New Horizons heading to Pluto

by Chris Bergin

An Atlas V carrying Pluto-bound probe New Horizons has successfully launched on its third attempt to start its voyage to the outer reaches of the solar system today.

Two previous attempts were scrubbed for reasons varying from high winds to a power outage. Cloud cover cleared just long enough to allow the launch to go ahead.

The pre-launch to spacecraft seperation live thread – with images – can be viewed on the link at the end of the article.

Tuesday’s scrub came after five delays during the built in hold at T-4 minutes, lift-off was set for 20:23pm UK time (15:23 US Eastern) from Cape Canaveral, Florida. However, it was scrubbed with just a few minutes out of the hold.

Wednesday’s mission was also scrubbed, following a power outage at the Applied Physics Lab at Johns Hopkins University. APL is New Horizons Mission Control.

Today’s attempt launched at 2pm Eastern (7pm UK time), rising into patchy cloud cover before seperating its booster rockets.

Gaining speed over the Atlantis, the Centuar second stage completed two burns before spin up and separation of its third stage. A short time later, spacecraft seperation was confirmed and New Horizons was on the opening part of its journey to Pluto.

The nuclear powered probe will take at least nine years to reach Pluto and its moons – before pressing on to explore the region of space known as the Kuiper Belt.

The $700m mission is speeding away from Earth at 36,000 mph, the fastest spacecraft ever launched. It will reach Earth’s moon in about nine hours and arrive in 13 months at Jupiter, where it will use the giant planet’s gravity as a slingshot, shaving five years off the three-billion mile trip.

NASA is hoping New Horizons will successfully gain a gravity assist as it passes Jupiter, boosting its speed to 75,000 kilometers an hour.

The earliest arrival could be 2015, and it’s imperative it gets there by 2020 before Pluto’s winter sets in and its atmosphere of methane and other gasses starts to freeze and ‘fall as snow’ again.

Pluto, the only planet that routinely eludes amateur and even professional astronomers, is so far out on the mysterious, cold, dark edge of the solar system that even the Hubble telescope can’t get a clear picture of it.

As the Pluto team prepared for launch, Stardust mission experts have been busy since Sunday removing the precious contents of the probe after its seven-year, 4.6-billion-kilometre round-trip journey to the comet Wild 2.

Stardust’s particle-collecting aerogel contains the first-ever comet particles and star dust for study on Earth, and the scientists worked in pristine laboratory conditions at the Dugway Proving Ground in Utah to avoid contamination.

Both the Stardust and Pluto missions are expected to shed light on the 4 billion year plus history of the solar system.

Pluto’s far flung location has intrigued astronomers, who say the 700-million-dollar mission is like a trip 4 billion years back in time. To reach Pluto, New Horizons must also cross the crowded Kuiper Belt, the collection of debris that girds the solar system beyond Neptune and that astronomers believe was left over from formation of the solar system. Pluto is on the outer rim of the belt.

‘Exploring Pluto and the Kuiper Belt is like conducting an archaeological dig into the history of the outer solar system, a place where we can peek into the ancient era of planetary formation,’ said Alan Stern, New Horizons principal investigator.

Pluto was only discovered 75 years ago, and its moon, Charon, half its size, was found in 1978. Just in May, two smaller moons were discovered rotating around the solar system’s only ‘binary’ planet – so called because Charon’s gravity pulls the two bodies into an orbit around a center of mass that is outside Pluto’s surface.

Pluto takes 248 Earth years to complete an orbit around sun, causing one of the most ‘complex seasonal patterns’ of any planet.

The probe is expected to photograph and map the surface of Pluto and its moons and determine the composition of its atmosphere, which likely contains nitrogen, carbon monoxide and methane.

New Horizons is expected to approach Pluto as close as 10,000 kilometres. The probe, about the size and shape of an upright piano, is carrying seven instruments including a spectrometer named ‘Alice’, to examine the atmosphere, and a camera named ‘Ralph’, with ultra sensitivity to light levels that are 1,000 times fainter than daylight on Earth.

Live thread: – Background thread.

Related Articles