Cassini takes the ring- route past Saturn
Nasa spacecraft survives hazardous trip at speeds of more than 100,000km/ h
Nasa’s Cassini spacecraft has survived an unprecedented trip between Saturn and its rings, and has amazing pictures to show for it.
Flight controllers regained contact with Cassini yesterday, a day after it became the first craft to cross this hazardous region. The rings are made up of countless icy particles, any of which could have smacked Cassini. Cassini was travelling at speeds of 123,900km/ h. The spacecraft’s big dish antenna served as a shield as it hurtled through the narrow gap, temporarily cutting off communications.
All day, scientists anxiously awaited confirmation that their brave little space robot had made it through.
“We are just ecstatic,” project science engineer Jo Pitesky said by phone from Nasa’s Jet Propulsion Laboratory in Pasadena, California.
Cassini skimmed 3100km above Saturn’s cloud tops, closer than ever before, and came within 320km of the innermost visible ring. Scientists say the pictures show details never seen before — there’s an incredible closeup, for instance, of the gigantic swirling hurricane at Saturn’s north pole.
After 13 years of Cassini orbiting the planet, “Saturn continues to surprise us”, Pitesky said.
Given their importance, data from the crossing are being sent to Earth twice, to make certain nothing is lost. It takes more than an hour for the signals to travel the approximately 1.6 billion km between Saturn and Earth.
Twenty- one more crossings are planned — about one a week — before Cassini’s fatal plunge in midSeptember. The next one is Tuesday. Some of those passages will bring Cassini even closer to the planet as well as the innermost D ring.
The gap between the rings and the top of Saturn’s atmosphere between 1900km to 2400km.
While risky, this four- and- a- half month grand finale i s expected to yield a treasure trove of science. There’s little to lose, even if the spacecraft is lost, given that its fuel tank is practically empty, according to Nasa.
Cassini was launched in 1997 from Cape Canaveral, Florida, and reached Saturn in 2004.
Jo Pitesky
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