New
Camera: Seeing More for Less
With its wide field
of view, superb image quality, and exquisite sensitivity,
Hubble's newest science instrument,
the Advanced Camera for Surveys (ACS) will have 10 times more
“discovery power” than the Faint Object Camera (FOC)
it replaces. In other words, the ACS will be able to collect 10
times more data than the FOC was capable of gathering.
ACS sees in wavelengths ranging from visible
to far ultraviolet.
It is actually a team of three different cameras with specialized
capabilities: Its high-resolution camera will take very detailed
pictures of the inner regions of galaxies and search neighboring
stars for planets and planets-to-be. Its “solar blind”
camera, which blocks visible light to enhance ultraviolet sensitivity,
will study weather on planets in our own solar system, among other
things. And its "wide field" camera will help scientists
understand how our universe evolved by surveying the nature and
distribution of galaxies.
The ACS is the only new instrument being
added to the telescope on this mission. After it is installed,
the rest of the mission is devoted to bringing a dormant instrument
back to life.
Getting
a Lift
If possible, before the last EVA, the
shuttle will carry Hubble to a higher altitude.
Although the atmosphere is quite thin at
satellite altitudes, it is not a perfect vacuum. Over time, all
Low Earth Orbiting (LEO) satellites feel the effects of atmospheric
drag and lose altitude. If the altitude is not restored, the satellite
will eventually re-enter the Earth’s atmosphere and fall to
Earth.
Hubble has no on-board propulsion, so the
only way to restore lost altitude is by carefully firing the shuttle’s
jets, boosting the telescope's orbit while it is still attached
to the shuttle.
