As the astronauts aboard the International Space Station (ISS) orbit Earth once every 90 minutes, they will experience New Year's Eve 16 times, NASA pointed out. That is 16 sunrise and sunsets 402.3 km above Earth, the US space agency said in a blog post on Thursday. The six astronauts and cosmonauts will go into the last weekend of 2017 with light duty and family conferences before taking the New Year's Day off.

The current six crew members on the orbital laboratory comprise three US astronauts, two Russian cosmonauts and a Japanese astronaut. Ahead of the New Year, the astronauts are conducting life science studies to help mission doctors keep astronauts healthier and stronger while living in outer space.

Japanese astronaut Norishige Kanai took his turn on the exercise bike on Thursday for a study researching physical exertion in space. Doctors measure the astronauts breathing and other parameters during exercise to ensure they have the strength to perform strenuous activities such as spacewalks and even emergency procedures.

Flight Engineer Scott Tingle of NASA was harvesting plants for the Advanced Plants Experiment-05 (APEX) and stowing the botany samples in a science freezer for further analysis, the blog post said.

Scientists are exploring how plants respond to microgravity and observing molecular and genetic changes. The two other NASA astronauts living and working aboard the space station are Vande Hei and Joe Acaba. Anton Shkaplerov and Alexander Misurkin of the Russian space agency Roscosmos are the other two other crew members.