NASA has officially
announced that its $1 billion Juno mission is getting a critical life extension
to study planet Jupiter. Instead of being crashed into the planet's cloud tops
next month, Juno will fly until at least July 2021, according to a press
release issued on Thursday by the Southwest Research Institute, which operates
the pinwheel-shaped, tennis-court-size robot.
Business Insider reported on
Monday that Juno's mission would be extended. The probe has orbited Jupiter
since July 2015, but engine trouble forced scientists to collect data about
four times more slowly than they'd originally hoped.
"Juno needs more time
to gather our planned scientific measurements," Scott Bolton, the Juno
mission's leader and a planetary scientist at the SwRI, told Gizmodo on
Tuesday.
Jupiter's icy moon Europa
may be habitable to alien life, so carefully and deliberately ending the
mission will keep Juno from crashing into that moon. This will in turn keep
Europa's ocean — which may have twice as much water as exists on Earth — from
getting contaminated by any earthly microbes stuck to Juno.
Now that Juno can fly
through July 2021 (and scientific work is funded through September 2022),
scientists have a chance to complete the mission's main goal: mapping Jupiter's
magnetic and gravitational fields in exhausting detail.
Spending too much time in
Jupiter's powerful radiation field can damage sensitive electronics. As a
result, Juno orbits the planet on a highly elliptical path that regularly zooms
it at 130,000 mph over the cloud tops for detailed observations — a maneuver
called a perijove.
Each perijove helps protect
Juno from harm while enabling it to build a global, slice-by-slice map of
Jupiter using a suite of scientific instruments. Tools record data about the
planet's gravitational field, magnetism, brilliant auroras, and lightning.
But due to lingering trouble
with Juno's propulsion system, the team would only have completed 14 of the 32
perijoves that it needs to finish mapping Jupiter by July 2018, the mission's
prior end date.
When Juno arrived in July
2016, mission managers had the spacecraft orbit Jupiter once every 53.5 days.
In October 2016, they planned to fire up the probe's engines and speed Juno's
orbits to once every 14 days — until the team discovered some sticky valves in
the engine system's plumbing. NASA ultimately played it safe by not using the
engines to achieve shorter orbits, delaying Juno's mapping pace nearly four-fold.
"During a thorough
review, we looked at multiple scenarios that would place Juno in a
shorter-period orbit, but there was concern that another main engine burn could
result in a less-than-desirable orbit," Rick Nybakken, Juno's project
manager at NASA's Jet Propulsion Laboratory, said in a 2017 press release.
"The bottom line is a burn represented a risk to completion of Juno's
science objectives."
The Juno mission leaders
received a memo authorizing the extension in mid-May. That decision will help scientists
construct a detailed map of Jupiter's gravitational field. That data may reveal
what is going on deep inside the giant yet mysterious world.
"It is very exciting
for us to be able to complete the mission pretty much as it was originally
proposed, except with longer orbits," Frederic Allegrini, a staff
scientist at Southwest Research Institute who works on the Juno mission, told
Business Insider on Monday.
If Juno stays operational
and productive over the next few years, NASA might again decide to keep flying
the probe around Jupiter beyond July 2021.
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