I just wanted to ask, what kind of technology or science understanding do they have now which was required to make this happen now rather than X years ago? (Al

I just wanted to ask, what kind of technology or science understanding do they have now which was required to make this happen now rather than X years ago? (Also, is it fair to say that while this is an achievement, it is only more-so when they can reliably repeat it; I mean it's not exactly safe yet for people, who knows what a gust of wind could do?)