If space programs evolution is to be seen then it will be found that a lot of improvements have been made. One of the biggest achievements being made by the NASA is its space shuttle program.

Experts were of the view that it was not possible to take some many people into space in initial years. However, now things have changed, as now not only astronauts, but even a common man can travel to space.

If to look at the data then progress has been seen in last three decades. In the journey, it is not that they have achieved complete success. There have been moments when NASA has to witness failure and they have to start from scratch.

Many times, programmes are being cancelled and time gaps extend between two projects. But it is all part of the growth, which one can witness today. If to talk about some of the wonderful expeditions then shuttles Discovery, Enterprise, and Endeavour are at the top. Meanwhile, space shuttle is at the top.

Experts were of the view, "This final shuttle flight marks the end of an era, but today, we recommit ourselves to continuing human space flight and taking the necessary—and difficult—steps”.