Sputnik 1 was the first artifical satellite put into orbit. Based on how you define “first rocket in space”, it might have been Nazi Germany with their V2 rockets
en.wikipedia.org/wiki/History_of_spaceflight en.wikipedia.org/wiki/Spaceflight_before_1951
but LMDE especially will be subject to dealing with older software
Are you sure about this? As far as I know, debian modernized their repos quite a bit even compared to ubuntu, that also sparked some controversy from debian long time fans especially because they wanted more dated, stable software. Never used LMDE though, so I’m not sure if it applies
Quite significant in theory, DDR3 maxes out at about 2000 MT/s (mega transfer per seconds) while DDR5 can go above 8000 MT/s, so about 3x-4x. I don’t know if this metric already includes the capability of DDR ram to access multiple data in a clock cycle, but I think it does. If it doesn’t, tje difference is even higher.
Of course in practice the difference is not as remarkable, but still noticeable. Still, DDR3 is perfectly usable with a decent processor (light gaming and professional software), my main righ is a 4th generation i7 and I have no intention in upgrading for the foreseeable future.