
Key breakthrough achieved in data simulation for China's Space Telescope
Eighteen sets of precious archival materials related to David Nelson Sutton, a U.S. assistant prosecutor at the Tokyo Trials and one of the earliest international prosecutors to investigate the Nanjing Massacre, were officially donated on Wednesday to the Memorial Hall of the Victims in Nanjing Massacre by Japanese Invaders.
Sunday marks the 80th anniversary of the opening of the International Military Tribunal for the Far East (IMTFE, also known as the Tokyo Trials). To commemorate the milestone, six diaries written by Sutton between 1946 and 1948, when he was conducting investigations for the tribunal, were donated together with a series of reports titled Reports from China.
"It is necessary to let more Chinese, even people all over the world, to see these archival materials. Let all the world know why the Tokyo Trials 80 years ago were described as a trial of justice, and how the Nanjing Massacre nearly 90 years ago was unprecedentedly brutal and tragic beyond compare," said Zou Dehuai, the donor.
From May 3, 1946 to Nov 12, 1948, the International Military Tribunal for the Far East was held in Tokyo by 11 countries, including the United States, China, Britain and the Soviet Union, to try Japan's Class-A war criminals after World War II.
"Why do we say the Tokyo Trials were a trial of justice? It was a trial witnessed by the world, with judges from 11 countries. Major war criminals, such as Iwane Matsui, a crime culprit for the Nanjing Massacre, and Hideki Tojo, all ultimately received the punishment they deserved. That is why the Tokyo Trials are called a trial of justice. These archives are of immense importance," Zou said.
Sutton came to China with the International Prosecution Section in 1946 and was tasked with investigating Japanese war crimes in China, with a particular focus on collecting evidence related to the Nanjing Massacre.
The six diaries recorded many details of Sutton's work during the Tokyo Trials. In one entry, dated March 9, he wrote that he had received formal orders to go to Shanghai, Nanking (Nanjing), Peiping (Beijing) and other sites in the China theater to investigate war crimes and gather evidence. Another entry recorded his arrival in Nanjing at 11:20 on April 2. On May 3, the day the trial opened, he described the defendants as looking like "insignificant beaten men."
The donated materials also include Sutton's "Reports from China," which further exposed Japanese wartime atrocities in China, including mass killings, violence against civilians, germ warfare and the coercion of Chinese people into opium cultivation.
Zou is a collector born in the 1990s who has long searched for wartime historical evidence. He first found the Sutton materials in November 2025 on a U.S.-based auction website specialized in military artifacts. After confirming Sutton's identity and reviewing preview images that indicated the items were original archival materials, Zou placed a bid for the collection and later, ultimately paying a price nearly 100,000 U.S. dollars, far more than his original budget. And he arranged for its return to China, with assistance from others.
At the donation ceremony, Zou received a donation certificate. He said the Sutton archives were the most expensive items he had acquired in a decade of collecting. "These archives, these ironclad evidences, expose the crimes committed by the invading Japanese army in China and serve as a warning to all humanity. When you look at these documents, you cannot imagine that a human army could commit such massive and horrible atrocities. I believe that any Japanese person with conscience, after reading the Sutton archives, would firmly recognize what kind of a massacre took place in Nanjing. For the young people of future China, Japan and the United States, we must tell them the truth of history, and why we must cherish the hard-won peace, and how heavy the cost of peace truly was," Zou said.
Tokyo Trials prosecutor's diaries donated to Nanjing Massacre memorial hall
