Paul Gregg a retired aerospace engineer, couple of years ago decided to put his skills to use by making backyard roller coaster coasters for his grand kids. He calls it the Out-n-Back “Negative G” Backyard Roller Coaster. Paul created a full fledged roller coaster in his backyard that has struck praise from others on the… Continue reading Retired Aerospace Engineer Builds a Backyard Roller Coaster for His Grandchildren