Japanese astronaut Norishige Kanai admitted that he made a mistake in saying that he got 9 cm taller over a three-week period aboard the ISS. He apologized for the mismeasurement and the “fake news.”

Kanai re-measured himself after his captain questioned his apparent growth. It turned out that he only stretched 2cm aboard the International Space Station (ISS) from his Earth-bound height. “This mismeasurement appears to have become a big deal, so I must apologize for this terrible fake news,” he tweeted early Wednesday.

“It appears I can fit on the Soyuz, so I’m relieved,” wrote Kanai, who is the flight engineer on the Expedition 54/55.

計測ミス（？）なのに、大変な話題になってしまったみたいで、とんだフェイクニュースを大変失礼しました。腰や背中は痛くないし、むしろ肩こりがなくなったくらいなので、やっぱり9cmは伸びてないと思います。さすがベテランのシュカプレロフ飛行士。帰りのソユーズにも乗れそうで、少し安心です。 — 金井 宣茂 (@Astro_Kanai) January 9, 2018

41-year-old Kanai made headlines on Tuesday after he tweeted that he had rapidly grown in height during the past three weeks aboard the ISS. “We had our bodies measured after reaching space, and wow, wow, wow, I had actually grown by as much as 9 centimeters!” he wrote, adding that his height had reached 182 cm. Kanai said he had not experienced such a growth spurt since he was in school and wondered whether he would fit into the Soyuz spacecraft to return to Earth.

This is the first space mission for Kanai who arrived at the station in December 2017, along with NASA’s Scott Tingle and Russia’s Anton Shkaplerov. He is scheduled to return from the ISS in a Soyuz space capsule which can accommodate crew members of up to 190cm in height and 95kg in weight.

Height increase is a well-known phenomenon in space missions. A human body changes in the absence of normal gravity, with the spine getting longer. “On Earth, gravity pulls on you, and so your spine is compressed,” explained Clayton Anderson, a former NASA astronaut. He added that when you go into space, gravity is lessened and so your body begins to stretch. Growth in height is usually recorded between 3 and 5cm. The spine returns to its normal length once an astronaut is brought down to Earth.