— China's latest astronauts to launch into space have landed on a series of stamps and related postal souvenirs celebrating their on-going mission.

Jing Haipeng and Chen Dong, who docked their Shenzhou 11 spacecraft to China's Tiangong-2 space lab on Tuesday (Oct. 18) beginning a month-long stay at the complex, are featured on the new postage stamps issued by the China National Philatelic Corporation, which is authorized by the China Post to sell stamp products to the public.

The stamps feature the portraits of Jing and Chen. A third issue depicts the crew's Shenzhou 11-Tiangong 2 mission patch. There is also a dated pictorial cancellation mark that includes an image of the two spacecraft docked together.

The China National Philatelic Corporation is also offering stamped envelopes — "covers" as referred to by collectors — that are also adorned with photos of the taikonauts and a graphic design showing the launch of their Long March 2F rocket. The stamps and covers, which were first issued on Oct. 17, are offered individually or as sets presented in collectible folders.

Jing, who turned 50 on board Tiangong-2 on Monday (Oct. 24), is the first Chinese astronaut to make three flights into space. As part of his current mission, Jing is filing journals for the state-run Xinhua news agency.

"This is my third time to fly into space," wrote Jing. "This is also my second time to enter a Tiangong. Tiangong-1 was quite good, but Tiangong-2 is much more comfortable. It is perfect in layout, decoration and matching of colors."

Shenzhou 11 is Chen's first spaceflight. He, too, is writing reports about his experience for Xinhua.

"Being in space for the first time is unusual," Chen wrote. "My big brother Jing Haipeng has really helped me adjust to life up here, and I am slowly getting used to the feeling of zero gravity, and, you know what — I'm starting to enjoy it more and more."

In addition to penning journals, the astronauts have also begun conducting an array of experiments on Tiangong-2, including working with a student-suggested study of live silkworms to see how the larvae react to the microgravity environment.

The orbiting laboratory, which is intended as a precursor to a Chinese modular space station, is also equipped with a cold atomic clock and a gamma ray burst study, the latter a joint project by Swiss, Polish and Chinese scientists.

Shenzhou 11 is not the first Chinese crewed mission to be honored on the country's stamps. Similar commemorative issues date back to China's first taikonaut in space, Yang Liwei, and his Shenzhou 5 mission in 2003.

China also established a "virtual post office" aboard its first space lab, Tiangong-1, in 2011. The so-called "China Post Space Office" invited the public to e-mail visiting taikonaut crews. They could also purchase stamps and covers via a ground-based counterpart office in Beijing Aerospace City.