The Cassini-Huygens spacecraft is one of the great collaborations in spaceflight history, with the combination of NASA, ESA and the Italian Space Agency proving to be a resounding success. The mission is considered by most in the field of space and astronomy to be one of the greatest scientific endeavours in space, giving us a greater knowledge of the ringed gas giant Saturn and its intriguing moons. The Huygens lander visited the surface of Titan in 2005 and Cassini has orbited the ringed planet since arriving in 2004, collecting valuable data for scientists back on Earth.
The spacecraft was launched on October 15, 1997 by the Titan-IVB/Centaur rocket from Space Launch Complex 40 at Cape Canaveral, Florida. In order to reduce the fuel required, the spacecraft used a number of gravity assists to increase velocity and extend its orbit around the Sun further out. Cassini flew past Venus twice (in April 1998 and June 1999), once by Earth (in August 1999) and finally Jupiter (in December 2000). In July 2004 the spacecraft at last arrived at the ringed gas giant Saturn.
In December the Huygens probe was ejected from the spacecraft and set on a trajectory towards Titan. The probe arrived at Saturn’s largest moon in January and began descending through Titan’s atmosphere on January 14, 2005. The probe revealed an unprecedented view of a mysterious world as it descended through the moon’s atmosphere. Huygens survived for 72 minutes on the surface, before the batteries ran out and data ceased to be sent back to Earth.
Cassini has maintained orbit around Saturn and its moon since its arrival in 2004. It carries 12 scientific instruments able to carry out scientific measurements such as examining the gravitational field of Saturn and its moons, determining structural and chemical composition of surfaces and atmospheres of the Saturn system, and much, much more. The probe is powered by radioisotope thermoelectric generators (RTGs), designed to power the probe for way over a decade. Cassini communicates with scientists back on Earth using three microwave antennas. The large white dish located at the head of the spacecraft is the high-gain antenna, making it the fastest antenna to send and receive data with. This is used to send back the incredible images we stare in awe at.
Like all good things, they must come to an end. Indeed, the Cassini-Huygens spacecraft will complete its mission in 2017. The Cassini probe will carry out daring new orbits, known as proximal orbits, in 2016 as NASA scientists aim to gather as much data with the remaining fuel available. Assuming all goes to plan, the Cassini spacecraft will plunge into Saturn’s gaseous atmosphere to a fiery finale, marking the end of one of the greatest missions in spaceflight.
Following the successful launch of the Soyuz rocket and a six hour journey to the ISS, the Soyuz capsule carrying astronauts Tim Peake, Tim Kopra and cosmonaut Yuri Malenchenko has arrived at the Space Station. The docking occurred at a slightly later time than expected of 17:33 GMT (12:33 ET) due to an issue with the automatic docking system.
The launch from the Baikonur Cosmodrome in Kazakhstan took place earlier in the day at 11:03 GMT (06:03 ET). The Soyuz capsule containing three new crew members were lifted away from Earth by the tireless workhorse that is the Soyuz rocket. The Russian rocket is considered to be the most reliable and successful rockets ever built and flown, with over 1500 flights and numerous human launches. It took just 8 minutes and 48 seconds for the Soyuz capsule to reach orbit and for the capsule to be put on path for an encounter with the ISS just six hours later.
The six hour travel time to the ISS is the shortest time possible to get to the ISS from Baikonur Cosmodrome. In order for the travel time to be achieved, the launch must occur precisely on time and no problems can occur in orbit. In cases where problems do occur, the travel time to the ISS is extended to two days, a long time for astronauts in the highly enclosed Soyuz spacecraft.
Following four orbits of Earth, final approach began approximately 15 minutes prior to docking. The Russian spacecraft lined up with the Rassvet docking port and approached it at a very slow speed relative to the ISS, minimising any risk of a high-speed impact. However, just 20 metres from the Space Station, the Soyuz suffered KURS failure ending the possibility of an automatic docking. Instead, cosmonaut Yuri Malenchenko, the most experienced of the three crew members onboard the Soyuz, manually docked the spacecraft over India at 17:33 GMT (12:33 ET).
The Tim Peake, Tim Kopra and Yuri Malenchenko later disembarked the capsule and were greeted by Scott Kelly, Mikhail Kornienko and Sergey Volkov in the ISS. The occasion is particularly monumental for Tim Peake, as he is the first British astronaut to live onboard the Space Station. The new crew members will spend some time getting used to living in space, before work begins on scientific experiments which will dominate their next six months on the ISS. Meanwhile, the Soyuz capsule will remain attached to the ISS and serve as an emergency escape vehicle during their stay.
Up until very recently the icy rock has been a mystery, but since the flyby of New Horizons, more information than ever before is now known about Pluto. The flyby was long awaited, as the distant dwarf planet Pluto was first discovered by Clyde Tombaugh eighty-five years earlier in 1930.
Despite the discovery of Neptune in 1846, the irregularities in the orbit of Uranus remained unexplained. A number of astronomers speculated that a ninth planet was the cause of this. First attempts to find a possible ninth planet were made by founder of the Lowell Observatory, Percival Lowell, from 1905 to 1909. Using data from the observations of Uranus’ orbit, Lowell was able to estimate where in the sky the ninth planet could be. Using a number of different telescopes, Lowell searched the sky for Planet X. He estimated locations of the planet and published them in the ‘Memoir on a Trans-Neptunian Planet’ in 1915. A year later he passed away, with no sighting of the mysterious planet.
Eleven years later the search resumed. Percival’s brother Abbott Lowell took control of the search, and hired Clyde Tombaugh to operate the new 13-inch telescope. Tombaugh began searching in 1929 for the ninth planet in the region that Lowell had identified, but was unable to locate the mystery planet. Tombaugh decided that Lowell’s predictions were wrong, and began scanning the entire sky for movements indicative of a planet. On February 19, 1930, Tombaugh discovered Pluto, finally putting an end to the work that Lowell had started 25 years earlier.
Following the discovery of the ninth planet, astronomers around the world were in celebration. Using the findings, orbits were calculated and the planet’s place in our Solar System was understood. Names began flooding in, with Lowell’s wife Constance suggesting it be named after her husband. In the end, the name Pluto was chosen, after a suggestion by Venetia Burney, an eleven year old schoolgirl from England. Pluto is the Greek god of the underworld, which was considered appropriate for the dark, mysterious world on the edge of the Solar System. It was officially proposed on May 1, 1930.
The first moon of Pluto to be discovered was Charon in 1978. The moon, which measures 648 miles (1043 km) in diameter, orbits just 12,200 miles (19,640 km) from Pluto. Charon’s orbit around Pluto takes the same amount of time as one Pluto rotation. This means that Charon always hovers over the same spot on the surface of Pluto, and the same side of Charon is always facing Pluto – tidal locking. Pluto’s four other moons were discovered by Hubble in the last decade. Nix and Hydra were discovered in 2005 by scientists in preparation of the New Horizons mission, and the smallest moons Kerberos and Styx were discovered in 2011 and 2012 respectively.
It was only until July 2015 that the Pluto system was finally revealed, with the flyby of the NASA spacecraft New Horizons. The mission brought an end to the mystery which shrouded the dwarf planet’s existence, and uncovered incredible information about Pluto and its five moons.