Lisbet woke from a fitful slumber and disentangled herself from her sleeping bag. She felt the weightlessness of microgravity in her arms and legs as she pushed herself across the captain's quarters in a gentle arc from her bunk to her dressing cabinet. Black hair floated in a loose halo around the face that looked out of the mirror at her and slowly settled around her shoulders. The one-quarter g of acceleration from the ship’s engines was enough to pull her feet gently to the “floor” of the cabin, but even after several months aboard the Photon it still occasionally gave her the impression that things were happening in slow motion. Lisbet touched the dark circles under her eyes as she looked at her reflection. She had not slept well the previous shift, and she could not put a finger on why.
As she dressed, she thought over her previous duty shift. Nothing out of the ordinary came to mind that would cause her a restless night. Her meals had been standard and eaten at the proper intervals. Ship’s operations were all nominal, engine output within tolerances and all critical systems running green. There had been nothing of note in Lambert’s end-of-duty briefing, and communication from Earth had been routine, confirming that their position and trajectory were still as expected. Or at least that they had been at the time the messages were broadcast from Earth. The reports were now two weeks old by the time they reached her. No, she reminded herself, they were a set and a half old. Earth time didn’t mean anything onboard the Photon. It was past time that she got used to the new naming conventions.
That’s when it occurred to her. Something at the end of the broadcast had been tugging at her subconscious since she had first read it. “By our calculations and by the time you receive this broadcast, you will be passing into the Oort cloud--the birthplace of comets. The Sol system says ‘farewell.’”
Someone back at mission control had been waxing poetic. But thoughts of the Oort cloud stuck with Lisbet. In comparison, it had taken the Photon just 25 days to reach the inner edge of the Kuiper belt--the vast asteroid field that stretched out beyond Neptune’s orbit and contained the dwarf planet Pluto. At the time they reached the Kuiper belt, they had been traveling less than 2 percent the speed of light, but it had only taken them three additional months to reach the belt’s outer edge. Now they were almost seven months into their journey and traveling at 14 percent light speed, and yet, they were just now reaching the inner edge of the Oort cloud, and it would be years before they came out the other side, traveling 70 percent the speed of light. The immensity of interstellar distances had been playing in her head since her last duty shift.
The birthplace of comets, she thought to herself as she finished dressing. In reality it was unlikely they would pass within visual range of even one of the trillions of icy objects in the Oort cloud. Even so, the ship’s sensors were constantly scanning and mapping the trajectories of all of the nearest objects. Anything within a million miles would be tagged well before it posed a threat to the Photon and her charges.
Lisbet pushed gently off the floor of her cabin and reached for the handles of the grav ring. This slowly spinning section about ten feet from the floor of her cabin was the only entry or exit. It contained two color-coded openings: blue, leading to command, and yellow, leading to the gym. In one smooth motion she sent herself feet first through the yellow opening and into a long, narrow shaft that extended out from the center axis of the ship. She kept her arms outstretched, brushing the sides of the corridor and keeping herself centered within it. Eventually she felt herself begin to accelerate and she caught the rungs that lined one wall of the shaft. She moved hand over hand farther outward, which began to feel like downward as the rotational force simulated gravity. She dropped to the floor of the gym and felt a familiar weight in her limbs. She knew she was actually experiencing 1.3 times earth gravity, but her body couldn’t tell the difference.
She hit the treadmill first, slowly working her heart rate up to 225 beats per hund, then she switched to her prescribed resistance workout. By the time she finished she could feel the sweat dripping between her shoulder blades and her workout clothes clung to her. She pulled a water pouch from a chilled alcove in the wall. She drank until it was empty and dropped it into a receptacle, where the ship would collect, sterilize, and refill it before returning it to the cooler.
Then she began to climb the ladder back to her cabin; the workout after the workout, she called it. Eventually the rotational force decreased enough that she could launch herself upward, executing a midair somersault as she passed through her cabin and into the blue tunnel. Again she caught the rungs as she felt herself accelerate and climbed down into the command module. There, she retrieved a trio of pouches from the meal kiosk and plugged two of them into the rehydrator in succession. After the first finished hydrating, she shook it and dropped into the heating drawer. After a moment she gathered the three pouches again as well as her dishes and moved to her command chair. She opened the two cold packets and dumped them both into her bowl. The contents of the hot pouch she squeezed onto her plate and began to mash them around with her fork. Ostensibly they were eggs, but nothing she did could make them taste, or feel, like they used to back on Earth.
As she ate the eggs and cereal she checked her morning reports. She listened as the computer read the transcripts aloud to her. She smiled to herself as Lambert’s end-of-shift mentioned their milestone. “By distance traveled we’ve successfully passed into the Oort cloud, however, long-range sensors are still reporting we’re at least six-kay from the nearest celestial objects.” Of course his end-of-duty reports always used the new time conventions, so did hers, but Lisbet wondered if the terms came more naturally to Lambert than herself. She checked the timestamp on the report. It had been filed just over 2 hours ago, or eight-kay pulsars. The computer voice continued, “Long range sensors are currently tracking and tagging up to 50 million kilometers out and haven’t identified any potential close encounters. We’ll continue to push that envelope outward to give the navigational software as much reaction time as possible. I estimate we should be close to 70 million clicks by the time you start your shift.”
She checked her sensor display, sure enough, the sensors were currently identifying objects at a distance of 67.4 million kilometers. This progress would slow, she knew, both because each additional kilometer meant exponentially more volume for them to check, and also because the farther into the Oort cloud they travelled, the denser the concentration of celestial objects might be. Back on Earth the engineers had estimated that the sensors’ maximum effective range would be around 100 million kilometers until the Oort cloud began to thin as they reached its outer limit.
That meant that while they now had nearly 30 minutes lead time on any potential collision threats, as they accelerated that would be cut to roughly 9 minutes. Still plenty of time for the sensors to plot an object’s trajectory and recommend a course correction and for navigation to execute it. This would all happen automatically, of course. The sooner the course correction happened, the less fuel was needed, and the easier it would be to adjust back to their desired course. Human interference would only slow the computers down.
Lisbet noted that the sensors had flagged two nearby objects whose trajectories would bring them close to the Photon. One, the size of a bus, would pass within 90 kilometers, while another, over a hundred kilometers in diameter, was estimated to pass within 35 kilometers. She whistled to herself. So much for not getting within visible range of anything! They were on their first day in the Oort cloud and already they were going to get a flyby. And a close one!
She double checked her sensor display. The smaller object would pass by first, but wouldn’t be visible. The larger one was still about 15 minutes out. The computer was recommending no course correction, reporting with 99.7% confidence the object would not enter the 25 km safe zone around the Photon. She knew that this far out there wasn’t enough sunlight to illuminate the object. It would remain virtually invisible until it was close enough for the ship’s lights to pick it up.
She waited patiently as the time ticked by. Suddenly the viewports around her were all filled with a bright blue-white light, there and gone in the briefest fraction of a second like a flash of lightning, but with no accompanying thunder. She felt a rush of adrenaline. For months she had barely bothered to look out the viewports at all. Nothing but the unchanging stars looked back from them. The sun and planets had long ago faded to insignificance. Just more lights in the sky. But this! She had just been the closest any human had ever come to a comet, while also being the furthest from Earth any human had ever been.
She sat, trying to comprehend an experience that no one in human history has ever had, and might never have again. She found comprehension impossible. Lisbet turned back to her breakfast and her reports. After breakfast she returned to her cabin to use the refresher and change from her workout clothes to her uniform. The day became routine, but the joy of discovery stayed with her. She pored over the sensor readings and infrared images of the object, which confirmed that it was an icy body. The birthplace of comets indeed! She would be sure to flag the images and readouts for Lambert in her end-of-shift.
The rest of her duty shift passed without event, as did the next, and the one after that, and the next hundred or so after that. The Oort cloud was truly as empty as the scientists had predicted. Their unbelievable luck of the first day never repeated. In that time, the Photon had seven more visible flybys, but none as impressive or as close as that first day. Not day--cycle, Lisbet thought.
Any sense of solar time should have died then, when they were beyond even the furthest solar objects. But Lisbet found that the old names clung to her. She understood the logic of the new system. She even agreed with the necessity of it. Hundreds of light years from humanity’s birthplace, no one needed to keep track of how many times an impossibly distant ball of dirt and water spun in place or orbited it’s star. So the scientists and bureaucrats, at the same time they were deciding Photon’s destination, crew roster and cargo manifest, devised a simple, logical time construct that would create a uniform structure for an entirely new star system.
Just 30 light years from their destination was a pulsar which rotated slightly faster than once a second. This rotational period, simply called a “pulsar,” would become the basis for the new time convention. A hundred pulsars, or “hund”, was about a minute and a half. A thousand pulsars, or one “kay”, was 15 minutes. And the values increased by powers of ten from there. Kays were grouped into tenkays, which were about two-and-a-half hours. Ten tenkays made a cycle, ten cycles made a set, and four sets were a block.
There had been much debate about this as it broke the metric convention, but ultimately it was agreed that people may need familiar time constructs and measurements. A set was longer than a week, and a block was longer than a month, but they were similar enough to maintain some familiarity and to keep human civilization recognizable even so far from Earth. The scientists assumed humans would still need “days off” and thus expected most people to work seven or eight cycles per set and to get one set of vacation every few blocks. And of course, every ten blocks was an annum, marking the passage of just over one earth year. Messages from their destination would travel 250 annum at light speed to reach Earth. And messages from Earth would travel 285 years back.