For Cravero, whose only eyeball experience with the centrifuge was seeing it, the encounter led to a small-business plan to make money off it while spreading the word of its historic significance.
He has just started renting out, for proms, trade shows, weddings, and other events, the circular room where Glenn and dozens of other astronauts - from the Mercury Seven to the first few shuttle crews - learned how many g-forces they could withstand.
Cravero has converted research labs adjacent to the centrifuge into offices available for leasing, and he is supporting a local effort to develop a museum, a science/technology/engineering library, and a learning center at the site.
"The biggest accomplishment in American history in the 20th century was sending a man into space and landing on the moon," Cravero, 42, of Riegelsville, said, the centrifuge looming overhead. "This facility played a huge role in accomplishing that task."
His efforts come as the U.S. space program winds down, with the final two shuttle flights scheduled to take place by the end of June.
Thursday is the 50th anniversary of another centrifuge alumnus' achievement: Alan Shepard's becoming the first American in space. In commemoration, Johnsville Centrifuge & Science Museum Inc. has made arrangements to transport to Warminster that day the centrifuge's original gondola, replaced in 1964 by the one still attached. The museum group found it at a Smithsonian warehouse in Maryland two years ago.
It is the gondola in which Glenn suffered EIEOs and barely endured 16 g's.
"You had to strain every muscle to keep enough blood in your head to keep from passing out," Glenn said in a phone interview last week from his office at Ohio State University, where he heads the advisory board to the John Glenn School of Public Affairs. "It wasn't a pleasure trip."
Capable of reaching speeds of 178 m.p.h. in less than seven seconds and generating up to 40 g's, Johnsville's was one of the world's largest human centrifuges.
Cravero's first visit to it was not planned.
He was touring what he thought was a vacant, run-of-the-mill office building completed in 1950 by the Navy. It had been part of the 800-acre Naval Air Development Center, which the Navy purchased in 1944 and closed in 1996. Cravero was considering buying the building, in part for his security-systems company.
As if common knowledge, the person showing him the property casually said with the wave of a hand, "The centrifuge is down there."
A bewildered Cravero asked, "Centrifuge?"
On the other side of heavy metal-and-wood doors on the second floor, he found a windowless, copper-lined room 125 feet in diameter and 24 feet high. It was empty but for the mechanical monstrosity used to help determine who had the right stuff.
Just like that, what had been known as both the Johnsville Centrifuge and the Aviation Medical Acceleration Laboratory had a buyer for $1.4 million. A very enthusiastic buyer.
"I . . . thought, 'Now, this is cool! I have to have this,' " Cravero recalled.
It was not long before he realized what a money pit he had taken on. The first month's heating bill was $5,000, more than double what Cravero had expected.
He stripped the 90,000 pounds of copper from the walls of the centrifuge room - a move a manager at the Pennsylvania Historical and Museum Commission last week said was "unfortunate" but understandable from an acoustical perspective. The copper led to echoing.
Cravero said the $200,000 he recouped from selling the copper offset the building's utility bills that first year, while he embarked on much-needed renovations to attract tenants. The building, made of poured concrete, had been vacant for two years, its windows and mechanical systems last upgraded in the late 1980s.
Financed with a second mortgage on the property, Cravero said he spent more than $500,000 on the office renovations, doing most of the work himself.
The building is now more than 90 percent occupied by 34 office and six storage tenants. An auditorium and a conference room also are available for daily rental.
There is no disputing that the star of the building is the centrifuge. In the middle of the space where it sits, which Cravero recently renamed "The Fuge," a granite-topped bar encircling the motor room is almost finished. Those getting drinks there will have an up-close view of the centrifuge's power source: a 180-ton, 4,000-horsepower General Electric motor bolted into the bedrock below - terrain that made the area perfect for such a load and torque-heavy device as the centrifuge.
The stripped walls soon will be dressed with drapes and LED lights to give the room's perimeter the look of outer space. That is a topic of ongoing negotiation with the state museum commission, said grant manager Karen Arnold, who characterized the centrifuge as "a very important historic structure."
Though 780 Falcon Circle is not designated a national historic site, it carries, because of its previous federal ownership, a protective covenant that requires that "important character-defining features have to be maintained," Arnold said.
The centrifuge room's original copper-lined walls were painted white, a color the commission would like to see restored, Arnold said.
There is no clear penalty for noncompliance. Not that she expects that. She said Cravero has been "really receptive" and described him as a "good caretaker."
While renovations and leasings have progressed without major hitches, Cravero's relationship with the centrifuge and museum group has been a more complicated affair.
He evicted them, including his wife's uncle, Mike Maguire, after the group's $500-a-month lease expired Oct. 31.
Asked at the end of 2009 to resign from the museum board over conflict-of-interest concerns about his dual role as building owner and museum director, Cravero said the eviction decision was motivated by one thing: a lack of progress.
Maguire, 53, a Richboro resident and quality-assurance employee with the Department of Defense, blamed the museum's slow evolution on eight months of "bureaucracy" to establish its 501(c)(3) nonprofit status in February 2009.
Funding has been a problem, too. A July 2009 celebration at the centrifuge to honor the 40th anniversary of the first moon landing raised $6,000. "More than twice that" was spent, Maguire said, to stage the event, which included a paid appearance by Mercury astronaut M. Scott Carpenter.
Sunday afternoon tours of the centrifuge - and adjacent control rooms that contain banks of computers and heart-monitoring equipment - generated $25,000, Maguire said. But financial constraints ultimately led to the lease's expiring last fall, with no consensus on renewal conditions until March.
Under a new lease arrangement with Cravero, the museum group will use the building at least two hours a week for $50 an hour. Last month, it resumed Sunday tours twice a month, for which it seeks donations.
The 16,000-pound gondola being relocated this week from Maryland - the $10,000 cost of which is being covered by History channel and Comcast Corp., Maguire said - will initially sit along Bristol Road, on township parkland once part of the Navy base, "where it can serve as a billboard for us," Maguire said.
Eventually, the group hopes to raise enough money to construct housing for it near the centrifuge, he said, and possibly buy 780 Falcon Circle from Cravero.
At least for now, however, the building is not on the market, Cravero said. He has booked three events for The Fuge. The current rate is $500 for five hours, likely to rise to $1,000 in January.
Told last week of the centrifuge's new role, Glenn said he would favor it as long as aerospace history could be preserved as "an inspiration for our young folks."
To many, Glenn, now 89, is the embodiment of inspiration. When he made his second trip into space in 1998, aboard the shuttle Discovery, he was 77 years old.
For an interactive graphic, videos, image galleries and more, go to www.philly.com/centrifuge
Contact staff writer Diane Mastrull at 215-854-2466 or firstname.lastname@example.org.