On Titan


There will only be one first landing on Titan said Alphonso Diaz, associate administrator for science at NASA…and this is it.” “There aren’t too many places with liquid,” said scientist Marty Tomasko of the Lunar and Planetary Laboratory at the University of Arizona, in Tucson, which made the probe’s camera. “There’s Earth, and now there’s Titan.”

Jean-Jacques Dordain, director general of the European Space Agency, celebrated their successful landing on Saturn‘s largest moon today, as the Huygens lander provided the first-ever close look at Titan’s hydrocarbon-rich surface an environment that scientists believe is much like the one that gave rise to life on Earth billions of years ago..

The Huygens probe and Cassini relay have continued to transmit data more than two hours after the spacecraft landed, reports the BBC.

“In the morning we had an engineering success and this afternoon we can also say we have a scientific success,” Mr Dordain said. Professor John Zarnecki of the Open University in Milton Keynes, principal investigator for the of the Surface Science Package (SSP) on Huygens, said he was confident his instrument had detected an impact on the surface.

Jean-Pierre Lebreton, mission manager for Huygens said the craft had been active for up to seven hours. He added this was probably down to good design keeping Huygens’ instruments warmer than expected despite the temperatures of -179C outside.

Four NASA spacecraft have been sent to explore Saturn. Pioneer 11 was first to fly past Saturn in 1979. Voyager 1 flew past a year later, followed by its twin, Voyager 2, in 1981. Cassini, with Huygens riding piggy-back, was launched on a Titan 4 rocket from Cape Canaveral, in October, 1997, and went into orbit around Saturn June 30, last year (2004). On Christmas Eve, Huygens was sent on a three-week transit to Titan that culminated Friday in a two-hour-and-27-minute parachute drop to the moon’s chilly surface.

“We might even have three floppy disks now,” said Professor Zarnecki, referring to the previous assumption that the SSP would only collect enough data to fill a floppy disk.

The Cassini-Huygens spacecraft is equipped with 18 instruments, 12 on the Cassini orbiter and six on the Huygens probe.

The Arizona/Republic tells the tale of the two U/A professors, Marty Tomasko and Lyn Doose, who designed the Descent Imaging Sensor:

“We got excited by Titan when Pioneer 11 flew by (it) in 1979. It was an orange ping-pong ball.”

Doose picked up the narrative.

“Voyager went by the next year, and we got excited again, and we saw the same orange ping-pong ball.”

When NASA and the European Space Agency confirmed there would be a Titan mission, the two professors began developing ideas. They stopped and started, then went to a conference and found that someone from NASA’s Jet Propulsion Laboratory had the same idea but was doing it better. So they came up with a new one.

The descent imager spectral radiometer would be their project. Seven instruments bolted onto a plate of metal and incorporated onto the Huygens craft. The DISR, or “disser,” would have its instruments split between those that would take pictures and those that would collect atmospheric particles, particularly the aerosols that make up the thick haze that obscures the moon’s surface. Each of the cameras in the imaging system takes a picture in a different direction.

And through three years of development work, of revisions and brainstorming, the DISR, was selected as one of six science packages to go to Titan.

Many of these instruments are capable of multiple functions, and the data that they gather will be studied by scientists worldwide.

  • Aerosol Collector and Pyrolyser (ACP) will collect aerosols for chemical-composition analysis. After extension of the sampling device, a pump will draw the atmosphere through filters which capture aerosols. Each sampling device can collect about 30 micrograms of material.
  • Descent Imager/Spectral Radiometer (DISR) can take images and make spectral measurements using sensors covering a wide spectral range. A few hundred metres before impact, the instrument will switch on its lamp in order to acquire spectra of the surface material.
  • Doppler Wind Experiment (DWE) uses radio signals to deduce atmospheric properties. The probe drift caused by winds in Titan’s atmosphere will induce a measurable Doppler shift in the carrier signal. The swinging motion of the probe beneath its parachute and other radio-signal-perturbing effects, such as atmospheric attenuation, may also be detectable from the signal.
  • Gas Chromatograph and Mass Spectrometer (GCMS) is a versatile gas chemical analyser designed to identify and quantify various atmospheric constituents. It is also equipped with gas samplers which will be filled at high altitude for analysis later in the descent when more time is available.
  • Huygens Atmosphere Structure Instrument (HASI) comprises sensors for measuring the physical and electrical properties of the atmosphere and an on-board microphone that will send back sounds from Titan.
  • Surface Science Package (SSP) is a suite of sensors to determine the physical properties of the surface at the impact site and to provide unique information about its composition. The package includes an accelerometer to measure the impact deceleration, and other sensors to measure the index of refraction, temperature, thermal conductivity, heat capacity, speed of sound, and dielectric constant of the (liquid) material at the impact

Full Coverage is available from Google News, The BBC, CBS, CBC, CNN, MSN, NPR, Radio 4, and space-oriented sites like NASA, European Space Agency, Italian Space Agency, Russian Space Web, United Nations Office for Outer Space Affairs, British National Space Centre, The Planetary Society, Astrobiology, Space.com, Spaceflight Now, SpaceRef, WikiPedia: Titan, Houston Space Chronicle, Encyclopedia Astronautica, Kennedy Space Center, Nasa Watch (not a Nasa site), Mars Global Surveyor, Galileo: Journey to Jupiter, NASA: Cassini/Huygens and Search for Extraterrestrial Intelligence (SETI).

Now what?

To entertain any Titan extra-terrestrials, four original pieces of music were composed by French musicians Julien Civange and Louis Ha ri, and placed on board (video).

Related Dailywireless articles include Contact, Spirit Telecommunications, Martian Bombshell?, Beagle 2 systems, Spirit is Willing, The Mission to Mars, the 1999 Mission to Mars, Spirit In Dirt, Good News from Mars, Deep Impact, Wireless Recon Airplanes, Space Mist, and Telepresence Now!.

Posted by Sam Churchill on .

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