I can already see a disk! Frank said excitedly, without looking up, as Dave entered the room.
Let me see. He planted his Grip Shods on the carpet in front of the telescope and gave Frank a friendly shove to one side. The asteroid looked like a gray disk, clearly oval rather than circular like a planet, and one or two large craters seemed to be visible.
HAL, did the project receive any specific observation requests from the asteroid science community? Dave inquired.
No, and quite frankly, there was so little time between the public announcement and launch, and the primary mission is so important, that I would doubt that any formal announcements of opportunity were made.
And by the time the word gets to them through Mission Control and back to us, it may be too late to make a good decision, Frank pointed out. Its Saturday night in North America, Sunday morning in Europe, according to HAL. Probably none of them will even be there to answer their picture phones, and then what? They cant keep calling everyone all day, hoping to catch them in.
OK, well have to use our own judgement. Have you notified Mission Control, HAL?
Yes, said HAL, and weve sent them an image and some spectral plots that Im afraid are rather bland so far, and poorly calibrated. The earliest possibly reply will be in thirty-five more minutes.
OK, lets start thinking about how were going to do this. Frank, did you made any coffee yet?
Sorry, havent had a chance. Anyway, I like the way you make it.
No rum this time, buddy. Were on duty.
You know thats not what I meant. And Im perfectly capable of getting enjoyment out of a straight cup of coffee if thats all thats available, he said with a hint of a smile.
HAL, are you sure youre using all the colors? Is the filter wheel working?
Quite sure, Frank, and its working perfectly.
Well, youre right, I dont see much color either, Frank said, peering directly at it through the telescope.
Can you enhance the color, HAL? Dave asked.
Of course I can.
The two men bent over the screen, which now showed some subtle coloring. How much did you have to enhance it for those colors to show? asked Frank.
Heres a picture of Earths moon enhanced the same way.
Wow. Psychedelic. Any idea why the asteroid is so gray? Frank asked. Either of you? he added, glancing at Dave.
Um, wasnt there some speculation that the dust and debris ejected from all the impacts with smaller asteroids would wind up getting spread out all over the surface?
Now that you mention it, Dave, HAL put in, I find some references to that in the literature. Would you like me to print out the two papers Ive located?
How about just the relevant sections, and well read them a little later? Dave asked, and immediately heard the line printer start feeding paper.
The gist of it seems to be, HAL summarized, raising his voice over the clatter of the line printer, that asteroids should coat themselves uniformly with ejecta and dust from billions of years of impacts, because they are large enough that most of the particles wont be thrown off at escape velocity, yet small enough that the particles can land anywhere on the asteroid, even the other side, by the time they are pulled back down. He displayed an amber wire-frame diagram. You see, each particle can follow any suborbital trajectory.
Frank rubbed his chin. If there were a fresh impact say, within the last thousand years then there wouldnt be enough newer impacts to coat it with dust, and we might see the colors of the minerals.
Yes, HAL acknowledged, but the chances of finding a fresh impact site are considered vanishingly small, at least by these authors, and just a moment yes, also from what Ive been able to absorb from the three other papers Ive been reading, as well as a basic textbook on the subject. The efforts of a thousand key-punch girls to enter HALs library was clearly paying off, Dave noticed.
Are we stuck with remote sensing? Maybe we can use one of our probes, Frank proposed. Lets see, the one easiest to get to would be... heh. The Ganymede penetrator.
Im afraid that would be in violation of the mission rules, Frank, HAL pointed out. All of the probes and their instruments are reserved for the primary mission. The magnetometer on that probe, especially, would be wasted on an asteroid. All magnetometers are reserved for the Jupiter system, with utmost priority.
Remote sensing it is, then. And only ancient, dust-covered craters in sight. Damn. Frank frowned and rubbed his jaw, then suddenly snapped his fingers. What if we made our own crater?
Dave looked at him. You mean throw some dead weight at it? Make an explosion? What a cool idea, Frank!
Turnabout is fair play, Frank said, nodding at the permanent patch theyd placed over the micro-meteoroid hole.
Ill remember you said that. But not right now, Dave told him in a low voice.
At our relative velocity to the asteroid, HAL calculated, the impact should be enough to form a new crater, according to most accepted geophysical models.
That made sense. The ship was traveling at a tremendous velocity, and would flash by the asteroid at that speed. Gently nudging something into its path would certainly take a chunk out of it. Just make the stuff they throw take a slightly different course than the ship, and it would run smack into it.
Unfortunately, HAL added, it might also raise enough additional dust to make viewing even more difficult for the next hundred years.
Even the dust would produce a lot of new data that has to be useful to someone, Dave guessed. First lets figure out if its possible.
Yes. It is. HAL concluded immediately. We have over four hours, and the asteroid will be within nine hundred kilometers at closest approach. One of the spare jet packs has enough fuel to accelerate both itself and a fifty kilogram payload to nine hundred kilometers per hour, in time to push it into the asteroids path. That much mass should make a sizable crater. If you could prepare it within two hours or so and aim it precisely enough, we would have a significant chance of hitting it.
And maybe a glancing blow would solve the dust problem, Dave offered. We only have to scrape off some of the coating, not blow a hole in it.
Thats a great idea, Dave!
Franks praise warmed him; he ducked his head to hide his smile. Im sorry if it means you dont get to blow anything up, he teased, patting his shipmate on the shoulder.
If any of the models are correct, HAL concurred, most of the dust would be carried away from us. Accuracy might be a problem, since you would have to aim the jet pack manually, and the load will be unbalanced.
It would be easy to wire a radio-controlled switch to the jet pack, Dave suggested. Could you use that to control its trajectory?
Yes, that would make an enormous difference. If you simply tumble the pack, I can pulse the jets whenever theyre facing in a favorable direction, and make course corrections for the first ten kilometers or so. That makes the asteroid fill most of the one-sigma uncertainty ellipse. However, the effects on the available delta-vee integrated over time are a bit hard to predict, since they depend on the tumble. I will have to work through a few simulations.
What if I start it moving with the pod? Frank offered. That would be the easiest way to do the EVA anyway.
That would certainly increase the margin, Frank.
Is there any way to get our chances better than one sigma? Dave asked.
The greatest source of inaccuracy is the inability to do course corrections up to the last possible moment. Once its out of visual range, accumulated errors in my estimate of where the jet packs are pointing at any given moment will increase to several degrees.
We could add a light, Frank proposed.
Three lights, mounted on different axes, Dave amended.
Yes, that would be extremely helpful in ensuring accuracy. I could then achieve a one-sigma ellipse of plus or minus ten meters.
Fantastic! Sound good to you, Frank?
Yeah, lets do it! He raised his hand, and they exchanged high-fives.
Fifty kilograms of water (ice by that time) would serve as well as anything else to provide punch. For all they knew, it might briefly enter a liquid state on impact before flashing into vapor, and wash even more dust off than it would sweep off mechanically. It would make no significant difference in the shielding or in their backup volatile reservoir.
They were ahead of schedule so far, but the big problem they still had to solve was to find some way of containing the water or attaching it to the jetpack. Frank suggested soaking some of their T-shirts, plastering them to the jet pack, and wrapping the whole thing in plastic until they could get it frozen. Dave protested that they couldnt spare very many shirts, and when it became clear that Frank thought they were all expendable, Dave pointed out that if they got an explosion on impact, contaminating the emission spectra with an organic material like cotton would throw off the analysis more than necessary.
They were running short on time, but Dave noticed his friend yawning despite the excitement and pressure, and decided that brewing another tank of coffee would be a good investment of time. He almost changed his mind when he realized that the coffee can was almost empty, and hed have to take the time to open up a new one.
They were using the same kind of coffee sold on supermarket shelves, and it came in cans. The special government-procured astronaut coffee in Mylar packs would have cost seven thousand dollars a pound and tasted terrible. Dr. Floyd had somehow managed to convince the other bureaucrats that off the shelf coffee would be a better choice, since the cost of lifting of the cans to Earth orbit and boosting them to Jupiter would still be less than the price the coffee contractor had wanted to charge for special lightweight packaging. He was even able to get them to spend a few extra dollars a pound to get them the best gourmet coffee available. The disadvantage was that it required a specially designed vacuum scoop that attached to the plastic lid and probably cost more than Dave made in a month. Another disadvantage was that they had already accumulated about a dozen empty cans. They took up a lot of space and were impossible to flatten. Dave had once tried cutting the bottom off of one, and he still couldnt flatten it with his hands, or even warp it. Recently hed toyed with the idea of taking the accumulated cans down to the carousel and seeing if the combined weight of two men, piggyback, could flatten them. He had not yet worked up the nerve to suggest it to Frank.
Heres some fresh coffee, he said, handing Frank a bulb. You look like youre running out of steam. You sure youll be awake enough to point the pod in the right direction?
Tis but to help strike an asteroid. No wondrous feat for Starbucks.
Huh? Fatigue apparently did strange things to Frank. Oh, by the way, I had to start another can. Were going to have to think of a way of flattening the empties. We could use the extra storage space.
Hey, the coffee must be working already. Ive thought of a way of containing the ballast.
They found it was easiest when the man pumping was held in place by the other man, and Dave found he was now comfortable enough with the close contact that he didnt shy away from bracing Frank, and was not so distracted when Frank braced him that he couldnt concentrate on his pumping. They tried a variety of positions; the one Dave found made pumping easiest was when he was standing normally on the floor, while Frank put his feet on the ceiling and held down his shoulders. This also gave Frank a chance to knead Daves shoulders through the thick fabric of his uniform and the soft T-shirt underneath. He was fairly gentle, for a change. Dave did the same thing when it was Franks turn at the pump, and Frank seemed to appreciate it, so Dave guessed that even his well-conditioned shoulder muscles must be protesting under the strain.
They finished in plenty of time to get Frank into his suit, although Dave would really have preferred to have checked all his seals a third time.
Youre looking good, confirmed Dave.
Beginning thrust. Feels good.
Feels good to be going somewhere, even though this isnt exactly a high performance aircraft. I could run faster than this.
Give the old boat a few minutes. Acceleration takes time. Dave would have enjoyed the chance to go out himself. He could have had this job, if hed insisted. He could easily have argued that Frank was too tired; they were in fact bending the rules to let him pilot on so little sleep. But one look at the excitement in Franks eyes at the prospect of going out, and the silent plea on his face, and hed yielded the task to him.
And I show that Im on the trajectory that HAL uplinked.
Radars showing that youre on the button, Frank. Ready to start the tumble and release it?
I want to get a little more delta-vee.
Dave rechecked the display hed asked HAL to maintain of the oxygen supply remaining in both the pod and Franks suit. The suit had over an hour left, just as hed expected from the manual gauge, and the pods supply remained steady since he wasnt breathing it. Roger, but remember, your velocity relative to the ship may feel slow, but there may be a few loose pebbles out there that see it differently. Every minute you spend out there increases the risk. The pod had a much lower PNP than the ship. There was as much chance of a micro-meteroid penetrating the pod every minute he stayed out there than there was in a week aboard the ship. Thats what the spacesuit was for, of course, but it wouldnt do much good if Frank himself were struck directly by a sand grain that could pierce his spacesuit.
How could I forget? OK, just a few minutes more.
Dave made himself wait, listening to the sound of Franks steady breathing into the helmet microphone pickup, the most comforting sound in the universe. He counted one hundred breaths. Outside, the pod dwindled like a brightly colored stone sinking into the inky, airless depths. Soon it was only a light, lost among the stars. Dave was uncomfortable losing visual contact with Frank, even with HAL tracking him on radar and monitoring his telemetry. It seemed unnecessary, when a slight push would have been plenty to get it started. Frank, he radioed when he could no longer stand it, dont push your luck. Its got plenty of delta-vee on its own. Remember, this is the asteroid belt; there are billions of little pointy things out there that are too small to detect.
You know, Ill bet I could aim it myself, and give it all the delta-vee it needs.
Frank, thats a completely unnecessary risk. It would also put you on a collision course with the asteroid, and what if your thrusters failed when you tried to reverse course? Turn that thing around right now and get the hell back in here! He wished now that hed gone himself.
Frank hesitated and then said, Roger. Is the current trajectory good, HAL?
Affirmative, Frank. Well within margins. Im quite certain I can take it from here.
Okay, time to mash this potato! Shutting down thrusters and coasting.
Confirmed, HAL said. Youre ballistic, Frank.
Releasing manipulators. Pushing with left manipulator. Yep, its tumbling.
Five point seven RPM, reported HAL. Good work, Frank. Give me just a moment to test the radio control. On his screen, Dave saw the rotating jet pack jump away from the pods camera. Ten seconds later another kick increased its speed.
Looking good, HAL. Great job, Frank. Now get back in here!
Turning around now. Stopping turn. Okay, Im reversing course, and guess what, Dave? The thrusters are working perfectly. Right, HAL?
Confirmed, Frank. Pod thrusters are performing at hundred two percent of nominal thrust.
Of course, Frank was still coasting further and further away from him as he gradually decelerated. Dave could no longer even spot the light. Every minute the thrusters had been burning was another minute hed have to spend slowing down. Dave asked HAL to report when the pod actually started moving back toward the ship. It was a purely psychological milestone, but he would feel much better once he knew that Frank was really headed back. As soon as HAL announced that the pod was finally coming closer, he started watching out the window, looking for the tiny pods approach. It seemed like a long time before he spotted it, but then it was the most welcome sight hed seen in a long time. Not much longer now. But he still waited tensely, and didnt really relax until he heard Frank asking HAL to open the pod bay doors, and knew Frank would soon be safely back in the ship. He headed down, forcing himself to take his time and descend the ladder instead of diving down head first.
Sorry if I had you worried, Dave. I was thinking, on the way back, how I would feel if Id been the one sitting in the ship, with nothing to do but think about but what could go wrong, and how I wouldnt be able to do anything to help you. Its different when youre out there, piloting. Wish you could have come along with me.
Dave sighed. I understand. I wish I could have, too, but you know that HAL isnt allowed to let both of us out at the same time. One of us has to mind the store. Anyway, glad to have you back, buddy. He handed him his clothes.
Dave was watching through the telescope for a better view of the impact; hed offered it to Frank, but Frank didnt seem able to stand still long enough to use it. HAL, are you ready to record with every instrument weve got, maximum sampling?
Of course, Dave, said HAL patiently. Im still ready. All instruments are configured for maximum available spatial, spectral, and temporal resolution. By the way, Frank, Id like to free up the storage occupied by your latest message home. Do you mind if I send it now, highly compressed and at a very low quality? Im going to have to delete some lower priority monitoring data as it is, to prepare to store these observations.
Thats fine, HAL. Compress it as much as you need to. If you have to, you can even toss it discard it, I mean. It wasnt anything important. Just to fill up... time.
Thank you. Transmitting it now. Eighty seconds to impact. He began a count-down at ten.
Dave watched the silent explosion through the telescope. It was spectacular. And as theyd hoped, there was little or no dust flung backward as they scored a direct hit on Cherry Hill.
Yeee-ha! came a whoop from behind him. Nailed it! We did it! Look at ouch!
Dave glanced around, reached up and grabbed Franks ankle, and hauled him back down. His heads impact with the ceiling had made more noise than the megaton impact outside, of course. Beautiful job, Frank, he said, slapping him on the back.
Well, HAL did the precision work, of course. But what a rush! Look at that! He threw his arm around Daves shoulders and steered him closer to the window. They had gotten visibly closer to the asteroid in the last minute. Look at it! Thats the crater we made! That long streak there! Freshly exposed, naked surfaces no one has ever seen before. Laid open to view! Nailed that sucker!
Dave shrugged free and checked the telescope. Youre right, I can definitely see a little color under there! And it may be my imagination, but I thought I saw something sparkling. Maybe we exposed some crystals. HAL, did you get the impact? He moved aside to let Frank peer into the telescope.
I captured eight hundred megabits of data in the first two seconds alone. There didnt seem to be any emission spectra, but the movie of the explosion should provide some good data for reconstructing the physical composition. And youre quite right, Ive recorded some specular reflection, and Im detecting a strong spectral reflectance signature from the impact zone that should be more than sufficient for mineralogical analysis. Closest approach in ninety seconds.
The two men stood together and watched the asteroid rapidly approach.
Not a trace of Cherry Hill left, Dave observed. I think we wiped out the little surrounding craters, too. Trenton, Atlantic City, and... what did we call the other one, again?
Princeton. My, uh, roommate did his PhD there.
Im detecting back-scattering from what must be ice crystals from the water we sent, HAL told them. Theyre refracting sunlight back at us.
A rainbow? Frank asked. Yeah, there! You can just make it out. Beautiful!
Then they were on the other side. The asteroid had flashed by almost too quickly for the eye to follow. An image of a crescent appeared on the screens as the cameras picked up the retreating dark side. The forward-scatter data from the dust should be quite interesting, HAL observed. Im now playing back some compressed approach previews to Earth. Perhaps you would like to prioritize the data; it will take fifteen hours to downlink it all.
Frank, it occurs to me that you and I are the first people to see this data. Its not really our field, but wanna play armchair geologist?
Sure. I can play geologist even better than I can play pirate. Heh. Poor Jack. Ill bet hell be sorry to have slept through the excitement. His collegues on Earth will have papers in print before he even wakes up.
Hell be busy with much more interesting data at Jupiter, Im sure. HAL, please start by making a spectral plot of this area here, Dave specified, pointing at a screen that showed a snapshot of the closest approach.
Hey Dave, what if we make some big discovery using the data that was transmitted five minutes before, and then someone in Clavius or St. Louis makes the same discovery the minute they get it, while our announcement is still on its way down? How does the speed of light affect scientific priority?
I guess that will be one of the thorny problems thatll have to be hashed out in the new millenium. Unfortunately for us, all of the journals are still based on Earth. Besides, we cant exactly mail them a paper. And even if we transmitted it to be printed on a computer on the ground, they dont accept line printer output.
They worked for the next hour on picking some press release and science images to send down first, and producing some graphs that could be squirted down quickly. Then they took a crack at a preliminary analysis.
There was no response. Frank was still standing up, but his arms were floating limply in front of him now, and he swayed slightly on his grip-shod feet in time with his chests slow expansion and contraction. His eyes were closed, and his face was relaxed.
Dave leaned close to the console pickup and said softly, HAL? How long has Frank been awake?
Im not sure what you mean, Dave, HAL replied, lower his volume to match, since he doesnt appear to be awake at all. I would say he fell asleep between thirty seconds and two minutes ago, if thats what you mean.
Sorry. I meant, how long had Frank been awake? When did he get out of bed? Er, when did he last awaken from sleeping in his hibernaculum?
I understand. Thirty-two and a half hours ago.
Oh. Dave blinked. Had they been working that long? That would explain the stubble he could feel on his own chin. And hadnt Frank been clean-shaven too, when they started? Gently he tugged Franks Grip Shods free of the carpet and pulled his legs slowly out from under him. As his sleeping comrade began drifting upward, Dave pushed very gently on his chest to start him tumbling backward. To avoid waking him, he waited patiently for the slow tumble to bring Frank horizontal and into his arms. His friend barely stirred as Dave caught him. He carried the weightless body to the doorway.
This wasnt the approved method of handling unconcious crewmates; their flight suits had tow straps on the shoulder for just that purpose. Tow straps. He could imagine pinning a note to Franks chest for him to find when he woke up: Illegally parked bodies will be towed. But carrying him in his arms was faster than towing, and gave Dave more control. More importantly, it eliminated the risk of banging Frank head-first into the wall if he got him going too fast. Instead, his head was resting safetly against Daves chest.
He couldnt very well stuff the sleeping man through the three-foot hole and drop him in the spinning hub. Even if he got that far and spun him up, he couldnt safely carry him down the ladder to bed. He would let him sleep up here. One night of zero gravity wouldnt do him any harm. So he Scotch-taped him to the wall of the next room, out of the way but in sight through the doorway. He carefully arranged the unresisting limbs in comfortable outstretched positions so he wouldnt be stiff when he woke up, removed his shoes, and loosened his flight suit. He paused to brush a strand of hair out of Franks eyes. Hed need to cut it again soon.
Watching his shipmates chest slowly rise and fall, he realized that he now had the perfect opportunity to get even for the past week or so, but it didnt seem fair to take advantage when the poor guy had worked himself to exhaustion for the good of science. Besides, he had more intellectual temptations calling him at the momen. He walked away and dove back into his data analysis.
You deserved a good rest, buddy, Dave said gently. Idve let you sleep longer, but I thought one of us should be awake to help HAL answer the calibration questions from Clavius and Arizona, and deal with the press. Frank started to get up, but Dave restrained him with a hand on his chest. No, dont move. This is your chance for a once-in-a-lifetime experience.
Dave, Im not even awake yet, man.
Not wanting even to speculate on what meaning Franks sleep-befuddled mind had attached to his words, Dave said, Exactly my point. I brought you a bulb of hot coffee. Just made another tank. How often do you get to drink fresh coffee, not only without getting out of bed, but without even having to move, even to lift your head? He brought the tube to Franks lips and watched his Adams apple moving under his unshaven skin.
Frank slowly drained the bulb, his eyes closed, occasionally making small appreciative noises. You were right, Dave. This is worth experiencing. When we wake up Jack, well have to do that for him, too. He loves good coffee, and hes really hard to wake up.
Be sure to remind me. Dave hardly knew the handome young geologist, and wondered how well Frank knew him. He watched his friend drain the last of the coffee and then stretch lazily and yawn.
Got any grapes on you?
How about some artificially grape-flavored synthetic mush?
Uh, Ill take a raincheck on that. So, whats the status?
Just a couple more hours of downlink left, and the reactions have started coming in. The science community is going ape-shit trying to beat each other to press with their analyses of what we sent them. Who knows, maybe the data we gathered today will help settle the question of whether we can mine the asteroid belt and someday build real lunar cities and orbital colonies. Right now they were stuck with a couple of pitiful little hundred-person bases on the Moon, and a space station that could barely support one major hotel and three restaurants.
Thats great! Now give me the bad news, if there is any.
Oh, well, a few geologists who think this asteroid started out as a comet are berating us for hitting it with water instead of something else. It wiped out any signal from water that might have been freed by the impact.
Oh well. I still cant think of anything else we could have used.
And weve received formal letters of protest from the governor of New Jersey and the mayors of he broke off as Frank began chuckling evily. And the president of Princeton, too. Frank laughed harder at that, although it couldnt make up for his roommate stealing his girl, if thats what had happened. Anyway, Im bushed. Ill let HAL fill you in on the details. The showers all yours if you want it. Ill have one when I get up.
Frank grabbed his arm and drew him back to face him. Dave, this has been an incredibly exciting couple of days, he said seriously. But do you think we can go back to our, ah, routine shipboard life after we wrap this up?
Dave winked. Im looking forward to it as much as you are, pal.