by CAPE CANAVERAL, Fla. (AP) — SpaceX will use a powerful soup capsule to push the International Space Station out of orbit once the sprawling lab’s time is up.
NASA and Elon Musk’s company outlined the plan on Wednesday to burn up the space station on re-entry and submerge what’s left in the ocean, ideally in early 2031 when it reaches the 32-year mark. The space agency rejected other options, such as taking the station apart and taking everything home or giving the keys to someone else.
NASA awarded SpaceX an $843 million contract to bring down the station – the largest structure ever built from the planet.
Here is a summary of the work and the challenges ahead:
Why get rid of the space station?
The space station is already showing signs of age. Russia and the US launched the first pieces in late 1998, and astronauts moved in two years later. Europe and Japan contributed their own parts, while Canada provided robotic arms. By the time NASA’s shuttles retired in 2011, the station had grown to the size of a football field, with a mass of nearly 1 million pounds (430,000 kilograms). NASA indicates that the station will last until at least 2030. The goal is for private companies to launch their own space stations by then, with NASA serving as one of many customers. That strategy — already in place for station cargo and crew deliveries — will free NASA to focus on lunar and Mars travel. NASA could also decide to extend the life of the station, if there are no commercial jobs yet. The aim is to overlap so as not to interfere with scientific research.
Why don’t you bring it back to Earth?
NASA considered dismantling the space station and hauling the pieces back to Earth, or letting private companies salvage the parts for their own planned jobs. But the station was never intended to be taken apart in orbit, according to NASA, and any such attempt would be expensive and dangerous for the astronauts handling the disassembly. Besides, there are no spacecraft as big as NASA’s old shuttles to bring everything down. Another option would be to boost the empty station to a higher and more stable orbit. But that too was ruled out, due to the logistical issues and the increased risk of junk space.
How will it be brought down?
Visiting spacecraft periodically boost the space station so that it remains in orbit at an altitude of about 260 miles (420 kilometers). Otherwise, it would continue to go lower and lower until it would fall, uncontrolled, from orbit. NASA wants to ensure a safe re-entry over a remote part of the South Pacific or perhaps the Indian Ocean, so that means sending a spacecraft to dock with the station and steer it towards a watery grave. NASA expects some more compact pieces, ranging in size from a microwave oven to a sedan, to survive in a narrow field of debris 1,200 miles (2,000 kilometers) long. NASA and its partners considered using three Russian supply ships for the job, but stronger craft were needed. The call went out to industry and, in June, SpaceX won the contract for a deorbit vehicle.
What will the deorbit spacecraft look like?
SpaceX plans to use a conventional Dragon capsule – the kind that carries supplies and astronauts to the space station – but with a much larger trunk containing 46 engines and more than 35,000 pounds (16,000 kilograms) of fuel. SpaceX’s Sarah Walker said the challenge will be to create a spacecraft powerful enough to navigate the space station while resisting the tugs and forces from the increased atmospheric drag during the final descent. . According to NASA, this spacecraft will need an extremely powerful rocket to get into orbit. The capsule would be launched 1 1/2 years before the planned demise of the station. Astronauts would still be on board because it is lowered gradually. Six months before the destruction of the station, the crew would abandon ship and return home. Once the station is down to about 137 miles (220 kilometers), the Dragon would touch down four days later.
Has this been done before?
NASA’s first space station, Skylab, crashed in 1979, with debris raining down on Australia and the surrounding Pacific Ocean. The space agency hoped that one of the first space shuttle crews could attach a rocket to control Skylab’s arrival or boost its orbit. But the shuttle wasn’t ready by then, and its first flight wasn’t until 1981. Ground controllers managed to put Skylab into a slow orbit, aiming for the Indian Ocean. But some pieces also landed in Western Australia. Russia had more experience with incoming space stations. Mir operated for 15 years before it was directed to a fiery reentry over the Pacific Ocean in 2001. Before that, several Salyut stations bit the dust.
Will anything be saved?
NASA wants to bring back some small items from inside the space station to display in the museum, such as the ship’s bell and logs, patch panels and other mementos. Those may come down in SpaceX supply ships in the last year or two. “Unfortunately, we can’t bring really big things home,” said NASA’s Ken Bowersox. , he said.
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