Lunar atmospheric composition experiment (LACE)

Katie Pazamickas

LACEFlew on Apollo 17 as

a part of ALSEP.Deployed in the

Taurus-Littrow Valley (30° 45’ 53.6” E and 20° 11’ 31.6” N)

Turned on Dec. 27, 1972 at 18:07

The moon has an atmosphere?Gas molecules travel in ballistic trajectories

between collisions with the lunar surface classic exosphere.

Sources come from solar wind, lunar volcanism or meteoroid impacts.

No dipolar magnetic field, however once every lunar orbit the moon will pass through the Earth’s magnetotail for approximately 6 days.

How LACE WorksGas molecules enter

and are ionized by an electron bombardment ion source, collimated into a beam and sent through a magnetic analyzer to a detection system.

3 mass ranges scanned simultaneously.

The RiddleEach record consists of 90 x 16 array of

numbers, or 1440 numbers, with only 1330 numbers of actual data.

1330 steps, with a time between steps of .6 sec

10 steps of background and 10 steps of internal calibration are inserted between sweeps

A sweep is 13.5 min

1 88 175 262 349 436 523 610 697 784 871 958 10451132121913061

10

100

1000

10000MASS AR

3.2

amu

3.4

amu

2.8

amu

2.2

amu

1.2

amu

3.9

amu

3.8

amu

1 88 175 262 349 436 523 610 697 784 871 958 10451132121913061

10

100

1000

MASS BR

45.4

am

u44

.4 a

mu 43

.7 a

mu

42.5

am

u41

.7 a

mu 40

.2 a

mu

36.6

am

u

34.2

am

u 32 amu

23.4

am

u

22.3

am

u21

.6 a

mu

19.8

am

u

18.7

am

u

1 91 181 271 361 451 541 631 721 811 901 991 1081117112611

10

100

1000

10000

MASS CR

100.

4 am

u99

am

u

89 a

mu

58.8

am

u

51.5

am

u

40 a

mu

34 a

mu

Thank You!Dr. Dave WilliamsDr. Kent HillsDr. Ed GrayzeckDr. Mark AdrianCori Quirk