Last week, Nature painted a pessimistic picture of the Google Lunar X Prize challenge in space exploration — which asks firms to land a robot explorer on the Moon by the end of next year. The technical hurdles are too high, critics say, and the financial incentives too low. A halfway house has been announced to offer encouragement: US$6 million for groups that can demonstrate that their lander works on Earth by September this year (see Nature 506, 278; 2014).

By then, the X Prize model to encourage scientific progress could have launched its most successful venture yet. The word ‘could’ is pertinent, for the man talking up the chances of the venture is Richard Branson, the business tycoon with an ear for a catchy and ambitious sound bite. This is a man who does not do pessimism.

Branson said in the British newspaper The Guardian last week that the maiden flight of his private suborbital space-plane will blast off later this year — and that he and his family will be on board. We have been here before. Branson first promised that his company Virgin Galactic would start its space rides for paying customers in 2007, and it has been selling tickets for a decade.

He now says that work to launch the vehicle, SpaceShipTwo, is almost done. It is the successor to SpaceShipOne, which won the $10-million Ansari X Prize for repeatable space flight with a manned craft in 2004, and for which Virgin bought the rights. And Branson is typically bullish about the craft’s prospects. The re-entry technology, always the most risky part, is foolproof, he claims: “The pilot could be sound asleep on re-entry.” Branson wants SpaceShipTwo to fly to the edge of space “100 times, maybe 1,000 times”, he said.

SpaceShipOne hangs from the ceiling of the Smithsonian National Air and Space Museum in Washington DC, alongside the Spirit of St. Louis monoplane. SpaceShipTwo will have large windows, and white and silver seats. Engineers will customize those seats to the rears of the wealthy guests, to minimize the effects of g force and to allow them to get the most of their estimated five minutes of weightlessness.

The Guardian spoke to astronaut Chris Hadfield, veteran of the NASA space shuttle and former commander of the International Space Station, who was sceptical of Branson’s guarantees that nothing could go wrong. “To come into any programme with any vehicle and think you’re somehow immune from what everybody else has always experienced with every machine in history is unrealistic,” he said. “They don’t know everything yet.”

One thing that Branson does know (almost) everything about is how to keep a jumbo jet flying. As we report on page 420, that is more difficult than it sounds, particularly when the jet has a 2.5-metre infrared telescope sticking out of a hole in its fuselage. More than $1 billion has so far gone into the modified Boeing 747, formally called the Stratospheric Observatory for Infrared Astronomy. After years of delays (sound familiar?) it is now fully operational, and could do some valuable science. And with annual running costs of $78 million, it needs to.

There is something brilliantly simple about sticking a telescope on an aircraft as a way to beat atmospheric interference. But in 2014, doesn’t such a solution seem a bit, well, twentieth century?

Back in the mid-1980s, Branson was invited by then Soviet leader Mikhail Gorbachev to become the first civilian in space. The ticket would have cost $50 million. “I thought,” Branson said, “wouldn’t it be better to spend that $50 million building a spaceship company instead?” Optimism is not for everyone, but it has its benefits.