What are the current capabilities of space travel?

In terms of speed, distance they can travel, fuel efficiency, cost, and reliability.


Thanks!

speed, well no friction in space so you can accelerate indefinitely. distance, well depends on how much o2, food and water you brought along i guess. fuel efficiency, ion engines are looking pretty good no? cost, pretty cheap but they tell us otherwise. reliability, i think the failure rate is around 5-10 percent mark for those arianes.

If you see the space programs, you will get an idea of the speeds and distances. The latter half of your question can not be answered accurately, since most data is still classified.