Saturn Rukh (9 page)

“So the air will be a little thick,” said Pete. “That just means my meta factory will be working at higher efficiency—the sooner to get us home.”

“It’ll be like living in an ocean of air instead of water,” said Sandra. “I can’t wait until I get to go out in my saturnsuit and collect some specimens swimming around in that ocean.” Later that evening, the crew gathered on the upper deck to listen to the latest report from Space Unlimited Mission Control. Art Dooley was there.

“Good work!” he said with a smile. “You’ve gotten there. Now comes the hard part, getting down and getting back up. Telemetry says that the ship is working fine, but of course you know that, with Jeeves right there monitoring everything as well as we can. CrewComm says that the microwave and laser links to the orbiters around Saturn are also working fine, so you should have no problem communicating with us as you climb down the rings—except, of course, for this blasted two-and-a-half-hour time delay.” He turned around to look at the small group in the control room. “Anybody else have anything to say?”

The head of the imaging science team stepped forward from the group of scientists standing at the back. “Take your time going in,” he said.
“Sexdent
has on board the largest, most sensitive, highest-resolution telescopic camera that has ever been to Saturn. Make sure you take the time to get
lots
of good pictures of the rings and all the moons, especially Iapetus—it’s quite volcanically active, and we have yet to figure out how it maintains its two-toned color pattern.”

“Will do,” Sandra reassured him, then shook her head at the stupidity of her reply. He wouldn’t hear her response for over an hour.

No one else stepped forward, so Art turned to look at the person sitting behind the CrewComm console.

“Take her down, Commander Morgan,” said CrewComm.

~ * ~

Three days later
Sexdent
reached the orbit of the outermost moon of Saturn, Phoebe. The small planetoid, in its highly inclined orbit, happened to be up near their incoming path, so everyone gathered at one viewport or another to watch as they passed over it. Chastity rotated the capsule until its nose was pointing at Phoebe so all of the ports had a good view.

“Looks like a small red version of Luna,” said Dan, looking through one of the biviewers. “Dark reddish-gray dust with craters in it.”

“It is a very much smaller moon than Luna,” remarked Seichi. “Only two hundred twenty kilometers in diameter compared to Luna’s thirty-five hundred.”

“I wouldn’t even call it a moon,” added Chastity. “Its orbit is not only way up out of Saturn’s equatorial plane, it’s orbiting the wrong way. It’s just a stray carbonaceous chondrite asteroid that Saturn probably captured in the distant past when it had an extended atmosphere.”

Phoebe quickly passed out of view and Chastity turned the capsule back again to face Saturn. The orange planet was now a half a degree across in the sky—as big as Luna in the skies of Earth.

“I’m beginning to see bands,” said Sandra.

“You should try these biviewers,” said Dan, pushing the multispectral binoculars toward her on their pantograph. “I’ve got it set for wide-band visible with color stretching. The UV Spot in the lighter band about thirty degrees north of the equator really shows up well with that setting.”

“Wow!” said Sandra, impressed. She flipped the setting back to normal visual band. “In real life, however, UV Spot is really kind of dull. Just an orange blob on an orange band on an orange sphere.”

~ * ~

Three days later Saturn was much larger.

Sandra and Dan were at two of the consoles, while Chastity flew the capsule for them from the pilot’s console. On Sandra’s console screen was an enlarged image of some small features on the giant planet taken by a telescope looking out through a vacuum port in the engineering compartment on the facilities deck.

The rapidly rotating planet had a day of only ten and a half hours, so interesting features were at good viewing angles for only two or three hours. Since a good set of scientific images required a dozen images taken at different spectral bands, and the sunlight at Saturn was one percent as bright as sunlight at Earth, it took a good fraction of an hour to do the job right. So Dan, acting as spotter, used the biviewer above the scotty console to find interesting objects for Sandra to focus the large telescope on.

There were lots of features to be seen. Saturn had dozens of east-west bands of differing shades of orange. The bands moved with different wind speeds. Most of the winds blew in the direction that the planet rotated, so that features in those bands actually moved faster than the planet rotated. There were brown and white spots—various types of temporary cloud features—that moved along these bands. Some weather bands near the poles had repetitive swirls of clouds. In the northern hemisphere, there was one band that had what looked like a circumpolar river of clear air snaking back and forth through the center of the continuous cloud bank that made up the band. Strangely enough, there was no comparable feature in the southern hemisphere. With so many features to look at, and the rapid rotation of the planet that brought more features into view each minute, the real problem was to choose which features to take pictures of.

“Anne’s Spot is now well over the horizon,” reported Dan.

“I’m finished with White Spot Two,” said Sandra. “What are the coordinates of Anne’s Spot?”

Dan switched on the holoprojector for the viewport and Saturn suddenly had latitude and longitude lines superimposed on it. Two of the lines crossed near the center of a large oval red spot. A miniature version of the Great Red Spot on Jupiter, Anne’s Spot was five thousand by three thousand kilometers in size, a third the diameter of Earth. Although nothing but a gigantic cyclonic storm, it was a very long-lived one. It was first seen during the flyby of the first
Voyager
spacecraft and had not changed much since. It could well be hundreds of years old.

Dan read off the numbers where the two lines crossed the red oval. “Anne’s Spot is now at one hundred fifteen degrees east and fifty-five degrees south.”

“You might want to consider an alternate subject,” interrupted Jeeves. “We are crossing the orbit of Iapetus. Closest approach will be in three hours. We will be flying by to the north of its leading hemisphere.”

“Iapetus,” said Dan. “Isn’t that the yin-yang moon? One half black and the other half white?”

“Not quite half and half. More like one-third black and two-thirds white,” replied Sandra. “Hmmm...” she added, obviously in a quandary. “During the last transmission the planetologists reminded me to take as many shots of Iapetus as I could. They’re hoping to catch a dust volcano that is keeping the leading sector covered with dark material. It’s their best guess as to what is causing the color difference, but there’s no proof. But I’d hate to cut my photo session of Anne’s Spot short—”

“We can do both,” suggested Chastity. “I can rotate the capsule around the line of sight of the telescope so you can keep shooting White Spot, while Dan can take photos of Iapetus out his viewport using the biviewer.”

“The biviewer won’t have the resolution of the telescope, but it should be good enough to spot a volcanic eruption,” said Sandra. “Do it.”

Chastity stuck her right hand into the controller and carefully rotated the joyball inside. The capsule turned over so that Dan’s up was now south instead of north.

“Got it!” he said shortly. He adjusted fingerwheels along the grips of the biviewer. “Expanding…” The tiny image in the biviewer grew into a picture of a cratered moon. The north pole was the bright white color of ice while the leading pole was almost a soot black. The demarcation between the white and the black was almost as if someone had used black spray paint to create a black crescent-shaped segment that stretched across the leading hemisphere from inner pole to outer pole. Dan looked carefully for the hypothesized “dust volcano” in the center of the black that would have acted as the spray can for the black paint, but it wasn’t there.

“Sorry. No volcanoes today.”

“Take pictures anyway,” said Sandra.

The two were trying to collect as much scientific data about the giant planet as they could during this close approach to add to that already in the scientific archives back on Earth. Pretty soon they would be inside Saturn’s atmosphere, and although they would learn a lot there, they would lose the synoptic overview that came from having the whole planet in their view at one time.

Saturn and its moons had been well explored by robotic probes and orbiters in the past, but the Earth scientists had emphasized that the images they were gathering would be useful for finding changes that had occurred since the last robotic visits.

After dinner that evening of macaroni and cheese, Rod made an announcement.

“We have less than twenty-four hours left. Get a good night’s sleep. Tomorrow we pull the habitats in and go onto shifts. For the next few days we’ll be using sleeping-bag hammocks in the airlock.”

By noon the next day, all the habitats had been emptied of personal belongings, stripped of bedframes, and stacked one inside the next on the facilities deck. The bedframes had been rearranged into acceleration couches on the control deck for the high-gee maneuvers that would be coming next.

They were eight hours out when they passed over the orbits of Hyperion and Titan. Titan was on the other side of Saturn, which now filled six degrees of the sky, but Hyperion passed under them. They got some long-distance pictures of the oddly shaped object. Since they were moving so fast, Sandra was able to make a three-dimensional holographic strip from a series of images taken a few minutes apart. She had Jeeves display the reconstructed three-dimensional image on one of the holoviewports.

“Looks like a hockey puck,” said Pete.

“Or a skipping stone,” said Dan.

“Looks like a hamburger to me,” said Rod. “A nice, big, juicy, flame-broiled, fat burger—”

“Stop it!” said Chastity. The crew had a choice of many excellent entrees for their meals on
Sexdent,
but grilled fresh-ground beef was not one of the options. All of them had agreed one evening that one of the first things they would do when they got home was visit a McDonald’s and have a Big Mac— although Pete held out for a Quarter Pounder.

~ * ~

Saturn grew in size until its disk was thirteen degrees across. It was tilted toward the Sun, with its north pole and upper ring surface illuminated.

Pete and Chastity were hanging in the sleeping bags in the airlock. They were merely resting, for it was too early to sleep. Up on the operations deck, Rod controlled the orientation of
Sexdent,
while Dan and Sandra continued their photographic survey of the features on the planet. It was now obvious to Dan that they were heading for the eastern edge of the giant planet, right at the point where the shadow line of the Sun on Saturn passed under the rings.

“Doesn’t look like there’s much room between the D ring and the cloud deck,” said Dan, using the biviewer to bring out the faint arcs of the innermost ring.

“Isn’t...” said Rod. “Technically, there’s zero margin because of the bits of junk spiraling in from the D ring. But it’s pretty sparse—we’ll just have to take our chances when we pass through the ring plane.”

“That’s going to be a very nervous couple of minutes.”

“Milliseconds ...” corrected Rod. “The rings are something like ten to a hundred meters thick. At our speed of over fifty klecs, we’ll pass through the ring plane in less than two milliseconds. At the speed we’re going, if there’s something big in our way, we’ll never know what hit us.” He noticed Dan’s frown. “But don’t worry, Doc, I’m going to do my best to miss it. I’m going to have
Sexdent
kiss the upper atmosphere with its heat shield, so we should be below nearly all the junk.”

“What about when we come out around on the other side?” asked Doc. “Will we still be able to make it through under the D ring?”

“Doesn’t work that way,” said Rod. “I’m going to make our new periapsis point right over the eastern terminator. That way, our new elliptical orbit will be at right angles to our incoming trajectory. Our track will stay well away from the rings because the peak of the new orbit will be high over the rings on the western side of Saturn. Our orbit will be in the ecliptic plane with its long axis at right angles to the Sun direction, while Saturn’s rings are tilted at twenty-six degrees to the ecliptic and are facing the Sun. The only place the orbit gets near the rings is when it passes just under the rings over the eastern terminator. We plan on meeting Titan out at the apoapsis point and stopping there. Titan’s orbit is also tilted, so we will be coming in at it at a steep angle, but by picking the right firing point I should have no problem stopping. Even if we miss that rendezvous, all we’ll do is come back in and go under the rings at the same place over the eastern terminator where we started the new orbit.”

Dan continued to search the western limb for new targets for Sandra to image. Because she now had a lot more targets to photograph, instead of a dozen different spectral band images of the same feature, Sandra was now taking only four “color” shots of each one: red-infrared, blue, green, and ultraviolet.

“A small white spot is colliding with Brown Spot One at thirty-three degrees east and forty-two degrees north,” reported Dan.

“We’re starting over the E ring,” reported Rod.