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People watching rover landing coverage on TV
Live coverage of key events during robotic missions, like the Mars rover landings last year, can be both enlightening and entertaining. (credit: NASA)

Live from another world

The Huygens probe separated from the Cassini orbiter last month, heading for the largest and easily the most mysterious planetary satellite in the solar system, haze-shrouded Titan. While the probe enters its dense atmosphere and slowly descends on its parachute this Friday, only sparse telemetry will be received on Earth by big radio telescopes even in the best case: The vast amount of data collected during the atmospheric part of the mission—and perhaps a few minutes on the ground—is being transmitted to the Cassini orbiter, which will eventually turn its high-gain antenna around towards Earth and starts relaying the precious data stream, including about 700 images from the probe’s Descent Imager/Spectral Radiometer (DISR) cameras, to Earth.

For us Earth-dwellers it doesn’t make much of difference whether we get transmissions from our deep space probes directly or delayed by a few hours: They are never really “live”, not even from the Moon or Mars, let alone Saturn. Thus the downlink of the Huygens data via Cassini is as real-time as any interplanetary broadcast of the past 40+ years. A very similar situation occurred twice this past January when NASA’s Mars Exploration Rovers landed on Mars and relayed a first burst of data and Navcam images through Mars Odyssey—and NASA did exactly the right thing: The whole world was allowed to watch, together with the MER scientists, when one stunning Martian vista after the other popped up on screen, in a unorganized burst of raw images that soon filled every corner of the screen.

NASA TV was carrying the pictures—as well as views of the cheering scientists—without any delay, and TV news channels around the world picked up that feed: The triumph of Spirit and Opportunity was transported to the homes of millions of space enthusiasts (and also those who might have become supporters of the space program only that very day), with an immediacy that only live television can convey. Downloading the same images on your computer and viewing them on a high-resolution screen—as uncounted users soon started doing, too—may have brought out more details, and the processed versions released later were another improvement in quality, but the sheer drama (and, yes, entertainment value) of the live broadcast of the arrival of the raw images was never again matched. Having been able to share the emotions of the scientists and engineers went a long way to make the MER mission so hugely popular.

The triumph of Spirit and Opportunity was transported to the homes of millions of space enthusiasts (and also those who might have become supporters of the space program only that very day), with an immediacy that only live television can convey.

NASA had done it before, several times: When the Mars Pathfinder arrived in 1997, the incoming imagery was released in real-time for many hours on NASA Select—and even for days on the closed-circuit TV system of the Jet Propulsion Lab—before the plug for the public was pulled eventually. And when the Voyager spacecraft flew by one giant planet after another from 1979 to 1989, every picture arriving from them immediately appeared on TV screens all over the JPL: Scientists and reporters alike got them at the same instant. I still remember vividly the August night in 1989 when the first close-ups of the surface of Neptune’s satellite Triton arrived and the top Voyager scientists marveled at the mysterious streaky features, together with hundreds of space journalists. A unique atmosphere of adventure was created this way, and a huge and overwhelmingly positive response in the (American) media was the well-deserved outcome.

You could even have your own “Voyager Exclusive” in these days: I once watched a Reuters photographer snap a particularly attractive view of Neptune’s and Triton’s crescents off a TV screen (and then asking me on advice for the picture caption). With Galileo, no live feed was available, of course, because of the malfunctioning high-gain antenna, a fact that substantially diminished the public impact of a hugely successful mission. With orbiters even NASA has hardly ever tried to provide a feed in real time, with the notable exception of the downlinking of the first and only high-resolution views of Saturn’s rings that the Cassini orbiter had obtained during the orbital insertion this past July. Here NASA TV was showing the pictures—still full of artifacts but remarkable nonetheless—coming in from Saturn, together with the voices of Cassini scientists trying to make sense of what they were seeing.

Now fast forward to January 2005 and half way around the globe: Nothing remotely like the Voyager, Pathfinder, or MER experience is about to repeat when Huygens lands on Titan, according at least to the current plans by the European Space Agency. The incoming raw images for the DISR cameras will only be seen by the scientists directly involved in the project: They will work on them and release them only hours later, after much processing of contrast and resolution. A few glimpses of the DISR images may be shown some hours after they arrived, but the majority of them, plus all the other data collected during the descent, are only to be released during a news briefing the next day. Now it is understandable that the European Space Agency wants to release only the best material, but to deprive the public of the chance to experience the mission as it happens (or happened) is a major blunder.

There may be some hope left for a “Touchdown on Titan” event that could capture the public’s imagination: You have to go back in time 12½ years for the right recipe.

ESA’s data release policy has been criticized before, especially in connection with the Mars Express orbiter, whose vast amounts of imagery have been overshadowed all but completely by the adventures and results of the Mars Exploration Rovers (see e.g. a commentary in the British science magazine New Scientist of Dec. 11, 2004, p. 19) even in Europe where Mars Express should at least get a decent share of the news. The German mineralogy experiments on the MER have gotten more airtime here than the results from Mars Express (which have also been rather sporadic in the technical literature, by the way, with just a few isolated papers, while the science results from NASA interplanetary missions usually get published a dozen at a time in dedicated issues of major science journals). As rightly noted in the New Scientist commentary, the Huygens arrival at Titan may be the one last chance for ESA to “shout about” its achievements.

There may be some hope left for a “Touchdown on Titan” event that could capture the public’s imagination: You have to go back in time 12½ years for the right recipe. In the summer of 1992 ESA’s Giotto spacecraft passed by its second comet, Grigg-Skjellerup, and—against all odds—was still capable of substantial science, despite the damage sustained during the encounter with Halley’s Comet six years earlier. There was no working camera left, but ESA nonetheless managed to arrange an absolutely gripping media event around the brief comet encounter that was also carried live on several European TV stations. Actually, it was a fully choreographed TV show, hosted by a leading British TV journalist and with her co-host “embedded” (as one would say nowadays) with the Giotto scientists and their computers: Whenever some interesting data came in, be it dust impacts or strange plasma effects, that presenter would rush towards that computer and quiz the respective scientist about the meaning of the observation.

Allowing the world to take part in this greatest adventure of European spaceflight since the Giotto mission could finally put ESA on a par with NASA in the public’s mind in Europe and elsewhere.

Amazingly this daring concept worked to perfection: Never before—and never since—could one experience the thrill of space science with an unmanned probe in such a direct, gripping manner. It was a case of “instant science” even more instant that what one knows from NASA during planetary encounters, and at the same time you could almost feel you were on that battered, blind spacecraft racing past the comet nucleus. This was the way to go, and yet ESA has never done anything remotely like this since. It kind of tried during the orbit insertion of Mars Express, but there were no data to report, only engineering information, which was shared with the media with remarkable openness, though (see “Christmas on Mars”, The Space Review, January 5, 2004). One can only speculate how that night may have turned out if Beagle 2 had made it and would have sent just a few pictures (well, perhaps the usual fighting over whose logo would have to appear where on the images would have started that very minute.)

The Huygens arrival at Titan is the one chance for a long time to surpass the long-forgotten 1992 comet encounter experience, let alone the flawed, but still exciting, show around the first Giotto encounter in 1986: Give us, give the world, access to the data as they come in and let us share the drama with the scientists! In a way it will be more difficult as the data stream from Cassini will first have to be decompressed, but then again this time there will be pictures—hundreds of them. Many will be fuzzy, especially the first ones when Huygens was still floating through the hazy upper atmosphere, but the later images should show something, even in their rawest form. It will be a world we have not been before and one where we don’t even have any reliable predictions of what we will see. Allowing the world to take part in this greatest adventure of European spaceflight since the Giotto mission could finally put ESA on a par with NASA in the public’s mind in Europe and elsewhere.


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