Radio Ham-Operator’s Field Day
(Walter B. Lane. 1946)
NASA’s Cassini spacecraft is set to make its first dive through the narrow gap between Saturn and its rings on April 26, 2017. Because that gap is a region no spacecraft has ever explored, Cassini will use its dish-shaped high-gain antenna (13 feet or 4 meters across) as a protective shield while passing through the ring plane. No particles larger than smoke particles are expected, but the precautionary measure is being taken on the first dive. The Cassini team will use data collected by one of the spacecraft’s science instruments (the Radio and Plasma Wave Subsystem, or RPWS) to ascertain the size and density of ring particles in the gap in advance of future dives. As a result of its antenna-forward orientation, the spacecraft will be out of contact with Earth during the dive.
Below is a list of milestones expected to occur during the event, if all goes as planned:
– 5 p.m. PDT (8 p.m. EDT) on April 25: Cassini is approaching Saturn over the planet’s northern hemisphere in advance of its first of 22 planned dives through the gap between the planet and its rings.
– 1:34 a.m. PDT (4:34 a.m. EDT) on April 26: As it passes from north to south over Saturn, Cassini begins a 14-minute turn to point its high-gain antenna into the direction of oncoming ring particles. In this orientation, the antenna acts as a protective shield for Cassini’s instruments and engineering systems.
– 2 a.m. PDT (5 a.m. EDT) on April 26: Cassini crosses the ring plane during its dive between the rings and Saturn. The spacecraft’s science instruments are collecting data, but Cassini is not in contact with Earth at this time.
– No earlier than around midnight PDT on April 26 (3 a.m. EDT on April 27): Earth has its first opportunity to regain contact with Cassini as the giant, 230-foot (70-meter) Deep Space Network antenna at Goldstone, California, listens for the spacecraft’s radio signal.
Cassini prepares for final orbital “Grand Finale” at Saturn.
Erik Wernquist, the same filmmaker who created 2014’s “Wanderers” and a stunning New Horizons promotional film in 2015, has created a new video highlighting NASA’s Cassini mission’s final days at Saturn. The Cassini spacecraft will begin its final series of orbits to cap a 13-year groundbreaking science mission known as the Grand Finale. For the first time ever in Cassini’s time at Saturn, the spacecraft will fly in between the planet’s rings and atmosphere. No spacecraft has ever before flown in this region of any of the solar system’s ringed planets. After 23 orbits, Cassini will dive into Saturn’s upper atmosphere September 15 where it will be destroyed. In 2008, mission managers explored a range of End of Mission scenarios that would protect Saturn’s moon’s from Earthly contaminants before ultimately deciding on atmospheric reentry. Cassini began her End of Mission manoeuvres on November 26, 2016, when it began the first of 20 ring-grazing orbits. A close flyby of Titan April 22 will alter the spacecraft’s trajectory to begin the first of 23 orbits in the Grand Finale, which will begin April 26.
Cassini launched from Earth on October 15, 1997, and entered Saturn orbit June 30, 2004. Six months later, on January 14, 2005, the European-built Huygens probe attached to the spacecraft landed on Titan, becoming the first probe to land in the outer solar system.
Originally scheduled for a four-year mission ending in 2008, Cassini received two mission extensions in 2008 and 2010, with the latter ending in 2017. With the spacecraft’s fuel reserves low, the Cassini team decided to end the mission. P/C: JPL/Erik Wernquist
⚠️️ BREAKTHROUGH ⚠️️
Nasa is currently livestreaming a conference about the discovery of a new solar system !
“Astronomers have detected no less than seven Earth-sized worlds orbiting a cool dwarf star known as TRAPPIST-1.The six inner planets lie in a temperate zone where surface temperatures range from zero to 100C.
Of these, at least three are thought to be capable of having oceans, increasing the likelihood of life.
No other star system known contains such a large number of Earth-sized and probably rocky planets.”
I AM SO EXCITED
Ground those antennas kids, winter’s got more than the white stuff today for us!
Comet shapes and characteristics from a Chinese silk book (Boshu) written during the Han dynasty (206 BC-22 AD)
The Great Red Spot
Great Red Spot closeup
via reddit