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Moore's Law chart
While Moore’s Law has demonstrated rapid change in the power of microprocessors, a similar relationship may be unlikely for spaceflight. (credit: Intel)

“Permission to believe” in a Moore’s Law for space launch?

In the heady aftermath of SpaceShipOne’s record-breaking flight over the Mojave Desert, Rick Tumlinson and Michael Potter, in their SpaceDaily op-ed of June 22nd, naturally exulted over this latest shattering of precedents. Then these two settled down to what any excited pair of space enthusiasts would naturally want to talk about: where to go from here. They feel they have been given what VLSI pioneer and evangelist Carver Mead felt was a driving force in the exponentially increasing scale of integration in microelectronics: a tentative “permission to believe that it will keep going.” As he said in an interview at Stanford in 1992:

…it looks like a physical law and people talk about it that way. But actually if you’re living it… it doesn’t feel like a physical law. It’s really a thing about human activity, it’s about vision, it’s about what you’re allowed to believe. Because people are really limited by their beliefs… The wonderful thing about [Moore’s Law] is that it is not a static law, it forces everyone to live in a dynamic, evolving world.

Can space launch be forced into a more dynamic, evolving world? A world of ever cheaper, ever faster, ever better?

SpaceShipOne and the Diamandis Ladder

Potter and Tumlinson speculate about what’s needed to climb the remaining rungs of the Diamandis Ladder, that hoped-for progression of privately funded recreational space travel taking us from the quick suborbital fun ride, to the orbital ride, and on to the space hotel experience. In this, they draw an analogy to what Carver Mead was talking about: the dynamic, evolving world of ever-smaller technology.

Is there a Moore’s Law for space launch starting to happen? Not so fast.

“A central question revolves around whether Moore’s Law can apply to space technologies and systems,” they write. They are hardly the first to ask this question. Attempting an answer, they note a glimmer on the horizon, one that may or may not be a mirage:

PayPal Founder, Elon Musk, through his rocket company SpaceX, is trying to change the entire satellite space launch vehicle industry by dramatically shifting the cost equation from the $50 million dollar price tag to less than $10 million per launch.

Conveniently neglecting that satellite launch differs in meaningful ways from man-rated launch, they compare apples and oranges:

If one looks at the human side of the equation, the amount of money Tito paid to experience space for a week approached $20 million dollars.

Is there a Moore’s Law for space launch starting to happen? Not so fast. Electronics is not, well, rocket science.

To infinitesimal and beyond

Moore’s Law stems from Intel co-founder Gordon Moore’s 1965 observation that improvements in IC technology were yielding exponential increases in chip capacity, a trend he expected to continue. Moore articulated this “law” in a short article (unceremoniously entitled “Cramming more components onto integrated circuits”) in the 35th anniversary issue of Electronics Magazine, hardly four years after the first planar transistor. In this article, which can be found sandwiched between one on consumer electronics and another by a NASA official about advances in space technologies, Moore wrote:

The complexity for minimum component costs has increased at a rate of roughly a factor of two per year. Certainly over the short term this rate can be expected to continue, if not to increase. Over the longer term, the rate of increase is a bit more uncertain…

It seemed a bold prediction, but Moore’s “law” (he didn’t characterize it as a law, and it actually reflected an industry consensus at the time) has held up remarkably well, further into the future than he dared project. In fact, it has been in force through several cycles of the 7-year outlook that another Intel co-founder, Andrew Grove, has since said is Intel’s “event horizon”: the number of years Intel could peer, albeit through a glass darkly, into the future of its industry.

But is going up susceptible to the dynamics of scaling down? It’s not that easy.

Reality check: the rocket scientists

As if the question of a Moore’s Law for space travel were almost answered, Potter and Tumlinson blithely continued: “[While] orbital space is a much harder place to reach, one can expect a dramatic cost reduction there too.”

This confident invocation of a Moore’s Law analogy extending even unto orbit put me in mind of a conference I attended in Japan about a year ago, the 19th International Colloquium on the Dynamics of Combustion and Reactive Systems. “Ickders,” as it’s known to those who attend, is a biennial gathering of some of the world’s best minds in the venerable field of, well, burning things and blowing things up. Some real rocket scientists show up regularly.

At that conference, I interviewed Gabriel Roy, chief investigator for the Office of Naval Research’s Pulse Detonation Engine effort. He’s a man with many of America’s jet propulsion geniuses under his purview. The goal of that Navy program: to make PDEs truly practical.

Doctor Roy’s frustration was as palpable as his ambition. “My wife says to me, ‘I can now call India from the U.S. and hear a pin drop on the other end of the line,’” he told me. “And she asks, ‘So what is it that’s so hard about what you’re trying do?’” His brow furrowed. “She doesn’t understand—this isn’t like electronics, computers, communications. There are no quantum leaps in combustion.” His hands go up in the air, and the pitch of his voice goes up a notch. “We are still trying to figure out how to burn things.”

A Moore’s Law for space propulsion? Some very smart people would just love to see one.

The chips are down

As SpaceDaily’s eyes on the floor at ICDERS 19, I naturally attended every launch-related presentation I could find. Pulse detonation engines were the hot topic of the conference, reflecting a recent surge in funding. A handful of Japanese researchers announced they were determined to launch a PDE rocket—a potential air-breathing lower-stage technology.

Several researchers presented intriguing results in laser-assisted propulsion. However, activity in this area seemed to amount to paper designs or the wrapping up of research programs on their last legs.

“This isn’t like electronics, computers, communications. There are no quantum leaps in combustion,” said Roy. “We are still trying to figure out how to burn things.”

Ram accelerators, a potential projectile launch technology, were clearly still in a funding drought: running on fumes, with no obvious prospect except slowly rolling to a stop. Mentioning ram accelerators to some of the researchers at the conference elicited only blank looks, or worse, snorts of derision. One German researcher explained it to another: “Remember? They were going to shoot stuff to the Moon.”

Breakthrough propulsion efforts seem to go in 10- to 15-year cycles, with a bit of progress eked out in the funding peaks. Progress seems linear, even sublinear in some cases.

Could there be a Moore’s Law for space launch? To answer this question, we need to look at why it has held for over four decades.

The difference in the engines

At a 1975 IEEE International Electron Devices Meeting Gordon Moore, with a decade of vindication behind him, noted that Moore’s Law applied across all families of integrated circuit processes. The reasons Moore gave for an ongoing avalanche of progress:

  • chip dimensions kept getting bigger,
  • feature sizes kept getting finer,
  • “circuit cleverness”—pure ingenuity

“Circuit cleverness” was to explain the one-third of the growth in transistors per chip that wasn’t purely physical. He suggested that cleverness was at an end, but somehow, the exponential trend didn’t change after 1975. Engineers kept pushing the limits of the possible, and what was impossible? That horizon was still far off. “There’s plenty of room at the bottom,” quipped Richard Feynman in 1959, the title of his talk that prefigured both VLSI chips and nanotechnology. IC engineers would be just the first engineers to see how much room there was.

However, in exploring the design space in ICs, electronics engineers, unlike aerospace engineers, had electron physics on their side. Writing in a 1995 paper, “Lithography and the Future of Moore’s Law”, Moore said:

By making things smaller, everything gets better simultaneously. There is little need for tradeoffs. The speed of our products goes up, the power consumption goes down, system reliability, as we put more of the system on a chip, improves by leaps and bounds…

Leaps and bounds. To infinitesimal and beyond. If only life were so easy everywhere.

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