WEBVTT FILE

1
00:00:00.120 --> 00:00:04.549
Originally scheduled for launch in June of
2000. Hubble’s third servicing mission was

2
00:00:04.549 --> 00:00:09.000
going to upgrade and refurbish the telescope,
just as the first two servicing missions had

3
00:00:09.000 --> 00:00:10.000
done.

4
00:00:10.000 --> 00:00:14.790
But in quick succession, Hubble’s all-important
gyroscopes began to fail… A Hubble emergency

5
00:00:14.790 --> 00:00:18.380
was declared, and Servicing Mission 3 was
split in two.

6
00:00:18.380 --> 00:00:22.930
SM3A’s main priority would be switching
out all the gyroscopes with new and improved

7
00:00:22.930 --> 00:00:27.570
versions, while SM3B was scheduled for a few
years later and would work on the updates

8
00:00:27.570 --> 00:00:30.230
that Hubble still needed, but weren’t as
urgent.

9
00:00:30.230 --> 00:00:34.720
The 8-day mission had 3 spacewalks planned;
the first was the gyro replacement, and by

10
00:00:34.720 --> 00:00:37.930
the end of the day Hubble’s gyro troubles
were over.

11
00:00:37.930 --> 00:00:42.850
The next two days had their own spacewalks:
updating Hubble with a more advanced computer,

12
00:00:42.850 --> 00:00:48.249
adding a new fine guidance sensor, installing
a new solid-state digital recorder, and replacing

13
00:00:48.249 --> 00:00:51.940
the outer insulation in order to protect Hubble’s
scientific equipment.

14
00:00:51.940 --> 00:00:56.020
When all the work was finished, Hubble was
released back into orbit on Christmas day,

15
00:00:56.020 --> 00:01:00.609
and as the crew of Discovery landed at Kennedy
Space Center, it became clear that this mission

16
00:01:00.609 --> 00:01:05.690
was a resounding success. Allowing Hubble
to continue forward with its mission of uncovering

17
00:01:05.690 --> 00:01:07.410
the mysteries of the universe.