This month for our public lecture, we welcome Dr Stuart Eves as our guest speaker, who will be talking about “Exploring the Solar System by Satellite”.
Stuart Eves is a principal engineer at Surrey Satellite Technology Ltd (SSTL), a company which designs and constructs small satellites. He spent over a decade with the Ministry Of Defence in several space-related positions before joining SSTL.
The public meeting takes place at the Henry Dixon Hall, Rivenhall End on Wednesday 17th April at 7:30pm. For further information, see the Events page.
Following on from his models of the Magellan, Cassini-Huygens and Galileo spacecraft, Terry Regan went on a grand tour of the Solar System and guides us through his scratchbuilt scale model of the famous Voyager spacecraft.
Voyager 1 & 2 – The Grand Tour
The planetary grand tour was an ambitious plan to send two unmanned probes to the outer planets of the Solar System. The idea was conceived at NASA & JPL in the 1960s when it found that all four gas giant planets could be visited using gravity assists while needing a minimal amount of propellant and a shorter travel time between planets.
The original proposed mission was to send four probes under the Mariner programme: the first two, with proposed launch dates in 1976 and 1977 were to fly by Jupiter, Saturn and Pluto and the other two with launch dates in 1979 were to fly by Jupiter , Uranus and Neptune. The spacecraft were to have been designed with multiple redundant system onboard to ensure they would last over the missions spanning up to 12 years.
Due to NASA budget cuts in 1972, the grand tour missions were downsized to two “mini Grand Tour” probes and the Voyager programme was born.
The two Voyagers were launched in 1977 on board Titan 111E/Centaur rocket s – Voyager 2 on 20th August 1977 and Voyager 1 on 5th September 1977 on a faster trajectory which enabled it to reach Jupiter and Saturn sooner but at a cost of not visiting the outer planets. Although Pluto was possible destination in its trajectory, while examining Saturn it was decided to make a close flyby of Titan which would remove the chance for the Pluto flyby.
On 17th February 1998, Voyager 1 overtook Pioneer 10 to become the most distance man-made object from Earth – at the time it was 6.5 Billion miles from Earth. Pioneer 10 and Voyager 1 are heading almost in the opposite direction outward from the Solar System. One 18thDecember 2004, Voyager 1 passed the “termination shock” – the point where the solar winds slow to subsonic speeds and the tenuous point where the solar system can be said to end. Now in 2012, Voyager 1 is 10 billion miles from Earth travelling at about 38,200mph and it takes over 33 hours to transmit and receive radio signals.
Voyager 2 is currently 9.1 billion miles from Earth and is travelling at about 35,000 mph, taking over 27 hours to transmit and receive radio signals.
Each Voyager probe carries a Golden Record – a gold-plated copper phonograph disc containing sounds and images selected to portray the Earth and its inhabitants. They were intended for any intelligent extraterrestrial lifeforms, or even for future humans life, who may find them.
Both are still sending back information and are expected carry on until 2025 when their power runs out (or when they can no longer be monitored) – what an amazing pair of spacecraft!
This is the fourth spacecraft model to be made in my collection and as with the last three all have been scratchbuilt from plans available online and using plans from a card model.
I first started to build the main body using styrene plasticard, the material that professional model makers use . A ten sided body, 12mm high and 55mm in diameter, was made and glued, and then shaped and cleaned up to form the main body. I added detail around the sides to represent the four thermal control louvres, and also not forgetting the famous gold record. I then added three V-shaped struts that supports the antenna dish, and another four to support the rocket engine to give which powered the probe’s thrust. The struts was made from plastic rod and the whole thing was then sprayed black, with the louvres sprayed in chrome silver .
Next I made the R.T.G or Radioisotope Thermo Generator. 6mm diameter plastic rod was cut to a length of 50mm and formed into cooling fins. The RTG was sprayed a metallic black and the support structure chrome silver and then attached to the body.
Next came the long magnetometer boom which holds two sensitive instruments away from any electrical interference of the space craft. This boom on the model is about 400mm long and made out of 0.5mm plastic rod formed into a triangle – over a thousand pieces and three days of work went into making the boom, which was then sprayed metallic dull yellow. The science boom, which is mounted opposite from the RTG, holds cameras, sensors, various instruments and a large Infrared Interferometer Spectrometer / Radiometer .The boom was again made from 1.2mm rod made into a square lattice frame work and which supports the plastic instruments sprayed up in black.
Now for the antenna dish – I clamped a piece of 0.030mm plasticard over a large piece of plywood with a hole in it, softened the card and plunged the bottom of a truck oil filter through to form a dish shape. The dish sits on a tripod, and was sprayed in Appliance White which makes a great antenna dish white.
Finally, Voyager was mounted on a square piece of varnished wood, which has the Voyager mission badge and NASA logo on it.