As the winter holiday season approaches, preparations for Christmas and other religious and festive celebrations are stepped up on planet Earth. But there are also celebrations being readied in space.
Every year since 2000 there have also been people up in space, in orbit around the Earth on the International Space Station.
Being 420 km above the Earth is no impediment to celebrating the holidays.
With 20 Christmases passed by humans in orbit so far, astronauts have found a host of ways to mark the occasion.
From video messages to loved ones back home, a well-earned day off, and even traditional Christmas dinner served in space-food form, here’s what happens during the festive season in space.
Who’s onboard this Christmas?
Those onboard the ISS now and over the festive period are ESA’s Matthias Maurer from Germany, Russian Roscosmos cosmonauts Anton Shkaplerov and Pyotr Dubrov, and NASA astronauts Raja Chari, Thomas Marshburn, Kayla Barron, and Mark Vande Hei.
For two of them, it won’t be their first Christmas in space.
Mark Vande Hei (2017), and especially Anton Shkaplerov (2011, 2014, and 2017) will know all about how it feels to spend the holidays travelling at over 27,000 km/h in orbit around the Earth.
How have previous crews celebrated the holidays?
Last Christmas, five of the astronauts on board sent a Christmas message via video, spreading some festive cheer from orbit after a gruelling year on Earth marked by the coronavirus pandemic.
More of that festive cheer may be in order this Christmas too, with Earthlings once again dealing with the spread of COVID-19, amid worries over the new Omicron variant.
In that message, astronaut Kate Rubins announced the crew was taking part in a Christmas decoration contest with those working back on Earth in mission control.
"We have to make Christmas items to decorate the space station, it has to be obviously items that are up in space, and our challenge to mission control is you have to make a Christmas decoration from items in building 30," she said.
The challenge harked back to the first Christmas on a US space station, Skylab which was occupied between 1973 and 1974.
Those astronauts built a homemade Christmas tree from leftover food containers, colored decals, and cardboard.
In 2000, the first ISS crew read Christmas messages on camera, with Expedition 1 commander and NASA astronaut William M Shepherd penning a new year’s day poem in the logbook.
No festive celebration would be complete without the appropriate food.
Space food is pretty different from what we get to enjoy back down on solid ground. There are a number of constraints associated with it, such as storage, lack of dedicated refrigeration, only very basic reheating equipment, and the requirement that food contains enough nutrients to justify its place on the ISS.
Holiday meals such as at Thanksgiving or Christmastime have become something of a tradition on the space station.
In 2016, French astronaut Thomas Pesquet showed off the food he was going to enjoy for Christmas, which included tinned chicken supreme with morels, and tinned gingerbread.
And in 2018 a Space-X dragon capsule played the role of Santa in delivering a hearty festive feast to the crew, which included smoked turkey, green bean casserole, candied yams, cranberry sauce, fruitcake, shortbread and butter cookies.
When is Christmas in space?
While for many of the NASA astronauts Christmas is observed on December 25, their Russian colleagues actually celebrate the holiday based on the Julian calendar, which is used by the Russian Orthodox Church.
Therefore they will celebrate Christmas on January 7.
The start of the new year is also marked on board. Those celebrations are when the clock hits midnight using GMT time.