'The Big Bang Theory' Finale Preview: Wedding Fever is in the Air

The Big Bang Theory Launch Acceleration - H 2012
Sonja Flemming/CBS

The Big Bang Theory Launch Acceleration - H 2012

Wedding fever is in the air on CBS' The Big Bang Theory as two couples each have matrimony on their mind during Thursday's Season 5 finale.

With NASA moving Howard's (Simon Helberg) launch dangerously close to the formal wedding he and Bernadette's (Melissa Rauch) have planned, Howard was tasked with going toe-to-toe with his bride-to-be's tough-guy father and request that their pricey plans be postponed in order for him to head to the International Space Station.

After gaining Mr. Rostenkowski's (Casey Sander) blessing in a heart-warming scene during the May 3 episode, Leonard, Sheldon, Penny, Amy and Raj now must find a way to make their friends official in this week's fifth-season finale.

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"All season there have been so many ups and downs with Bernadette and Howard as far as what any couple has to go through while they're making these life decisions," Rauch tells The Hollywood Reporter. "They are such compatible opposites but they always figure out a way to come to a resolution that works for both of them."

Ultimately, Rauch teases, the nerdy lovebirds will try everything in their power to make their marriage official before Howard's mission to space -- but it won't be easy. "They hit a lot of obstacles along the way, which may put actually tying the knot in jeopardy," she warns. "They've always hit speed bumps along the way with navigating each other's personalities -- and Howard's past as we found out in the bachelor party. So it's only fitting that in trying to make it to the altar they hit a ton of obstacles along the way."

With time at a premium before Howard's mission, the couple will mull a few less-than-romantic ideas: heading to Las Vegas and a more reasonable jaunt to City Hall. "It's definitely an effort along the way, and it's symbolic of the fact that nothing has ever been easy between Bernadette and Howard and their relationship," Rauch says. "They make a valiant effort in trying to do it."

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While the wedding planning is all systems go ahead of the launch, whether or not Howard will actually go through with the mission continues to remain a mystery as he continues to express his fears -- and reaffirm that he's an astronaut even if he doesn't make into space.

Meanwhile, Leonard (Johnny Galecki) and Penny (Kaley Cuoco) will have their own unique brand of awkwardness going on after Leonard's heat-of-passion marriage proposal. Although Penny declined his proposal -- while still confirming that it didn't mean splitsville for the duo -- executive producer Bill Prady teases that the uneasiness between the two will continue into the finale.

"The aftermath of what Leonard did, that kind of thing can't be swept under the rug," Prady says, noting that Leonard's proposal echoes his early profession of love that went unreturned and led to the couple's previous breakup. "They could come back from this, they could not come back from it. To me, it's always been that they met each other at the wrong point relative to each other in their lives. It's just a messy, rocky relationship. I think that there's any possibility that they could say, 'This is crazy, let's just stop this.' [Or] they could say, 'Let's push forward.' "

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"They have very strong feelings for each other and their issues have to do with what they currently want in their lives right now," Prady says. "I don't think Penny wants to be married and Leonard is five years older than her."

Rauch, meanwhile, remains hopeful for the show's long-running couple, noting that they'll never allow relationship issues to impact the group. "There is just some wedding fever in the air all around and I think it got the best of some of the other characters, Leonard in particular," she says. "As much as we've seen them in their will-they-or-won't-they relationship, they've always managed to still be able to hang out with their friends and not let their relationship affect the people around them."

Do you think Howard and Bernadette will tie the knot? The Big Bang Theory Season 5 finale airs Thursday at 8 p.m. on CBS. Season 6 will premiere in the fall.

Email: Lesley.Goldberg@thr.com; Twitter: @Snoodit