>> JOHN: So at the end I can lift this up and say “John out”
and drop it? [LAUGHTER] >> OFF: If you want to?
[UPBEAT MUSIC]
>> JOHN: Hello, I’m John Grunsfeld, NASA astronaut.
>> ED: And I’m Ed Rezac, EVA engineer for the Hubble Space
Telescope project at Goddard. >> JOHN: Hubble is an amazing
observatory orbiting the Earth, it’s allowing us to unravel the
mysteries of the Universe. But in 1998, Hubble lost its
gyroscopes, and it stopped doing science.
At the time I was training for the third Hubble
servicing mission. But because all of those gyroscopes had
failed it was a Hubble emergency. And so NASA decided
to split our mission in two, >> ED: That’s right. >> JOHN: So
that we had Servicing Mission 3A and sometime later there would
be mission 3B. And on 3A our primary job was to replace all
of the gyros on the Hubble Space Telescope. Now, this is what’s
called a rate sensor unit, this is a mockup and inside are two
tiny gyros. Each rate sensor unit held two gyros. So we went
up there to replace this, and just like all the other items on
Hubble, it has bolts that are a standard size and the doors open
and close on Hubble so that we could open the doors and go
inside, take out the old ones, put in the new ones and it’s
really easy right? >> ED: No, it isn’t easy. There’s a lot that
has to be done and it’s gotta be done in a very tight spot. The
astronauts have to enter a part of the aft shroud where the
fixed head star trackers are and these are very very sensitive
instruments that help find a target for the telescope to look
at. In addition, there’s a lot going on to hook up and remove
one of these RSUs, we’ve got cables to disconnect and the
three bolts that John pointed out. So, it’s a tough spot.
>> JOHN: This was one of the hardest things I did on the
Hubble Space Telescope, and I can tell you it was a very dark
and scary place in there. Not because space is dark and scary,
but because we were told if we bonked into the star trackers or
we hit the side of the telescope, we could break the
Hubble. And rule number one was don’t break the Hubble.
>> ED: Don’t break the telescope. >> JOHN: Yep.
>> ED: And the astronaut had to enter on your back, and the,
let's see, Steve held you by the feet didn’t he? >> JOHN: I, I
inserted Steve- >>ED: That’s right! >> JOHN: who’s six feet
two into the telescope and >>ED: Those long arms came in handy
>>JOHN: Yep! >> ED: cause he’s gotta reach up over his head and
between the fixed head star trackers to access the cable
disconnects and to get a socket on these bolt heads. >> JOHN: So
it was tough! But we were successful on that mission. We
also put in a new fine guidance sensor, we changed out one of
the transmitters, we put in a solid-state recorder
>> ED: Upgraded the computer. >> JOHN: Yep! And we also put
some new installation on the outside of the telescope
to keep Hubble cool. >> ED: Hubble is cool!
JOHN: Hubble is very cool! Now one of the things I learned on
that mission from you, and from doing the rate sensor unit swap
is that it is a really hard task to be inserted up in there.
>> ED: The neat thing about doing the
multiple servicing missions is that we learn
from each one. >> JOHN: And on the most recent
Hubble servicing mission in 2009. we also had to replace the
gyros, cause they wear out. >> ED: John was faced with doing
the same task again, and he came up with kind of a novel way to
uh make the task easier. >> JOHN: I was thinking, you
know, it’s really hard to get into that spot to replace these,
wouldn’t it be great if you had a super long arm that you could
reach in and grab the gyro to take it out? So I went to the
hardware store and I got one of those pick sticks that allow you
to grab cans off a high shelf, and I brought it into the
neutral buoyancy laboratory one day and we put that pick stick
into the water to see if we could reach the gyro and we
could. Now that was a 20 buck pick stick, and because of that
it inspired a new tool. >> ED: It did, and, that was, I call
those “pet rock moments” cause you see something and you go
[SMACK] well why didn’t I think of that! But it was a beautiful
idea, so we took the concept and we built the RSU changeout tool.
We used it, it came in handy for the last servicing mission in
2009. >> JOHN: Want to demonstrate? >> ED: Absolutely!
>> JOHN: So this is the handrail I had to grab that was so hard,
but now. [RSU TOOL CLACKS] >> ED: Lock it on. >> JOHN: To
reach into the telescope and grab it. >> ED: Pretty sweet.
>> JOHN: So that’s how we develop new tools sometimes,
simple idea and a hard task, make it easier. >> ED: It works!
>> JOHN: Thanks Ed. >> ED: Thanks John.
[UPBEAT MUSIC]
[SILENCE]
JOHN: Hello, I’m John Grunsfeld, NASA astronaut. >> ED: I’m Frank
Cepollina and I’ll never retire. [SOFT LAUGHTER] >> OFF: Should
we do that one over? >> JOHN: Yep. >> ED: Start over.
>> JOHN: Hello, I’m Edwin Hubble, a deceased astronomer.
[UPBEAT MUSIC]
>> JOHN: Got that out of your system? >> ED: I
did, I’m good. [LAUGHTER] >> JOHN: How’s that >> ED: You
started it! [LAUGHTER] >> JOHN: How’s that feel? [LAUGHTER]