NASA / European Space Agency

The European Space Agentcies Huygens Probe made its seven-year journey to Saturn's moon Titan, aboard NASA's Cassini spacecraft. The joint NASA / ESA mission was successfully launched by a Titan Centaur launch vehicle on 15 October 1997 04:43 EDT. It reached Saturn in 2004.

While the Cassini Orbiter continues to explore Saturn and its rings, the Huygens probe will be released to parachute through the atmosphere of Titan.( pictured above left). Shrouded in an orange haze that hides its surface, Titan is one of the most mysterious objects in our solar system. It is the second largest moon (only Jupiter's Ganymede is bigger) and the only one with a thick atmosphere. It is this atmosphere that excites scientific interest, since it is thought to resemble that of a very young Earth.

At the end of a 22-day cruise to Titan, the Probe will plunge through the atmosphere at 20,000 km/h (12,000 mph), taking from 2 to 2 1/2 hours to reach Titan's surface. A heat shield protects it from temperatures of more than12,000 degrees and acts as a brake. As it slows to 1400 km/h (840 mph) a series of parachutes will be deployed to provide a controlled descent and a stable platform for scientific measurements.

Flight Logistics became involved when we received a call with the question "What would happen if you dropped an 8ft (2.7m) saucer over Salisbury plain from 12000ft (3658m)?" We replied, as its frisbee shaped, it would probably kill someone in Belgium. They liked the answer and so started two years of meetings, more meetings, months of trials and testing.and waiting for weather.

Our caller was Martin Baker Aircraft Ltd, the world famous aircraft ejector seat manufacturer. With their expertise in sequential parachute deployment, in association with Irving parachutes, they had been selected to develop and test the system for the Huygens probe.

Martin Baker operate this specially modified Meteor. It makes for an excellant platform for high speed ejector seat testing. As then Chief Pilot Stan Hodgkin remarked, " I must be the only pilot who's employers are dissapointed if I land back, still with a passenger!" ( Test dummies, we stress).

Although the final pod was to have a saucer shaped heat shield, for test and calibration purposes it was decided that a different shape was required. Flight Logistics manufactured to a Martin Baker design the initial dummy "bomb" above. For a short while it gave visitors to our office quite a shock.

The bomb shape presented a problem. How do you lift it off the ground whithout damaging the delicate fins or the air data Pitot probe on the nose? Enter former Royal Navy helicopter engineer Mike Wright (part of the Fight Logistics team). Mike came up with an outstanding design. Two cantilever arms weighted at each end but held together prior to lift by the weight of the bomb. Add a remotely releasable hook and a clean lift and release was always achieved.

Pilot Jerry Grayson positions to attach the strop. Jerry's consistent accurate flying was fundamental to the success of the task. It would have been very easy to swing the bomb into the rig as the weight was transferred to the aircraft. There were no problems on dozens of lifts.

Released from 3000ft (914m) Data telemetry was recorded both on board and transmitted to the ground. As shown above right landing was never kind to the either Pitot or the nosecone!

The lift sequence as the arms fall outwards and the bomb is lifted clear of the rig.

HUYGENS PROBE

Launched in October 1997 it successfully landed on Titan 8 years later in 2005..The Cassini Orbiter will continue until 2008. We were very careful to negotiate payment on completion of testing rather than completion of the job!

Vital statistics

How the mission was named: Jean-Dominque Cassini (1625-1712), was a French-Italian astronomer who identified the gap between Saturn's rings (the Cassini division). Christian Huygens (1629-1695), was a Dutch astronomer who discovered Saturn's rings and in 1655, its largest moon Titan.

Mass of Orbiter + Huygens 5.82 tonnes (6000 Kilos) Swingbys To reach Saturn, Cassini must use a series of gravity-assist manoeuvres, with the following swingbys:

Venus 24 June 1999 Earth 18 August 1999 Jupiter 30 December 2000

Arrival at Saturn Saturn Orbit insertion 1 July 2004 Cassini Orbiter mission duration at Saturn Four years (nominal mission ends July 2008). Huygens arrival at Titan 14 January 2005

Courtesy: Spaceflightnow.com