Last Tuesday night, my colleague said that he spotted the final burn stage of the SpaceX rocket Falcon Heavy, which blasted into orbit earlier in the day from Florida. I guess there are a few who also watched the wonder of the space event. what is more interesting is that SpaceX landed the boosters successfully after the launching the payload, a Tesla roadster. If you reuse the rocket many times, you can save the money to build another ones, which makes the SpaceX mission cost-effective. Mars exploration seems to be closer than ever.