Thirty years after the first shuttle launch and on the weekend of the space shuttle's final mission, it's a good time to take stock of what the world has gained from the exciting adventure of space.
The gifts of space are many ... and no they don't include Teflon
Nasa, the story goes, once spent millions of dollars developing a pen that would work in zero gravity. The Russians, obliged by budgetary constraints to think a little further out of the box, bypassed the problem by issuing its cosmonauts with pencils.
Though delightful, the story is unfortunately an urban-spaceman myth.
The "Space Pen" is just one of many developments with which Nasa has been credited erroneously. In fact, the AG7 Anti-Gravity Pen - US patent No 3,285,228 - was developed by Paul Fisher, an American who in 1953 invented a refill cartridge that could be used in most pens and later filled it with a special ink mixture, pressurised with nitrogen, that enabled it to work in extremes of heat and cold, and even upside down.
In fact, it was the US astronauts who were working with pencils until Nasa equipped them with Fisher's AG7, which first went into space in October 1968, with astronauts Schirra, Eisele and Cunningham, onboard Apollo 7, the first manned mission in the lunar programme.
Fifty years after President John Kennedy fired the starting pistol on the US race to land a man on the moon and, as the US manned space programme nears its end for the foreseeable future with the final mission of the last space shuttle, it's a good time to take stock of what the US - and the wider world - has gained from Kennedy's "exciting adventure of space".
Well, obviously not the Space Pen, for starters, says Daniel Lockney, Nasa's technology transfer programme executive (who offers a fascinating postscript to the story: a typical ballpoint pen, he says, "works just fine in space").
There is, Mr Lockney says, a long list of other inventions regularly and wrongly credited to Nasa, including Velcro (popularised after Nasa adopted it but patented in 1955 by a Swiss engineer); Teflon (used in Nasa spacesuits but registered as a trademark by DuPont in 1945), and the microwave oven (invented by accident in 1945 by a Raytheon engineer, who noticed that a chocolate bar he had in his pocket started to melt when he stood too close to a radar set).
Such myths have proved irresistible, even to the White House. In a speech at Nasa in 2004, President George W Bush said: "Medical technologies that help prolong life - such as the imaging processing used in Cat scanners and MRI machines - trace their origins to technology engineered for use in space."
Except they don't. The myth-making, Mr Lockney says, "speaks to the excitement that surrounds the space programme and the space age. In a lot of cases, new technologies were created out of necessity, as opposed to the investment in space technology. However, many of them were popularised by Nasa's use of them."
So much for what space didn't give us.
In April 2009, on the 40th anniversary of the moon landing, President Barack Obama told the National Academy of Sciences that the Apollo programme had led "not just to those first steps on the moon, but also to giant leaps in our understanding here at home".
This time, the presidential research was more accurate, and he correctly listed a few of the specific products that had sprung from the Apollo decade: "Improved kidney dialysis and water purification systems; sensors to test for hazardous gasses; energy-saving building materials, and fire-resistant fabrics used by firefighters and soldiers."
But he also made the point that "the enormous investment of that era", in science and technology, education and research funding, had produced "a great outpouring of curiosity and creativity, the benefits of which have been incalculable".
Nasa is keen to point out it is not in the business of making money from its inventions. "That has never been the intent of technology transfer," Mr Lockney says. "If, for example, you wanted to develop something like the miniaturised heart pump that Nasa helped create, building the shuttle main engines would not be the most efficient way to do it. Or, if you wanted to improve digital imaging, you don't need the Hubble space telescope."
Such spinoffs are "secondary, even tertiary benefits, but they are part of Nasa's mission; when we create these new technologies it is our responsibility, written into the founding documentation, to also find practical uses for them."
The money raised by the licensing of patents, which goes to the Department of Commerce, "is really a nominal fee; it goes towards the maintenance of the patent and the cost of the research; it's not a money-making proposition. The goal is not to generate funds … our goal is to get it out to as many people as possible."
Consequently, there is no big universal figure for the money Nasa patents have generated. "We could start to try to extrapolate quantifiable benefits from what we do know about where these technologies have gone and what they've done," says Mr Lockney, "but the return on the investment is filling science textbooks; it's pictures of the Earth from space; it's learning how to explore the universe and our place in it. These are the big questions and the returns are the large-scale benefits to humanity."
Nevertheless, he says, if one feels the need to talk in terms of numbers, the success of technology transfer can be measured "in terms of thousands of lives saved due to life-saving technology, whether it's implantable heart devices, landmine deactivation or rescue tools or emergency medical devices or protocols. Tens of thousands of jobs have been created by the new industries that are sparked by Nasa technology; tens of millions of dollars in revenue generated.
"And in terms of touching or improving our lives, people all around the globe benefit from Nasa technology. It's ubiquitous; it's in your kitchen, your bathroom, your grocery store. If you have flown on an airplane you have benefited from Nasa technology."
Nasa, required by the National Aeronautics and Space Act of 1958 to "provide for the widest practicable and appropriate dissemination of information concerning its activities and the results thereof", launched its industrial applications programme - later known as the technology utilisation programme - in June 1962. It was designed "to foster greater utilisation of beneficial, new innovations beyond their initial aerospace applications" and requests for permission to use Nasa technologies grew quickly, from several thousand in the early 1960s to more than 70,000 customers by the early 1970s.
Nasa started publicising its commercial triumphs in 1973, when it composed and submitted its first Technology Utilisation Report; this evolved into the annual journal Spinoff, which since 1976 has recorded more than 1,650 "breakout" technologies, at the rate of up to 50 a year.
In terms of technology transfer, the most successful Nasa programme to date has been the shuttle, outgunning even Apollo by 120 spin-offs (and counting) to 80.
Though Nasa is not obliged to justify its space programmes in terms of such spin-offs, the space agency is sufficiently worldly to know that spreading the word doesn't hurt when it comes to budget-allocation hearings, and in 2007 its Office of Strategic Communications conducted research to determine the best way for the agency to sell its mission to the US public.
It found that although there was almost universal awareness of the Nasa "brand" and "enormous public support" for the organisation, on the downside there was little public knowledge and even less excitement about what the agency was then up to, and a widespread lack of grasp of the relevance of its work to everyday life.
While a majority (71 per cent) believed that it was important for Nasa to continue with space exploration, only 53 per cent thought its work was relevant to their lives. However, this figure jumped dramatically to 94 per cent when those surveyed were shown examples of everyday technologies that had sprung from the various Nasa programmes.
The end of the shuttle, says Mr Lockney, does not mean the end of the space-technology harvest.
"Far from being the end of human space flight we are also investing in the industry of space flight. A lot of the buzz is that the Americans have ended their shuttle programme, when actually I think the story should be that the US is the only country in the world that's investing in and trusts in its industry enough to develop a commercial space flight industry.
"We will have, in short order, humans being ferried into space by these commercial providers much in the same way that Nasa's predecessor, the NACA [National Advisory Committee for Aeronautics], provided the guidance and the start-ups for the modern commercial aircraft industry."
This exciting new era will generate many more spin-offs, Nasa believes.
"There are many benefits we can forecast," Mr Lockney says. "For example, we will have lighter, stronger composites, we will have more efficient battery technology, we will understand how to deliver medicine to people who are in remote areas without immediate access to medical professionals and equipment."
Most exciting of all, however, there will also be "new technology that we can't anticipate, technologies we don't even know we need yet". One thing he says Nasa does know "after 50-plus years of history, is that whatever we do will end up providing substantial and practical benefits to the public".
Practical returns, however, may be the least important of the gifts Nasa has brought back to Earth.
The true value of space research, Mr Lockney told the conference of the American Institute of Aeronautics and Astronautics last year, was often felt "in immeasurable ways", such as in "the shift in global understanding of the Earth as a fragile ecosystem that came about after the widespread distribution of [Apollo 8's] historic Earthrise photographs, oft cited as integral to the birth of the environmental movement in the 1970s".
Indeed, that one photograph may yet prove to be the greatest spin-off of the space race. As William Anders, an Apollo 8 astronaut, said of the famous photograph he took on Christmas Eve, 1968: "We came all this way to explore the moon, and the most important thing is that we discovered the Earth."