Antares rocket prepares for launch at NASA's Wallops Flight Facility on Wallops Island, Virginia.
But a boat got in the way. A sailboat. How can a sailboat deter a rocket?
The boat was about 40 miles from the launch site and if the rocket had taken off, it would have flown over the boat. If something had gone wrong with the rocket, say it exploded in mid-air over the boat, it could have put the boat's passengers at risk.
NASA designates a hazard zone for each rocket launch, and if there is any danger to bystanders or the rocket itself near launch time, then mission control will scrub the launch. Despite attempts by mission controllers to contact the boat, they didn't move their vessel. Because the launch window was only 10 minutes, NASA had to cancel the launch.
In preparation for the launch, NASA's Wallops Spaceflight Facility, where the launch is scheduled to take place, issued a release to local mariners outlining two danger zones. Because these boaters didn't follow these restrictions, there's a chance that the passengers on this boat could be arrested.
According to Spaceflight Now, the release states that anyone who disregarded the guidelines could be subject to fines and even arrest by the US Coast Guard and the Virginia Marine Police.
Luckily, if today's launch is successful, the cargo will still reach its destination, the International Space Station, on time.
This isn't the first time a boat has gotten in the way of a launch. In 2000, the launch of an Atlas rocket coincided with a fishing tournament and multiple boats steered into the restricted zones, so the launch was cancelled. Planes can also interfere and mission controllers must simply wait for the planes to fly clear of the rocket's path - though sometimes these launch windows are very small - just minutes - and even a responsive interloper can become a major issue and cause the launch to be rescheduled.
Boats and planes aren't the only thing that interferes with rocket launches. In August 2012, NASA postponed an Atlas V rocket due to inclement weather. And earlier this year in July, the launch of a Delta IV rocket was scrubbed four times also for inclement weather.
The launch has been rescheduled for today, Tuesday at 6:22 pm EDT. If everything goes well this evening, then most observers in the Eastern US will have the opportunity to see the rocket in the sky. NASA will begin broadcasting the event live at 5:30 pm EDT.