These days we're used to jaw-dropping photos getting snapped from the International Space Station, but the latest one NASA astronaut Christina Koch recently posted to Twitter comes with a special message, too.

The image shows the Soyuz MS-15 spaceflight taking three people to the ISS: Roscosmos cosmonaut Oleg Skripochka and NASA astronaut Jessica Meir as part of Expedition 61, and Hazzaa Ali Almansoori from the United Arab Emirates, whose mission on the ISS will last eight days.

The photo is made all the more special by the fact it marks a lovely moment in Koch and Meir's friendship. They were in astronaut training together, and have now been reunited on board the ISS, where they will live and work alongside until February next year.

"What it looks like from @Space_Station when your best friend achieves her lifelong dream to go to space," wrote Koch. "Caught the second stage in progress! We can't wait to welcome you on board, crew of Soyuz 61!"

That mention of the "second stage" refers to the multistage rockets used to get spacecraft into orbit: as each one burns out of propellant, it's jettisoned to reduce weight. This is an effective (albeit very expensive) way of getting people into space, which is why scientists have started experimenting with reusable rockets for certain missions.

For an alternative view, here's what the same event looked like from the ground.

The current ISS mission marks a couple of milestones. By the time Christina Koch heads home, she will have completed the longest single spaceflight by a woman, a total of 335 days. Meanwhile, Hazzaa Ali Almansoori is the first Emirati to reach space.

Koch, Meir and their fellow astronauts are going to be busy over the next five months. On the team's agenda is the task of replacing 12 ageing batteries around the outside of the ISS, with further spacewalks planned to repair the Alpha Magnetic Spectrometer, designed to measure antimatter in cosmic rays.

If the work is busy, at least the views will be fantastic. Koch's latest snap joins many previous photos shared by ISS residents: photos of hurricanes, the passing of day into night, and of a blood Moon.

Every so often the ISS itself appears in a dramatic photoshoot, further reminding us of just how big the Universe is and how small we are by comparison.

Jessica Meir sounds excited to get started. "Coming in through the hatch and seeing all these familiar faces… it feels like home already," she said after docking, as CBS reports. "It's going to be an amazing six months."