1
00:00:00,000 --> 00:00:04,000
[Music throughout] NASA’s Wide Field Infrared Survey

2
00:00:04,000 --> 00:00:08,000
Telescope, WFIRST, is designed to answer big questions about

3
00:00:08,000 --> 00:00:12,000
the universe: What is dark energy, which seems to be speeding up

4
00:00:12,000 --> 00:00:16,000
the expansion of the universe? How many planets exist among the 

5
00:00:16,000 --> 00:00:20,000
stars, and what are they like? WFIRST is similar to 

6
00:00:20,000 --> 00:00:24,000
Hubble, but benefits from 30 years of technological development.

7
00:00:24,000 --> 00:00:28,000
It will view the sky on a scale never before accomplished from space.

8
00:00:28,000 --> 00:00:32,000
[Primary mirror] This is where WFIRST is closest to Hubble. It has the

9
00:00:32,000 --> 00:00:36,000
same size and type of main mirror, a 2.4-meter precisely

10
00:00:36,000 --> 00:00:40,000
shaped piece of silver-coated glass. The size of this mirror

11
00:00:40,000 --> 00:00:44,000
is partly how WFIRST matches Hubble’s resolution.

12
00:00:44,000 --> 00:00:48,000
[Wide Field Instrument] WFIRST’s main camera is the Wide Field Instrument which will take

13
00:00:48,000 --> 00:00:52,000
infrared pictures of the sky to study dark energy, observe galaxies

14
00:00:52,000 --> 00:00:56,000
and stars, and find exoplanets. Instead of Hubble’s single

15
00:00:56,000 --> 00:01:00,000
first-generation image sensor, the WFI incorporates 18

16
00:01:00,000 --> 00:01:04,000
third-generation chips that allow it to take pictures capturing 100 times

17
00:01:04,000 --> 00:01:08,000
greater sky area than Hubble’s. Each 300-megapixel

18
00:01:08,000 --> 00:01:12,000
image will enable scientists to study a large portion of the sky.

19
00:01:12,000 --> 00:01:16,000
At WFIRST’s back is its primary means of communication

20
00:01:16,000 --> 00:01:20,000
with Earth, the High Gain Antenna. [High Gain Antenna] This antenna will be 

21
00:01:20,000 --> 00:01:24,000
responsible for sending nearly 1.4 terabytes of data to ground stations

22
00:01:24,000 --> 00:01:28,000
every day. That’s the equivalent of 460 hours-worth

23
00:01:28,000 --> 00:01:32,000
of streaming video. WFIRST’s critical systems,

24
00:01:32,000 --> 00:01:36,000
such as power and data handling, are located in six modules at the spacecraft’s

25
00:01:36,000 --> 00:01:40,000
rear. [Avionics Modules] These include six rotating “reaction wheels”

26
00:01:40,000 --> 00:01:44,000
that control where the spacecraft points, nearly one ton of propellant

27
00:01:44,000 --> 00:01:48,000
for larger movements, and a 10 terabyte data recorder.

28
00:01:48,000 --> 00:01:52,000
WFIRST’s other instrument is its

29
00:01:52,000 --> 00:01:56,000
Coronagraph Technology Demonstration. [Coronagraph Technology Demonstration] A coronagraph blocks a

30
00:01:56,000 --> 00:02:00,000
star’s light to capture the faint light from orbiting planets.

31
00:02:00,000 --> 00:02:04,000
It will be the first time a space telescope has used deformable mirrors to

32
00:02:04,000 --> 00:02:08,000
precisely control the incoming light and special masks to block only

33
00:02:08,000 --> 00:02:12,000
the starlight. This method will enable WFIRST to capture direct

34
00:02:12,000 --> 00:02:16,000
images of distant planets and analyze the light that is

35
00:02:16,000 --> 00:02:20,000
reflected off their surfaces, allowing scientists to learn about their composition

36
00:02:20,000 --> 00:02:24,000
and atmospheres. The spacecraft’s solar panels

37
00:02:24,000 --> 00:02:28,000
provide its power by converting sunlight into electricity. [Solar Panels]

38
00:02:28,000 --> 00:02:32,000
They also shade the spacecraft, helping to keep its instruments at their design

39
00:02:32,000 --> 00:02:36,000
temperatures. The solar panels will be able to provide

40
00:02:36,000 --> 00:02:40,000
4,100 watts of power, enough to run two commercial microwave

41
00:02:40,000 --> 00:02:44,000
ovens. With all these systems working together,

42
00:02:44,000 --> 00:02:48,000
and in partnership with powerful future telescopes, WFIRST

43
00:02:48,000 --> 00:02:52,000
will be able to usher in a new era of studying our universe.

44
00:02:52,000 --> 00:02:56,000
[Music]

45
00:02:56,000 --> 00:03:01,717
[Explore: Solar system & beyond] [NASA]