From comets to planets near and far, space probes reveal the universe

NASA/JHUAPL/SwRI

If space is humankind’s ultimate challenge, then the first step starts close to home – we have still to explore much of our solar system that spans across enormous distances, never mind those galaxies and stars more distant still.

To learn more we must get closer, dispatching spacecraft such as New Horizons – which has just returned our first ever close-up images of Pluto after a nine year journey. Here are my top five missions that are chipping away at what we don’t know and building up a better sense of universe around us.

1. New Horizons

Time for your close-up, Pluto. NASA/JHU APL/SwRI

Rocketing past at 14km/s, the New Horizons spacecraft has provided our first close view of Pluto which will enormously improve our understanding of this distant body. Our facts regarding this icy dwarf are sketchy at best. Just knowing what Pluto looks like makes it much more real.

The probe’s brief two-hour visit captured images of parts of Pluto and its largest moon Charon at high resolution, improving our understanding of planet formation. This is an amazing feat, considering the signals take more than 4.5 hours to reach Earth and that the sun is so weak at this extreme distance that solar power is not an option.

But the mission doesn’t end here: in 2019 New Horizons will visit a small object in the Kuiper belt, a region of space filled with small rocky planetoids, giving us a chance to examine the make-up of these remnants of the early solar system. And by 2026, it will reach the outer edges of the solar system.

2. Rosetta

Comet 67P/Churyumov-Gerasimenko, as seen from Rosetta 20km above. ESA, CC BY-SA

Conceived decades ago, Rosetta flew alone through space for years before it reached the tiny comet that was its target and swung into orbit around it. Given the comet’s highly irregular shape this is an outstanding feat by itself.

The lander Philae managed to touch down and collect surface data of the comet, and while it was forced to shut down from lack of sunlight falling on its solar panels, it has now awoken and is transmitting data again. The Rosetta orbiter mission has also been extended to 2016 when it will also attempt to land on the comet.

The missions have improved our understanding of comets which contain frozen, icy rocks, and have measured the gas composition of jets streaming off the comet before they are altered by solar radiation.

But more than just hard numbers, this mission has been capturing images that speak for themselves, showing an ambitious mission conceived by many nations working together. Images such as Rosetta’s pictures of Philae descending resonates with us more than just hard facts and figures.

3. Dawn

Dawn is another mission expanding our knowledge of dwarf planets, in this case Ceres. It is now orbiting this interesting object having spent 2011 conducting similar work around nearby Vesta. Both Vesta and Ceres in the asteroid belt are protoplanets but of quite different composition.

Dawn has illustrated how powerful imagery can be. The most intriguing image is a crater that contains a handful of bright white spots on a surface otherwise darker than coal – unexpected, unexplored, challenging terrain.

What is the bright spot on the surface of Ceres? Dawn will find out. NASA

4. Messenger

Incredibly detailed images from Messenger’s visit to Mercury. NASA/JHU APL/Carnegie Institution of Washington

Messenger is still in my list of impressive space probes even though the mission ended with its controlled crash on Mercury’s surface this April. Sent to explore a planet of which we had barely any imagery of its surface, in four years Messenger managed to not only give us high-resolution maps of the innermost planet, it discovered water in its dark polar craters. On a planet baked by the sun this could only arrive from comets and water-rich asteroids – objects currently under investigation by Rosetta and New Horizons.

5. Curiosity

Curiosity Rover’s famous off-world self-portrait from Mars. NASA/JPL-Caltech/Malin Space Science Systems

The last is the Curiosity rover. For me it sums up the efforts to explore our neighbour, Mars. These missions went in search of life and traces of water, carrying a complex laboratory, drills, laser and high resolution cameras.

Curiosity particularly illustrates the challenges we are capable of mastering to land a probe on Mars – described by NASA themselves as “seven minutes of terror”.

These rovers have achieved an outstanding feat, where now those exploring beyond Earth are not astronomers but geologists, the rovers' equipment replacing the hammer and microscope used during fieldwork. The missions have added Mars to the “territory” that humans have access to. It’s even on Google Maps – imagery so good that we can see its surface as if we were there and can look at rocks in such detail as if we were picking up pebbles at the beach.

It’s out there waiting for us

Probes have witnessed solar eclipses and comet fly-bys that provide an entirely different view than is possible from Earth – something that adds a feel of awe and wonder, like looking back on Earth from the moon.

The sort of incredible images provided by these probes connects us with the solar system, bringing it closer to home. Famous images of Earth from space, such as the Blue Marble and the Pale Blue Dot catalysed our ecological conscience, reminding us of the fragility of our world in comparison to the vast, cold emptiness of outer space.

Such images lead us on to explore the universe and ourselves, and the findings of these remarkable spacecraft that have travelled millions, sometimes billions of miles through space over many years remind us that it’s out there to be discovered. The challenge and rewards await, as J F Kennedy said: we choose to go to space not because it is easy, but because it is hard.

Fly-by missions: what is the point when we have the technology to go into orbit?

Preparation of Mariner 4 before its fly-by of Mars, exactly 50 years ago. NASA/JPL

New Horizons' fly-by of Pluto and its moons is the latest in a historic string of missions to objects in the solar system. But given that a fly-by lasts for just a short time, how much can we really get out of it? There’s no doubt that the mission will yield a great deal of interesting data, but surely more would be gained if the spacecraft could go into orbit for a number of days or actually land on the surface and take physical samples.

New Horizons is hugely important because it is giving us a first glimpse into the unseen world of a third class of objects in the Kuiper belt – the building blocks of the outer solar system, located beyond the terrestrial and gas-giant planets. Fly-bys such as this are very exciting as they provide just one chance for unique measurements at the target.

While we are only at the very first stage of exploring Pluto and its moons, the fly-by will provide the foundations for future missions. Indeed, a fly-by is the first in the classical four stages of solar-system exploration and is followed – in this order – by an orbiter, a lander and the return of a sample from a body (marked 1-4 in the table below).

Lessons from the past

The first fly-by was of our Moon, made in 1959 by the Russian Luna-1 spacecraft. And 50 years ago, nearly to the day (July 15), the US Mariner 4 made the first fly-by of Mars.

My generation was captivated by the historic fly-bys of the outer planets and some of their moons, and I’ve been lucky enough in my own career to have been involved in instrument teams for several historic fly-bys. These were the Giotto mission to comets Halley (1986) and Grigg-Skjellerup (1992), as well as several close “fly-by firsts” in the Saturn system with the Cassini mission (such as moons Titan, Enceladus, Rhea, Dione, Hyperion).

Flyby firsts. Author provided

The Giotto fly-by of comet Halley only lasted a few days, but our knowledge of comets was revolutionised by this encounter. One of several probes to explore Halley in the mid-1980s, Giotto had the widest and most capable set of instruments and passed closer to its target than any of its companions.

It found cometary jet activity, a surprisingly dark surface, hydrocarbons in a crust and a complex bow shock and tail formation mechanism. These discoveries are now being followed up by the Rosetta mission and Philae lander at comet 67P.

Artist’s impression of Giotto approaching a comet. Mirecki/wikimedia, CC BY-SA

But the fact that fly-bys happen so quickly can also make them very stressful and difficult to manage. When we were monitoring the Giotto spacecraft, flying past Halley at 68.4 km/s, it suddenly started spinning off its axis after encountering a dust particle near its closest approach. Fortunately it was possible to stop the wobble.

Comet Wild 2 as seen from Stardust on January 2, 2004 NASA/wikimedia

There are many other examples where data have been rescued – including with New Horizons during its worrying glitch (now fixed) on July 4.

New Horizons and beyond

After launch on an Atlas V in 2006, the 478kg spacecraft passed Jupiter only 13 months later, which was an express route. The main reason for the hurry was to reach Pluto before its tenuous atmosphere collapses by freezing as the planet moves further away from the Sun. The mission design of New Horizons gives a very fast fly-by at over 14 km/s (50,000 km/hour), with only a few hours and days for the highest resolution measurements.

Measured in “astronomical units” (one AU is about 149.6m kilometres), Pluto’s orbit takes it from its closest point to the Sun (29.7 AU, 1989), inside Neptune’s orbit (30.1 AU), through its current distance (nearly 33 AU) out to its furthest distance from the Sun (48.9 AU, 2113). Receding from the Sun, the surface temperature reduces from its current 40 Kelvin, leading to freezing of the atmosphere.

But why fly past, rather than going into orbit? The most simple answer is that a lot of energy, meaning a lot of fuel, would be needed to slow New Horizons enough to capture it into orbit. Instead, NASA opted to get to the Pluto-Charon system quickly with a relatively capable 30 kg payload, rather than taking a large amount of extra fuel using a different fly-by scheme, to get there before the atmosphere collapses.

New Horizons is already expanding the thin textbooks on the Pluto-Charon system with early images, and the data to be returned over the next 16 months from visible, infrared and ultraviolet spectrometers as well as plasma, dust and radio science instruments will broaden and rewrite them again.

Image of Pluto and Charon, taken with New Horizons. NASA

But new questions will almost certainly arise, which can only be answered by a more detailed orbiter mission, following the usual exploration sequence. When that would happen is hard to say. The relative priority will need to be compared with missions to other objects, particularly those where the exploration stage is low, before possible implementation.

In the future, we can look forward to more detailed fly-by missions of objects where our knowledge is limited and later-stage missions such as Rosetta. Also we will visit new dimensions, such as ExoMars drilling underneath the Mars surface by up to 2 metres for the first time. The JUICE fly-bys of Jupiter’s moons Europa, Ganymede, and Callisto, before entering Ganymede orbit, will allow comparison of subsurface oceans, and Europa Clipper will fly past Europa 45 times to complete a detailed reconnaissance there.

These missions, and their follow-ons, will help us discover more about the humankind’s place in the universe – and whether we are alone. But it is clear that, while we have achieved a lot in solar-system exploration so far, there is still a large amount left to do.

New Horizons finally gets up close with Pluto – for 15 minutes

Latest and most detailed image of Pluto, just before the fly-by. NASA

As I began typing this column, NASA’s New Horizon mission was on its final approach to its primary target, Pluto. By the time I finished composing my deathless prose, the main mission was over. And I’m not a slow writer.

Launched in January 2006, the spacecraft has travelled for nine and a half years for a flyby lasting only 15 minutes or so. It doesn’t sound much of a reward for all the effort of designing and building the spacecraft – but for planetary scientists, the data coming back from the mission is pure gold.

For now all we can do is wait. Early in the morning on July 15, New Horizons is expected to phone home and confirm that the fly-by went well. Later that day the first high-resolution images should start trickle back to Earth – revealing what Pluto and its moon Charon actually look like up close. However, it will take nearly a year for all the data from the instruments aboard the spacecraft to come back.

But what is so exciting about Pluto? It isn’t even a planet anymore! When the New Horizons mission was conceived, Pluto stood (or rather, orbited) proudly as the ninth, and newest, planet in the Solar System. But eight months after New Horizons left Earth on its journey to Pluto, the International Astronomical Union downgraded Pluto from “planet” to “minor planet”.

Pluto’s change in status has, however, definitely not diminished the importance of the mission. Indeed, it has probably enhanced the scientific significance of the findings. Back when we thought Pluto was a planet, it was merely the last member of a series which represented a progression from the inner rocky and metallic bodies such as Mercury, through the gas and ice giants like Jupiter and Neptune, to Pluto – a small body of ice and rock.

But we now know that Pluto is not an isolated entity – it is the largest body in a huge family of primitive objects, many of which have their own moons. According to current models of how the solar system formed, there were once several hundred thousands of objects beyond Neptune, but Jupiter’s motion scattered most of them much further out from the Sun.

There are, however, still likely to be more such remaining bodies, known as Trans-Neptunian Objects, than the asteroids in the main belt between Mars and Jupiter. These objects are probably even more primitive in nature than some comets, which have been modified as they approach the Sun.

We already know that methane and ammonia ices are present on Pluto – but are there any higher hydrocarbons, or biologically interesting compounds such as amino acids? It will be interesting to see how analysis of the surface ices compare with results from the Rosetta mission or from the Dawn mission at Ceres. Can we draw any comparisons with the photo-chemistry on Saturn’s giant moon, Titan? Will Pluto demonstrate that trans-Neptunian objects are the most unchanged and unprocessed objects in the Solar System?

First look

Previous images of Pluto have been poorly resolved – the best view by the Hubble Space Telescope is of a fuzzy grey blob (see image below). But over the past few weeks, we have been able to enjoy increasingly more detailed images taken by the New Horizons spacecraft on its approach to Pluto. For example, we’ve learned that the planet is slightly bigger than we thought. We have also seen features on the surface, including what are probably ice-caps.

Images of Pluto generated with the Hubble Space Telescope and advanced computers. NASA, ESA, and Marc W. Buie/wikimedia

Although the closest approach to Pluto will be over in a matter of minutes, the amount of data captured will be immense. It could help us answer a number of questions about Pluto – such as the distribution of different ices (water, ammonia, methane), the relationship between rock and ice and the presence of a thin atmosphere. The fly-by could also shed light on whether there are indeed craters on the body and whether there is any evidence of resurfacing.

Image of Pluto and its moon Charon, taken with New Horizons. NASA

There is no expectation that cryovolcanism or ice geysers will be observed on Pluto, it doesn’t have the same gravitational heat source derived from a giant companion such as the case for Jupiter’s moon Europa. But it is in a binary system with its almost equally-sized moon, Charon – so it may surprise us yet.

For me, one of the highlights of the coming months will be synthesis of three sets of data - from New Horizons on Pluto, Dawn on Ceres and Rosetta-Philae on comet 67P/Churyumov-Gerasimenko. This will give us real insight to comet-asteroid interrelationships, and the primitive material from which the Solar System was built.

Whatever comes from the fly-by, we already have enough fresh information about our far-distant neighbour to ensure it is no longer seen as an underworld, the underdog of our planetary system. It is not the last planet to be visited but it is the first trans-Neptunian object to be seen – and so becomes a member of a very exclusive club.

Disclosure

Monica Grady receives funding from the STFC and is a Trustee of Lunar Mission One.

New Horizons is an old spacecraft – but it will transform our knowledge of Pluto

What would New Horizons be able to achieve if it had been built today rather than 20 years ago? Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/NASA

After travelling for nearly 10 years, NASA’s New Horizons spacecraft is finally set to fly past Pluto in humankind’s first close encounter with the dwarf planet.

But the spacecraft is at least a decade old (arguably more like two decades, as spacecraft need to use tried-and-tested components). If it had been built with today’s technology, New Horizons could have been able to send back a lot more data a lot faster. So how do space scientists cope with using old technology to make new discoveries and how will it affect the science they can do?

The search for Pluto began in 1906 when Percival Lowell started a project to find a ninth planet. Unfortunately, he died just ten years later, but the search was eventually continued by Clyde Tombaugh who found the first indications of the planet on 18 February 1930, when he noticed a tiny speck of light moving between two pictures taken in January that year.

New Horizons is actually carrying Tombaug’s ashes aboard, on his request.

Some 60 years after this discovery, a group of scientists started to work getting a spacecraft to Pluto and its moon Charon. This was being done at a time when we didn’t know about its four additional companions, the moons Nix and Hydra (discovered in 2005), and Kerberos and Styx (discovered in 2011 and 2012 respectively). We also didn’t know that Pluto had an atmosphere.

Various ideas were developed, from Pluto 350, which was a small spacecraft with only four instruments, to a large and highly capable spacecraft similar to Cassini, which is exploring Saturn and its surroundings. Ultimately these ideas didn’t get beyond the design phase.

But the race was on. By the late 1990s astronomers knew about Pluto’s atmosphere and believed it would freeze onto the surface before 2020 as Pluto moved away from the Sun. So in order to be able to study Pluto’s atmosphere it was important to get something launched quickly. Pressure from the public and the scientific community led to the selection of the New Horizons project in November 2001, which launched in January 2006.

Old technology, new horizons?

New Horizons, like any space mission, has different parts: the spacecraft, its scientific instruments and the equipment back at the mission base on Earth – such as the radio telescopes used to communicate with deep space missions.

Obviously we can continually improve the part on the ground as technology advances. This was done to support NASA’s Galileo mission to Jupiter and the Voyager mission to the giant planets. But we obviously can’t go and change anything on a spacecraft to Pluto which has been in space since 2006.

Technicians working on the New Horizons spacecraft in 2005. NASA/wikimedia

Spacecraft communicate with Earth by transmitting microwave signals to radio telescopes on Earth. The speed that we can receive images and other data gets slower the further away a spacecraft gets, just like being far from the telephone exchange can mean you get slower broadband at home. If a spacecraft took two minutes to transmit an image from Mars to Earth then it would take more than 10 minutes at Jupiter, 20 minutes at Saturn, and an hour at Pluto! This was a difficult problem that the designers of New Horizons had to overcome.

Generally speaking, higher-frequency microwaves allow us to reduce those times. If you want to map the entire surface of Pluto this is very important. At the birth of the space age, missions such as Mariner 4 which flew past Mars in 1964 used “S-band”, which is a frequency between 2 and 4 GHz (FM radio is about 100 MHz).

More than a decade later Voyager used the higher frequency “X-band”, between 8 and 12 GHz, allowing Voyager to return much more data than Mariner. Most spacecraft still use X-band (including New Horizons) but there is a move to use higher frequencies and NASA launched its first mission using “Ka-band”, 27-40 GHz, in 2009, just two years after New Horizons was launched.

If New Horizons had been able to use Ka-band it would have potentially been able to return much more data (by a factor of three-to-four times), or return a similar amount of data more quickly than the year it will take to send back all the measurements made at Pluto (to around three to four months). But this might not have led to such large improvements. The design of spacecraft is not straightforward. One small change in a particular area can affect the entire spacecraft design and mission plan.

NASA’s 70m diameter Deep Space Network antenna in Goldstone, California, is communicating with New Horizons NASA

As for the actual instruments it is harder to know how things could have been different. The Cassini spacecraft carries a camera known as the wide-angle camera which used a telescope that was built as a spare part for Voyager. This is a camera designed in the early 1970s, put on a spacecraft designed in the 1990s, and is still returning amazing scientific images 40 years later that continue to enable us to understand Saturn’s secrets.

In a similar vein, Galileo was launched in 1989 and carried an instrument to measure charged particles around Jupiter that was based on an updated instrument from Voyager, also designed in the early 1970s. So having instrumentation that is 10-15 years old doesn’t appear to be a problem.

Space missions are mainly restricted by costs and are designed for what they are to study. If they are overly restricted by the available technology then they usually don’t get selected for launch. NASA could have spent more money on New Horizons to include more instruments, or more power to have allowed it to send back more data more quickly, but this could have resulted in a mission that was never sent in the first place or one that got there much later and missed something exciting.

The main thing is that we are continuing our exploration of the solar system. Humankind is continuing a journey that started 115 years ago in an astronomical observatory in Arizona.

As CEO exits, Reddit finds to its cost that even unpaid workers can go on strike

Reddit broke Reddit, it seems. torley, CC BY-SA

The volunteer moderators that run the boards at Reddit, an online community built of thousands of themed discussion groups, recently staged an uprising against the firm’s management. That this uprising ultimately claimed the scalp of Reddit chief exec Ellen Pao says much about how the world of work is changing, particularly the challenges of managing relationships between paid and unpaid workers in an increasingly virtual workplace.

To recap: Victoria Taylor, a member of Reddit’s staff who worked with moderators to help them run the popular Ask Me Anything (AMA) discussions was sacked by management. The moderators, who liked Taylor and regarded her as an important advocate, were furious. Many shut down their boards and demanded her reinstatement and apologies. When none were forthcoming, a petition demanding Pao’s resignation was signed by 200,000 people, more moderators shut more boards, and AMA-geddon ensued. It took a week for management to apologise, but the rot had already set in.

Worker frustration and disputes that result in forms of organised industrial action such as strikes, go-slows, even sabotage, are as old as waged labour. The powerlessness and alienation of the industrial worker were well documented by Karl Marx back in 1887, and generations of sociologists have explored the relationship between control and resistance in the workplace. But soulless, alienating production line work or even long, low-paid hours in a call centre seem a world away from the creative web-enabled knowledge work of Reddit’s unpaid editors and moderators.

Work has changed, and even those who aren’t ‘workers’ can have an impact. Bain News Service

Many of them will be working from home or the local coffee shop, choosing the hours they dedicate to “mod” work, perhaps juggling it with online gaming, freelance software development, or maybe a PhD in bioethics. Nevertheless, the important point is that they are workers even if they are unpaid, and as such organisational structures and relationships are important to their experiences of work.

The value of free

Reddit’s reliance on the work of unpaid mods became all too apparent once they had withdrawn their labour, forcing the site to offer a restricted service. For Reddit’s senior staff this isn’t just an unfortunate moment in the company’s labour relations history. It has an impact on their bottom line, reducing the all-important advertising income that comes from page views. It might also lead to the loss of members to competitors such as Voat. This financial leverage gives the Reddit volunteers power over their “employer”, while the lack of contractual relationship reduces management’s control over them.

Website moderators are a relatively new occupational group but their recent display of worker resistance suggests that web-based organisations operating virtual networks of paid and unpaid staff need to better understand their workers. They could start by asking some fundamental questions about motivation – what are the moderators getting from their work? Research on volunteers in charities that assumptions about the rewards of altruism are far too simplistic. The example of the Reddit mods and other unpaid workers on the web suggest that motivations for unpaid work are diverse and complex.

A gift culture

More useful understandings are provided by the “hacker ethnography” of writers like Chris Kelty and Eric Raymond. Both explore the question of why hackers write open source software for free, describing how individuals compete for prestige, recognition and reputation among their collective group of peers by giving away their labour.

For Reddit moderators we might speculate about the social capital and resources that come with the work of maintaining such a busy online virtual community, similar to that of blogging communities (for example, parenting bloggers), which provides some explanation for their huge investment of labour. Potentially this unpaid work is also a pathway into paid work, an imaginative response to inflexible working patterns or a creative sideline to a dull nine-to-five.

The Reddit rebellion has shown that employers cannot rely upon unpaid workers to offer their labour passively. Even without union representation the global reach of the marketplace in which Reddit operates makes industrial unrest highly visible, and its effects immediate with potentially serious consequences in terms of loss of audience and revenue.

It seems that in some situations volunteers may be a great untapped source of industrial activism. Perhaps more so than paid workers due to the ineffectiveness of the threat of financial sanction to moderators in a virtual economy where their skills are in demand. Through its public apology and the loss of its chief exec, Reddit’s management are, belatedly, realising this.

Obituary: Caspar Bowden, a fearless privacy pioneer

Caspar Bowden, privacy advocate and campaigner. Rama, CC BY-SA

The world’s privacy advocates are reeling over the loss of one of their most influential and feared campaigners, Caspar Bowden, who has died of cancer. His fierce and combative evangelism for online privacy over two decades and surgical analysis of complex surveillance legislation raised the standard of commentary that influenced advocacy groups at home and abroad.

I had the honour and the pleasure of becoming a close friend and co-conspirator of Caspar. It wasn’t always easy – he held high expectations of his colleagues, who could often experience his wrath whenever they dared to negotiate with “the bastards” (whoever they happened to be at the time). The archaic American expression “ornery” could well have been invented for Caspar Bowden, as his opponents well knew.

In conferences and meetings where officials and ministers appeared there was frequently what became known as the “popcorn moment”, when Caspar would stand up and, from the back of the hall, clear his throat and launch into a devastating critique that would utterly destroy the credibility of his opponents. Within two years, ministerial staffers were routinely calling me to find out whether Caspar would be in the audience. No better tribute could ever be awarded to any campaigner.

Caspar Bowden, mid ‘popcorn moment’. Rama, CC BY-SA

Caspar joined the mainstream privacy world in 1997 during the Scrambling for Safety encryption event that I organised at the London School of Economics, and soon after he co-founded the Foundation for Information Policy Research (FIPR), which became the most astute think-tank in Britain in the field of surveillance.

At the time Caspar chaired Scientists for Labour, an organisation which at the time believed that the Labour Party (which had been elected to government only 18 days earlier) would actually respect scientific advice. The reams of dangerous and intrusive legislation the Labour government subsequently passed caused him to ditch this fantasy. In the years since Caspar appeared to abandon all faith in parties, taking pride in comparisons with TV character Mr MacKay in the comedy series Porridge, who famously said: “I have a job to do and, whatever else I am, I’m firm but fair. I want you to know that I treat you all with equal contempt”.

In 2002 Caspar joined Microsoft’s operation in Europe as chief privacy strategist, but the arrangement was a bad fit. Caspar continued to be outspoken, eventually parting company with Microsoft after he criticised the lack of privacy measures in its software and the firm’s cosiness with US government spooks. Years before Snowden’s revelations about US and UK mass surveillance in 2013, Bowden had already become deeply worried about the relationship between companies and security agencies – with his arguments about the safety of cloud data proven true by the subsequent leaks.

Gus Hosein, executive director of Privacy International and an an old friend and colleague said:

I’m not new to this issue, but whenever I struggle to get my head around the implications of a new policy or technology, I always looked to Caspar. I sought his guidance to navigate it, but I feared what he would say if I came out with something stupid. The future is uncertain enough, but without him it is even more daunting.

Caspar was very accurately described by another close friend and colleague Ian Brown, professor of Information Security and Privacy at Oxford University:

Caspar was a truly unique individual, one of the most passionate, methodical, relentless advocates of any cause I have met. I learnt so much from him as we worked together on and off for nearly 20 years on privacy issues. His forensic analysis of UK surveillance laws, and later European and US legislation, was essential reading for anyone who wanted to understand the implications of some extremely obscure language – including legislators themselves.

Brown believes UK internet users are still benefiting from Caspar’s successful campaign to remove “Big Browser” surveillance powers from the Regulation of Investigatory Powers Act 2000, and to ensure the burden of proof was not put onto individuals who might have actually forgotten passwords later demanded by police. His important reports for the European Parliament will also be key in the long-term decisions made by the EU to protect the privacy of its 500m citizens.

Anyone who knew Caspar understood that he was dogged in his later years by a deep cynicism about progress in privacy. Deeply mistrustful of governments, corporations and even the law, he eschewed mobile phones and came to place his faith almost solely on mathematical solutions, for example by heavily promoting the concept of differential privacy, which attempts to prevent a loss of privacy in situations where details can be inferred from other data.

Perhaps Caspar’s greatest legacy is that, in an age of increasing compromise, he showed us the importance of dogged, non-negotiable persistence. As George Bernard Shaw observed, all progress depends on the unreasonable man. In that respect, Caspar was a beacon of progress.

How 3D printing helped robots tackle their greatest obstacle: stairs

Is there a lift? I'm trying to conquer the universe and I need to reach the first floor. Les Chatfield/Flickr, CC BY-SA

We’ve long attempted to recreate living creatures in robot form. From very early age of robotics, there has been attempts to reproduce systems similar to human arms and hands. This has been extended to flexible and mobile platforms reproducing different animals from dogs to snakes to climbing spider octopods, and even entire humanoids.

One of the key actions performed by animals from mantises to kangaroos is jumping. But incorporating a jumping mechanism into autonomous robots requires much more effort from designers. One of the main challenges for robots is still travelling efficiently over rugged surfaces and obstacles. Even the simple task of going up or down a staircase has proven to be rather difficult for robot engineers.

A jumping robot could provide access to areas that are inaccessible to traditional mobile wheeled or legged robots. In the case of some search-and-rescue or exploration missions, in collapsed buildings for example, such a robot might even be preferable to unmanned aerial vehicles (UAVs) or quadcopter “drones”.

There has been increasing research in the robotics field to take on the challenges of designing a mobile platform capable of jumping. Different techniques have been implemented for jumping robots such as using double jointed hydraulic legs or a carbon dioxide-powered piston to push the robot off the ground. Other methods include using “shape memory alloy” – metal that alters its shape when heated with electrical current to create a jumping force – and even controlled explosions. But currently there is no universally accepted standard solution to this complex task.

A new approach explored by researchers at the University of California San Diego and Harvard University uses a robot with a partially soft body. Most robots have largely rigid frames incorporating sensors, actuators and controllers, but a specific branch of robotic design aims to make robots that are soft, flexible and compliant with their environment – just like biological organisms. Soft frames and structures help to produce complex movements that could not be achieved by rigid frames.

Soft landing Jacobs School of Engineering/UC San Diego/Harvard University

The new robot was created using 3D printing technology to produce a design that seamlessly integrates rigid and soft parts. The main segment comprises two hemispheres nestled inside one inside the other to create a flexible compartment. Oxygen and butane are injected into the compartment and ignited, causing it to expand and launching the robot into the air. Pneumatic legs are used to tilt the robot body in the intended jump direction.

Unlike many other mechanisms, this allows the robot to jump continuously without a pause between each movement as it recharges. For example, a spring-and-clutch mechanism would require the robot to wait for the spring to recompress and then release. The downside is that this mechanism would be difficult to mass-manufacture because of its reliance on 3D printing.

The use of a 3D printer to combine the robot’s soft and hard elements in a single structure is a big part of what makes it possible. There are now masses of different materials for different purposes in the world of 3D printing, from flexible NinjaFlex to high-strength Nylon and even traditional materials such as wood and copper.

The creation of “multi-extrusion” printers with multiple print heads means that two or more materials can be used to create one object using whatever complex design the engineer can come up with, including animal-like structures. For example, Ninjaflex, with its high flexibility could be used to create a skin or muscle-like outer material combined with Nylon near the core to protect vital inner components, just like a rib cage.

In the new robot, the top hemisphere is printed as a single component but with nine different layers of stiffness, from rubber-like flexibility on the outside to full rigidity on the inside. This gives it the necessary strength and resilience to survive the impact when it lands. By 3D printing and trialling multiple versions of the robot with different material combinations, the engineers realised a fully rigid model would jump higher but would be more likely to break and so went with the more flexible outer shell.

Once robots are capable of performing more tasks with the skill of humans or animals, such as climbing stairs, navigating on their own and manipulating objects, they will start to become more integrated into our daily lives. This latest project highlights how 3D printing can help engineers design and test different ideas along the road to that goal.