Life has been quite a trip for Sir Richard Branson so far, and this weekend will be no exception as he flies to the US from Tel Aviv via London with space rockets on his mind.

He is heading to Wall Street to ring the opening bell on the New York Stock Exchange as his spaceflight company, Virgin Galactic, becomes a listed company tomorrow.

Speaking to the Observer on board Virgin Atlantic’s inaugural flight from London to Tel Aviv last week, Branson revisited his long-delayed promise: “Next year I hope to be floating in space.”

There is a certain urgency. It is 35 years since he launched his airline, Virgin Atlantic, and Branson is contemplating his 70th birthday next year. While apparently he hasn’t tired of hamming it up for the cameras, there is perhaps a little less spring in his step. But he remains Virgin’s rock-star draw on the Tel Aviv trip.

Brexit is a particular source of sadness. “It must have become apparent to most people in the last three-and-a-half years just what a mistake it was,” Branson says. “In my ideal world there should be another referendum. If a soft Brexit happens, it won’t bankrupt the country – but it will be very sad for young people, who won’t be able to live or work in these beautiful countries.”

He attributes Thomas Cook’s demise directly to the Brexit vote, Monarch’s likewise, “and Flybe we picked up for a pound”. A hard Brexit would do irreparable damage to Britain, he says, but those airlines had already suffered too much from the 20% drop in the value of the pound. “All their costs would have been in dollars – maintenance, leasing, fuel – and less people could travel overseas.”

Virgin Atlantic is another airline failing to make a profit, but it is not in danger, Branson says. “We are survivors. And it’s got the advantage of other Virgin companies: if the worst comes to the worst we can help it out, occasionally.”

The airline is now backed (or controlled, rivals say) by US giant Delta. “No question, Delta have been fantastic partners,” says Branson, whose sale of his majority stake to Air France-KLM has yet to get full regulatory approval.

Expansion to new routes has been off the agenda until recently, but now Virgin is planning on growth: back to Mumbai, adding São Paulo in Brazil, as well as the new Israel route. Sensitivities are such that cabin crew were sent for cultural awareness training among the Jewish community in Golders Green, north London. Last year, the airline took “Palestinian couscous” off the inflight menu. Branson says he wasn’t aware of the couscous controversy, but “if it was done for political reasons, I would say it was a mistake”.

Domestically, he remains animated by Virgin Atlantic’s push to engage the old enemy, British Airways, at Heathrow. Branson and Virgin have informally aligned with the airport’s management against BA to build the third runway and get more slots.

“Our team punch above its weight out of Heathrow but BA should have a competitor that has 35-40% [of slots] at least … We’re going to fight our corner.”

A Virgin Galactic test flight in the Mojave desert last year. Photograph: Virgin Galactic/PA

Meanwhile, the climate emergency has enveloped aviation. BA recently pledged to reach net-zero emissions by 2050, and Branson says Virgin will do the same: “We have said we’re going to go net zero by 2050, we’ve been very clear, and I think we should try to make it less than that.” (Virgin Atlantic’s chief executive, Shai Weiss, is more coy: “We’ve kind of said it.”)

In Branson’s view, “realistically, people are not going to stop flying – the most avid of marchers are going to fly. What’s critical is that we enable them to fly as environmentally friendly as possible.”

He says there is a “whole list of things” that Virgin is doing. “I’m lobbying to get government to impose the equivalent of a carbon tax on all companies in Britain, to have the companies invest 100% of that money directly into green energy investment.” He has championed LanzaTech, “a wonderful company that turn waste from aluminium and steel [processing] into aviation fuel. They need billions to build more factories.” More modern planes are cutting Virgin’s fuel burn by 25-30%. And, he adds, “by the time we get those slots at Heathrow, hopefully some short-haul planes will be completely battery-driven”.

Is this wishful thinking? “They are not hypotheticals, it’s just getting the quantity. We need to make sure we get the trillions and trillions needed to speed up the processes of all these things.”

He remains resolutely positive: “Some people think that every other problem apart from aviation in the world will be ticked, and aviation will never be ticked. I disagree: I think aviation can also be carbon neutral, and sooner than people realise.”

Meanwhile, fresh adventures remain on planet Earth. Next month Branson will join the sea trials off Marseille of Virgin’s first cruise ship, pitching his lone vessel to – once again – disrupt a market dominated by two or three big players.

And his optimism remains undimmed. Next time you are in the US, he says, don’t just hop over to the Mojave desert to see the Galactic set-up – “stunning, beautiful rockets” – but also go and see Hyperloop One – the magnetically propelled high-speed transport system being developed with the aim of moving people and things at airline speeds on the ground. Its test track in Nevada could be followed by a full-scale project in India, pending approval: “We’ve got the first track we’re building soon, between Mumbai to Pune.

“It’s definitely going to work.”

Branson’s businesses

Virgin Atlantic

Launched in 1984, the airline was successful for many years but has struggled recently. Branson cashed in by selling 49% to Singapore Airways for £600m in 1999 and in 2017 he agreed to sell 31% to Air France-KLM.

Virgin Records

The young Branson founded his record label in the early 70s. Its first release was Mike Oldfield’s global hit LP Tubular Bells. It then signed the Sex Pistols and 80s names such as Culture Club before being sold in 1992 for a reported $1bn.

Virgin Trains

Virgin received more than £300m in dividends during its 22-year operation of the London-Glasgow line. In April, Branson protested when the government refused to approve its partner, Stagecoach, for rail franchise bids. Now the name will vanish from UK rail.

Virgin Money

Branson bought the remnants of Northern Rock in 2011 for £747m and merged it with his financial firm. It was sold last year to the owner of Clydesdale and Yorkshire banks for £1.7bn but will pay to use the Virgin brand.

Virgin Brides

Launched in 1996 with a shot of Branson in a wedding dress, the one-stop marriage shop was the idea of a member of Virgin Atlantic’s cabin crew. It closed in 2007. “Maybe it was the picture that put people off,” he said.

Virgin Cola

Branson rammed a tank into a wall of Coke cans in New York in 1998 to launch this venture in the US. But Virgin’s version offered nothing new and Coke applied pressure to distributors. Branson concluded: “Declaring a soft drink war on Coke was madness.”

Virgin Vie

In 1997 Branson predicted his cosmetics line would be in 100 high street stores within five years. The venture never took off and in 2009 Virgin paid £8.8m and wrote off £21m of debt for new owners to take over.

Virgin America

Branson launched his domestic US airline in 2007 because flying in the US was “awful”. It was sold to Alaska Airlines in 2016 for $2.6bn against his wishes. Still, he received about £550m from the sale.