When he was 5, Glenn Martin dreamed of flying to school. His imagination was fuelled by characters from 1960s television shows such as Thunderbirds, Lost in Space and The Jetsons, who travelled around by jetpack.
Fast forward 50 years and Martin's childhood vision is on the verge of becoming a reality - a jetpack that can be used commercially and privately.
The Kiwi inventor, who happily describes himself as a "mad boffin", has worked tirelessly for more than three decades to bring his dream of seeing people whizzing through the skies to life. Now that single-minded determination is paying off.
His Christchurch-based Martin Aircraft Company is valued at more than $180 million after it was floated on the Australian Securities Exchange last month. Practical jetpacks will be available within the next 18 months.
Martin's device has made the front page of the New York Times and has been listed among Time magazine's Top 50 Inventions.
The cutting-edge technology will initially be targeted at the overseas emergency services sector.
Wealthy individuals, such as business tycoon Richard Branson, have also expressed an interest in having one, Martin says. So has a brazen South American drug cartel boss, interested in its potential uses.
"Many people thought I was mad for dedicating so much time to coming up with a commercial jetpack," he says. "But I couldn't care less. It is the crazy people who change the world."
Crazy or not, jetpacks intrigued people as fantasy travel devices long before Martin started daydreaming in the classroom.
Plans for their design first appeared in popular media in the 1920s. In the 1950s, the first serious attempts to build one, the Bell Rocket Belt, got under way but it was dangerous, required a lightweight pilot and could fly for only 30 seconds.
Martin set out to address these shortcomings in 1981 after a eureka moment in the old Captain Cook Tavern in Dunedin while studying at Otago University. "I grew up in the early days of the Apollo space programme and we thought we would soon be taking holidays on the moon and going to work in little flying cars," he says.
"I was drinking with some mates and we got to talking about whatever happened to those flying cars and jetpacks.
"Something went off in my head and the next day I was down at the library researching jetpacks. The mission to build one was on."
The son of a Dunedin electrician, Martin used to help his dad piece together engines at his home workshop. There his entrepreneurial skills first emerged when he constructed and sold kayaks to pay his way through university.
But his abilities for building things from scratch were not enough to master jetpack technology. The ambitious biochemistry student started sneaking into mathematics lectures, realising he needed to understand and perform complex calculations.
To fund his ambitions, Martin became a pharmaceutical salesman after graduating and moved to Christchurch to be close to the mechanical engineering department at Canterbury University, where he recruited converts to his cause.
By 1998, the driven inventor, working long hours in his garage, had built the first of 12 jetpack prototypes and was confident it could lift a person off the ground.
He persuaded his wife, Vanessa, to become a test pilot as he was too heavy. It worked, and he packed in his day job.
"People tinker with old cars in their garage. I tinkered with jetpacks."
Six years later, he attracted several million dollars in investment from a New Zealand venture capitalist firm - and his business dream of producing jetpacks was finally under way.
Two years ago, Martin Aircraft had a staff of only six. Now there are 21, a number expected to reach 50 by the end of this year.
Martin's trailblazing jetpack idea has even received a big tick from his childhood hero, American astronaut Neil Armstrong. The first man to set foot on the moon emailed him out the blue congratulating him on his invention.
Martin, however, admits tunnel-visioned efforts to get his jetpack to market often came at a price to family life and time with his two sons, Harrison, 22, and William, 17. Harrison is one of his test pilots.
"We mortgaged the house three times to keep going and have sacrificed a lot," he says.
"At one point, Vanessa knew 101 different recipes for serving up potatoes as things were pretty tight. She worked late shifts as a nurse and we were like passing ships in the night. Any spare cash we had was spent on hiring student engineers and part-time staff when we could and we often had nothing much left for ourselves."
His youngest son, William, once got into trouble at school after discussing dad's top-secret project with his classmates.
"The teacher was worried that William had developed a vivid fantasy life because he was talking about me having a jetpack in the garage," he explains.
"In the end, we got the teacher to sign a confidentiality agreement so as not to disclose what I was up to."
Vanessa, however, drew the line at plans for eldest son, Harrison, to fly a jetpack at the Los Angeles Playboy Mansion in 2008. The device was being publicly unveiled during a promotional tour of the United States.
"We were wanted for a photo shoot with some of the playmates and it seemed like a good idea to generate publicity," Martin says.
"However, the only person available to fly it was Harrison. He was only 16 and Vanessa would have none of it."
Martin insists only two things could have persuaded him to abandon his decades-long mission; if his wife ever wanted him to stop or if his mathematics were proved incorrect.
"Thankfully, Vanessa never did want me to quit and she has been an incredible support throughout," he says. "She is just as crazy as I am.
"I have also always known my mathematical calculations for the jetpack were right. I believe that two and two makes four and if the maths say something is possible, it is."
It looks like the sky could be the limit when it comes to jetpacks being used commercially as the technology continues to advance and flying time capabilities increase from the present 30 minutes.
In New Zealand, jetpacks are classified as a microlight aircraft and pilots must gain appropriate certification to operate one.
But although jetpacks may eventually become common for use by emergency services, Martin does not envisage a day when we will use them to fly to work.
"They are ideal for first responders for city use as they can quickly get to places even a helicopter can't get to," he says "But I can't ever see 30,000 jetpacks buzzing about in the sky above Christchurch. Not in my lifetime, anyway.
"We have a bad enough record on the roads in New Zealand. If we can't trust people to get behind the wheel of a car without crashing into one another, what would it be like if they were operating jetpacks hundreds of metres above the ground?"
News the first of Martin's jetpacks will be available towards the end of next year has sparked a surge of interest from rescue, military and security agencies worldwide.
The company has been speaking to the United States Department of Homeland Security and Department of Defence with a view to using and developing its airborne technology capabilities.
Jetpacks for the leisure market will be next off the rank but Martin has already turned down a few requests from rich individuals keen to get their hands on one.
"I took a call from a gentleman in Bogota, Colombia, who asked how much weight the jetpacks could carry and if they could fly from his country to the United States," he says. "I found out he was from a drugs cartel so that is one order that did not go through."
He also turned down Virgin boss Richard Branson, who wants to be the first to fly across the English Channel using a jetpack. "I had a beer with Richard and discussed it," he says. "I had to decline because he wanted one for free and if anyone is going to be the first to cross the Channel in a jetpack, it will be me."
Emergency services first to get jetpacks
The first commercial jetpacks are expected to have a pricetag of about $273,000. They will be available from the Christchurch-based Martin Aircraft Company by the end of next year, with the first aimed at the overseas first responders market, including search and rescue, firefighters, medics, police and army.
But what is a jetpack and what can it do?
It is a carbon-fibre frame housing a 2L, 200-horsepower petrol engine, which powers two large rotors positioned on either side of the standing pilot.
It has been described as looking like two giant leaf-blowers welded together.
It can carry 120kg and fly at up to 74km/h for 30 minutes at altitudes of 1000m. The pilot navigates by two joysticks positioned next to each hand. Its makers say the flight process is smoother than a helicopter. Martin Aircraft's managing director and chief executive Peter Coker believes jetpack technology will change the dynamics of light aircraft.
"It will also be vital for saving human lives by getting in and out of places quickly that a helicopter couldn't do," he says. "Once we have launched to the first responder sector we will target areas like oil, gas and agriculture before servicing the discretionary spend and leisure market.
"Our first customers will be mostly government agencies looking to use them for fire, police, ambulance and disaster recovery rescues."
The company also recently secured a cornerstone investment agreement with Hong Kong-listed KuangChi Science, an innovative technology business, opening up the possibility of selling jetpacks to China.