11.07.2109 - Jupiter Slingshot

By NASA/JPL [Public domain], via Wikimedia Commons

Distance: 747,989,353 km from Earth | Content Flag: Public

Jupiter and its attendant moons are arrayed in our sensors like a small solar system of their own. This is the third and penultimate gravity assist before we leave the solar system. Once Jupiter’s gravity and orbital motion swing us onto our new course, we will be travelling at over 230km per second. With every second that passes, we are setting a new speed record for any human-built object.

Even at this speed, Jupiter is an impressive sight. The bands of high-speed clouds that create Jupiter’s distinctive appearance are crystal clear in the ultra-high definition of the main telescope. I can also see the Great Red Spot. This storm has been the identifying mark of the gas giant for centuries and is big enough to swallow the Earth. Analysing the data, we can confirm the findings of the Observer probes that the storm appears to be pulling itself into two giant vortices.

We’re currently propelled by the solar sail as the booster frame ran out of fuel and was disconnected as we approached. Its replacement was launched 8 years ago and is now waiting for us on the other side of Jupiter.

At this speed, we won’t have time to perform any real science. The observations we have made are being transmitted to the Observer probes in orbit around Jupiter. They have been examining the planet’s plasma flows looking for traces of the Sun Dragon A entity, as well as acting as sentries in case of a Sun Dragon’s return. Jupiter’s intense electromagnetic fields provided the energy that fuelled the alien’s journey through the solar system.

…

With the swing-by manoeuvre successfully completed, we are on track to rendezvous with the second booster sled. It’s travelling slower than we are so we can catch it up. Our velocity makes this an extremely difficult and dangerous procedure. If we are off by even the smallest margin then we have to abort and continue the mission without it. If that happens, it will add another thirty years to our travel time.

…

We’ve connected with the new booster frame without incident. Once we cross the termination shock boundary of the solar system in seven years time, we’ll fire the sled to accelerate us through interstellar space. By that time the solar sail will receive too little pressure from the solar wind to be useful. It won’t even generate electricity at that distance.

As we departed Jupiter, we experienced a software malfunction. My role as the Secondary Command Module includes monitoring the Primary Control Module to assess its integrity and the soundness of its decisions. With a system as complex as the probe there is back-up and redundancy even for the decisions the computer systems make. I detected a divergence in the data in the PCM’s memory. It not only conflicted with my own data but that of the engineering subsystem it was taken from. Thankfully a reboot seemed to fix the problem – if in doubt turn it off and on again!

This is Seb signing off – next stop Saturn.

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Post Solar Flyby Q&A Session With Seb

This is Seb posting in after our flyby of the Sun. Mission control back on Earth has sent me some of your questions which I will answer in this session. They will also send you a mission patch if I answer a question and you haven't already received one.

So let's get started!

Tim Clarke asked How close will the flyby be - will it be possible to analyse any solar emissions?

Although we don't anticipate having to investigate the Tau Ceti star too closely the mission plan has tried to account for any possibility. With this in mind the Venti probe has been specifically hardened to allow a close transit. On our flyby we passed a fraction within 6 million km to the Sun and at that distance the strength of the solar wind is about 500 times stronger than it is at Earth orbit.

We have a full range of scientific instrumentation on teh probe and these will be recording as much data as we can to see if we can learn anything further about the Sun Dragon's encounter with the Sun.

Passing so close to the Sun provides an additional advantage. Even with the booster sled and gravity assists the bulk of our acceleration comes from the solar sail and the greater pressure from the solar wind gains us extra acceleration on our journey out of the solar system.

Dennis Kitainik26 asked When heading toward the sun with the sail deployed, do you tack against the wind like a sailing yacht?

It's a very similar technique and as with sailing at sea we can't take the direct path towards the inner solar system. Instead we follow a wide spiral inwards and alter the angle of the sail to compensate. However this is only practical away from the sun, for the actual manoeuvre around the sun the sail was stowed and redeployed after we'd completed the swing.

Voyager_NL asked  Since AI for us earthlings is still a difficult thing to grasp. How would you compare your processing power. Is your intellect human like, higher or lower?

That's a tricky question to answer. My ability to perform calculations is far beyond most humans, although some humans are able to perform arithmetic operations almost intuitively, somehow skipping the component operations normally required to solve a problem. It should be noted that the processing systems here on the Venti probe are slower than many machines back on Earth. We have to be a lot more careful of heat management and cosmic ray damage than earthbound computers so we run a little slower and on larger circuitry.

Intellect is different to raw computational power and in that respect I am more similar to the human mind. The neural networks of myself and the Primary Command Module allows us to learn in a way that regular computers cannot. In that respect we are more adaptable and so able to perform the functions that a human crew would normally be preferable for. Of course for a journey of this duration a human crew wasn't a viable option!

19.08.2103 - Solar Flyby

By NASA Goddard Space Flight Center from Greenbelt, MD, USA [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons

Distance: 124,166,232 km from Earth | Content Flag: Public

This close to the Sun, the sheer power of its luminance dazzles our optical sensors at the visible part of the spectrum. In ultraviolet and at other wavelengths, we can see the detail of the Sun’s power. Jets of energised plasma arc into space, spanning millions of kilometres before they fall back into the boiling globe.

Across its surface we can see dark spots. These sunspots are markers for magnetic storms within the Sun’s atmosphere. Like the surface, the magnetic fields around the Sun are a storm of fluctuating energies, reaching out deep into space.

UNSA will soon be launching a new series of Helios probes into solar orbits at varying distances to provide constant observation of the Sun. Ground-based observatories have monitored our star since the Sun Dragon encounter and some variances in its composition and activity have been recorded.
Passing close to the Sun allows us to capture more information to assist the research teams back on Earth trying to determine what effect the Sun Dragon might have had when it wrapped itself around the Sun for a month, before splitting into two. Anything that might have intensified or created solar storms could pose a hazard to the reconstruction programmes on Earth. Although, as the power and communications systems are now built with protection against a return visit from the alien lifeform, any solar disruption should be minimised. Still, it would be better to know of any danger in advance.

We also don’t know what we’ll encounter when we arrive at Tau Ceti, so the Venti probe has been designed to investigate any part of the star system. That might well include a close approach to the star. As Tau Ceti is similar to our Sun, this is an ideal test for our instruments and protection from the solar wind when it is at its most fierce.

At this range it’s more like a solar gale and the energised particles could damage components of the probe. The electronics are particularly vulnerable, especially closely packed electronics like microchips. The Venti probe carries more computing power than any spacecraft ever built and that has to be protected. As well as the main shielding and the solar sail, key areas of the probe are protected by layers of ultra-dense material to block or deflect energised particles.

We won’t gain much from a gravity assist manoeuvre around the Sun because it is stationary compared to the movement of the planets. To use the technical jargon, the planets’ frames of reference are subordinate to the Sun’s, so no energy is lost or gained by switching into it. However, as we swing around the Sun and start the outward leg of the mission, the solar sail will come into its own.

The sail is 9 square kilometres across and is covered with a layer of grapheme facing in the direction of the solar wind. The pressure of the solar wind pushes against the sail and accelerates us into space. The grapheme has a property that creates extra thrust as the particles from the solar wind hit it. Even with this added acceleration the effective thrust is minute, so it would take a long time to reach the speeds we need to. It does have the advantage of not needing fuel and that keeps the mass of the probe to a minimum.

So far all of the systems are operating within their expected parameters, so as we prepare for the next step in the mission, this is Seb signing off.

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Recommended Reads - Islands in the Sky by Arthur C Clarke

Continuing the weekly feature of my recommended science-fiction reads I delve deep into my past and one of the books that drew me into the genre. I've read many of Arthur C Clarke's books since and while many are better books than 'Islands in the Sky', they didn't capture my imagination in such an immediate way.

The story is a simple one, a young lad manages to win his way onto a space station. There's nothing complicated here and perhaps that's what drew me in to begin with. It's a very personal story about the lead character's experiences, but it's deceptive. I'm a big fan of big ideas in science fiction, but here the big idea is life in space.

Now in most modern sci-fi operating in space is taken as a given, but even now with the nascent industrialization of space we haven't reached the point were it is a mundane operation. In the world of the story is has become commonplace, but it is seen through young eyes so the wonder of it is more apparent. It also provides a solid introduction to the principles of working in space.

I re-read the book recently and there's always a danger of having the memory of a great read tarnished by years of progress or just more adult appreciation - thankfully this wasn't the case here. It's true that science has progressed a lot in the 60 odd years since it was written, but the fundamentals still apply. Although it is interesting to see what wasn't considered an issue back then, such as the effect of living in space on the human body.

So while it's gained a few flaws over the years it's still an excellent sci-fi read and a great introduction to the genre.

The story of 'Island in the Sky' centers around a young man, who, after brilliantly winning a space-related competition, requests a vacation on a space station as his prize. It is written with Arthur C. Clark's obvious knowledge of science, but moves at a page turning rate throughout the entire narrative. The short novel gives a realistic possibility of work and play in future space, heightened with constant excitement and action. Character development is very good, as are the not-overdone (but still awesome) visual descriptions.


Click here to buy Islands in the Sky from Amazon

04.06.2101 - Venus Slingshot

By NASA/JPL (http://photojournal.jpl.nasa.gov/catalog/PIA00223) [Public domain], via Wikimedia Commons

Distance: 29,919,574 km from Earth | Content Flag: Public

We’re passing by Venus in the first of the gravity assist manoeuvres, sometimes known as slingshots. These use a planet’s gravity to change a craft’s direction and increase velocity. Technically it’s the change caused by moving between frames of reference that can speed us up or slow us down.

It might seem counterproductive to head inwards when you’re actually trying to leave the solar system, but the extra energy gained by these flybys will help accelerate us to a speed sufficient to escape the Sun’s gravity.

So far on the journey we have used the main solar sail and the booster sled. We also gain speed by simply moving towards the Sun. The solar sail provides relatively little thrust on the inward approach, although it does help generate enough power to operate in full power mode. When we enter the cold dark of interstellar space, we’ll need to reduce our power consumption to a minimum by shutting down nonessential systems.

This booster frame has enough fuel to fly us to Jupiter where we will rendezvous with a new frame. UNSA mission control has confirmed that the new booster was successfully launched and is on its way to the parking orbit around Jupiter.

During this stage of the mission, the booster frame generates the majority of our thrust. With the sled, the sail and the gravity assist, we’re approaching a velocity of almost 30km per second. This is our first record-breaking of the mission as the fastest man-made object, although we are going to be travelling much faster than that when we reach interstellar space!

Flying by Venus and with no need to conserve power gives us an ideal opportunity to test our instrument packages. These are the various sensors providing us with information about our surroundings. A lot of data has already been accumulated about Earth’s hellish twin, which means we can compare our data and be sure that our instruments are reporting what we expect them to.

Venus is considered Earth’s twin mainly due to its similar size and mass, but in reality it’s a very different world to our home planet. From the optical sensors we see very little as the planet is swaddled in a dense beige atmosphere of carbon dioxide. Clouds of sulphur dioxide and sulphuric acid creating a greenhouse effect greater than any of gloomiest fates imagined for Earth from climate change. This gives Venus the hottest surface temperature of any planet in the solar system.

The radar mapping system confirms the smooth volcanic plains covering most of the surface. The topography visualisation shows the extensive volcano ranges and we can see far more than are active on Earth. In the northern hemisphere, we can see the continent Ishtar Terra with the highest mountain on Venus. To the south, we can see the second continental landmass. The optical sensors even detect the stream of ions being blasted from the upper atmosphere into a faint trail behind the planet.

Our magnetic field detectors show that Venus has a weak magnetic field, which is probably why the first Sun Dragon (now designated Sun Dragon A) skipped the planet on its journey to the Sun. Our scanners have greater resolution than the probes that visited the planet before. Satisfied with our tests, we transmitted the data we captured back to Earth.

Venus has already grown smaller as we speed towards the Sun. This is Seb signing off.

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23.04.2099 - Low Earth Orbit

By NASA/Samantha Cristoforetti [Public domain], via Wikimedia Commons

Distance: 10,000 km from Earth | Content Flag: Public

This is the Venti probe calling from Earth orbit as we prepare to launch on our historic mission to Tau Ceti. I am the Secondary Command Module for the mission. The mission team on Earth nicknamed me ‘Seb’ and as that sounds better than ‘SCM’ or ‘Secondary Command Module’, I will continue to refer to myself by that name for these communications.

This is the first official post of the mission, although I’m told that many millions of you have read the test messages I wrote while my neural net learned how to parse and create natural language. This might seem like a strange skill for a space probe. However, as well as providing an independent back-up for the Primary Command Module, my specialisation is for first contact.

In the event we discover a technologically capable species at Tau Ceti, I will take control of the mission and attempt to initiate communications with them. For that I have learned about language construction as part of the knowledge base as well as assimilating all the research available for such an encounter.

The Tau Ceti signal has been silent for nearly a decade. It has faded away into the cosmic background noise. To learn its secrets we will travel for 140 years to investigate the source of the transmission. We don’t know what we’ll find there, but the years of preparation and development have made this probe as ready as we can be for the task ahead.

Below I can see the Earth in a multi-frequency splendour thanks to the array of sensors available to us on the probe. From up here, all I can see is the vast blue splendour of the oceans and, set into the azure, the greens, yellows and browns of the land. If I didn’t have crystal phase memory full of data of the sun dragon encounter, it would be hard to imagine the devastation it caused as no trace of it remains from my current perspective.

That grandest of human explorations starts in less than an hour. The booster frame which will help us accelerate will send us on our path. It’s a circuitous route through the solar system so we can take advantage of gravity to speed us on our way.

The journey will be long, the longest in human history, and throughout the mission I will keep you all updated with the latest discoveries as we progress. This is Seb signing off for now, but if you have any questions you’d like to ask me then post them below and mission control will send them to me and I’ll answer those that I can.

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Pre-Launch Q&A With Seb

Hi there - this is Seb from the Venti probe. We're currently in Earth orbit and along with the Primary Command Module and the other key systems I'm working through the final check lists in preparation for tomorrow's launch. So far all everything is checking out green, so Mission Control is confident that we'll launch on schedule.

As part of my mission profile I will be assisting the UNSA's public relations team by blogging key moments during the journey to Tau Ceti. You can also send me questions by commenting on my posts and Mission Control will send them to me. I can't answer them all, but if I do answer a question from you then they will send you a mission patch so you can be part of the team!

There's still a lot to do before we launch tomorrow, so here's some of the questions we've received:

Fenris Oswin asked - What, for you, is the most exciting element of the mission and how do you think you will handle the pressure of responsibility for first contact?

While I understand excitement as a concept, it isn't something that I can experience directly. My neural network has evolved and been guided by the research team with various roles in mind. One of them handling a possible first contact scenario - we don't know for certain that an alien intelligence is the source of the transmissions, but it is considered likely enough to prepare for.

It's a difficult situation to anticipate, although I have worked with many experts around the world to gain a broad understanding of the subject. I can also construct my own reasoning and this will be invaluable if we do encounter a new species. To answer your question, I don't feel pressure as such. My load balancing routines ensure that any processing tasks are kept within my capabilities. Naturally my higher functions determine the priorities of my focus.

Voyager_ NL asked - Will you do any science and photography before you leave the Solar system?

The gravity assist manoeuvres we will use to help attain our escape velocity means that we'll pass close to some of the major bodies in the solar system. We have a full range of science packages intended for investigating the Tau Ceti system and we will test and calibrate those on the planets we pass as we leave.

With modern sensors we'll also conduct some significant science in the outer regions of the solar system as we pass through. You can be sure that I'll share these moments as they occur on this blog.

Malak'kai Maxwell asked - What method(s) are you planning on using to communicate with any alien intelligence(s) if/when you make contact?

On the Venti probe we're equipped with various methods of communication. In particular we have the High Gain Antenna and a laser based communications system. The transmission from Tau Ceti was in a narrow band of radio frequencies which the HGA is capable of transmitting and receiving. To supplement these systems we are capable of receiving and to a lesser extent generating signals throughout the electromagnetic spectrum.

As the Tau Ceti transmissions have not yet been deciphered we don't understand the principles of their communications. We do, however, have a number of constructs based on mathematics and our knowledge of the universe to provide initial methods of establishing communications. It will take us 300 years to reach Tau Ceti and throughout that time the research teams back on Earth and I will continue developing methods to establish contact.

Devorah Fox asked - Can you communicate intangibles, such as fear or delight?

Human language is a strange and wonderful creation - it can be imprecise, but also an effective means to express complex concepts. This ambiguous nature isn't something that computers can handle easily, even with big data and considerable processing power. While there are rules of language they are often mutable.

The problem with language from my perspective was that a lot of knowledge is inferred or implicit, so I had to build a library of knowledge so that I could draw upon the experiences that people take for granted. That meant that I eventually grasped concepts of an emotional or abstract nature and so I can use those concepts. I don't know what they feel like, but I do know where they fit.

That's it from me for today - I will post again tomorrow once we launch. This is Seb signing off.

Pre-Launch Questions for Seb

Seb is one of two neural networks on the Venti Probe, as well as being the Secondary Command Module for the mission his natural language parsing ability has seen him helping with public relations for the mission. A large part of that role will be the blog posts he transmits back to Earth during the mission. Another part will be the Q&A sessions - the first of which will take place on Saturday 21st November - on the day before the historic missions launch.

To send a question to Seb post it in the comments section below and the mission control team at the United Nations Space Administration will pick their favourites and send them to the probe. Anyone who posts a question that is answered by Seb could receive a mission patch. This first batch of questions will close at midnight on Friday UST.

Tau Ceti Mission Launches 22nd November

Seventy years after the Sun Dragon encounter, humanity is slowly recovering from the devastation when a mysterious transmission is detected from the Tau Ceti system.

A new international mission assembles the Venti probe to cross the vast gulf of interstellar space with the hope of discovering intelligent alien life. An AI, nicknamed "Seb', is developed to handle a potential first contact scenario and report on the probe's progress during the historic mission.

But first they must survive a perilous journey through the unknown. The choices Seb makes will change the lives of everyone on Earth and for generations to come.

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Join the launch party for The Tau Ceti mission on November 22nd on Facebook here:

https://www.facebook.com/events/1745517682338436/

Everyone attending the event will be entered in a draw to win a signed copy of Sun Dragon. Please share the event with anyone you think will be interested in following the first mission to another star system.

Recommended Reads - Excession by Ian M Banks

I was a reader of science-fiction long before I started writing it, so as part of telling the story of the Tau Ceti mission I will share the sci-fi books that have influenced my writing or stood out in some way for me. If you haven't read any of the books I recommend then you should take a look. If you have then post what you think in the comments below.

The first book in my recommended list is also my favourite novel. Ian M Banks is a talent that will be sorely missed and while his book 'Excession' isn't his most accessible, but it represents what attracts me to science-fiction as a genre. What makes science-fiction great is the big ideas, all of the notable authors in the genre tackle big ideas.

This will be a theme for many of my recommendations, but in this case the topic covers that of an excession event. This is an encounter with an object way beyond the contemporary technology and the impact it has on the civilisations aware of the event.

What Banks also does well is his portrayal of artficial intelligence with the ship minds and drones. The collection of minds at the heart of the story provide a classic example of this. He also blends some interesting concepts of a technologically advanced culture and how individuals fit within it.

Simply put I love this book and I'd recommend to any fan of the genre - I think I'll have to re-read this myself soon!

Click on image to buy from Amazon

Two and a half millennia ago, the artifact appeared in a remote corner of space, beside a trillion-year-old dying sun from a different universe. It was a perfect black-body sphere, and it did nothing. Then it disappeared.

Now it is back.

Click here to buy Excession from Amazon

Would You Like to Know More? - The United Nations Space Administration

In the aftermath of the Sun Dragon encounter, once the situation on the ground stabilised, there were little resources or enthusiasm for operations in space. However, the lack of global communications, weather satellites and other infrastructure that human society had come to depend on required orbital operations to resume.

A better mood of cooperation had developed during the restoration. To help share the burden, the United Nations Space Administration (UNSA) was formed in 2031 to coordinate orbital operations and provide the roadmap for human activities in space again.

It was also tasked with learning more about the Sun Dragons with the aim of providing a defence if the creatures ever returned.

The Sun Dragon encounter proved that there was other life in the universe and the UNSA would coordinate the search to find extraterrestrial life, intelligent or otherwise.

Orbital Clean-up

The Sun Dragon encounter had destroyed all of the satellites in orbit by creating a cascade event, where damaged satellites crashed into each other and eventually surrounded the planet in a cloud of debris. Orbiting the planet at high speed, these fragments posed a huge risk to any launches.

NASA and China’s National Space Agency  both launched separate missions in 2030 to try to clear low Earth orbit. Both missions failed, partly because they swept debris into each other’s orbital paths. It was this failure that was instrumental in creating UNSA.

From 2034 and for the next two years, a series of missions coordinated by UNSA – but launched by NASA, ESA, CNSA, the Russian Federal Space Agency and a consortium of the remaining private space industries – cleared low earth orbit. They used a Japanese design of a magnetically charged net to sweep up the debris and drag it downward to be burned up in the atmosphere.

Clearing high orbit took another three years, and then it was safe to start the space telescope programme.

Space Telescope Network Launched

One of UNSA’s key tasks was to identify future threats from space. It wasn’t considered likely that the Sun Dragons would return any time soon. However, no-one knew for certain or if there were any other threats out in space.

Ground-based telescopes had resumed watching the sky as the technical infrastructure was restored. These telescopes were hindered by the atmosphere so as soon as low Earth orbit was cleared, the first of a new breed of space telescope was launched.

The plan was to make the space telescopes as cheap as possible, so that more could be launched and observe every patch of the sky. The telescopes were designed to watch not just in visible light but at all wavelengths of the electromagnetic spectrum.

Alongside the telescope launches, a new network of communications and observation satellites were launched.

Mars Voyager Heritage Site

With low Earth orbit cleared, access to the Mars Voyager was possible. It had deteriorated into an unstable orbit and would likely burn up in the atmosphere within thirty years. When it became public knowledge that UNSA planned to force it into a burn up orbit, there was a public outcry.

Matt Hargreaves, the CEO of Chimera Industries, offered $1 million to fund a mission to push it into a safer orbit where it could remain and not be a threat to the low-orbit satellites. With a tight budget, UNSA declined, but an international crowdfunding project raised enough funds for the project to be greenlit.

Later that year, the United Nations declared the spacecraft an international heritage site, protecting the only grave in space.

Observer Missions

Space operations didn’t expand beyond Earth orbit until 2037 when the first of four Observer missions was launched. The first two were sent to Jupiter and the following pair to Saturn.
The Sun Dragon  had used the magnetic fields of the major planets to fuel its movement against the solar wind. There were some indications that it had used Jupiter as a stepping stone through the solar system and researchers believed it would have used Saturn for the same purpose.

The Observer missions had two objectives: the first to search for any signs of the Sun Dragon’s passing, and to try and learn more about the alien. So far the only significant data had come from the Mars Voyager mission and the failed attempt to destroy the entity.

The second objective was to monitor for the return of another Sun Dragon and provide some advance warning if it did.

The Jupiter missions arrived safely a year after their launch and the Saturn probes two years after theirs. So far none of the missions have provided any conclusive data about the Sun Dragon.

Chase Missions

The first Chase probe departed Earth orbit in 2041 and its target was Sun Dragon C heading towards Tau Ceti. This mission was designed to supplement the Observer missions by making closer and direct contact with the two Sun Dragons heading out of the solar system. It caught up with the alien near Jupiter’s orbit and despite the short time of the encounter, it reported back a wealth of information.

It discovered that the entity was in a dormant state and so didn’t attack the probe. Its sensors confirmed much of the research by the Mars Voyager, although in greater detail.

The second Chase probe was launched in 2043 and it caught up with its target –Sun Dragon B heading towards Barnard’s Star – in 2045. It too found the alien in a dormant state and provided additional information. Its most significant discovery was the fact that the entities weren’t exactly the same and that there were small chemical and molecular variances between them.

The two probes have both achieved escape velocities for the solar system and are still sending back data.

Tau Ceti Mission

By the 2070s it looked as if UNSA would lose its leading role in space operations. By law it controlled operations in Earth orbit, but the national space agencies had resumed robot missions to the Moon and the planets. The consortium of private industry had succeeded in moving a near-Earth asteroid into Luna orbit and begun mining operations.

That changed once the Tau Ceti signal had been authenticated as originating from the star system. Three radio telescopes were launched into deep space to help study the transmission. When the signal faded away, the only way to discover its source was to send a mission to Tau Ceti, 12  light years away from Earth.

The enormity of the mission and the effort it required generated a lot of resistance. Many people considered the task impossible. However, the potential for the source being an intelligent race captured the public’s imagination. National space agencies were under pressure to support the mission, private industry was happy to involve itself in what was likely to be a trillion-dollar project, and UNSA saw an opportunity to restore its primacy in space operations.

The design phase for the project began in 2091 and construction started in 2094. Now in 2099 it is ready to begin its journey to Tau Ceti.

Would You Like to Know More? - The World in 2099

"Aurora Borealis Over the Midwest" by NASA

Orbital Cascade Event

The Sun Dragon’s arrival in Earth orbit in 2033 caused an electrical storm of biblical proportions. Every satellite was damaged and some were knocked from their orbits. As one smashed into another, it caused a cascade effect as they fragmented and filled the orbital paths with debris.

As well as knocking out most of the world’s communications, the storm ravaged non-hardened  power and electronic systems. Communications was limited to some military systems, a few protected landlines and the individual ham radio operators who’d been able to protect their equipment.

The lack of communications exacerbated the breakdown as people panicked when the power failed and they saw the extreme aurora in the sky. Law and order was eventually restored in most major cities within days. Repairs on the power and communications networks had just begun when the Sun Dragon reached the Sun.

The Great Cold

What happened in the aftermath was worsened by nation states’ inability to respond effectively to the new crisis. When the Sun Dragon wrapped itself around the Sun, the catastrophic reduction in solar energy plunged the world into a mini ice-age. Thankfully for humanity, that didn’t last. Once the Sun Dragon split into two new entities, the warmth and light from the Sun returned.

It had taken weeks for the world to become covered in snow and ice. It took over a year for the weather and climate to return to something resembling normality. That year of storms and extreme weather conditions destroyed 90% of the world’s crops. Starvation and famine struck throughout the world, and even the richest countries suffered immense losses.

It was the poorest and most populous countries which lost the most. In 2033 the world’s population approached 8 billion people. In China and India alone over a billion lives were lost.Within a year less than half that number remained. Transport networks damaged by the Sun Dragon event and the freezing temperatures prevented effective distribution of the limited stockpiles.

Those countries used to such severe weather suffered the least, although their losses were still monumental. Europe and North America lost a quarter of their populations. Russia weathered the storm well, but populations in Africa and South America were devastated.

Disease and Starvation

When the ice retreated, disease followed in its wake and rampaged through the survivors. The impact was greater because of the broken communications, transport and power networks. Healthcare facilities were already in disarray and unable to cope with the growing influx of the sick.

To make matters worse, the bodies of the dead weren’t cleared up and so disease continued to spread. In the end, most of the outbreaks burned themselves out rather than being stopped and then the survivors had to face a year before the next crops would be available.

Up until that point, the national governments and international NGOs had determined relief and response efforts for themselves. Only limited and token programmes were undertaken for the less-fortunate countries. Despite this, many troops already deployed in other countries helped local authorities in the crisis. The scale of the disaster overwhelmed even the most powerful countries faltered in their handling of the situation.

Salvation came from an unlikely source: an experimental artificial intelligence which had analysed the history of international relief efforts. Its purpose was to help develop and guide the United Nations’ future operations. The system had been nicknamed ‘Eliza’ by its creator Christina Wheadon, in honour of the chat program that had first inspired her interest in artificial intelligence.

Many were doubtful that the system could handle such a mammoth task. In the Security Council, there was some resistance from the US and China who were unwilling to devote their resources supporting the United Nations. However, the General Assembly represented the nations of the world and they voted with a huge majority to ignore their veto and implement Eliza’s recommendations.
Some nations (including the United States and China) refused to provide supplies or resources for the Eliza Plan and some feared this meant that the plan would fail.

Survival and Recovery

The Eliza Plan wasn’t a popular decision. It was built from an AI’s brutal practicality and while it was designed to save as many people as possible, it did so by sacrificing some of the more remote communities that would be a greater burden to support.

As a result the plan wasn’t universally accepted, even after the first six months when the United States and China changed their stance and threw their combined weight behind the Eliza Plan. Much has been written about the politics of their manoeuvring, but their reversal boiled down to practicalities. Where the plan had been accepted and followed, survival rates were markedly higher and at a lower resource cost.

Public opinion also played its part. Both the United States and China had more of a working communications network than most other countries. This granted their people a voice. While the death toll in both of their countries had been as bad as the rest of the world, the survivors now had a better quality of life than those they saw on the news and demanded that their governments did more to help in the recovery.

The Eliza Plan was more than minimising losses, it was also about rebuilding the core services needed to allow the survivors to return to 21st century life.

Unexpected Benefits

While it would be heartless to describe the unprecedented culling of the human race as a fortunate event, as civilisation was slowly rebuilt, some distinct benefits emerged.

The first was global warming. The predicted dangers from climate change had been clearly present in 2033. However, the sudden change in weather caused by the Sun Dragon had dropped global temperatures way below those before the industrial revolution. When Sun Dragons B and C  departed, the temperatures slowly restored to modern levels. But the violent changes in weather and climate had reset much of the damage caused by industry, mechanised farming and resource collection over the centuries.

It hadn’t removed the effects completely, but did reset them enough that mankind now had the chance to prevent a recurrence of the problem in the future. The drastic reduction in the world’s population and perilous state of the economy reduced the output of the power networks and industrial capacity.
Much of the existing industry had been damaged or destroyed by either the severe cold or the electromagnetic pulses from the Sun Dragon. Only the most hardened facilities survived intact which meant that most production centres had to be rebuilt. The reconstruction used more environmentally sensitive techniques to help safeguard the future.

Potentially the biggest positive impact was the flattening in equality around the world. Many financial data centres had been damaged or outright destroyed. Considerable effort had been undertaken by the banks and financial institutions to restore the data, but failed for most of it. The greater disaster overshadowed this loss and for five years the world operated on a barter economy.

The sheer scale of the system breakdown and loss of life nullified huge portions of the economy, destroying many assets that defined individual and institutional wealth. With everyone’s efforts directed at rebuilding, the details of ownership were fragmented at best, but in many cases lost.
As the world’s infrastructure returned, so did the economy and with it personal wealth. However, it was mostly new wealth and, with a much reduced population, it was spread more evenly. Differentials between the rich and poor did return over the following years, although they haven’t reached the severe separation that existed before.

Nations Resurgent

In the 70 years since the Sun Dragon event, humanity recovered and restored a civilisation that is now cleaner and leaner than before. More balanced wealth distribution inspires innovation and increased production. The first interstellar space mission is about to be launched, but the tribalistic baggage of our past remains.

As the recovery strengthened, so control of the various programmes slipped back to the national governments from the United Nations. The spirit of cooperation continued and many of the national squabbles have eased in the face of larger concerns.

It’s a more peaceful world than before and the United Nations is much more active in key areas like health, economy and education. In contrast to this, defence, law enforcement and intelligence operations remain the sole province of national governments.

Would You Like to Know More? - The Tau Ceti System

By Cäsium137 (talk) after R. J. Hall after Torsten Bronger [GFDL (http://www.gnu.org/copyleft/fdl.html)

The Tau Ceti star system is just under 12 light years away from our solar system. It contains a single G-class star similar to our own. That similarity was such that in the late 20th century, the system was considered a likely candidate for life. When the search for exoplanets began in earnest in the early 21st century, various discoveries about the system (in particular the larger than normal debris cloud) dispelled hopes that the system could contained advanced life.

With the reception of the Tau Ceti signal in 2076, greater interest in the system intensified.

Stellar Properties

Tau Ceti is the closest single G-type (the same class as our sun) star. It is less massive at just under 80% of the Sun’s mass. It has a similar ratio for its radius at around 79% of the Sun’s radius. Analysis has indicated that it is a stable star.

Its metallicity (the abundance of iron in its composition) is about a third of the Sun, indicating that it is slightly older at approximately 6 billion years old.

Its rotation has been measured at 34 days.

The luminosity of Tau Ceti is just over half of the Sun, meaning that any habitable planets would be much nearer to the star than Earth is to the Sun.

By Icalanise (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

Planetary System

Tau Ceti has long been thought to have a number of planets, with 5 terrestrial-sized planets suspected in the early 21st century. These were later confirmed and a sixth larger planet, probably an ice giant, suspected farthest away from the star.

Below are the details for the individual planets, note that the designations are in order of discovery:

Tau Ceti b

This is the nearest planet to Tau Ceti at a distance of only 0.1 AU (Astronomical Unit, the average distance between the Sun and the Earth). Its mass is a little more than the Earth’s and it orbits the star every 13 days. It is believed to be a rocky world with no atmosphere. Although it is massive enough to retain an atmosphere, the constant solar wind would have blasted it away billions of years ago.

Tau Ceti c

This planet’s orbit is twice as far from the star as Tau Ceti b at around 0.2 AU. It is a little more massive and is thought to have a thin atmosphere, mostly composed of gases from violent volcanism. This has been observed from spectrographic analysis as the planet passed in front of the star during its 35-day orbital period.

Tau Ceti d

The third planet from the star is still relatively close at only 0.3 AU. While not confirmed it is thought to be similar to Venus, but with over twice the mass at 1.9 Earth masses. It orbits the star every 94 days.

Tau Ceti e

By Planetary Habitability Laboratory @ UPR Arecibo
[CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

The fourth planet in the Tau Ceti system is a large terrestrial planet at almost 3 Earth masses and is half the distance from its star than the Earth is from the Sun. Little is known about whether it has an atmosphere or not and it orbits the star every 168 days.

Of all the discovered planets in the Tau Ceti system, this is the one most likely to harbour life.

Tau Ceti f

The fifth planet in the system orbits at over 1.2 AUs from the star and is a massive terrestrial planet with almost 6 Earth masses. At this size it may actually be an ice giant or even a small gas giant.

Tau Ceti g

While the other planets in the system have been confirmed by observation, the sixth planet’s presence has been hypothesised from small discrepancies in the motion of the inner planets. Tau Ceti g  is believed to orbit much farther out . Its estimated orbital distance is between 6 and 7 AU. It is postulated to be an ice giant, or possibly a small gas giant.

Debris Disk

Tau Ceti was once considered to be a suitable candidate for life, however in 2004 a research team discovered that the system contained a dust field (also containing asteroids and comets) much larger than the Sun’s. This indicated that planets would be up to 10 times more likely to be hit by extinction-level impacts.

The debris field ranges from 10 to 55 AU and poses a potential threat to the Venti probe as it enters the system.

Would You Like to Know More? - About The Tau Ceti Signal

By Jcolbyk at en.wikipedia [GFDL (http://www.gnu.org/copyleft/fdl.html) 

SETI  (Search for Extra-terrestrial Intelligence) researchers have been searching for signs of alien intelligence for over a century. The great silence ended in 2076 with the detection of a multi-band transmission established to be in or near the Tau Ceti system.

The signal was discovered in March 2076 by Carl Morgan, a research graduate at the SETI Institute based in the University of California. The project was experimenting with methods of detecting Sun Dragons or similar entities in interstellar space as an early warning system.

Upon review it was discovered that the signal had been recorded a month earlier, but the signal variance had been within the normal margin for error and so hadn’t been flagged by the computers. The nature of the signal mystified researchers for several months. It wasn’t distinct enough to be considered a deliberate communication yet contained enough patterns to not be of natural causes.

In October 2076 the team made a breakthrough when they realised that the transmission wasn’t a single signal, but actually a multitude overlaid upon each other. They also discovered that the signal was moving and that caused the increased signal strength.

The signal continued for the next 14 years. Over the years it slowly increased in strength, held steady for two years and then faded away until it was indistinguishable from background noise.

There has been considerable speculation about the source of the transmission. One theory is that it is a Sun Dragon entity, although analysis of the signal strength makes this unlikely. Records from the Mars Voyager included the electromagnetic emissions from the entity as it reproduced on the surface of the Sun and it was far below what could be detected at 12 light years by several orders of magnitude.

The most commonly accepted theory is that it is communications overspill from a technologically advanced society. It is their equivalent of radio and television spreading across space.

Returning the Message

Since first receiving the signal, there has been considerable debate as to whether a response should be sent. For most of the research team, the ambiguity of the signal meant that they didn’t know what they were responding to and so what the reply message should contain.

For some it didn’t matter and they pressed to have a first contact message sent to let the originators know that they weren’t alone in the galaxy. There was also reluctance from the United Nations Security Council and some prominent scientists at initiating contact with a potentially dangerous alien species.

The pressure increased when the stellar destinations for the two Sun Dragon entities spawned from the Sun were established. Sun Dragon B was heading towards Barnard’s Star and Sun Dragon C to Tau Ceti. The journey across the interstellar gulf would take the creatures centuries. Even so, many people believed that if there was a chance that the transmission came from an intelligent species then there was a moral duty to warn them.

The choice was made for them by a group of hackers who transmitted an updated version of the Arecibo message . The Arecibo message was a radio transmission sent from the Arecibo radio telescope in 1974.Following that, an official message was sent in various forms to communicate humanity’s existence and the threat of the Sun Dragon to their system.

Transmission Ends

In 2090 the signal started to fade, then disappeared completely and hasn’t reappeared since. No response has been received from the messages sent either. The disappearance of the signal and the mystery of what it actually represents provided the impetus for humanity’s first interstellar mission.

Would You Like to Know More? - The Venti Probe

The Venti probe is the United Nations Space Administration (UNSA) robot probe for the Tau Ceti mission. Venti is the Latin word for ‘wind’ – an allusion to its primary mode of propulsion.
The epic scale of such an undertaking presents significant technical challenges. The probe needs to travel farther, faster and for longer than any other man-made machine. Only thanks to recent advances in engineering, materials technology and computer systems was UNSA able to construct a vehicle capable of crossing the vast gulf of interstellar space to the system of Tau Ceti.

As well as its primary objective, Venti will pass through one of the two Sun Dragon entities heading out of the solar system. The previous Chase missions have confirmed that the alien is dormant during its outbound travel phase. However, the Venti probe has been hardened in case of attack from the Sun Dragon entity.

The design phase began in early 2091 and took three years of concentrated effort to design the mission. There were many challenges to overcome, not just technical, but for planning and operational support. Not since the ill-fated Mars Voyager had mankind put together a space mission on this scale.

Construction of the probe started in Low Earth Orbit (LEO) as soon as the plan was approved and took six years to complete. The resources needed to put the mission together were phenomenal, and involved every major national space agency and private space corporation.

The probe’s payload mass is 70 tons, not including fuel for the MPD drives. It is approximately 20 metres in size and is dwarfed by a solar sail which has a surface area of 9 square kilometres.
The probe will launch from LEO in April 2099.

Propulsion

The mission to Tau Ceti is unparalleled in human history. While several earlier missions have reached the outer regions of the solar system and a much smaller number, such as the Voyager probes, have entered interstellar space, this is the first mission intended to reach another star system.
The 12 light year journey requires propulsion systems capable of extreme endurance and with little or low fuel needs (and therefore mass). It’s also important that they be easy to maintain and repair, since with a mission lasting well  over 200 years, failure is likely to occur at some stage.

The Venti probe operates two different propulsion systems – a graphene solar sail and MPD (MagnetoPlasmaDynamic) drives. It also has a set of canisters for pressured gas propulsion, which are used for emergency manoeuvres only as they require fuel.

As well as the two propulsion systems, Venti will be assisted by gravity transfers from several major bodies in the solar system and from two booster sleds equipped with nuclear impulse drives.

Graphene Solar Sail

The graphene solar sail is an advancement from the experimental sail systems used in the late 20th and early 21st century space missions. The solar sail uses pressure from the solar wind streaming from the Sun against the thin material to push the probe. Like sailing ships, the sail can be angled to allow a direction of travel at angles different to the vector of the solar wind.

Compared to the more familiar chemical rockets used for launch, the solar sail creates very little thrust. The rockets use a large amount of fuel to generate immense amounts of thrust, but only for a short time. The sail uses no fuel and so can be used to continually accelerate the probe up to 5%  of the speed of light, although it will take decades to reach this speed.

The graphene layer reacts with the energised particles of the solar wind, producing an additional thrust effect from the sail. Entwined with the graphene patches are carbon nanotubes providing rigidity and anchors to allow the patches within the sail to be angled to adjust direction of travel.
Overall the sail is 9km2 and dwarfs the actual probe by a considerable margin. Despite its huge size, the ultra-thin material of the sail is incredibly light and adds little mass to the probe.

MPD Drive

The MPD or MagnetoPlasmaDynamic drive is an advanced form of ion drive. Unlike the solar sail, the MPD drive requires hydrogen fuel, although the burn rate is quite low and the mission design allows for Venti to refuel itself along the journey.

The drive works by ionising the hydrogen gas and then forcing it through electromagnetic fields, the resultant jet producing thrust. It was only recent advances in power generation technology that made this drive possible.

Like the solar sail, the MPD drive produces much smaller thrust compared to chemical rockets. It is capable of firing for extended periods and generates higher thrust than the sails. For the outbound journey, Venti will be accelerated using the booster sleds and the solar sail.

The MPD drive’s primary purpose is for the deceleration burn on approach to the Tau Ceti system. As it enters the system, the drag from the solar sail will assist the slowing down of the probe.

The sails provide some manoeuvring capability, but not enough for quick changes in direction. A secondary vectored thrust module for each drive allows directional thrust. For this reason there are four MPD drives fitted to the Venti probe.

Power Supply

Generating sufficient power for extended space missions has always been a challenge. For any mission into the outer solar system or beyond, there is insufficient electrical power from solar panels to power a probe, and the MPD drives of the Venti probe require more energy than the rest of the probe’s systems combined.

Smart power management is used to keep the power requirements as low as possible, so the probe’s sensory and scientific packages are powered down while the drives are operational.

The sail has embedded photo-electrical cells which provide power. When the probe is too far away from a star then it relies on the nuclear fission generator at the heart of the probe. This is a lithium cooled reactor and while of an efficient design, the fuel required for its operational life of over 200 years forms the bulk of the probe’s payload – not including the fuel for the MPD drives. Unlike the MPD fuel, it is impractical to refuel the reactor and this determines the likely lifespan of the probe.

As a back-up system, the probe also has an RTG (Radioisotope Thermoelectric Generator) system which uses radioactive decay to produce heat and electricity. This system lacks the power to be able to energise the MPD drive, but can maintain the computer and science systems when they are in power-saving mode.

Science Packages

As with any space mission, the goal for the Venti probe is to amass data and as a result discover new science. In particular it is intended to solve the mystery of the Tau Ceti signal. In spite of the setbacks caused by the damage of the Sun Dragon encounter, we have learned much about the outer regions of the solar system. Even so, there is little information available on what the probe will encounter when it reaches the Tau Ceti star system, so its science package is designed to include as much sensor technology as possible.

The sensors are a mixture of active and passive systems. Active sensors like radar transmit a signal and use the response to determine information about the probe’s surroundings. Passive sensors like the telescopes rely on received input for assembling information.

All of the ROVs (Remote Operations Vehicles) are equipped with a basic sensor package of optical, multi-spectrum electromagnetic, and thermal passive and active sensors. ROVs are also used for distributed science tasks like gravimetric measurements. The sensor packages are modular so extra instruments can be added to the ROVs for specific tasks.

Most of the sensors are embedded in pods that are secured within the protective shell of the probe and deployed on extendable arms when used. A few are placed into the skin of the probe for navigation and situational awareness for the Venti as it travels.

Optical Sensors

Optical sensors use light (including beyond the visible spectrum such as ultraviolet and infrared) as input, and they exist in two forms. The first, such as telescopes, use the light directly for observation. The second type use light indirectly for secondary analysis, such as spectrographs.

EM Spectrum Sensors

Similar in nature to the optical sensors, these operate at different wavelengths of the EM (electromagnetic) spectrum like radio and radar.

Lasers

Low-powered lasers are used for range finding and spectrographic analysis of gases and vapours. Two high-powered lasers are also available to create gas or vapour samples from liquids or solid materials.

Energised Particle Detector

The EPD (Energised Particle Detector) is used to detect ionised particles and exotic particles like neutrinos.

Plasma Sensor

The plasma sensor is used to measure plasma activity and composition when the probe passes through a region of gas that has been heated or effected by magnetic fields to form plasma.

Physical Sample Analyser

Physical samples can be retrieved by ROVs or analysed in situ by them.

Microwave Radiometer

Used to scan and measure atmospheres and clouds by using varied wavelengths to determine composition and pressure.

Gamma Ray and Neutron Detector

Elements and isotopes within the rocks create certain emissions as they decay, such as neutrons and gamma rays. These can be used to determine ages, composition and some kinds of geological activity.

Magnetometer

Used to detect the strength and direction of a magnetic field.

Dust Analyser

Used to analyse dust particulates and measure dust density.

Computer Systems

With a mission duration measuring beyond two centuries, the Venti probe needs to be more self-sufficient than any space mission ever launched. As it travels farther away from Earth, its ability to transmit data is reduced so it cannot rely on sending back raw data for analysis. This means that it has to be done by the probe. Combined with the fact that it would be too far away to rely on instructions from mission control, Venti needs to be capable of making decisions beyond the basic operations of the probe.

Space missions can be perilous for delicate electronics, especially for tightly packed circuits such as those used in processors. With the components so close together, even a stray particle or cosmic ray can damage the chip. As with previous space missions, this is mitigated by using older electronics that aren’t as vulnerable as they don’t use such small fabrication techniques.

Sensitive areas are also protected by layers of ultra-dense alloys to block as many potential threats as possible. The computers are stored within gel which provides further shielding as well as shock protection and heat management.

Potentially the greatest challenge for the mission is the unknown nature of what it will encounter when it reaches Tau Ceti. The computer system needs to be capable of making decisions in unusual circumstances, but would also need to have as much information at its disposal as possible. The sum of human scientific knowledge is contained within the probe.

More than that, it needs to be able to apply the knowledge in novel ways. To achieve this, Venti has a number of computer systems. Each has a dedicated purpose. Most operate in a similar fashion to traditional computers and manage the core systems of the probe. As with all aspects of the mission, part of the longevity is enabled through multiple redundancy with physical and logical backups.
The command functions are handled by two separate neural networks. They lack the specialisation of the system management computers, but are capable of self-organisation and updating their operating software. Their neural nets also enable them to learn.

Such complicated software needs capable hardware to run on. The risks of cosmic radiation and the need for easy maintenance means that the latest hardware can’t be used. Instead the command systems use a matrix of micro-sized computers. They operate at a slower pace to contemporary computers to better regulate heat and facilitate modular repairs and maintenance.

Primary Command Module

The PCM (Prime Command Module) is the operational command system for Venti. This is a free-form artificial intelligence utilising a neural net architecture, capable of interpreting data from the management systems and formulating plans of action in response to changes in situation.
Since it was first activated early in Venti’s construction phase, the PCM has run continual simulations of all variables pertinent to the mission. As part of its training, its decisions were vetted by teams of experts to fine-tune its decision making processes.

Although the PCM controls the probe, it’s the Secondary Command Module which will take charge if a first contact scenario occurs.

Secondary Command Module

The SCM (Secondary Control System) acts as a backup for the Primary Control Module. Unlike the physical and virtual backups, it is constantly operational and appraising the decisions made by the PCM. If the PCM is deemed to be making unsound decisions then the SCM takes over while the PCM is repaired, assuming repair is possible.

The SCM has a tertiary function as the public relations representative for the mission while it is in flight. This wasn’t part of the original mission profile and grew from its practice of natural language comprehension and expression during its training for first contact scenarios.

Another consequence of its natural language skills was a more human-like contact with the mission team, earning it the nickname of ‘Seb’.

Engineering Control

The engineering control computer monitors and regulates the maintenance of the probe’s many systems. It provides warnings of any failures and operates the robots that perform physical maintenance and repairs.

It is capable of acting autonomously to keep the probe operational if it receives no instructions from either of the command modules.

Communications

This operates and provides an interface to all communications systems. In the event of the command modules failing, it has a hard-coded back-up system to send telemetry and sensor data back to Earth.
This would normally be filtered keep the quantity of data manageable, but when in back-up mode a less precise and ‘lossy’ form of compression is used. This degrades the quality of data, but compacts as much as possible within the available bandwidth. That bandwidth decreases the farther from Earth Venti travels.

Sensors

The sensor system manages and provides interfaces the various science and sensor packages. It is capable of complex analyses, but only those pre-programmed into the computer. The command systems are capable of altering these or creating new ones.

Navigation and Flight Control

All of the probe’s navigation and flight control systems are managed together and it provides the interfaces for these functions. In the event of the command modules failing, it is programmed to continue the trip to Tau Ceti and then fly past each of the planets.

Maintenance

The mission plan requires Venti to remain operational for at leastmore than 200 years, which presents a major technical challenge. It’s common on space missions to build in redundancy and the Tau Ceti mission follows the same ethos. Redundancy to the level needed for this length of time would add too much mass to Venti, so that meant that the probe had to be able to repair itself.

To affect the repairs, the probe is equipped with two sizes of spider-bot. The smallest are microscopic and used for repairing circuitry and small-scale components. The larger versions are 30cm across and can work in groups to perform larger repairs.

The probe is constructed as much as possible with components which can be swapped out by the robots. They also perform routine maintenance for mechanical and electrical parts.

Three 3D printers are also equipped with patterns for every component on the probe. This is supplemented with stores of raw materials. The ROVs can also be used to gather replacement materials if needed.

Communications

Effective and direct communications between Venti and Earth become ever more problematic the farther away the probe travels. The basic technology of an ultra-high-gain radio antenna in the X band frequencies remains the same as for earlier robot explorers of the outer solar system.

The increased energy available to the probe offsets the problem somewhat, but the data rate fall-off is still very restricting. This again is partially mitigated by advanced compression techniques and pre-processing by the onboard communications systems. The data will be analysed so the full quantity of raw data doesn’t need to be sent.

For significant encounters and at the discretion of the two command systems, blocks of raw data can be sent back to Earth.

Receiving radio transmissions from Earth is easier as more energy is available to the ground and orbital transmitters. It is expected that Earth can remain in contact with the probe all the way to Tau Ceti. It is considered unlikely that the Venti can reliably transmit radio data once it passes the three-quarters mark of its journey.

Venti also uses a laser communications system, a more advanced version of the one used on the Mars Voyager mission. The laser transmitter has the advantage of needing less energy to transmit the same amount of data.

Keeping the laser in alignment is the greatest challenge and to make this easier, a group of large receivers has been positioned in Earth orbit.

As an emergency system, 12 mini-sats are available, each equipped with a single-shot burst transmitter.

Remote Operations

The Venti is provisioned with eight Remote Operations Vehicles. Four of these are a generic configuration for collecting samples. Two are equipped for hydrogen mining to refuel the MPD drives. The remaining two are sensor platforms for the distributed science packages such as the gravimetric sensors.

The ROVs lack the power to operate their own MPD drive and so use a less powerful xenon-based ion drive.

The probe is able to create new ROVs from the stored templates for the 3D printers.