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It's 1990 and we just got
the first images back

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from the Hubble Telescope.

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But, there's a big problem;

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the pictures are out of focus.

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How do you solve that?

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Well first of all, you're
gonna need one of these.

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That's the space shuttle
Endeavour and it was used

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in one of the greatest
engineering fixes in history.

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We'll talk all about that

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on this episode
of Crazy Engineering.

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[Music Open]

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The Hubble telescope is composed
of several different

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instruments, and outside of
those is something called the

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primary mirror, where all
the light bounces off of

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and goes into the instruments --
that's where the flaw was.

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So, the problem was something
called a spherical aberration.

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What exactly does that mean?

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It means the primary mirror
had the wrong shape.

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That is, it's a shallow
bowl, effectively,

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that brings light to a focus.

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It's a little too shallow.

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It rendered the telescope
fundamentally unfocusable.

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So, it was a little bit out of
tolerance in that primary mirror

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and it was effecting all the
instruments in Hubble?

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All five scientific instruments
on the Hubble

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depend on a sharp image.
That's the whole point.

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Meacham: So, Hubble is sitting
doctor's chair and

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it has the eye chart
in front of it

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and instead of the letter E
it sees the letter F.

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Trauger: Worse! What it sees
looks like a squashed spider.

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Meacham: But it's
way up in space,

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and you can't get it back here,
so how do you fix it?

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Well, if you're born with
eyeballs that don't quite work,

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you don't go and
buy new eyeballs,

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you buy a pair of glasses.

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And that's the approach
that we took.

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Meacham: The Wide Field
and Planetary Camera,

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known as WFPC,

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relied on light from
the primary mirror.

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Trauger: The light from
that primary mirror

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all comes down to a focus
inside our camera

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on a mirror that
looks just like this.

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And, this is now an opportunity
for us to correct the curvature,

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the shape of the primary
mirror right here.

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We simply put the same error in,
reversed, and correct it.

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The Hubble Telescope was
designed from the outset

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to be serviced every three
years by astronauts.

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[Astronaut talking]

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Trauger: The camera is designed
to be replaced in space.

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That's the one thing
that was really

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just waiting for us to
take advantage of.

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[Astronauts talking]

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So, what was the outcome?

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Trauger: At the Space
Telescope Science Institute,

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way down in the basement, there
were a bunch of us watching.

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And the first image, which
was a star, looked good.

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So, we knew right away that we
had a fix and everything that

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Hubble was suppose to do
was now going to happen.

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Meacham: I think I speak for
everyone when I just say thanks

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to you and your team
for all the hard work

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you put in fixing Hubble.

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Because now we have these
images really forever

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that we can appreciate.

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[Music]

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WFPC2 went on to become
the workhorse for the

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Hubble telescope and it lasted
for more than 15 years.

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Well, now you guys
can check it out

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at the National Air and Space
Museum in Washington D.C.,

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and we'll see all of you