See Tianzhou 9 cargo mission dock at China's Tiangong space station (video)

A new Chinese freighter spacecraft arrived at the Tiangong space station last week, packed with supplies.

Tianzhou 9 launched July 14 atop a Long March 7 rocket at 5:34 p.m. EDT (2134 GMT; 5:34 a.m. on July 15 China Standard Time), sending the spacecraft into orbit. Just over three hours later, at 8:52 p.m. EDT (0052 GMT; 8:52 p.m. China Standard Time on July 15), Tianzhou 9 docked at the rear docking port of the Tiangong space station's Tianhe core module, according to China's human spaceflight agency, CMSA.

Packed aboard Tianzhou 9 was 7.2 tons (6.5 metric tons) of cargo, including 1.65 tons (1.5 metric tons) of food for the three Shenzhou 20 mission astronauts, who arrived at Tiangong on April 24, and the Shenzhou 21 crew, expected to launch to the space station around October to begin their own six-month-long stay in orbit.

Also aboard Tianzhou 9 were two new sets of Feitian extravehicular spacesuits, which have been upgraded with greater durability and mission lifetime; core muscle exercise equipment for astronaut fitness; and scientific payloads for various fields of research.

Astronaut core strength was highlighted as key to performance and health while in orbit and for recovery back on the ground, as well as for grand future plans.

"The stronger [our astronauts are], the longer and farther we can go. Core strength is crucial not only for space station operations but also for future missions to the moon," Li Yinghui, researcher at the China Astronaut Research and Training Center, told China Central Television, regarding the 287-pound (130 kilograms) core exercise device.

Among the science payloads were three sets of samples for cellular biology experiments. These are bone marrow mesenchymal stem cells for studying bone loss caused by the prolonged absence of gravitational stimulation, cells derived from failing hearts with the aim of developing therapeutic measures, and samples related to anti-aging research.

Another experiment will involve cutting-edge biotechnology, using human pluripotent stem cells to build miniature brain-like organoid models on chips roughly the size of a credit card, hosted in the biotechnology experiment cabinet onboard the Wentian lab module.

The Tianzhou 9 spacecraft itself features a number of upgrades over previous models. It has the greatest payload volume of any of the Tianzhou spacecraft so far launched by China. It is also more easily prepared for space launch in the event of an emergency.

"Tianzhou 9 is the first cargo spacecraft capable of emergency launch, able to be launched to the space station within three months if required. This is the significance of an emergency response spacecraft," Li Zhiyong, a member of the Tianzhou spacecraft development team with the China Aerospace Science and Technology Corporation (CASC), told CCTV.

The first Tianzhou vehicle launched in April 2017 and docked with Tiangong 2, a prototype lab used as a stepping stone toward building the three-module Tiangong, which was constructed across 2021 and 2022.

Tiangong is about 20% as massive as the International Space Station. China has suggested, however, that it will expand the orbital outpost in the coming years.