Finnegan and Fulmor will be having their weightless wedding, and exchanging vows aboard G-Force One, the "vomit comet" operated by the Zero Gravity Corporation.
The couple, who live in New York City, are both self-professed space fanatics, and as children they had both wanted to be astronauts.
The plane, set to launch on June 20 from Cape Canaveral in Florida, will fly a series of 15 parabolas, rendering the couple and their guests weightless for 30 seconds at a time.
They plan to perform the ceremony in five parabolas, leaving room for "second takes" in case anything goes wrong.
Richard Garriott, the sixth private space tourist and son of a NASA astronaut, will be officiating the wedding.
"Buzz Aldrin was way too expensive, so Zero G suggested Richard Garriott," New Scientist quoted Finnegan as saying.
The cost of the ticket per person is 5400 dollars, and it had at first been an obstacle for Finnegan, until an anonymous soldier in Iraq offered to pay for half.
Onboard the flight will be a photographer, videographer and seven of the couple's friends and family, including Finnegan's mother, who was at first reluctant to go until she got a reassuring phone call from Garriott's mother.
Japanese designer Eri Matsui created Finnegan's gown, which is specially designed to suit the zero gravity wedding, and it has a high neckline, austere bodice and a tiered skirt, which is made to billow out in all directions as the bride tumbles and twirls about.
The couple will be exchanging rings that incorporate meteorites, and the bride will attempt the traditional bouquet toss.
Planning for the zero gravity wedding did not come easy, as the couple had to make sure that the marriage would be legal. Fortunately for them Florida law covers the airspace over Cape Canaveral.
The wedding is uninsurable, though, and figuring out the best zero gravity hairstyle was a challenge for Finnegan.
But, the couple is enthusiastic about their spacey nuptials, and see it as serving a larger purpose.
"We're trying to raise interest in private space exploration," Fulmor added.