SpaceX, an American aerospace manufacturer and space transport company founded by entrepreneur Elon Musk, did something on March 30 that really hadn’t been done before: launch a cheaper, partially-used rocket into orbit.
That may be a stride toward slashing the price tag of sending payload to space. For Musk, successfully flying reusable rockets is a crucial step toward his dream of sending people to Mars.
The rocket, carrying a telecommunications satellite, launched from the Kennedy Space Center in Florida.
Until now, rockets have almost all been single-use. Once the fuel is expended, a rocket stage plummets to Earth, a quick demise for a complex machine that cost tens of millions of dollars to build.
Musk has likened that to scrapping a 747 jet after one flight, which would make air travel impossibly expensive.
He has suggested that rocket launches could eventually be much cheaper since the cost of the rocket propellants are less than 1 percent of the full-price ticket for a launch. So, if a rocket could be simply refueled like a jetliner for another flight, the cost of space travel could drop to a fraction of what it is now.
The stresses of spaceflight on reused boosters, however, are much greater than those on jetliners. The economics will depend on how many times a booster can be flown, and how much the individual expense will be to refurbish the booster — and particularly the engines — each time.
Reusable spaceships are not a new idea. NASA’s space shuttles were the first real attempt at a reusable spaceship, but the shuttles proved more delicate than hoped, requiring an army of technicians to refurbish them between flights. As a result, they ended up being more expensive, not cheaper, than expendable rockets — close to half a billion dollars a flight.
SpaceX’s next launch for NASA, a cargo mission currently scheduled for May, will continue the reusability theme. The rocket will be entirely new, but the mission will reuse one of the capsules from one of the earlier cargo runs.
Source article: http://www.taipeitimes.com/News/lang/archives/2017/04/16/2003668787