Troy Calhoun is embarking on a fresh football season, and he’s excited.

I’d try to explain his feelings, but divine help is needed to paraphrase Calhoun. We’ll let him talk.

“The unknown, quite frankly,” he says of the 2018 season as he stands in twilight following an evening practice. “You’re just forging a trail. Not exactly the way it was for Meriwether and Clark.”

Coach, I agree with you.

Air Force’s upcoming 2018 football season is not an exact match to the 8,000-mile 1804-1806 trek by Meriwether Lewis and William Clark from the Midwest to the Pacific Ocean, and back.

Lewis and Clark marched into uncharted wilderness to face raging waters and grizzlies and hunger and cold. Their struggle often was the most primal of all – remaining alive.

Calhoun trots into his 12th season as head man at Air Force Academy facing fewer and less frightening challenges. He must fix his broken, generous defense, the one that doomed him to sadness and a 5-7 record.

The 2017 Falcons surrendered 32.4 points per game, ranking 101st out of 130 teams. Four teams scored 40 or more points.

Ten of the Falcons final 11 opponents scored 28 or more points. Enemy ball carriers averaged 5.93 yards against the nation’s worst run defense.

Worst of all, Air Force allowed 69 points against Navy and Army in the same season Army allowed 13 points against Navy and Air Force. The defenseless Falcons finished third in the three-team service academy race.

Can the 2018 Falcons defense, composed of many of the same starters, get tough against the run?

“That’s a fair question,” Calhoun answers before walking along his trademark verbal route of declining to answer. “That’s where time will run its course. It can’t just be incrementally better. Now the work and the way you improve, that’s the way it is.”

Thanks, coach, for whatever that was.

Others speak more clearly. This summer, I saw former Air Force defensive coordinator Steve Russ jogging on the Santa Fe Trail through the eastern edge of the academy. Russ resigned in January to become linebackers coach with the Carolina Panthers.

Russ, one of the finest defensive players in Air Force history, offered a spirited endorsement of the 2018 defense. He promised defenders will be rugged and stingy. He just wished he could be there to watch. It was excruciatingly tough, he said, to depart his players.

He could be right.

A rapid transformation is possible, if not probable.

In 2013, the Falcons surrendered 40 points a game on their way to a 2-10 season. In 2014, under the direction of newly installed coordinator Russ, the Falcons allowed 24.2 points per game and soared to 10-3.

The 2014 players embraced humiliation. If someone fumbled in practice, he would hear “2-10” as the ball bounced away. If another strolled through a drill, he, too, would hear “2-10.”

What will be different for the defense in 2018?

I received two vastly different answers.

“You know, I don’t think anything is going to be different,” said 300-pound plus noseguard Mosese Fifita. “We all have the same goals. The same mindset. To win football games. I don’t think anything has really changed.

“I don’t look back to last year.”

Try looking over that big shoulder sometime, Mosese. There’s a lot to learn back there.

Linebacker Kyle Floyd offered an alternative answer.

“A lot of things are different,” he says. “People are hungry. Last season, we didn’t have a lot of experience on the field, and this year those people are back and they’re hungry and they have experience. That’s enough for belief alone.

“We’re here, and we’re ready. I don’t see why not turn it around.”

Why not?

The offense, designed by Calhoun and quarterbacked by Arion Worthman or Isaiah Sanders, will score around 30 points per game.

If Falcon defenders can chop, say, 10 points a game, expect program-shaking revival.

But only if almost everything is going to be different.