Did Polish astronaut Miroslaw Hermaszewski admit in a 2018 interview that that the Earth is flat? No, that's not true: The claim takes his remarks out of context -- it was an apparent joke aimed at flat-earthers and demonstrating obvious annoyance with an interviewer's questions. Elements of his descriptions of his space mission, later in the interview, are consistent with the scientific, photographic and navigational evidence that the earth is spherical.
The story appeared in a post (archived here) published on Instagram on July 11, 2023. The caption said:
When we are ready it will click- but otherwise it will trigger.
The post included a video with a top banner showing a quote:
'Earth is flat, as some expect...
But I didn't expect this question.
I assure you it is flat.'
This is what it looked like on Instagram as of this writing:
(Source: (Source: Instagram screenshot taken on Wed Jul 12 23:12:37 2023 UTC)
The video showed Miroslaw Hermaszewski, the first Polish astronaut who flew to space in 1978 and who died in December 2022. Some refer to him as a cosmonaut which is a term typically reserved for Soviet space explorers. Hermaszewski's flight was a part of the USSR's Intercosmos program designed specifically for non-Soviet pilots from the countries Moscow wanted to see as allies.
The footage of the interview reused on Instagram was first uploaded on YouTube in 2018. The exchange takes place at the 21:00 mark in the earlier version of the video:
Host: There was a so-called startup in Poland this year, an innovative venture to build a drone to confirm or deny that the Earth is indeed a sphere suspended in space. You were there, is the Earth really a ball suspended in space?
Hermaszewski: It is flat. Just as they expect. Admittedly, I did not expect this question, but I assure you that it is flat.
(Translated to English by DeepL.)
The footage captures the astronaut's reaction to the question which appears to be rather strange in the context of the interview. A celebrated general, Hermaszewski sighs at first, briefly showing disappointment in the question. But as he starts talking, a close-up demonstrates that he is stifling his laughter, making it clear that he is not serious at that point.
Over the course of the interview, Hermaszewski makes other remarks proving that he didn't share the conviction in the flatness of the Earth.
At the 12:20 mark, Hermaszewski recalls his flight, saying, as translated by Google Translate:
I wanted to look at the ground to see, because maybe we'll go down... But I see, I looked, [it is] round indeed...
At the 11:30 mark, he also mentions such concepts as "orbital altitude" and "orbital velocity." Both are characteristic of an orbit which is, according to NASA, a "repeating path that one object in space takes around another one." That doesn't fit into the flat Earth narrative debunked by Lead Stories multiple times.
A search for the related keywords in Polish ("Hermaszewski" AND "ziemia" AND "płaska") shows that the claim about Hermaszewski was previously debunked by the Polish-language press (for example, here and here), reaching the conclusion that the astronaut was trolling flat-earthers by giving sarcastic answers to what he considered ridiculous questions.