Tuesday, December 22, 2015

Arise and Come

Orbital launch vehicles are strange creatures. They are thuggish brutes, rising, roaring upward into the empty sky on an ecstasy of fire. They are delicate, their skin nearly thin as paper, every possible gram of metal whittled and etched away while retaining the faintest positive margin of strength. They are intelligent, able to pinpoint a plane, an altitude, and a speed, an imaginary keyhole past the atmosphere, and drive toward it with ferocious precision. They are dumb, carrying many tons of oxygen blasting through an oxygen-rich atmosphere, too busy to make use of what’s around them. They are expensive, a collaboration of the finest machinations of the stubbornest minds brought to bore on the problems of extreme performance in the last century. They are cheap, cast aside like garbage after doing their work to the bottom of the ocean or the depths of space.

By far the oddest quality of these rockets is their expendability. It’s hard to imagine any other machine of such careful engineering being jettisoned in such a careless way. But the carelessness is a clear product of the physics of spaceflight. It’s hard enough to get from the surface of the Earth to the lowest footholds of space, the argument goes. Why make a hard problem even more hopeless by trying to turn back to save what you’ve created? So we make sacrificial virgins of our launch vehicles, consigning them to a funeral pyre in the upper atmosphere after sending their payloads on their way.

If we’re serious about establishing an enduring, robust, human presence in the cosmos beyond the lushness of Earth, we need to have a better attitude toward rockets that have made the journey. They need to come back. Their tanks need to be refilled. They need to fly again. The economics of reusability are difficult to get right. The Space Shuttle certainly didn’t get them right. It was never cheaper to buy a launch on the shuttle (assuming NASA would let you) than it would have been to launch the same payload on an expendable rocket, despite the fact that most of the hardware that launched on each shuttle flight could be used again. But the economics of reusable rockets are the only method of getting stuff into orbit with any hope of getting it right. After a long hiatus full of scholarship but mostly devoid of action, we’re finally, as a civilization, starting to work on getting this right again, and SpaceX’s stunning return of the first stage of a Falcon 9 v 1.2 last night is a major step along this path.

There’s an eerie, entropy-defying quality to the videos, like somehow the arrow of time got flipped around. In hindsight it all looks so perfect that it’s difficult to remember how uncertain this success was. SpaceX built to this moment incrementally. They learned hard lessons about aerodynamics, retropropulsion, and controls along the way. They came agonizingly close to success only to see the results go up in flames. Last night the mountains of analysis, design, work, and sweat paid off with a used rocket standing on the landing zone pad, huffing and puffing from a 10 minute sprint, exhausted, toasted, but alive.

This stage will probably never fly again. The opportunity to pick apart a machine that’s harrowed the underworld of hypersonic flight into space and returned is almost as rare as opportunities come in the engineering world, and I expect that the people of SpaceX will inspect and document every weld, bolt, and valve before putting the stage on display at Hawthorne or McGregor. The first rocket to make it back will be a well-deserved trophy. The burden of truly proving the concept will fall to her younger sisters.

Space travel is very expensive, even after 58 years of on-again, off-again efforts to advance the state of the art and make it easier to get there. It’s possible to meaningfully reduce the cost of getting to space by making launch vehicles simpler and cheaper and being satisfied with a single launch per rocket. But consider the cost of the propellants that took the 11 Orbcomn satellites carried by last night’s launch to their new home compared to the cost of the vehicle. My naively conservative analysis suggests that SpaceX spent less than $400,000 on liquid oxygen and rocket-grade kerosene, while the list price for a Falcon 9 launch is over $60 million. I don’t believe it’s possible to build a truthful economic case that spaceflight will ever be affordable enough to enable things like commonplace research and manufacturing in microgravity, asteroid mining, and the human settlement of the solar system as long as orbital launch vehicles are one-time use. I don’t think it’s possible to make a machine that can get from the surface of the Earth into orbit cheaply enough. Even if reusable launch vehicles can’t do better than operate at 10 times the cost of the propellant they consume, that’s a factor of 15 improvement over where we are now. That’s where the (relatively) low-hanging fruit lies.

This matters because whether or not spaceflight becomes something that most people on Earth can take part in directly affects whether the future of our civilization is an optimistic one or a pessimistic one. The settlement of Mars and a widespread human presence throughout the solar system isn’t a flight of fancy. This is a practical, possible reality that’s the only viable alternative to a long-term future where we scramble to find ways to make slightly better use of the limits of Earth, confined to a single lonely mote of dust in the universe. The choice, in the long run, is between growth and discovery, and stagnation and decay. I’m assuming, if you’re not a member of the voluntary human extinction movement, that you’d prefer the former.

What SpaceX did last night is a bold step toward the optimistic future for humanity and Earth. Much more work needs to be done, by many people besides those working at Hawthorne, McGregor, and Cape Canaveral. SpaceX cannot by itself make humanity a multi-planet species. The work going on at my employer, Virgin Galactic, at Blue Origin, and at all the other small entrepreneurial space companies are an essential part of this effort. In no way does SpaceX’s success in their landing last night detract from how remarkable and wonderful Blue Origin’s successful flight was earlier this year of their New Shepard vehicle to the edge of space and back. Anyone who suggests otherwise would do well to tone down their Elon fever and embrace the effort to make spaceflight more affordable throughout the industry. It looks like the more established figures of the industry, from NASA to Boeing to United Launch Alliance, are starting to get on board with reusability, too. With a lot of work and some luck, this will be the start of the first real revolution in how things get to space since Sputnik.

Each night my wife and I read to our son the readings of the day from the Catholic lectionary. Last night’s readings were oddly appropriate given the historic events earlier that evening. The Old Testament piece was from the Song of Songs, and it’s a favorite of mine, one of the readings my wife and I had read at our wedding. It’s a poem that touches on love and hope, eros and thanksgiving. In part, it reads as follows:

“Arise, my beloved, my dove, my beautiful one,
and come!
“For see, the winter is past,
the rains are over and gone.
The flowers appear on the earth,
the time of pruning the vines has come,
and the song of the dove is heard in our land.
The fig tree puts forth its figs,
and the vines, in bloom, give forth fragrance.
Arise, my beloved, my beautiful one,
and come!"

Most of the universe is full of death. Not in the sense that it’s actually evil, but in the sense that it’s immersed in a dark night of inertness. Life, like light, fills a void, and precious little of the universe we live in has any of the light of life within it. The machines that sever our ties to Earth enable us, the intelligent part of the biosphere that can think of the future, plan for it, and make it better, to bring at least some of what’s out there into the bloom of life. Only if we rise from the Earth can the winter of death in our part of the cosmos end. I think this is worth doing.

So I celebrate what SpaceX has done to move us along this path. I’m glad I can play some part in this effort, too. Seeing what wild lovely celebration engulfed the men and women who made this a reality in Hawthorne, I can’t help but smile for what happened last night, and for what lies in store in the years to come.

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