The author wished the movie to be called "Rocket Boys," like the book it's based on, but the studio believed that title would not sell well. The compromise title "October Sky" works on two levels: it's the month when the hero is first inspired by Sputnik flying overhead, and it is an anagram of "Rocket Boys".
In real life and in the novel "Rocket Boys," Quentin Wilson was a traditionally handsome looking boy, whereas Homer Hickam looked like the stereotypical "nerd" that the film's Quentin is made to look like. Their physical appearances were switched due to the casting of then-teen heartthrob Jake Gyllenhaal.
The location of the slag dump where the Rocket Boys actually tested their rockets still exists. It is now a large grassy field. It is located in the actual town of Coalwood, WV which still exists today. They erected a replica test stand, launch pad, and "shed" after the movie brought the rocket boys story back into the public light. Every year the town of Coalwood celebrates the Rocket Boys with a festival in October called "October Sky Festival".
The town of Coalwood, West Virginia, has lost so many residents that it no longer holds the annual October Sky Festival. The event was moved to Beckley, West Virginia, in 2012 due to the lack of able-bodied volunteers remaining in Coalwood.
The boys rarely tested a single rocket per day. They often manufactured several rockets and tested them in sequence. The rocket that hit Homer's father's office during their early testing, when they were launching rockets near the mine, was actually the last rocket of several they launched that day.
On the commentary, one of Homer Hickam's regrets about the movie is that it does not show the more intellectual side of his father. He claims that his father was regularly reading and owned many books.
In the movie Homer Hickam is enamored with Wernher Von Braun, a former Nazi scientist. In real life Wernher von Braun and Jake Gyllenhaal (who plays Homer in the movie) are actually distant cousins. They are both descendants of William the Conqueror.
When watching the Vanguard rocket failure on TV Homer writes a letter of condolence to Von Braun and his team for their failure in launching it. In reality the Vanguard was the U.S. Navy's project and it was selected over Von Braun and his team for launching America's first satellite. When the Vanguard failed Von Braun successfully launched America's first satellite using his own rocket.
Homer Hickam served six years in Vietnam (1964-1970) as a Captain of the Fourth Infantry Division. He even received two awards: Army Commendation Medal and a Bronze Star, both notable awards for heroic acts and services.
The school exterior was actually two different schools - the football scene was shot in the soccer field of Gresham Middle School, Knoxville, Tennessee, and the other exterior scene, right before Homer and his friends are arrested, is the exterior of Fountain City Elementary school in Knoxville. The actual schools are directly across the street from each other.
It's true that many Americans were concerned about the Russians launching Sputnik into Earth orbit, mainly because they had beaten them into space, which fueled the Americans' determination to beat them to the Moon.
In the steam engine scene where the boys are salvaging iron rails from unused rail lines, the Norfolk & Western coal hauling steam locomotive they see is the former Southern Railway engine #4501. This engine is currently in use at the Tennessee Valley Railroad in Chattanooga, Tennessee. The scenes with the locomotive were filmed in upper Tennessee around Harriman, Oliver Springs, and Lake City with engine #4501 pulling a string of coal hopper cars lettered in authentic N&W livery.
Much of the filming took place in Petros Tennessee, which is a tiny little town just outside of Oak Ridge, Tennessee. Oak Ridge is known as The Secret City because it was built specifically to help develop nuclear weaponry during WWII. It is home to the Y-12 nuclear plant, still active today.
In the beginning of the movie they talk about the rivalry between their football team and that of Welch. Welch was a coal mining town in West Virginia as well and eventually the home of Jeanette Walls who wrote the book The Glass Castle about her life.
Many of the actors in the movie would go on to appear in Spider-Man films. Jake Gyllenhaal played Mysterio in Spider-Man Far From Home (2019), Chris Cooper played the ailing Norman Osborne in The Amazing Spider-Man 2, and Elya Baskin played landlord Mr. Ditkovitch in Spider-Man 2 (2004) and Spider-Man 3 (2007).
Although set in West Virginia, the film was actually shot in Tennessee, mainly because of weather concerns. Ironically, the weather turned bad (including tornadoes) and delayed production by several weeks.
In the mining disaster scene (at night, in the rain), the woman in front of the crowd, consoling her son, is local actress Jennifer Mitts, who lives in Chattanooga. She also starred as the lead character in Necking, a low-budget vampire/werewolf film, that was never released. She minored in theater at the University of Tennessee at Knoxville in the early 1990s.
The trivia items below may give away important plot points.
According to the DVD commentary, the final rocket launched in the film was not actually called "Miss Riley" like it is in the film, but had another "Auk" name, like their other rockets. In actually, Miss Riley was well enough to attend this launch in real life. Homer Hickam says on the commentary, however, that he wishes he had given the rocket that name in real life.
The experience of Homer's items being stolen at the National Science Fair is based on a real life incident that happened, but in real life, the thief did not take Homer's signed photo of Dr. Von Braun.