Nuclear thermal propulsion: not a new idea (Photo: Wikimedia Commons)
Tom Markusic, of Space Exploration Technologies (SpaceX), recently warned that spaceflight on its present course “will devolve into social welfare for nerds.” To escape federally funded self-indulgence, Markusic proposes developing a potentially game-changing technology: nuclear thermal propulsion. But its nominal prospects only make his unhappy prediction for the future of spaceflight more likely.
NASA chief Charles Bolden called for new ideas after President Obama earlier this year cancelled the Constellation project, which looked much like its antecedent, the half-century old Apollo program. Nuclear thermal propulsion, which Markusic advocates for getting to Mars, also dates back to the golden age of space. Beginning in the 1950s and continuing into the ‘60s, NASA extensively investigated thermal nuclear technology which combusts hydrogen at the extreme temperatures of a nuclear reactor, providing much greater thrust than the chemical reaction used in conventional rockets.
Clearly it’s not a new idea. Rather it underlines the paucity of new, workable technologies that meaningfully enhance the prospects for human exploration of space.
Nuclear thermal does work and it delivers about twice the kick from a given amount of hydrogen compared to burning it the usual way. But it’s expensive. And it’s nuclear. In the 1950s we looked forward to everything atomic. But no longer.
SpaceX founder Elon Musk contradicted Markusic a few days ago saying “I don’t think nuclear thermal is the way to go.” Musk, perhaps wanting to keep his company out of the nuclear fray, said the weight of the reactor would offset the benefit of greater combustion energy. However, Stanley Borowski and colleagues at NASA firmly contend that nuclear thermal rockets would roughly halve the transit time for a Mars mission from about 4.7 years to 2.5. But a not-quite-factor-of-two improvement has failed to captivate.
When Musk entered the rocket business, he was looking for a “Moore’s law of space,” exponential advances which would make humanity a spacefaring species. Markusic appears to have truer insight into the future of spaceflight.
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Goodbye Mars, Hello Malaria: Bill Gates’ Imprimatur on Science and the 21st Century
The X-51: making aeronautical engineering sexy again (Photo credit: United States Air Force.)
The space shuttle Atlantis landed for the last time yesterday while the hypersonic X-51 test aircraft flew for the first time. The X-51 "Waverider" flew for a little more than three minutes, hitting a top speed of Mach 5. The X-51 is not a replacement for the shuttle, but in contrast to the poor progress on ways to get into space, hypersonics are scorching a path forward in aeronautics.
Research on hypersonics has been going on for four decades, but it took until the 21st century for the first hypersonic vehicles to fly. The math gets extremely tricky. It's only been pretty recently that computing power has been overwhelming enough to begin replacing wind tunnel and flight testing for much slower moving objects like commercial passenger jets. Hypersonic flight presents a brand new set of modeling challenges. The extreme speed and temperatures mean you have to model the effects of, for instance, knocking oxygen atoms off nitrogen atoms.
However, actual hypersonic flight appears to be more a matter of grit than a product of particular advances. Michael Smart, head of the pioneering Hyshot Group in Australia says:
Computers have definitely given us more confidence in our predictions of scramjet performance, and CAD based manufacturing has also helped. I actually think it's more to do with different personalities pushing to “fly stuff” rather than just testing on the ground that has really moved things forward. As an engine guy who mainly tests on the ground, having to adapt my engines to a real flight vehicle has actually changed the way I design engines.
There are also interesting engineering parallels with synthetic biology. In both, elements of the design are highly interdependent in very complicated ways. Also (and perhaps consequently), design elements perform more than one function. The Waverider is in a sense, a flying engine, the interdependence of airframe and propulsion becoming extreme with the speed of the aircraft. Fuel serves not only to propel but to cool the X-51.
It's unlikely hypersonics will solve our space launch problem and right now the applications imagined are military. However, technologically, it's real deal, genuine gee-whiz stuff.
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The future of spaceflight: “social welfare for nerds”
Human Space Exploration: Scaled Back to Vanishing
Science both sets and reflects the agenda for American science. In the United States, cancer is the second biggest killer; malaria caused only four deaths in the most recent annual count, all from infections occurring abroad. Although coverage of cancer in Science still overwhelms that of malaria, in 2000 the count of cancer mentions in Science turned down for the first time in the history of the publication. At the same time, malaria coverage tilted up, reflecting a shift from developed to developing world health concerns. (As if in emphasis, last week Nature also ran a malaria cover story.)
Symbolic New Year’s Day 2000 saw the establishment of the Bill and Melinda Gates Foundation. Gates said then of his foundation’s mission: “I think that we could have the goal that every person in the world would have the same type of healthy life that people in the United States have.” His words now seem to have instantly reshaped the trajectory of science.
2000 marked an inflection point for NASA—and a turn in Science toward the terrestrial. Previously, the magazine's affections for space exploration had grown and grown even as the golden age of the 1960s receded. Ironically, coverage reached an apogee at the dawn of the 21st century and began falling back to earth in 2000. President Obama's subsequent cancellation of the Ares program earlier this year scaled back human space exploration to the vanishing point.
Neither are we on a trajectory to create a new, post-human species. In 2001, mentions of malaria in Science exceeded those of genetic engineering for the first time, a predominance that continues.
Can these shifts really be traced to the influence of Gates Foundation? Concerning the new emphasis on malaria, Gates is indisputably causal. The disease began gaining column inches in Science before Gates, from 1980 forward. However, the last decade’s spike to all-time highs not only coincides with Gates’ rhetoric but an enormous funding surge largely orchestrated by the Gates Foundation.
Research agendas are a zero-sum game. Consequently, the rise of malaria and global health automatically de-emphasizes all else. But difficulties specific to cancer, space, and genetic engineering also contributed to their demotion. The war on cancer and the space age are each roughly half a century old and not much nearer to victory or realization. By contrast, exponential advances in DNA sequencing technology seemed to be leading inexorably to a post-human species. However, genetic explanations of both complex diseases and complex traits have been—and might remain—elusive. As the number of genes involved in the relatively straightforward trait of height has grown, the prospects for and coverage of genetic engineering have dropped.
Gates still could have jumped on the spacewagon with fellow software billionaires Paul Allen, a major funder of SETI, or Jeff Bezos (with Blue Origin) and Elon Musk (SpaceX) who continue undeterred towards the spacefaring vision. Even software millionaires like John Carmack (Armadillo Aerospace) can’t help themselves. But Gates isn’t susceptible. In 1997, he praised the (unmanned) Mars Pathfinder mission as “a fine example of small science ... undertaken on a strict budget [with] limited, achievable goals.” He believed space would not be transformative: “Though humanity will do some great things in space in the next 100 years, and there will be enormous benefits, I don't think what goes on in space will fundamentally change the way we live.”
Concerning genetic engineering, Gates contended “It’s all a question of how, not if,” in 1995. He may still believe that, but his energies are going into saving rather than surpassing humans.
The opportunities (and imperatives) presented by global health might be greater than for any alternative research program. But nature yields to science only grudgingly no matter the frontier. Gates’ goal to eradicate malaria will be a multi-decade grind offering frequent parallels with the bogged down, four-decade war on cancer. Already polio eradication is a decade overdue.
It’s a volitional, pivotal moment. Gates, his full weight on Archimedes’ lever, is moving the world in a new direction altogether different from 20th century imagination and expectation.
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I have mostly denigrated space tourism, at least as a stepping stone to human space exploration. Proponents believe that attaching market forces to technology (which always advances) will lead inevitably to humanity exploring ever-more distant space.
About half of the equation works: market forces are driving down prices. Richard Branson's Virgin Galactic began by charging $200,000 for a ride aboard its SpaceShip Two. But now for just $100,000, Armadillo Aerospace is offering what Space.com called "sub-orbital joy rides." The mocking shift in nomenclature is perhaps a more important development than Armadillo's becoming the Budget Rent-a-car of space tourism.
Both Armadillo and Virgin only get you to the edge of space, about 62 miles up. To get higher, there is presently no alternative to a multi-stage rocket and not even market forces can change that. For the real deal, you still need to disgorge a million dollars to fly on the Soyuz.
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The Orion capsule at miniature scale. Photo credit: NASA
An elaborate ruse is taking place. Instead of Mars, we’re going to an asteroid. NASA’s budget is supposed to grow a seemingly hefty $6 billion but that’s only a 1.5% increase next year with just cost of living adjustments the four years after. Finally, NASA administrators assured the Johnson Space Center that it would continue to be the home of mission control for human spaceflight—when no flights are planned.
But not all are duped. “[I]t is clear that this is the end of America’s leadership in space,” said Senator Richard Selby from the aerospace-heavy state of Alabama, regarding the Obama administration’s plan for space exploration, announced yesterday.
Back in February, the President cancelled the Ares program to return to the moon and eventually Mars, a decision eliciting very little public consternation. Despite Congressional backlash from the Spacebelt states of Texas, Florida and Alabama, Ares remains cancelled. Also telling, part of the plan allocates $40 million for job retraining to Space Shuttle program employees put out of work by the Shuttle’s scheduled retirement later this year, making for an unexpected but revealing parallel with the Rustbelt.
Cagily, the President is deploying technology and market forces to defer human spaceflight—to infinity and beyond. NASA’s revised budget shifts billions into commercial space flight. Only left-wing socialists would argue against harnessing market forces to get into space. But the real jujitsu came in requiring that future rockets use new technology, not just a retread of the Apollo program. This is brilliant. Enthusiasts for space travel revere technology and so can hardly oppose Obama’s new, higher standard. However, in some respects, rocket technology has been unchanged for nearly a century. Konstantin Tsiolkovsky laid out many of the principles in 1903 in his Exploration of Cosmic Space by Means of Reaction Devices. Since Apollo forty years ago, no alternatives have been found to very large, multi-stage rockets burning liquid or solid fuel. Today, none are in near prospect. The chances of coming up with something novel by the new deadline of 2015 are very, very low. NASA chief Charles Bolden implored yesterday’s gathering at Cape Canaveral that “This is not for show. We want your ideas. We want your thoughts.” But because there are no ideas, it is for show.
The actual plan is to go nowhere or at least nowhere new. Even the gung-ho, final frontiers readers of Space.com think NASA will not get to Mars by the newly distant date of 2030.
Unless China reprises its 2009 Olympics extravagance in space with a mission to Mars, the Moon might mark the furthest extent of human space travel.
The brave and hopeful era of the Space Age deserves a better send-off than these dissimulations. Economics and myth dictate otherwise, stalling the redirection of noble aspiration toward terrestrial ends where giant leaps for humankind are both needed and possible.
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