They discovered the asteroid on September 11 — two years before that date really meant anything — and named it 1999 RQ36.

Scientists at the Lincoln Laboratory at MIT made the discovery. The laboratory had been founded in the 1950s during the height of the Cold War. The U.S. Air Force wanted a facility to keep an eye out for any incoming threats from the air. At the time, that meant war planes and ballistic missiles. A computer there called Whirlwind would synthesize data from scores of radar installations and maintain constant vigilance for any threats from above. The commies wouldn't catch us with our pants down, not if Lincoln Laboratory had anything to say about it.

When the Cold War ended, the threats from the skies above did not. Just the opposite: The threat seemed to grow by orders of magnitude. The commies and their intercontinental ballistic missiles were nothing. Astronomers had begun to identify a species of threat called "near-Earth objects" — huge rocks in space that, given a bad day in orbit, could fall from the sky and, if not end life on Earth, then certainly give survivors a very bad go of it. The more astronomers learned, the more they realized that Earth's orbit is downright terrifying, fraught with peril, and that we are, on a planetary scale, children playing games on a very busy highway. (The dinosaurs could have told us that, of course, but one of those space boulders put an end to that business.)

To keep an eye out for oncoming traffic, NASA, MIT, and the Air Force gave Lincoln Laboratory a new task, and established the Lincoln Near-Earth Asteroid Research project — LINEAR — whose job it would be to identify threats, still from above, but this time way, way above. Nuclear weapons are scary because they represent the darkest impulses of humanity coupled with our brightest minds. Asteroids, on the other hand, represent something exponentially more terrifying. Think you're so clever, humans, with your theories of relativity and advances in rocketry and targeting systems? Let's see how you fare against a giant rock.

But LINEAR and other such offices keep watch. They spot near-Earth objects by the hundreds and enter them into a database for future study. So it went with 1999 RQ36. Six years later, scientists got around to mounting an intensive campaign of study of the asteroid. What they found was so compelling in its implications for the scientific understanding of our solar system that they needed to know more — needed to learn things that our Earth- and space-based telescopes simply could not deliver with adequate certainty. Hypotheses and theories, however refined and reliable, simply weren't enough. We needed to know more, and we decided to go there and learn.

Today, asteroid 1999 RQ36 is called Bennu, after the Egyptian deity. It was named by a 9-year-old boy from North Carolina. The robot taking us there has an equally Egyptian name: OSIRIS-REx.

The spacecraft is the size of a minivan, its target the size of a mountain. When its solar panels are deployed, it seems to have wings spread. Its high gain antenna, shrouded in a pale sheet of insulation, looks like some ghostly face. Taken together, the spacecraft resembles an owl mid swoop. If aliens lived on the asteroid, they wouldn't like the looks of this thing flying toward it. They wouldn't like how it begins circling their asteroid home, and then continues to do so again and again and again and again, this bird of prey hulking above.

The round trip journey to Bennu is right around 1.35 billion kilometers, the outbound leg of the trip taking about two years. OSIRIS-REx is an acronym, short for "Origins Spectral Interpretation Resource Identification Security-Regolith Explorer," which has the virtue of spelling out each of the mission's scientific objectives: studying the origins of the solar system; mapping and characterizing the asteroid; learning whether it threatens the Earth; and uncovering the nature of its surface material. But what has scientists perhaps most excited is the mission's clincher: The spacecraft will grab a sample of the asteroid — anywhere from a couple of ounces to a couple of pounds, which is more than enough to keep researchers busy for generations — and bring it back to Earth.

OSIRIS-REx will arrive at Bennu in August 2018, and will then swoop around its quarry for just shy of two years. During that time, the spacecraft will first survey the asteroid surface for any signs of geysers or perhaps even tiny, heretofore unknown moons into which OSIRIS-REx might crash. It will then map the asteroid, noting conspicuous landmarks — significant craters, ridges, outcroppings, and so on — that the spacecraft can use for navigation. (Before this point, the spacecraft will use the relative positions of stars for navigational purposes.) Once our space owl has a good handle on the asteroid's basic geography, it will begin mapping in earnest, capturing not only imagery, but also spectral, thermal, and geologic data. It will return pictures of the asteroid's surface, information on where it might be especially hot or cold, and details on the sorts of minerals and elements that are present and might one day be useful for future mining operations. Prospecting maps from the Old West are about to go cosmic.

Scientists will be looking closely for especially interesting sites — places on Bennu that cause women and men hunched over terrestrial computers to scratch their heads and rub their chins and ask, "What in the hell is that?" or "What is that doing there?" They will be looking for mysteries to solve — about Bennu, of course, but also about the solar system and Earth.This asteroid is a pristine sample of our solar system's infancy, and scientists will be searching for something to take home and study. In anthropological terms, this challenge is akin to having a time machine, traveling to the Middle Stone Age, and being able to take only a single tiny artifact that can explain the next 12,000 years of human development.

Scientists will also study how to prevent catastrophic encounters between asteroids and Earth. Asteroids, generally, exist neither as dense fields into which the Millennium Falcon might fly to avoid Imperial TIE fighters, nor as plodding bodies moving along paths easily plotted using Kepler's laws of motion. Instead, they are subject to something called the Yarkovsky Effect. Put simply, asteroids absorb sunlight and later emit that energy as infrared radiation. The release of that radiation acts as tiny, natural thrusters. Accordingly, scientists cannot model with necessary accuracy where an asteroid might be in the distant future. Bennu, for one, has an alarmingly high chance of hitting our planet: 1 in 2,700. Not exactly odds to bet your retirement on, but still about the same likelihood as a person dying from exposure to smoke or fire. And since Bennu's discovery in 1999, the Yarkovsky Effect alone has changed its course by 100 miles. That uncertainty applied to tens or even hundreds of thousands of near-Earth objects is reason for alarm. If Bennu yields answers to how the Yarkovsky Effect works, scientists can apply the resultant model to every known object out there. The human race can then either breathe a collective sigh of relief, or get to work figuring out how to stop impact-induced chaos, if not doomsday.

OSIRIS-REx will map Bennu at very high resolutions, and a laser altimeter will create a refined topographic map. This will be the most accurately mapped asteroid in the solar system, and one of the best mapped of any celestial object orbiting the sun. To cap off the reconnaissance phase, OSIRIS-REx will make close passes over the candidate sample sites. Once a decision is reached — "That regolith will be ours!" — sample collection rehearsals will begin. OSIRIS-REx will then briefly — finally! — make physical contact with the asteroid, and bring home a scoop of it.

The mission was hatched in 2004 on the back of a cocktail napkin from the Audubon Bar at the Arizona Inn in Tucson. It was the brainchild of Michael Drake, the late, renowned head of the Lunar and Planetary Laboratory at the University of Arizona, and Dante Lauretta, a highly accomplished professor there and Michael's protégé. There was no target at the time, no refined science objectives. There were only wine, whiskey, and water glasses, a bottle of Kendall Jackson chardonnay, and assurances from Steve Price of Lockheed Martin that the spacecraft could be built. But was there the will to see such a project through?

Planetary missions don't just happen — a construction montage over an '80s power ballad, sparks flying as metal is cut and welded. A fiery launch and glorious pictures on Instagram of a job well done. Rather, these missions can be career-long commitments. The journey from PowerPoint to the launch pad might involve decades of silence, exile, and cunning; maybe fabrication, eventually, and launch, or maybe meticulous planning followed by cancellation — one more space mission confined to a university hard drive. Then there's travel time — years, usually, one, two, or even 10 — and that's before the science mission even begins. Years more of that, and the findings, and decades yet of data analysis. No, scientists go into these things young and emerge old, or go into them old and emerge very old at best.

But Dante and Michael were in. They would split the mission in half: Michael would lead it through launch — "up and out," he called it. He would shuffle the mission from a wine-ringed cocktail napkin through to about a week after liftoff, assuming it was ever actually selected. After that, Dante would take over as principal investigator. He would handle "down and in," bringing the spacecraft to the asteroid and leading the mission to study it and collect the sample. Neither men knew that it would not turn out that way in the end.

The main entrance to Kennedy Space Center materializes at the end of a six-mile stretch of road, the 405, a thin black ribbon laid across the Indian River. Down this runway of a highway every morning, the orange Florida sun rises dead ahead, its rays dancing on the Indian, and all is flat and wide, horizon and water alike, and on the narrow banks running along the road, separating asphalt from fresh water, the occasional sabal palmetto springing from thickets of reeds waist-high. If you are an astronaut and you're driving to work, Cape Canaveral is as indelible a vista of Earth as you might want before climbing into your capsule and flying to space.

To the northeast, far across the Indian, is a massive white cube — a structure impossibly large even from six, seven, eight miles away. The American flag is painted on one side, and NASA's blue and red logo — the "meatball," as old-schoolers call it — is painted adjacent. This is the Vehicle Assembly Building — the VAB — perhaps the best known of any NASA building on Earth. It is the largest single-story building in the world, and every millimeter of its 160-meter height is necessary. It is where rockets are assembled. From a distance, it is surrounded by nothing, though once on the grounds of Kennedy, a scattering of buildings can be found circling it, tiny birds at the feet of some lumbering mammal — offices and fabrication centers, a cafeteria, press buildings.

This part of Florida is as ideal for rocket launches as anywhere in the world. The land is near the equator relative to the rest of the United States, which means it gets a speed bonus from the Earth's rotation. Here on the ground the world feels still, but that's just the laws of physics playing tricks on us. In fact, the world rotates at quite a clip — 15 degrees per hour, and in practical terms of mileage, at the equator the Earth spins fastest of all: about 1,000 miles per hour. Moreover, the Earth spins eastwardly — the direction in which rockets generally launch. Cape Canaveral is surrounded by wide rivers and the Atlantic Ocean. Rockets launched from there do not have to fly (and possibly crash) over populated areas, and when rockets and boosters fall away during launch, they have a nice giant ocean waiting to catch them safely.

The VAB is being refitted for NASA's gargantuan rocket in development, the Space Launch System, designed to fill a gap in American lift capabilities. If we're going to send astronauts to Mars, or the Moon, or asteroids, or anywhere beyond low Earth orbit (the altitude at which such structures as satellites and the International Space Station circle the Earth), we need the ability to lift very heavy things, or to send lighter things along at very tremendous speeds. SLS will be the most powerful rocket ever built. The rocket uses the same engine as the space shuttle — four of them, in fact, at the same time. That's a lot of lift.

Nearby is Launch Complex 41, leased by United Launch Alliance, the manufacturer of the Atlas 5 rocket that will launch OSIRIS-REx into space. Fully loaded ― rocket engine, booster, Centaur second stage, and spacecraft fairings ― the rocket stands 189 feet tall. To a person staring up at the rocket from the launch complex grounds, it seems impossibly tall. What must the Saturn 5 rockets have looked like, the rockets that put men on the Moon? What will the Space Launch System look like? On the launch pad, the rocket is beautiful, elegant, all business, a slender white tube pointed in the right direction — up — and the sheer dignity of the thing makes you want NASA just to get on with it.

In the case of OSIRIS-REx, to get from cocktail napkin to an approved mission design took seven years of effort. Moving from an approved mission design to a spacecraft atop a rocket on a launch pad at Cape Canaveral took five years more. It required marshaling the forces of hundreds of scientists, engineers, and associates from scores of institutions, academic and otherwise. It demanded an absolute knowledge on the state of the spacecraft and its systems and scientific payload during design, manufacture, assembly, and testing. It meant wrangling a budget just shy of $1 billion, employing accounting principles that members of the corporate community might spend a lifetime learning. Mission leaders had to become diplomats of the first order, keeping NASA happy with the mission, and by proxy, the White House and Congress.

On its journey to this moment, mere hours from launch, OSIRIS-REx enountered problems, and not just technical ones. In April 2013, NASA eliminated education and public outreach funding, which meant the team lost the means by which to educate the public on what it was doing and why it was doing it. Dante had to find ways to get the word out. He eventually designed an acclaimed, bestselling board game called Xtronaut, which gives players a feel for the highs, lows, and challenges of launching a space mission, to name only one initiative. In October 2013, disagreements between Congress and the White House over spending priorities meant no federal budget was passed and no spending resolutions signed. The government shut down for the first time in 17 years. This caused a schedule slip on a key instrument on the OSIRIS-REx payload, costing the mission $1.7 million. In 2014, Russia invaded Ukraine, and in response the U.S. government banned the import of Russian-made rocket engines. Because the Atlas 5 launch vehicle uses RD-180 engines — made in Russia — every such engine in the existing U.S. inventory was carefully parceled out. OSIRIS-REx was okay — it had an engine assigned to it… until the U.S. Air Force decided that it needed an engine for a "national priority" launch. Suddenly, the team had a rocket with no way of making fire. A spacecraft with no way of going to space. The team scrambled to make sure a replacement engine eventually materialized.

Even after all this, when OSIRIS-REx was mounted atop an Atlas 5, the spacecraft secure in its fairings, the rocket stacked and protected in its vertical integration building and waiting for the big day, it was nearly destroyed. One week before the launch date, a SpaceX Falcon 9 rocket blew up during a freak "static firing" anomaly. (SpaceX is only just beginning to make sense of what happened.) While emergency crews worked frantically to douse the apocalyptic flames of the obliterated Falcon 9, Air Force specialists realized that the cooling system for the OSIRIS-REx launch complex was now losing pressure. They moved quickly to handle both crises. Had pressure not been restored (it was), the spacecraft would have been lost (it was not).

Press and a paying public can watch rocket launches from the grounds of Kennedy Space Center, at a viewing area called the Causeway, another stretch of black ribbon, this one across the Banana River, opposite the Indian in location but alike in every other way. A narrow, grassy bank separates the road from the river, and thickets of reeds separate the bank from the water. On the day of the launch, the Atlas 5 and its distinct nose cone adorned with the OSIRIS-REx mission crest are perfectly visible and sitting patiently on the pad. NASA makes quite a production of the launch from this viewing area. Folding chairs are provided, though most of the viewers present — around 1,260 in total — bring blankets and umbrella-style chairs of their own. Among the crowd, languages and accents from every corner of the world can be heard. Children no older than five walk about in bright orange astronaut jumpsuits. Officials offer expert commentary over a loudspeaker, and say things like "L minus one hour and counting" or "T minus 30 minutes and holding."

There is never a guarantee of a launch. Weather must permit, and a single anomaly can scrub the whole thing. You don't spend $1 billion on a spacecraft and just go for it, red lights be damned. But on Sept. 8 at 6:45 p.m., 20 minutes before ignition, the sky is perfect, clear and calm. Clouds are collected distantly and no threat to the day's big event. A welcome warm breeze from the northeast drifts through. The river Banana chops slightly, and the sun's rays tap dance on every peak of water. It is then that the NASA commentary ends, replaced with radio traffic from Atlas Launch Control. Now, voices that are All Business go back and forth, verifying this number or that, fuel or temperature, wind speed or computer status. Everyone knows that things are about get serious, because the polling begins.

"Status check to proceed with terminal count."

"Atlas system: propulsion—"

"Go."

"Hydraulics—"

"Go."

"Pneumatics—"

"Go."

"LO2—"

"Go."

"Water—"

"Go."

The polls and responses come like machine gun fire. The –er in water has barely reached its guttural, auditory conclusion before being sliced off at the end. Go. More impressive is that none of the voices are shouting. This is no country for exclamation points. Here are a couple dozen voices speaking with urgency, but very calmly so.

"Centaur systems: Propulsion—"

"Go."

"Pneumatics—"

"Go."

"LO2—"

"Go."

"LH2—"

"Go."

"Haz gas—"

"Go."

"Electrical systems: Airborne—"

"Go."

"Ground—"

"Go."

"Facility—"

"Go."

"RFFTS—"

"Go."

"Flight control—"

"Go."

"Comm—"

"Go."

"Timer—"

"Go."

"GCQ—"

"Go."

"Umbilicals—"

"Go."

"ECS—"

"Go."

"Red line monitor—"

"Go."

"Quality—"

"Go."

"Ops safety manager—"

"Go."

"ULA safety officer—"

"Go."

"Vehicle system engineer—"

"Go."

"Anomaly chief—"

"AC is Go."

"Range coordinator—"

"Clear to proceed."

"Launch director—"

It's a scherzo composed by engineers, beautiful staccato polls and approvals. Will someone say no-go? Will somebody dare — dare? — dare! — to say "No-go"? Nobody does, and so comes what feels at the time like the most beautiful words ever spoken, the launch director's response:

"You have permission to launch."

We're a minute out now, and no man, woman, or child at the viewing area is seated. No one is checking their Facebook status or noticing anything at all aside from the rocket ahead, buffered only by the Banana River.

"T minus 25. Status check—"

"Go Atlas."

"Go Centaur."

"Go OSIRIS-REx."

And then it happens, like New Years Eve, but not perfunctory, not predictable, not promised. T minus Ten — and the crowd gathered, the full 1,260 of us join in — Nine. Eight. Seven. Six. Five. Four —

Here, what simply cannot be real, but is. In the direct line of sight to the rocket, no more than 20 feet from the crowd along the Banana, dolphins — dolphins! — surface and dive, surface and dive in rapid succession, as though modeling for a Florida postcard.

— Three. Two. One!

Says the voice from Atlas Launch Control: "Liftoff of OSIRIS-REx, its seven-year mission: to boldly go to the asteroid Bennu and back." It rises, rises, a soul leaving the body, ascending to heaven. You see it first, the white beam pushing the thing upward; you hear it second, a primordial roar; you feel it third, in your chest and bones, the fury of the gods, the achievement of humankind.

Until "Liftoff!" nothing happens, and then everything happens. The billowing smoke, the white fire, the upward movement of the launch vehicle — it happens immediately and all at once. The fire is one long continuous and controlled explosion, but the word and attendant imagery — explosion — never enters the onlooker's mind. What you see is the opposite of an explosion. What you see is control. Total and utter control and focus. The rocket's fiery tail, it's not even fire. It is a prize fighter working a speedbag. Such focus! Such control! The rocket, its motion is somehow nauseating, not because it lacks grace, but because it possesses so much of it. You light a bottle rocket, and you hear sssssssss and then sssshhhhhwwwwwww as it suddenly zips into the sky. The Atlas 5, though, rises slowly, a methodical rejection of gravity. It is a ballerina. Grace. Grace.

The tail of flame is about as long as the rocket itself, but it is not orange. It's not even fire, really, as you understand fire to be. It is white. It hurts the eyes. It's like staring at a concentrated burst of manufactured sun. It's not the flamethrower's discharge, but that of the welding torch. It is blinding. It doesn't billow. It's all business, this white welding torch. So pure and focused and controlled.

The smoke is produced by ignited liquid oxygen and liquid kerosene. It is the color of cigarette smoke, and at ignition it shrouds the launch complex bottom to top, pad to candlestick-like lightning rods. The rocket rises above. The smoke follows the rocket up. It's a skywriter, this thing, drawing smoothly some great, fine arc to heaven. The higher it gets, the whiter the smoke, purer, purer, purer, until at last it seems humankind has surpassed the cloud itself as an object of stainless wonder against a curtain of blue.

Rocket launches are divided into stages. The rockets themselves do not travel to other planets, moons, or asteroids. They are but delivery mechanisms. The first stage carries the burden of the launch for about four minutes. Its size, grace, and seeming patience belie its speed. The rocket has crossed the sound barrier less than 60 seconds after launch, and it will reach 12,000 miles per hour shortly thereafter. At four minutes or so, the main engine of the first stage will cut off, and the great tube will fall away, its purpose served, its mission accomplished, its next stop the bottom of the ocean, to the terrible surprise of bewildered fish.

Now the second stage of the rocket gets to work. Ten seconds after separation, the Centaur, as it is called, fires its engines. It pushes forward OSIRIS-REx, which is still encapsulated in its protective fairing. Once the Centaur stage gets to work, the twin traumas of pressure and heating no longer pose a threat to the spacecraft, and the fairing hatches in two and falls away. This is OSIRIS-REx's first exposure to space. The Centaur will power along for another eight minutes, carrying the load a little farther, a little faster.

No longer is the vehicle fueled by liquid kerosene and liquid oxygen. To the extent that there is smoke, it's not smoke at all, but steam. Steam! What drove paddleboats down the Mississippi after Thomas Jefferson bought Louisiana, and powered locomotives across the Transcontinental Railroad in the aftermath of the Civil War. Steam, because the Centaur's engines are powered by ignited liquid hydrogen and liquid oxygen, the result: H2O.

Twelve minutes of this, and then the Centaur's engines will shut down and the vehicle will enter a coast phase. It will soon switch on again and steam-power our plucky explorer for six more minutes. The two will share a final 15-minute coast, and about one hour after liftoff from Launch Complex 41 at Cape Canaveral in Florida, the Centaur will detach and OSIRIS-REx will be away and alone on a journey that will take it around the Sun and back to Earth. Once back, it will get just close enough over the South Pole to feel the slight tug of Earth's gravity, and that gravity will in turn slingshot the spacecraft to the asteroid Bennu.

Is it that the Earth doesn't want us to leave? Does it use gravity to maintain a firm grip on us, its primitive denizens who only moments ago hunted mastodons and worshipped the sun? To dare now and leave this world after only having just left the trees? Such impudence! The very notion evokes the Iliad, and Apollo's warning to the Achaean commander on the field of battle: Beware Diomedês! Forbear, Diomedês! Do not try to put yourself on a level with the gods; that is too high for a man's ambition.

Where Earth is jealous, the attitude of space is all the more horrible. Space is indifferent. You want air? There's none to be found. You want food? Nothing grows here. You have a weakness against radiation? Not only will you get cancer here, and fast, but the nasty, aggressive kind. Space lobs Maslow's pyramid off at the base. None of the basics are there to be found. And so with launch after successful launch, mission after successful mission, we are Diomedês hacking away at Aeneas. We are the young Achaean wounding Ares!

We forget how hard it all is, how many things can go wrong. How many things have gone wrong. We forget that back when the Soviets were sending cosmonauts into orbit, the very name "NASA" was synonymous with rockets blowing up on the launch pad. We forget the spacecraft lost, again and again. Apollo 1 and Challenger and Columbia. The Mars Climate Orbiter, disintegrated at the Red Planet. The vanished Mars Explorer. The Mars Polar Lander. Antares blown to pieces, its Cygnus cargo spacecraft faring no better. The SpaceX "anomaly" that threatened OSIRIS-REx — the mystifying explosion that came without warning and seemingly without cause — that is space exploration. That is the reality. Not clockwork launches with clinical precision.

Stunning, almost spiritual launches like that of OSIRIS-REx are the best case scenario. If we launch another thousand rockets with only a single loss on the launch pad, it is the lost rocket that is the most authentic of the group. Every success is a testament to science and engineering, daring and hubris. Thousands of parts comprise every rocket and spacecraft, and thousands of hands touch them. Metals from every corner of the Earth go into the smelting, molding, and machining of every vehicle. The most innovative of instruments and computers work with laws of physics first formulated by the ancients. Space exploration is the summation of the complete history of human knowledge, and the leveraging of every resource forged and granted by geophysics. Space requires everything, and permits no errors.

Planes crash. Cars collide. Bicycles fall. Pedestrians stumble. No conceived conveyance has ever yet attained perfection. And so when humanity loses a spacecraft, it is sad, and sometimes tragic, but it is anything but unusual. And just as we get up, brush our knees, and amble forward after a fall, so too must we after an explosion leaves a launch pad a gnarled and melted mess. If anything, we have a moral imperative to launch again, and soon. After all, space isn't merely indifferent to humans and our vessels. It is indifferent to our entire little world. If some unknown asteroid's orbit brings it in direct contact with our planet, vaporizing the whole of our species, space, devoid of any interest, will go on, just as it did for the 14 billion years before we came into being.

For now, OSIRIS-REx is away. Michael Drake didn't live to see the launch. He toiled for seven years to win mission authorization from NASA. Twice during that time, proposals of extraordinary detail were rejected in favor of other missions to other places, but he pressed on. In September 2011 — 12 years after the discovery of Bennu, and four months after NASA finally, formally approved OSIRIS-REx as its next New Frontiers mission — Michael died of cancer at the age of 65, leaving a great hole in the field of planetary science. The mantle of leadership fell to Dante to lead "up and out," and he succeeded. Now comes "down and in."

In two years, the spacecraft will enter orbit around Bennu, and Dante and the University of Arizona team will spend just shy of two years scrutinizing every square inch of the mysterious asteroid, learning all that can be learned. When the time is right, the spacecraft will extend its sample collection arm, and ease down into its surface, 10 centimeters per second, until the sample collector makes contact and gives Bennu a five-second kiss. During that kiss, a burst of nitrogen will be released, agitating Bennu's loose surface material and sending it into the collector head. Bennu will then back away and begin to spin — a true first kiss indeed! If the sample collection was successful, the newly collected asteroid material will affect the angular momentum of the whirling spacecraft. Scientists can calculate the precise amount of sample from the spin maneuver. If there's not enough, it can sneak two more kisses. The sample collection arm has been in development and testing for a full decade. The OSIRIS-REx team is optimistic that its quarry might be measured not in grams, but in pounds. The arm will place the collected material in a sample canister, and the spacecraft will set a course for Earth. Just after arrival home on September 24, 2023, it will eject that canister. A parachute will deploy, and the protected sample will drift gently down into the Utah desert. From there, it will be transferred to Houston, to the very place where the Apollo moon samples were brought back for analysis.

This mission is not just for us, but for future scientists who will have at their disposal tools and techniques we can only scarcely imagine. Fifty years ago, computers were only just being applied to the field of geology. The tools of science 50 years from now are all but inconceivable. As such, three quarters of the asteroid sample will go into long term storage. Such foresight on the part of NASA and the OSIRIS-REx team is completely in keeping with the beliefs of Andrew Ellicott Douglass, the tenacious professor who fought fervidly to establish the first observatory at the University of Arizona nearly a century ago — the observatory that put the university on the map and allowed it to later attract luminaries in the burgeoning field of planetary science.

Looking back now, it is as though Douglas had anticipated Bennu's discovery and the mission there. "Astronomy was the first science developed by our primitive ancestors thousands of years ago because it measured time," he said at the observatory's 1923 dedication. "Performing that same function, it has played a vast part in human history, and today it is telling us facts, forever wonderful, about the size of our universe; perhaps tomorrow it will give us practical help in showing us how to predict climatic conditions in the future."