It's been a bad couple weeks in space.
A week ago, technical difficulties forced engineers to put the Hubble
Space Telescope's science mission on hold. Now, the Chandra X-ray
Observatory is in safe mode, too.
In a statement released on Friday, NASA confirmed Chandra, one of the
most powerful telescopes in space, transitioned to safe mode earlier
this week.
During safe mode, the observatory's mirrors are pointed away from the
sun and its solar panels are turned directly toward the sun. The
satellite's most critical hardware is transferred to backup drives.
"Analysis of available data indicates the transition to safe mode was
normal behavior for such an event," according to NASA. "All systems
functioned as expected and the scientific instruments are safe."
Engineers are still working to determine why Chandra went into safe mode.
As Chandra's Twitter account reminded readers, the powerful X-ray
telescope is getting up its in age: "Chandra is 19 years old, which is
well beyond the original design lifetime of 5 years."
In a separate release, NASA confirmed Hubble is still in safe mode. Last
week, NASA and European Space Agency engineers suspended the
telescopes' scientific activities after one of its gyroscopes failed.
Scientists turned on a replacement gyro, but the backup didn't perform as hoped.
"This past week, tests were conducted to assess the condition of that
backup gyro. The tests showed that the gyro is properly tracking
Hubble's movement, but the rates reported are consistently higher than
the true rates," according to NASA.
Because the gyro is reading rates of changes at a greater magnitude, it
can't be used to monitor smaller changes. Normally, when fixed on an
observation target, Hubble's gyros operate on low-mode.
"The extremely high rates currently being reported exceed the upper
limit of the gyro in this low mode, preventing the gyro from reporting
the spacecraft's small movements," NASA reported.
If followup troubleshooting efforts fail, Hubble will be forced to shut
down all but a single gyroscope. Previous tests showed Hubble can
conduct observation using a single gyro.
Hubble and Chandra aren't the only spacecraft in trouble. Earlier this
week, NASA astronaut Nick Hague and Roscosmos cosmonaut Alexey Ovchinin
were forced to abort their mission to the space station just moments
after launch, ejecting their Soyuz capsule from the rocket and executing
an emergency "ballistic descent."
And as NASA reported this week, the Mars rover Curiosity is still
silent. Engineers haven't communicated with the rover for four months.
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