WW2 never happens, Poland keeps an uneasy peace with the Soviets and continues to converge with the countries of Western Europe economically. In the late 40s, as interest in rocket technology spreads, the Polish government seizes on space exploration as a way to satisfy the Polish colonial lobby without getting any distracting colonies and as a means to develop a potential weapons system without unduly alarming the neighbours.
The Poles end up in a space race with the Soviets (not that they are the only powers exploring space, there is also a Franco-British space race and a German-American space race going on at the same time and any country claiming to be a great power has a satellite program going by 1970 at the latest). Both powers focus on Earth orbit activities - spy sats, space telescopes, GPS systems, men in orbit and eventually space stations in orbit.
(I ran some numbers for this TL-let - assuming Poland experiences an average level of population growth after 1938, by 1980, the country would have a population somewhere between 70-90 million people. If the ATL Poland had a GDP/capita on the level of 1980s Italy then the country would have a GDP of between 590 billion USD and 760 billion USD - in OTL the UK had a GDP of 567 billion USD in 1980, France had a GDP of 703 billion USD in 1980 and the USSR had something like 993 billion USD for their GDP in 1983 - of course, without WW2, the rest of Europe would also be richer and more populous - Germany, for example, has the potential of being a true super power in no-WW2 ATLs - I quote the numbers just to illustrate than Poland without WW2 would have the absolute wealth to afford a Soviet-sized space program - though something like an Apollo-style moonshot is beyond even a no-WW2-Poland.)
fasquardon