The Deputy First Minister made a special trip last Friday at the end of a visit to the United States to present students at the Scottish Space School in Houston, Texas, with their graduation awards.
Afterwards Mr Wallace described the Space School as "a very imaginative programme". He told The TES Scotland: "Scientists and engineers don't always get the respect they deserve in society. This kind of opportunity lets young people see the value of pursuing careers in science and engineering. It raises their aspirations.
"That in turn benefits not only them but also our country, because science is vital to Scotland's economic welfare. These students are among our brightest and most enthusiastic, and they have been telling me that their experiences this week have opened their eyes to all sorts of career possibilities they never dreamt of."
The Scottish Space Foundation, which runs the school, is a joint endeavour involving the Scottish Executive, Scottish Enterprise and Careers Scotland, with business and educational support. It now sends two groups of 25 fifth-year pupils from schools around the country to Houston each year to face a week-long set of challenges and meet the astronauts who train at the Johnson Space Center.
Daytime activities include working in teams to research and present rocket science and design and build working models. In the evening, it's barbecues and receptions with astronauts and their families.
At the start of the week this group talked on their own private downlink with the International Space Station, persuading a smiling Mike Foale, the British-born commander, to perform backflips for them. At the end of the week, four Scottish-built rockets soared spectacularly into the Houston sky.
"I have never seen so many astronauts in one room before," one guest said at the graduation dinner attended by Mr Wallace, "and I work for Nasa."
The goodwill built up with Nasa in recent years, Mr Wallace says, has generated valuable traffic across the Atlantic: students attend the Space School in Houston, while astronauts come to Scotland to inspire pupils with talks and presentations.
According to teachers, the astronauts' high-flying blend of education and daring - all have degrees in science, engineering or maths - makes them uniquely inspirational. "We have established something very worth while here," Mr Wallace commented, "and we are looking at ways to develop and build on what has been achieved."
The Scottish Space School is a rare mix of the two types of activity now considered vital to education and the economy - science and enterprise. Yet the Executive's Science Strategy for Scotland barely mentions enterprise, while its response to the Determined to Succeed report on enterprise education does not mention science at all.
Mr Wallace countered: "We have done a lot in recent years, with awards and co-investment funds, to improve the pipeline from university to market-place, and try to turn round that historic problem of Scotland being good at invention and innovation, but not so good at commercialisation.
"In fact when we were talking in Boston this week about the biosciences in Scotland, they were amazed at the scale of the investment we are making in that area over the next 10 years."
Mr Wallace, who is also Enterprise and Lifelong Learning Minister, said the Determined to Succeed report was about promoting an entrepreneurial culture in schools, rather than specifically a scientific one. "But that isn't just about young people learning to run a business - although that is part of it. It is about the creativity that comes with enterprise, the self-confidence it generates. It is about responsibility."
Such personal skills, which are developed by enterprise activities of all kinds, he says, are the key to a successful future, both for the individual and for Scotland as a whole. "When I ask youngsters in the schools I visit what they have learnt most from enterprise activities, invariably they say working together as a team.
"Interestingly enough, that is exactly what these kids have been telling me today. So there is a natural fit. The Scottish Space School has inspired these youngsters."
The second group from the Scottish Space School this year will go to Houston in September, and there will be a residential summer school at Strathclyde University in June supported by the European Space Agency and Nasa.