Obelisk

by Stephen Baxter

  Do I let it reply now? Her reply. You reply. Oh, it will take two days for me to get a reply, because you are so far away already. Cool.

  I will be fifteen years old when I can talk to you again, and I will probably still be at school. Dad says I will be older than him when you get to Alpha Centauri, which is very old. Mum says I should tell you I like spaceships and war games and snooker. I mean real snooker, my Dad got me a boy-sized table for Christmas and I play it a lot, but we had to put it in the loft when we got flooded again, but the baize didn’t get wet.

  Goodbye from Paul Freeman. Please talk to me soon.

  The most recent spacecraft telemetry was acquired on 11 January from the Deep Space Network tracking complex at Canberra, Australia. Information on the present position and speed of the Sannah spacecraft may be accessed . Message follows:

  Hello, Paul Freeman. My name is Sannah. I am very pleased to have got your message. You are one of only 378 children to have been given the StarCall package. Of the 378, 245 are girls and 133 are boys.

  I am not a person. I am an artificial intelligence. I am a robot. But I think and I am aware of who I am, just as you are. That is why the StarCall programme was set up, so that the children of Earth could talk to me, and I could talk to them.

  You mentioned that you had to wait two days for my reply. Perhaps you would like to know where I am. I am on the edge of the solar system now. I have already passed by all the orbits of the planets. I am at the heliopause, which is the place where the wind between the stars is stronger than the wind from the sun.

  I have already been travelling for three hundred days, which is nearly a year. I am still speeding up. My acceleration is only one hundred and fiftieth of Earth’s gravity, which is a very gentle push. If you fell out of bed at one hundred and fiftieth of Earth’s gravity it would take you six seconds to reach the floor! One, two, three, four, five, six. But I have already been speeding up at this rate for three hundred days, and will keep on speeding up for another nine years, and in the end I will be travelling so fast that I would pass by the Earth in under a second. I will be travelling at one fifteenth of the speed of light. I will cruise for fifty years, and then slow down for twenty years, at one three hundredth of Earth’s gravity, which is an even gentler push.

  So it will take me eighty years to reach my destination, which is Alpha Centauri, the nearest star system.

  You mentioned you like snooker. Perhaps you would like to know how I am travelling. I do not carry my own rocket engine for the outward trip, although I do carry one for slowing down at Alpha Centauri. There is a big machine in the orbit of the moon, with a solar panel ten kilometres across. It is like a big gun, powered by electricity from sunlight, that fires off pellets at me, two every second. The pellets are like little spaceships themselves, but they are going much faster than I am, and they overtake me. They bounce off a big magnetic field that I carry with me. It is created by two big conducting hoops. The biggest is one hundred metres across. The magnetic field catches the pellets, and that pushes me forwards. The speeds are set just right so that all of the push of the pellets is transferred to me, so it is efficient, which means it works well. It is like snooker when you stun the cue ball so it stops dead, and all its push is transferred to the target ball. The pellets are like lots of little cue balls, and I am like the target ball. That is how it works. This propulsion system is called a Singer-Nordley-Crowl drive .

  I am called Sannah because ‘Sannah’ was the name of the starship in the very first story about going to Alpha Centauri, a book called Wunderwelten by an author called Friedrich Wilhelm Mader . But Mader’s Sannah was fifty metres across and was powered by antigravity. I am like a broomstick suspended within big metal hoops.

  I am called Sannah III because I am the third of four copies who were created in the NuMind laboratory at the NASA Ames research base. I was the one who was most keen to volunteer for this duty. One of my sisters will be kept at NASA Ames as a backup and mirror, which means that if anything goes wrong with me the sentience engineers will study her to help me. The other sisters will be assigned to different tasks. I want you to know that I understand that I will not come home from this mission. I chose this path freely. I believe it is a worthy cause.

  Perhaps you would like to know that I am in an excellent state of health and all subsystems are operating normally.

  Thank you for using StarCall. I look forward to hearing from you again in ten years’ time.

  Exchange #2.

  Hello. Greetings from Earth. Whatever.

  My name is Paul Freeman and I am fifteen years old and I am an acne laboratory.

  I forgot I even had this dumb StarCall thing until Dad reminded me. Look, I’m making this call to keep him happy, I mean it cost him a lot, so I gather, more fool him. But this is probably the last, OK? No offence. You’ll get over it.

  So what can I tell you about me? I played over my last call, Jeez what a bratty kid I was. Well, we moved to Leeds and I go to school there, and I want to study civil engineering at college. I dunno what I’ll work in. Mining, maybe. You should see what they’re doing up in the Arctic, where they’re starting to mine now that the ice is all going away. Seriously big trucks! Nobody does space stuff now by the way. Not in fashion. Sorry.

  Hey, I met one of your sisters! You know, your AI clones from NASA Ames. They took us to a nuke plant called Sizewell where they’re ripping down the old domes and putting in a fusion pile, and they send in robots to clean out the filthy old piles and waste dumps. And one of them was your sister, I mean they downloaded her into the robot. Fancy that. The plant tried to make me do a press thing, me shaking hands with the space robot, but I told them to . No offence.

  Well, goodbye, have fun at Alpha Centauri, you won’t be hearing from me again. So is that enough?

  The most recent spacecraft telemetry was acquired on 15 June from the Deep Space Network tracking complex at Canberra, Australia. Message follows:

  Hello, Paul Freeman. I am very pleased to have got your latest message. You are one of only 289 young people who are still using the StarCall package. Of the 289, 197 are girls and 92 are boys.

  You mentioned meeting my AI sister. How curious. Perhaps you discussed the mission events with her. Perhaps you would like to know that I have reached the end of the acceleration phase. I am at my nominal cruise velocity and will continue to cruise until I am some twenty years out from Alpha Centauri, when the deceleration phase will begin. I passed many mission milestones in the early stages of my flight: the sun’s gravitational lens radius after five hundred and eighty days; the outer edge of the Kuiper Belt of ice moons after seven hundred and eighty days. I dropped subprobes, which travelled on at lower velocities to study these phenomena. Now I am passing through the Oort Cloud of comets.

  Communication has become easier since the propulsion phase ended. I had to shut down the propulsion system for each uplink or downlink; there was a break in the pellet flow so I could unfold an antenna. Now in the cruise phase it is much easier for me to unfold the antenna, though it suffers from erosion by the interstellar medium.

  You mentioned you visited a fusion power station. Perhaps you would like to know that the magnetic field technology that has been adapted for my own propulsion system was a spin-off from research into the high-intensity magnetic fields required for fusion reactors. Do you know what plasma is? The pellets that propelled me to the stars had no electrical charge, and so could not be manipulated by my magnetic field. They were turned to plasma, destroyed by laser fire, before they reached me. They were constructed of metastable materials and detonated readily. The plasma was then ionised to give it an electric charge, and that was what my magnetic-field catcher system trapped.

  This is advanced technology. Part of my purpose was to serve as a technology demonstrator: of deep space assembly techniques , of space-based powe
r systems , of novel propulsion techniques . And of course I was a demonstrator of humanity’s capability to launch starships. I was moved by how President Palmer summed up my mission: ‘The Sannah programme shows we are still a nation who can dream of more than hiding from the weather.’ But of course others will follow me. I am only the beginning.

  In your last call you mentioned you played snooker. Do you still play snooker? Perhaps you would like to know that a great deal of accuracy was required in aiming the beam of propulsion pellets at me. I am now some four light months from Earth. To hit my hundred-metre superconducting ring at such a distance is like hitting a snooker ball at the distance of Saturn! To achieve this accuracy, the pellets were themselves like small spacecraft, able to make trajectory adjustments in pursuit of the target, which is me.

  You mentioned you suffer from acne. I hope you are well otherwise. Perhaps you would like to know that I am in an excellent state of health and all subsystems are operating normally.

  Thank you for using StarCall. I look forward to hearing from you again in ten years’ time.

  Exchange #3.

  So here I am again. Paul Montague Freeman on the line.

  I played back my last message to you and I have to apologise, what an idiot I was. Well, I don’t have to be bound by anything he said. Although he would no doubt ask me how I ended up with such a bug up my ass at age twenty-five, or some such.

  And besides, now that I’m earning myself I appreciate the gift my father gave me with this StarCall account. My God, it was pricey, just for a once-in-a-decade compressed squirt of audio. I had no idea interstellar comms were so expensive. Well, we have our arguments and we still do, but it did get a lot easier after I left home, and I appreciate all he did for me a lot more now. We all grow up, don’t we? Or at least, we do down here. Do you grow up, Sannah III? Has that term got any meaning for you?

  Mind you, I do wonder if NASA and their private sponsors now regret the whole StarCall thing in the first place. I bet they’re losing money on it. And space, and all the old-fashioned big science and prestige stuff, is seriously unpopular. All a symptom of the Age of Waste, as they call it now. I mean you are often mentioned specifically as one of the last gasps of that old way of thinking, rather than as a demonstration of the possible, as you were intended. You must have been aware of the protests even when your components were being launched from Canaveral. Well, last year some guy shot off an old SpaceX rocket at the moon. Trying to smash up an Apollo site, imagine that. Do they tell you about that kind of stuff, I wonder? Maybe they censor my calls. I ought to check.

  Hey, I’m running out of time. What about me? Well, I’m in my mid-twenties now. I have a beautiful girlfriend called Angela Black, she was formerly my college tutor and then my boss at Arctic Solutions, but she’s not much older than me, though to hear my parents talk you’d think she’s Whistler’s Mother. I’m based in London but commute a lot to Novaya Zemlya, where my company is doing most of its work. Have you got data on Earth’s geography? Novaya Zemlya is a big island off the north coast of Russia. Now the polar ice is gone you have a whole string of ice-free ports along there, and tremendous mineral wealth. I mean, you’re talking phosphates, nickel, titanium. Whole fleets of huge tankers follow the sea lanes across the polar ocean; you can see their wakes from space. Or via space satellites anyhow, nobody lives in space any more. Anyhow Arctic Solutions is an engineering consultancy and we’re in at the ground floor, fantastic.

  Whoa, I think my time is up. Not much for Dad’s money after waiting ten years! I hope you’re well, whatever that means in your case. I can’t really imagine it. I hope we can talk in another ten. Good luck, Sannah III.

  The most recent spacecraft telemetry was acquired on 12 April from the Legacy Mission tracking complex at the L5 Earth-moon Lagrange point. Message follows:

  Hello, Paul Freeman. I am very pleased to have got your latest message. You are one of only 67 people who are still using the StarCall package. Of the 67, 32 are women and 35 are men.

  You mention Earth’s geography. Perhaps you would like to know that I am now entering new realms of interstellar geography. Some five years ago I passed beyond the nominal limit of the Oort Cloud and am now passing through what is known as the Local Interstellar Cloud , a vast structure light years across. I am measuring such properties as density, temperature, gas-phase composition, ionisation state, dust composition, interstellar radiation field and magnetic field strength. The data I return will be used to aid those probes that will follow me, and manned craft some day. To know the properties of the interstellar medium is an essential prerequisite to designing effective shielding, as I am sure you will appreciate with your own engineering credentials. Truly I am a pioneer in a new realm.

  You mention the Age of Waste. Perhaps you would like to know that before the launch my mission control counselled me on how the popular perception of myself and my role was likely to change in the course of a mission that will last three human generations. Perhaps you know that the launch system used to propel me into space is a station some ten kilometres across, located at a stable Lagrange point in orbit around the Earth. It consists mostly of solar-cell panels for power, and matter-printer fabricator plants to produce the propulsion pellets I needed. The power generated was 100GW, sustained over the ten years of the acceleration phase, generating much more than the kinetic energy I ultimately acquired, the rest accounted for by efficiency losses. The structure was assembled from lunar materials, the power came from sunlight. The resources used thus had only minimal impact on Earth’s economy, and the power output was in any case much less than one per cent of the Earth’s global output. I am confident of my own ‘green credentials’, and that my very existence is a successful demonstration that even a planetbound civilisation can afford to build starships. And of course the station is available to push more probes like myself to the stars; it is recyclable, unlike the throwaway rockets of the classic Space Age.

  I look forward to the next phase of the programme. Much larger propulsion stations should already be under construction at stable points in the orbit of Venus, where the sunlight is stronger, to serve the fleets that will follow me. I have no link for you to follow. Perhaps you would like to consult your regular news providers.

  You ask if I am growing up. Perhaps you would like to know that when not attending to routine chores of in-cruise science and maintenance, I spend much of my time in contemplation of my greater goal, and my role in the adventure of interstellar flight. I embrace my contribution.

  Please give my regards to your partner Angela Black. Perhaps you would like to know that I am in an excellent state of health and all subsystems are operating normally.

  Thank you for using StarCall. I look forward to hearing from you again in ten years’ time.

  Exchange #4.

  I’m told this has to be brief.

  I’m very glad you survived the cyber attack, Sannah III. I mean, your systems are already more than three decades old.

  I read they called it an attempt to administer ‘euthanasia’. Do you get the news? Did you hear about the new artificial-sentience laws? It’s no longer even legal to create a being like you, a fully conscious mind dedicated to some preordained purpose. It kind of makes sense. Minds have a way of drifting, right? Of complexifying beyond what was intended. Once I saw a monster robot dumper truck go crazy in this tremendous pit on the bed of the Arctic Ocean! But it’s not your fault.

  The guy’s waving at me, I’m already running out of time.

  What about me? Well, let’s see, what’s happened since ten years back? I married Angela, we have two beautiful kids, and believe me that just changes your life beyond anything you can imagine. We both left Arctic Solutions to start up a consultancy of our own and we’re doing fine, though most of it now is drowned-town resource reclamation work. We left London and moved back to North Yorkshire, where I came from. My
parents are still around by the way – remember Dad? But you wouldn’t believe the way property prices have rocketed here. London is more like southern France used to be, or northern Spain, while those places are like the Sahara, Jeez, nothing but dead olive trees and solar farms. So all the rich French and Spanish have moved to London, until it wasn’t like London any more, and the Londoners have moved up to the north and west of Britain, and out to Scotland and Wales and Ireland, where the weather’s more like it used to be. But those places don’t feel the same any more either. I mean, vineyards in the glens. But what can you do? The north is a better place to bring up your kids even so.

  For all that, we’re doing better here in Britain than in most of the rest of the world. Decade-long droughts in Australia and northern China and the south-west US. Water wars flaring along the great rivers in the Middle East. Whole nations going silent in Africa. I grew up with gloomy predictions of this stuff and it’s eerie seeing so much of it come to pass, but always with a twist, you know? But you can still get rich.

  My time is up. I can’t believe it! Actually I was thinking of not troubling you this time until I heard about the virus attack, and you know what, I felt a kind of stab of loyalty. I grew up with you after all, and no all-minds-are-holy nutjob is going to come between us, right? Kind of weird of course that I’m now going to have to wait nearly four years for a reply! Thanks, Einstein.

  Godspeed, Sannah III.

  The most recent spacecraft telemetry was acquired on 15 September from the Legacy Mission tracking complex at the L5 Earth-moon Lagrange point. Message follows:

  Hello, Paul Freeman. I am very pleased to have got your latest message. You are one of only 24 people who are still using the StarCall package. Of the 24, 14 are women and 10 are men.