Pirx's exploits are set during the 21st or 22nd centuries. Colonisationation of the Solar System is in full swing with settlements on the Moon and Mars. Pirx starts as a learner pilot and works his way up the promotional ladder to being the captain of a merchant vessel.
Interestingly, the article in Wikipedia considers the genre to be medium hard science fiction. I might have agreed with that when it was first published perhaps fifty years ago.
Lem's space travel is by nuclear-powered rocket. I'm not so familiar with the intricacies of modern spaceships as to be able to compare Lem's version with today's realities in a piece by piece way. The rich world building and the stories are what keeps me going.
The descriptions of the dirty gritty space stations; the age of the Blue Star, an old renamed and refurbished but still decrepit spaceship; and a starship's somewhat old-fashioned equipment, as per the detailed descriptions, all put me in mind of an alternate history or a parallel universe.
I laughed about the pilot, suitcase in hand, walking the length and breadth of a busy tarmac to join his ship unheralded. The electric fans, still very much a part of the cooling equipment as if air conditioning hadn't yet been invented.
And yet there is so much in these tales that reads modern. Pyrx has to do a practical exam, which turns out to be a simulated journey. Landing a shuttle on the Moon reads very realistic. And these were stories written before 1969, before the first man on the Moon.
A couple of times disasters happened that were eventually attributed to equipment glitches. The descriptions of these are intricate, logical and totally believable. As far as I can tell there is no shonky science in these tales. [By 'shonky science' I mean an invented fantasy science written up as if real.]
Modern space programs might have gone the way of Lem's future if it hadn't been for ... NASA? The need to economise? The essential difficulties of containing the nuclear genie? There seem to me to be a dozen possible places where present day reality separated from the progression of Lem's future.
As I'm reading translations I'm also sometimes wondering which bits of awkward English I have to thank Lem for and which bits the translators. In addition, despite a lot more misogyny and racism were part of the culture of the 1960's than in today's times, it's still possible to enjoy these fictions. Need to keep the cultural differences in mind and allow for them, that's all.