The ups and down of a virtual trip to the Moon in Zero G's 727

But what will the parabola specialist do when spares for Boeing's classic run dry?

interview Zero-G currently flies researchers and consumers in simulated lunar and zero gravity. And now a trip to Europe and beyond, as well as new aircraft are on the cards for the parabola specialist.

"There's tremendous demand right now for lunar research and lunar flights," CEO Kevin Sproge tells The Register, "with the launch of Artemis I ... it's becoming real."

Zero-G flies parabolas on a Boeing 727 to mimic micro and low gravity environments, and Sproge says there's an increase in bookings for research aboard the business's converted freighter.

Kevin Sproge in front of the Zero-G aircraft (click to enlarge) – pic: Steve Boxall, Zero-G

The Register took a ride on Zero-G's jet as a paying customer several years ago and we got to lope around in simulations of Martian, lunar, and microgravity as the aircraft performed parabolas.

It was quite the experience and left this reporter with a recurring feeling of imminent weightlessness every time an aircraft starts descending.

The Martian parabola experience is sadly long gone for consumers. Instead, on a 15 parabola consumer flight, three simulate lunar gravity while 12 simulate a zero gravity environment.

Sproge says: "On our research side, we do 30 parabolas, typically, and those are tailored to the experiment. So, on an all-zero-gravity flight, we'll do the three lunars as a warm-up, and then we'll do 27 zeros.

"We actually do all-lunar flights because there's a lot of interest in lunar research."

The company will sometimes perform ten Martian gravity, ten lunar, and ten zero gravity parabolas. It depends on the needs of the researchers.

Each parabola results in approximately 30 seconds of zero gravity while the aircraft dives. So, for 15 parabolas, a passenger will experience about seven and a half minutes of floating around the cabin. More parabolas mean more time, a hugely important consideration for researchers checking how their experiment will behave in space or on the lunar surface.

Almost half of Zero-G's flights are for research, another big percent involves consumer flights, and a small proportion are charters. Sproge is happy with the mix, although notes that it had been a while since the company's services were last used to train NASA astronauts.

"We have trained all the commercial orbital astronauts. We train all the Virgin Galactic astronauts, and we've trained some of the Blue Origin astronauts," he tells us.

Collins Aerospace also used the company in the development of a new spacesuit for the International Space Station (ISS). "We built a mock-up of the ISS airlock in the aircraft," explains Sproge, "and they had the suit maneuvering in and out of the airlock, opening hatches and testing handhold."

While Collins Aerospace's plans for an ISS suit might not have subsequently gone to plan, Sproge says, "NASA is really interested in our capabilities."

"Jared Isaacman, the incoming NASA administrator, has said that he thinks anyone who goes to space should do a Zero-G flight first."

Training and research aside, Sporge is also considering foreign expansion. At present, Zero-G operates within the US. However, a four- to six-week stint in Cornwall in the UK caught his attention, and running flights in June to July could be feasible as the weather is more likely to cooperate.

"The great thing about Spaceport Cornwall is that they have the airspace, they have the relationship with the British aviation authority. So all of that is basically done for us – we just have to show up and operate.

"That model is really attractive in places like the UK, Italy, Portugal, the Emirates, Saudi Arabia… All of the Gulf States are very very interested, but basing an airplane there right now is very challenging – the airspace is super challenging because of all the geopolitical stuff."

The Register is delighted to see that a rubber duck continues to be a feature in the cockpit of a Zero-G flight.

Sproge says, "We call it space duck, and it is the most accurate zero gravity/ parabolic indicator in the aircraft, [it] is more accurate than any of the instruments because it's real-time.

"The plane engineer places a duck between the two pilots, and they watch the duck as they're flying."

The idea is that whatever is happening to the duck is also is happening to the passengers behind the bulkhead.

Zero-G has competition. Blue Origin, where Sproge worked before joining Zero-G, recently simulated lunar gravity for a payload. And the European Space Agency (ESA) contracts with Novespace to perform parabolas on Air Zero G's Airbus 310.

Right now, Zero-G's flights depend on one Boeing 727. It's not one of the oldest, but is also no spring chicken, and the fact there's only one is a clear bottleneck as Zero-G seeks to ramp up its operations to meet demand.

Sproge plans to add a second Boeing 727 this year, with operations starting in 2026. Compared to modern aircraft, its wings are not particularly flexible, which is a good thing when it comes to parabolas, and "the characteristics of the airplane is everything we want."

However, eventually, Zero-G will need to move to a different aircraft. According to Sproge "The airplane itself will fly for another 20 years easy … we don't put a lot of hours on her every year compared to the cargo carriers, so she's got a lot of life left.

"The biggest challenge is parts."

The dearth of spare parts has killed the operations of many modern aircraft, and Zero-G's 727 is no exception. The replacement? There's the Airbus 310, but the challenge is the modifications needed, many of which are protected by patents.

Boeing is unlikely to want to get involved in certifying a new aircraft for parabolas – Sproge says understatedly that "Boeing is not having the best of several years..." – but its older aircraft have potential. "The older model 737s are potentials," says Sproge. "The 757 is actually a really attractive candidate for us."

And putting aside all the opportunities for research and lunar simulation for a moment, we're sure many readers will agree that doing a "Superman" through a 757's cabin would be quite the experience. ®