An American ice breaker became the first ever surface ship to reach the North Pole unaccompanied. After leaving Dutch Harbor, Alaska on August 9, US Coast Guard Cutter Healy reached the North Pole on September 5.

The ship carried 145 crewmembers and scientists through the deadly cold waters of the northern seas. The crew pressed on doggedly, ultimately reaching the North Pole ahead of schedule.

Worryingly, the icebreaker Healy did not encounter as much ice as expected. Indeed, many times the scientists efforts to gather ice measurements were thwarted by an all pervasive slush. It was only within the last 100 miles that solid ice appeared.

“It’s hard to believe how slushy the ice has been so close to the pole; this was the first area we were confident enough in the ice conditions to allow on-ice science experiments,” said the Coast Guard in a statement. “Despite being thick, the ice we encountered further south was simply too soft and unstable to safely put individuals on.”

The expedition was part of the GEOTRACES effort to better understand the geochemistry of the world’s oceans. Funded by the National Science Foundation, the voyage aimed to measure various elements of the Artic Ocean.

Additionally, the crew of the Healy had a chance to practice ice rescues and other safety maneuvers. Growing tourism and petrochemical development means that an increasing number of people will be on the top of the world at any one time. In particular, President Obama has announced that the US presence in the Artic will increase dramatically.

“As the Arctic region continues to open up to development, the data gathered on board Healy during this cruise will become ever more essential to understanding how the scientific processes of the Arctic work, and how to most responsibly exercise stewardship over the region,” said the Coast Guard.