While no one would rank it among the greatest of Professor Stephen Hawking’s achievements, he plainly had a unique impact on Richard Branson, founder of, among other things, Virgin Galactic, a space tourism company.

“I heard Stephen say in a radio interview,” Sir Richard wrote in a tribute, “that his ultimate ambition was to fly into space, but he thought no one would take him. I was on Necker Island and called him up straight away to offer him a seat. We have a strict no free tickets policy, but he was the exception that would prove the rule.”

This one-of-a-kind impulse presumably occurred before “Stephen”, who revered the NHS and campaigned against its privatisation, could have guessed that Branson’s Virgin Care would one day extract £328,000 in compensation from NHS funds. Equally, when Branson phoned from tax-exempt Necker Island with his offer of a free space ride, Professor Hawking had yet to advance the case for wealth redistribution. “Everyone,” he wrote, “can enjoy a life of luxurious leisure if the machine-produced wealth is shared.”

In the event, Hawking’s free trip would never take place, owing to unexpected delays on the Virgin intergalactic service. The honour of organising Hawking’s weightlessness fell, instead, to a US zero-gravity ride specialist, who offered a trip in a Boeing 747. Before embarking, in 2007, Hawking endorsed commercial space travel. “I think the human race has no future if it doesn’t go into space.”

Hawking’s blessing is understandably understandably cherished by a new subset of billionaires, composed of self-styled space explorers and colonists. “He was part of our Virgin Galactic family from day one,” writes Branson, for instance, and there is no reason to doubt him. Both “family” and “day one” may mean something quite different on faraway Necker Island.

For his part, a more ambitious space-explorer, Yuri Milner, a Russian billionaire who collaborated, sort of, with Hawking on a scheme that will involve shooting 100m mph “nanocrafts” at our nearest star system, told the BBC: “When future historians consider who were the outstanding people of our age, they will think of Professor Hawking.”

Will the same apply to plutocrats such as Milner and his principal counterparts in privately funded space discovery: Elon Musk (Tesla and SpaceX); Jeff Bezos (Amazon and Blue Origin); Robert Bigelow (hotels, Aerospace); Naveen Jain (formerly Infospace, Moon Express); and to a possibly lesser extent, Russia’s Igor Ashurbeyli (Socium Holding, founder of Asgardia)? Plans for space exploration have attracted, in all cases, a level of international interest these men might never have enjoyed as purely Earth-oriented speculators.

In fact, whatever becomes of their various tourist rockets and space colonies, their orbiting hotels and brave schemes for moon or Mars “harvesting”, the men have already served fellow entrepreneurs, if not all humankind, by demonstrating the awesome power of space talk to renew and refresh commercial reputations. Last week, Hawking’s advice to “look up to the stars, not down at your feet” was repeatedly quoted. Apart from anything, the above business leaders have confirmed, it is a fabulous marketing strategy.

Keep on looking up at the stars, not down, at virtually non-existent tax liabilities, and you might, like the world’s richest man, Amazon’s Jeff Bezos, winner of the 2017 worst ethical consumer rating, also win the Explorers Club’s 2018 Buzz Aldrin Space Exploration award. Even as Bezos invites US cities to compete to be Amazon’s new tax-avoiding base, his reputation gains from the traditional understanding of space travel as brave, clever, noble. “We have to go to space to save Earth,” he says. Look up and dream, like explorer Jeff, of a firmament blessed, for the first time, with heavy industry (waste disposal tbc).

Again, look up like Branson, Necker’s salvator mundi, not down, at his debt to generous British taxpayers. Think interplanetary laser thingies, like Yuri Milner, not the sublunary Gazprom money he once invested in Facebook and Twitter. Tweet inspirational spacey bollocks, like Jain – “You can have, be, or do anything; there are no limits” – not pedestrian explanations of his lawsuit-decorated business career.

Hypothesis one: even Philip Green, if he aimed at the moon, and not Monaco, could yet restore some of his former pomp. Look up to the stars, Sir Philip, not down, at the BHS pensioners.

Hypothesis two: the more hilariously inflated the plutocratic space ambition, the less critical will be the public response. Musk’s “Making Humans a Multi-Planetary Species”, with its fleeting glimpses of life in Elonville (or whatever he decides to call his “self-sustaining city”) is a document confidently unconcerned by the existence of international legislation designed to protect planets from human contamination. “It would be quite fun to be on Mars,” he predicts. “You would be able to lift heavy things and bound around.”

To planet Amazon Prime, then, or to Musk’s Elonia? Hard to choose. Especially when Musk writes, magnanimously: “I actually have nothing against going to the moon.” Either way, the adventurous traveller will find more practical detail in the pages of Jean de Brunhoff’s Babar the King, in which the elephant founds and builds Celesteville.

Musk does, however, seem aware of certain ethical objections to his priorities. “Life cannot just be about solving one sad problem after another,” he tweets. Why can’t it be? The answer, perhaps, is Bill and Melinda Gates. Compare the levels of excitement around their vaccines with the fuss made of Musk when he wittily dumps a car in space, or of Bezos, when he proposes state subsidy for his vanity space settlements. We are all in the gutter, but some of us are looking at never to be repeated investment opportunities.

• Catherine Bennett is an Observer columnist