Next up, on September 16 at 05:34 UTC the Chinese Shenzhou 12 spacecraft returned to Earth after spending 93 days in space, landing near the Jiuquan Satellite Launch Center. Ninety-three days in space may not sound like much, but it is a new record for China, nearly tripling their previous record of 33 days.

The off-nominal but safe landing resulted in the capsule resting on its side, which left the astronauts literally hanging in their seats and held in place by restraints. Fortunately, they weren’t left hanging for long as recovery crews were at the capsule minutes after landing, thanks to people at mission control who continuously updated the landing predictions from the moment the parachute opened.

The capsule laying on its side did present a challenge to the recovery team. On the bottom of the craft is a gamma-ray altimeter. For most of the mission, it’s protected by the heat shield. In order for the capsule to make a soft landing, the altimeter needs to be exposed, so the heat shield is jettisoned during descent.  A nominal landing would have seen this tiny little package of radiation in a safe orientation facing the ground. Since it was most definitely not pointed to the ground, the recovery team needed to take special care to ensure that no one was exposed to radiation.

The Soyuz version of the altimeter, which the Shenzhou is based on, has a Cesium 137 source. If you were to stand next to it for one hour at a one-centimeter distance, you would be exposed to thirteen times the career exposure limit of a NASA astronaut. This is enough to kill a human. If you were to move a meter away from the altimeter and stand there for an hour, you would be exposed to about the same amount of radiation experienced by a flight attendant in a year. The Chinese bought the Soyuz altimeter for Shenzhou and used it until Shenzhou 8 when they made their own. Patrons can read this week’s bonus content to find out more details about the gamma-ray altimeter.

So, back to the astronauts. The three crew members were helped out of the spacecraft and settled into fancy space beach chairs, where they made short remarks. The conclusion of this mission brought Nie Haisheng up to 111 days in space across three missions, Liu Boming to a total of 95 days from two flights, and Tang Honbo to 93 days, as this was his first spaceflight.

More Information

CASC press release (Chinese)

Landing video