After 17 years in orbit, how durable is the International Space Station?

FILE- In this April 20, 2014, image made from a frame grabbed from NASA-TV, the SpaceX Dragon resupply capsule begins the process of being berthed on to the ISS. (AP Photo/NASA-TV, File)

Even though the ammonia leak that forced a partial evacuation of the International Space Station’s U.S. section on Wednesday proved to be a false alarm, the news did raise questions on the station’s durability.

Since the station’s inception in 1998, the habitable satellite has endured a multitude of maintenance issues, from pump failures to damaged panels. “We’ve had other, what have turned out to be more serious, problems on the space station,” NASA spokeswoman Stephanie Schierholz told FoxNews.com. “For example, there was an actual ammonia pump failure [in 2010], and so it had to be replaced and required space walks. The actions we took [Wednesday] were for a worst-case scenario like that.”

The now 17 year-old International Space Station (ISS) has been occupied for 5,187 days and circled the Earth 92,357 times, so a little wear-and-tear would seem unavoidable.  While the station has been in orbit since 1998, it actually wasn’t completed until recently.

“The first piece of the space station was put in orbit [in 1998], but the assembly actually took quite a bit of time, and wasn’t completed until 2011,” Schierholz said. “We were using the space shuttle to complete the building of the ISS, because we would bring pieces of the station up in the space shuttle, so every time we brought up a new piece it’d change the configuration. So the building of the space station took quite a bit of time.”

The road to the station’s assembly saw more than its fair share of bumps along the way. Following the space shuttle Columbia disaster in 2003, there was a two-and-a-half year suspension of the U.S. shuttle program, leading to a large waste accumulation aboard the ISS that held up operations in 2004. A computer failure in 2007 left the station temporarily without thrusters and oxygen generation, followed by a torn solar panel that same year which required astronaut Scott Parazynski to make a daring impromptu spacewalk on the end of the space shuttle’s OBSS inspection arm. In 2010 there was the aforementioned ammonia pump failure, which, according to Schierholz, “would be the top [maintenance issue that has come up] from an unexpected work/volume of work-required [standpoint]. The interesting thing about all these [problems] is that they’re anticipated failures -- we train the astronauts for them. We do plan space walks to replace parts that we expect or are at the end of their life cycle. This failed sooner than we expected it to.”

The following year saw the station almost collide with what is becoming a rapidly rising threat: orbital debris. With more and more “dead” satellites in orbit, the possibility of one of them hitting the ISS is a growing one. These satellites sometimes slam into one another, the ensuing blast creating thousands of pieces of orbital debris.

“They are an issue,” Schierholz said, “because if something were to hit the space station - the ISS is traveling at 17,500 mph, a piece of debris could be travelling at the same speed, and there’s going to be some damage that’s caused as a result of that. The U.S. Air Force tracks any piece of debris that’s bigger than a golf ball, and there’s a certain amount of protection from micrometeroid debris, which is natural stuff in the universe that is too small to cause any real problems. But any debris that was put there as a result of an accident is a concern to us, especially because we have people on board.” To avoid disaster, thrusters are fired to adjust the station’s orbit out of harm’s way.

So after 17 years of dodging space junk and enduring technical problems, the question remains: how much longer can the ISS stay operational? According to NASA, for as long as the U.S. and its international partners pay to maintain it.

“The space station is certified for a particular lifetime,” Schierholz said. “So that’s how we assess the future lifespan of the space station."

The NASA spokeswoman explained that certification involves ensuring that spare parts and backup supplies are available to keep the space station running.

“Currently it’s certified through 2020, and the President of the United States has said that they will extend it to 2024,” she added. “But then the other piece of it is making sure that it’s funded, that we have more international support for continuing to operate the space station.” As for the ISS lasting beyond 2024, “that’s more of a matter of supplies and being able to repair parts that break,” said Schierholz.