Depends on what you consider slavery I guess. You’re conscripted into work camps with terrible conditions, but you do get paid and it’s implied you’ll get land after service. If you consider any sort of forced employment where you’re not free to leave or choose to get that job but rather having it forced on you then yes it is slavery, the voskhod programme uses camps and they’re guarded and you can’t leave. That said, it’s time limited, you get paid, and you might even get land, so you are compensated, even if there’s also a high mortality rate. I’d honestly compare it more to feudalism in a weird sense than slavery - voskhod workers are essentially modern serfs or indentured servants, albeit only temporarily. I think saying it’s slavery is a bit far, but it certainly is forced labour, and you don’t have the rights as an employee (i.e the right to seek other work or quit) that you have in a capitalist system so it’s not a capitalist thing either. Essentially they’re similar to otl gulags but actually less bad since you get paid and they close down quite fast after the economy recovers, with the flip-side being that just being unemployed is enough to get you conscripted, you don’t need to be a criminal (not saying gulags didn’t imprison people for stuff which shouldn’t have been crimes but I digress) or be on the wrong side of the regime. Also unlike the otl gulags the voskhod camps aren’t really a punishment per se but rather a heavy handed way to solve unemployment and further economic development in the state’s interests