General Disclaimer

One or more of the Following Statements may affect this Document

This document has been reproduced from the best copy furnished by the 

organizational source. It is being released in the interest of making available as 

much information as possible.

This document may contain data, which exceeds the sheet parameters. It was 

furnished in this condition by the organizational source and is the best copy 

available.

This document may contain tone-on-tone or color graphs, charts and/or pictures, 

which have been reproduced in black and white.

This document is paginated as submitted by the original source.

Portions of this document are not fully legible due to the historical nature of some 

of the material. However, it is the best reproduction available from the original 

submission.

Produced by the NASA Center for Aerospace Information (CASI)
fr y

4, E

Y

y^^

^ QI

I

I

l'1

1

3.

j,

^r

F:

4 !'

f

STELLAR ULTRAVIOLET ROCKET RESEARCH PROGRAM

FINAL REPORT

p 

:°7 

{1 A /-

^of C

(NASA-CE-175361) STELLAR ULTRAVIOLET ROCKET N84-18119

RESEARCH 

PROGRAM Final R::NUrt (Colorado

Univ.) 9 p HC A02/MF A01 CSCL 03A

Unclas

G3/89 00605

NASA CONTRACT NO. NGR 06-003-176
FINAL REPORT

STELLAR ULTRAVIOLET ROCKET RESEARCH PROGRAM

(NGR06-003-•1 76 )

OBJECTIVE:- y

The primary objective of the Stellar Ultraviolet Rocket Research Program

supported by NASA NGR 06-003-176 is to determine the physical properties

of weak stars and nebulae by means of rocket observations iit the 900-

3000A region of the spectrum.

In order to accomplish the primary objective, it was necessary to:

(1) determine the absolute energy distribution of standard stars in

the 1100 to 3400 A region to an accuracy of t 10%.

(2) develop rocket instrumentation capable of measuring the strength

= of emission lines in the 1200 to 1300 A region of the spectrum

from the hot plasma (20,000 to 200,000" K) surrounding weak

stars and nebulae like the crab nebula pulsar.

The data obtained concerning the relative strength of the ultraviolet 

emission lines in its spectrum make it possible to determine the temperature, density and composition of the emitting material. These data 

wc-+ld permit the discrimination between various theoretical models

describing the physical nature of the nebula.

SIGNIFICANT ACCOMPLISHMENTS:

1. Ultraviol et Calibration Star Data

A 4 meter ultraviolet spectrometer was developed to measure the ultraviolet flux from soveral standard type stars.

This 4 meter spectrometer was Flown successfully on Aerobee rockets

13.004 in July of 1972 and on 26.031 in February of 1974. The ultraviolet flux from uLyr, rU Ma, C Oph, x Ori, g Ori, « CMa, a CMa, and

a Leo were measured. These values agreed with the OAO data obtained by

Code in the 1200 to 3400 A region to + 9%.

2. Faint Object Spectrometer Development

A faint object spectrometer was developed to observe stars and

- - -- - _^.- - - ^...,..... - ... & x > -
nebula as faint as unreddened 10 m OB stars or equivalent nebula

in the region of 900 to 1800 A with a 3 A resolution and a 3% accuracy

in a 60 (c. observation.

The instrument consists of a multi-channel, photon locating, microchannel plate detector located at the focus of a Rowland circle

spectrometer. The use of this 'Codacon' detector increases the

sensitivity of the spectrometer by two or three magnitudes making

it possible to observe the ultraviolet spectrum of weak stars during

a 300 sec. rocket flight.

The detector consists of two 2.54mm x 25.5mm microchannel plates

placed next to a coded-anode photon locater which counts and encodes

each photon event into 1024 spectral storage bins. After a preselected integration time, the memory is then read-out producing

a. complete spectrum every 800 msec.

The spectrometer is located at the prime focus of a 16" f!^ 5 mirror

coated to give high reflectivity of ultraviolet light.

Extensive laboratory testing proved the spectrometer to be a

significant advancement in sensitivity and detector technology.

Laboratory calibration spectra of a helium and argon discharge

lamps are shown in figures 1 and 2. Individual lines have an intensity

half-width of 1.8 pixels or 2.8 A, suggesting that the optical performance exceeds the resolution of the detector.

:2 S
0 0

0

0

OD

I.; iNn. ,-) :) -1 vi 1 9 1 n

L-Li

LLJ

O^

U

Lli <

L

L0

LLJ

rn Lu

OM7-

ORIGINAL PAGE 19

OF, POOR QUALITY

C

S2

0

0

0

0

0

[\j
I^

WS

G FW 00

^a

^< O

d^a O- Q

Lt 

Lli 

co

Ltj 

s

U

co

qt

93

y 1

W Rr

Z AmqT

v

Om

rI

M ^

ti

is tD

^ N

0 0 0 ® 0 O 0

4 C%j

1f;fl^J -1 1vil 'lJ 
ff

10.0

^r

2.0

> 1.0

M

w q/1\^

L^I.

ww

0.2

0.1

--w,r

ORIGriNAL PAGE 10

OF POOR QUALITY

INSTRUMENTAL RESPONSE

®ole i I s

i^ ® I^

II

^ II

^ l0

1

I

i

A% Aft ..^ iavu 1500 1700

.WAVELENGTH (A)

F'IGUF% . E 3

•^^. ^ ... .. .{,ter a

^.. r .:. .,
ORIGINAL PAGE UV

OF POOR QUALITY

PIPE= -

CO

lWu

ui

LL-
3. Rocket Flight 25.020

The above described spectrometer and telescope were assembled

into a rocket payload as shown in figure 4. The payload was

launched 11 March of 1977 on an Astrobee F rocket at WSMR.

The objective of the "light was to measure the ultraviolet flux

from several stars and nebulae including the crab nebula in

the 1050 to 1750 A region with a 2.3 A wavelength resolution. The

temperature, density, and composition of the emitting material cou'd

then be determined.

A STRAP III attitude control system in conjunction with a BBRC star

tracker was ised to orient the telescope in the direction of the

various targets.

A standard PCM telemetry system was used to relay the information to

ground.

The specific targets viewed were:

(1) ce Car (used to update the roll gyro)

(2) fl Gem (guide star)

(3) Q Gem (off set pointing)

(4) a Aur (guide star)

(5) IC2149 (offset pointing)

(6) C Tau (guide star)

(7) NGC 1952 (offset pointing)

(8) O'CMa (guide star)

(9) HD5089 (offset pointing)

All support systems functioned properly.

Due to high voltage breakdown in une of the cables, no data were

obtained.
4. Rocket Flight 25.033

The recovery of 25.020 was very good. Only minor repairs were

required to refurbish the payload to flight readiness condition.

The entire high voltage system was reviewed and modified to ensure

that no high voltage breakdown problems would re-occur in the

reflight.

The teleLcope and spectrometer were again flown on an Astrobee F 

rocket on 3/20/79.

The objectives were again to measure the ultraviolet flux from

various stars and the crab nebula in the 1050 to 1750 region.

The entire support system remained as in 25.020.

The specific targets viewed w

(1) a Car (used to update the roll gyro) 

(2) a Aur

(3) C Tau (guide star)

(4) NGC 1952 (offset pointing)

(5) O'CMa

On this flight, more emphasis was given to obtaining data from the

crab nebula than on 25.020.

Good data were obtained on the first three targets, but due to

roll gyro error, the offset from C Tau to NGC 1952 was slightly

in the wrong direction just grazing the crab nebula. Only data

obtained in passing through the nebula edge we-e obtained. The

intensity of the ultraviolet radiation was not as high as expected

possibly inferring that the ultraviolet distribution from the

nebula is not as expected but more from a point source.

s

_ ., - -' ..:, ^.... . ....•.,...,..,,u.._.,,..,a.^.e..,;s.wer-^,."'"C`w'A'^'-r.'1