Cassini was powered by three radioisotope thermoelectric generators (RTGs). These generated heat, which converted into electrical energy for its instruments.
Mission was the largest and most complex interplanetary spacecraft ever constructed, weighing more than 5.6 tonnes, standing 6.7 metres tall, and four metres across at its widest point.
The Mission
Long-range goal was to conduct detailed studies of Saturn, its rings and moons as well as Titan, its largest moon. Equipped with cameras capable of taking exquisite photographs of alien landscapes as well as radar for penetrating atmospheric darkness as well as instruments designed to measure magnetic fields as well as dust particle composition and quantity, its mission succeeded successfully in reaching Saturn.
Cassini was packed with more than a dozen science instruments, powered by 32.7 kilograms (84 lb) of plutonium dioxide that converted radioactive decay to electricity. Its complex ball-of-thread orbits were guided by gravity so as to capture as much of Saturn’s sparkling rings while remaining outside its magnetosphere and remaining safe for continued exploration of our solar system.
Scientists were keen to address any lingering tensions between NASA and its European partners when planning this mission, emphasizing its shared benefits to both sides equally. Their efforts were rewarded with breathtaking discoveries like lakes on Saturn’s icy moon Enceladus!
The Spacecraft
Cassini was designed by scientists from both the US and 16 European countries, costing roughly $3.4 billion to develop and fly, with Huygens adding another billion or so to this total. Once in Saturn’s orbit, it conducted extensive studies of its magnetosphere, rings and moons–particularly Titan. Furthermore, gravity-assisted maneuvers brought it close enough for Huygens’ 22-day cruise over Titan’s surface until its eventual parachute delivery back onto earth’s surface.
At its launch, this spacecraft generated political controversy and protest because it carried 72 lbs (34 kg) of plutonium for electricity generation in deep space, where solar radiation is too weak to provide adequate power generation. Although stored safely within an underground bunker without creating dangerous waste products, over time its capacity declines as radiation consumes the material and degrades it over time.
The Huygens Probe
The spacecraft was equipped with an intricate system of instruments, including optical and radio sciences that enabled scientists to study Titan’s surface. Furthermore, its thermal subsystem controls vehicle temperatures using multilayer insulating blankets, radiators, louvers and shades as well as electrical heating units.
Christiaan Huygens Lander was designed to survive atmospheric entry and land safely on Titan’s liquid surface, sending back data for several minutes post-landing. Engineers hoped the probe could also transmit scientific findings back home.
Cassini provided clear images of Saturn’s rings during its early months, as well as discovering two small moons, Pallene and Methone. Later that year it conducted several flybys of Titan, unveiling more details of its surface and atmosphere – it even observed an oval-shaped atmospheric haze with bands of swirling winds moving in opposite directions!
The Cosmic Dust Analyzer
The Cosmic Dust Analyzer (CDA) is one of twelve scientific instruments aboard Cassini spacecraft. As a particle physics instrument, it measures particle sizes, velocity, composition and composition within space as well as Saturn’s rings and satellites.
The CDA is an advanced mass spectrometric instrument, using high-speed particle impacts and mass spec to precisely characterize individual dust grains and determine their chemical composition. It builds upon successful dust mass spectrometers deployed aboard Giotto (Kissel 1986) and Stardust (Klenner et al. 2007) during their visit to comet 67/P Churyumov-Gerasimenko as well as CIDA in Cassini’s mission to Saturn (Srama et al. 2004).
The instrument will measure both interplanetary dust, as well as dust ejected from Phaethon, during its journey to Saturn. Furthermore, particles present in Jupiterian and Saturnian atmospheres and rings will also be studied, along with how Saturn’s rings, satellites and magnetosphere interact with dust environments.