Pioneer 10 and 11, Voyager 1 and 2 and now Galileo. Galileo fits seamlessly into the roll-call of the extremely successful spacecrafts which have explored Jupiter since the early 1970s. The missions fulfilled and even exceeded the expectations of their planners (in Galileos case, by six years). Signals from both the Voyager probes are still being received today, twenty-six years after take-off.
In this artist's rendering the Galileo probe, with its heat shield below and a parachute above, enters the turbulent upper atmosphere of Jupiter.Source: NASA
Nasa-probe Galileo, planned in the 1970s, was launched on 18 October 1989: almost a quarter-century from initial conceptualisation to today. The evaluation of its data will take many more years. It is an indication of the truly astronomical dimensions which are at stake here, that one space probe mission can last as long as a scientists or scholars professional life.
Galileo was taken into space by the space shuttle Atlantis. This was common for probes in the early 1980s. At that time, Nasas shuttle-fleet was somewhat under-employed. Even today, there is no sign of the weekly flights originally anticipated. The system was and is too complicated to realise the vision of a robust, simple to maintain, space plane. The basic thinking behind the shuttle programme that in the long term a multi-use spacecraft should be much more efficient than disposable rockets has proved unfeasible.
After Galileo, economy
Galileo left the shuttles docking station as the Berlin Wall was shaking in the geopolitical winds of change. After its fall, the International Space Station (ISS) became a symbolic project of the wide-ranging political cooperation of former cold war enemies. The shuttle proved invaluable for building the ISS. But it concealed within it deep scientific-technical problems.
Organisations like the Deutsche Physikalische Gesellschaft / German Physics Society warned that its scientific use-value would not be worth the investment. They also feared that its effect would be to withdraw funds from the successful, comparatively cheap, unmanned spacecrafts.
This artist's concept depicts the Inertial Upper Stage booster rocket firing shortly after its deployment from the shuttle Atlantis. Galileo's complex trajectory to Jupiter flung it by Venus once and then back to Earth for two fly-bys. Each pass added kinetic energy to the spacecraft, increasing its velocity so that it could reach Jupiter with a relatively small amount of fuel Source: NASA
Such organisations were talking about unmanned spacecrafts like Galileo. The two Pioneer probes were launched in 1972 and 1973, and both Voyagers in 1977. Galileo was the last 20th century space probe aiming for Jupiter. Ulysses, launched in 1990, primarily used its flight past Jupiter for correcting its course. As a probe for climate and wind research, it was ill-suited for planetary research.
Today, the completion of the ISS is threatened by budget shortages and the second shuttle disaster. Successive ISS crews, like cosmonauts in the last years of the failing Soviet/Russian MIR, are increasingly preoccupied with guaranteeing the vital functions of the space station. There is almost no talk of scientific research. In this sense, the worst-case scenarios have even been surpassed.
The myth of technical progress
More than the Berlin Wall has fallen since Galileos launch. The world seems both faster and increasingly technology-dependent. In 1989, the internet as interactive mass medium with its massive economic and sociological consequences wasnt even on the horizon. Galileo was still far from Jupiter when Nasa began to use the net to keep their shuttles operative. The space agency even auctioned second-hand, early 1980s Intel processors at the auction site eBay, which were used in large numbers in the shuttle programme.
But Galileos sheer staying-power, its capacity to be repeatedly reprogrammed, throws any naïve belief in technological progress into sharp relief.
When, at the start of the project, the main antenna could not be extended, an extensive software update made efficient use of the remaining sender capacities. Programmes were adjusted to faulty hardware. (At home and in the office, the opposite process is more routine new programmes quickly turn out to be hardware-killers, so every two or three years, new computers have to be purchased to enable us to do with the new programmes what we used to do before. But for whose benefit?)
In the 1970s, four spacecrafts were sent to the outer planets but since then, only one. Pioneer and Voyager probes launched on disposable rockets needed up to two years to reach Jupiter. Galileo, on the other hand, took six years needing also three so-called swing-bys (from Earth to Venus and back), due to the weak booster for the spacecraft that the shuttle carried. Only its complicated itinerary made the project viable.
Natural scientists are mostly poor salespeople, and this is no different when it comes to space programmes. The same arguments are repeatedly deployed for promotional purposes, such as the promise to find final proof of life on Mars. Both the Viking Mars-Landers of the 1970s part of the same generation as Pioneer and Voyager, Skylab and Apollo 13 to 17 were looking for direct signs of life. Today, there would be satisfaction if a few traces of prehistoric microbes were found on the red planet. But it wont be long before such vague prospects will no longer suffice to justify a space project.
Science and media amnesia
There is a problem for science here: not only its need for good public relations (PR), but the more fundamental challenge of the scientific quest for knowledge. Big, epochal discoveries or ground-breaking theories are rare; above all, they cannot be planned in advance. T. S. Kuhn (in his 1962 book The Structure of Scientific Revolutions) gave a name to new scientific ways of thinking that so often emerge spontaneously: paradigm shift. In science-PR and not only there this seductive term was quickly inflated. Who wanted to pursue normal science when the new scientific paradigms seemed much more exciting?
In the late 1980s, for instance, some scientists tried to promote chaos theory as one such paradigm shift. The excess of hype without result has had the effect of discrediting of an actually quite interesting research area. The collapse of inflated promise leads to disillusion. Of course, the recycling of superlatives can always rely on some readers short memory particularly in the internet age. But collective amnesia has its limits.
Today, paradigms are not as casually thrown around as they were only a couple of years ago, but a taste for unnecessary embellishment has survived in media coverage of science. Yet where Jupiter research is concerned, the term paradigm shift if applicable at all is best applied not to Galileo but to the Voyager twins, which in 1979 delivered the first pictures of active volcanoes on Io and ice deserts on Europa.
Jupiter with Io and Europa. Voyager 1 took this photo of Jupiter and two of its satellites (Io, left, and Europa) on Feb. 13, 1979. Io is about 350,000 kilometers (220,000 miles) above Jupiter's Great Red Spot; Europa is about 600,000 kilometers (375,000 miles) above Jupiter's clouds. Spacecraft/Mission: Voyager 1. Source: NASA/JPL
Only three years after the Voyager photos, Arthur C. Clarke proposed the idea that under Europas surface, liquid water might be found. He did this in 2010: Odyssey Two (1982, his rather weak sequel to 2001: A Space Odyssey). Clarke here acknowledged Richard C. Hoaglands article The Europa Enigma published in Star and Sky (January 1980) as the inspiration of his hypothesis that there might be life in a hidden Europa ocean, continuing:
This quite brilliant concept has been taken seriously by a number of astronomers (notably NASA's Institute of Space Studies, Dr. Robert Jastrow), and may provide one of the best motives for the projected GALILEO Mission. Thorsten Dambeck of Spiegel Online, still considers all this quite new: Only ten years ago hardly any scholar would have thought about microbes on Europa. Galileo however has broken with the old ideas about possible life oases in the planetary system. Yet the thinking behind it began more than twenty years ago and contributed decisively to the the launching of project Galileo.
Science reporting: what it could be
Galileo has indeed delivered direct evidence of a saltwater ocean on planet Europa: a success no doubt based on the knowledge of the earlier probes measurements. Typical, however, of the comment on Galileos destiny, is Thomas De Padovass hyperbole in Der Tagesspiegel about the many surprises, which the reconnaissance of our cosmic neighbourhood unveils, where Jupiter and his... moons follow their paths... in that minus 140 degrees Celsius cold space. But instead of photos of clumsy ice rocks... Galileo radioed us photographs of very different objects.
There is no mention here that the supposedly surprising was actually expected. Since Voyager, it has been well known that Jupiters moons are multifarious; that is exactly why Galileo was launched! How often can you sell the identical discovery to the same public as epochal and ground-breaking?
In this image, blue areas represent the cleanest, brightest icy surfaces, while the reddest areas have the highest concentrations of darker, non-ice materials. Scientists disagree about the chemical makeup of the dark materials; both sulphuric acid (common battery acid) and salty minerals, perhaps from a subsurface ocean, have been suggested. Analysis of images like this one may help to resolve this controversy. Surprisingly, either material could help to produce conditions below the surface that could be favourable to the formation of living organisms. Spacecraft/Mission: Galileo. Release Date: 2000-04-19. Source: NASA/JPL
Yet scientists themselves have a natural propensity for understatement. Ulrich Köhler [PR officer for the Deutsches Zentrum für Luft- und Raumfahrt / German Aerospace Center (DLR)] described Galileos outstanding achievement of Galileo as the quite likely discovery of an ocean on Europa. A hypothetical discovery? This is hardly progress from the days of Christopher Columbus, who was convinced to the end that he had discovered the sea route to India or at least, that he had discovered something!
Instead of this perpetual hover between pompous hyperbole and cautious understatement, it would surely be much more exciting, entertaining and even useful for science and space travel, if the projects inner workings were illuminated as part of the fascinating process by which scientific knowledge gradually accumulates into the light of genuine discovery.
The Galileo project is only one example of how hollow yet endlessly reiterated claims of progress do no justice to the real history and true nature of scientific work. Even though that, after all, may be what the probe has in common with the great scientist it was named after.
Galileos Discovery of the Galilean Satellites This is a page from Galileo's published discovery of the Galilean Satellites which appeared in Sidereus Nuncius in March 1610.
I should disclose and publish to the world the occasion of discovering and observing four Planets, never seen from the beginning of the world up to our own times, their positions, and the observations made during the last two months about their movements and their changes of magnitude; and I summon all astronomers to apply themselves to examine and determine their periodic times, which it has not been permitted me to achieve up to this day . . . On the 7th day of January in the present year, 1610, in the first hour of the following night, when I was viewing the constellations of the heavens through a telescope, the planet Jupiter presented itself to my view, and as I had prepared for myself a very excellent instrument, I noticed a circumstance which I had never been able to notice before, namely that three little stars, small but very bright, were near the planet; and although I believed them to belong to a number of the fixed stars, yet they made me somewhat wonder, because they seemed to be arranged exactly in a straight line, parallel to the ecliptic, and to be brighter than the rest of the stars, equal to them in magnitude . . .When on January 8th, led by some fatality, I turned again to look at the same part of the heavens, I found a very different state of things, for there were three little stars all west of Jupiter, and nearer together than on the previous night.
I therefore concluded, and decided unhesitatingly, that there are three stars in the heavens moving about Jupiter, as Venus and Mercury around the Sun; which was at length established as clear as daylight by numerous other subsequent observations. These observations also established that there are not only three, but four, erratic sidereal bodies performing their revolutions around Jupiter. Source: NASA/JPL
A German version of this article appears on Telepolis. Translated from the original German by Michael Rebehn.
