MAUS (materials science autonomous experiments) is one out of a series of flight opportunities which the Space Program of West Germany offers to scientists from the disciplines of materials research and processing for performing materials science investigations under microgravity conditions. Up to now, ten MAUS experiments were flown which were dealing with the following scientific topics: decomposition of binary alloys with miscibility gap in the liquid state, interaction of a solidification front with dispersed particles, critical Marangoni number, investigation of the magnetic compound MnBi, shrinkage of gas bubbles in glass melts and slip casting. The ten future experiments are partly reflights with modification of the scientific objectives as well as new experiments in the fields of chemical reactions, heat transfer, glass technology and Ostwald ripening. Looking to ten flown payloads, the peculiarities of instrument technology in GAS-cans and its evolution is discussed with emphasis on structure, electronics and thermal design. A typical modern payload using 100 percent of the resource is presented

Doepkess, J.

Otto, G.

Staniek, S.

English

NASA Technical Reports Server

N 8 8 - 2 1 6 9 6  
Dr. S .  Staniek, Dr. G. Otto, Dr. J. Ddpkess * 
DFVLR, D-5000 K61n 90, *MBB/ERNO, D-2800 Bremen, FRG 
TEN PAST AND TEN FUTURE GAS/MAUS-PAYLOADS 
Abstract 
MAUS - a German acronym for materials science autonomous 
experiments - is one out of a series of flight opportunities 
which the Space Program of the Federal Republic of Germany 
offers to scientists from the disciplines of materials research 
and processing for performing materials science investgations 
under micro-gravity conditions. Up to now ten MAUS experiments 
were flown which were dealing with the following scientific 
topics: decomposition of binary alloys with miscibility gap in 
the liquid state, interaction of a solidification front with 
dispersed particles, critical marangoni number, investigation 
of the magnetic compound MnBi, shrinkage of gas bubbles in glas 
melts and slip casting. 
The ten future experiments are partly reflights with 
modification of the scientific objectives as well as new 
experiments in the fields of chemical reactions, heat-transfer, 
glass technology and Ostwald-ripening. 
Looking to ten flown payloads the peculiarities of instrument 
technology in GAS-cans and its evolution will be discussed with 
emphasis on structure, electronics and thermal design. A 
typical modern payload using 100 % of the resources will be 
presented. 
1. Proarammatic aspects of the MAUS-Project 
In 1979 the German Minister for Research and Technology (BMFT) 
signed 2 5  GAS-LSA’s and established the MAUS-GAS program. The 
MAUS-project management was assigned to the German Aerospace 
Research Establishment (DFVLR), and MBB/ERNO was selected as 
the industrial prime contractor. The programmatic concept of 
the project is based on 2 missions a year of dual MAUS-payloads 
in the GAS-program. To achieve this goal the MAUS-standard- 
system has been developed. To assure the feasibility of a 
multitude of materials science experiments the design of this 
system was based on the requirements profiles of 25 experi- 
ments. With the provision of 10 flight units of the 
MAUS-standard-system the possibility for accomodation of 
different experiment specific hardware designed by the 
experimenters themselves is given. 
31  
https://ntrs.nasa.gov/search.jsp?R=19880008312 2020-03-20T08:16:48+00:00Z
Scientific Objectives and Results 
GA s 
S P A S 0 1  
SPAS-01 
OSTA-2 
OSTA-2 
OSTA-2 
The ten experiments flown up to date within the MAUS Project 
cover a wide range of topics from the area of material 
sciences. Essential scientific results have been obtained which 
either stand on their own or serve as supportive data for 
Spacelab experiments. A listing of the experiment titles and 
the resonsible Principal Investigators is given in Table 1. 
V e r i f i c a t i o n  P a y l o a d  
C r i t i c a l  J l a r a n c o n i  Numher 
A l l o y s  o f  t h e  System h - U i  I 
S o l i d i f i c a t i o n  F r o n t  
Metallic D i s p e r s i o n s  I 
Metal l ic  D i s p e r s i o n s  I 1  
T a b l e  1: S u m a r v  o f  MA'JS P a v l o a d s  Flown 
Dr.  Chun 
D r .  Schwabe 
P r o f .  S t r a u b  
Prof. F r i s c h a t  
D r .  R a t k e  
P r o f .  F r i s c h a t  
STS- 11 
5 9 STS-5lG 
Un iv .  E s s e n  
Un iv .  G i e s s e n  
Univ.  Munchen 
Univ.  C l a u s t h a l  
blPI S t u t t g a r t  
Univ.  C l a u s t h a l  
Po I 
7 
7 
Launch 
Date  
13 
1 4  
11/11/82 
GAS 
GAS 
GAS 
GAS 
06/18/83 
0 2 / 0  1/84 
~ ~~ ~~ 
Pool B o i l i n g  
G a s  B u b b l e s  i n  Glass Melts 
O s t w a l d  R i p e n i n g  
R e a c t i o n  K i n e t i c s  
06/17/85 
Carrier I E x p e r i m e n t  T i t l e  I P r i m a r y  I n v e s t i g .  I n s t i t u t i o n  
Dr. O t t o  
Dr. Schwabe 
D i p l - I n g  P a n t  
Dr. K l e i n  
Dr. O t t o  
Dr. O t t o  
Dr. S c h w e i t z e r  
GAS S l i p  C a s t i n g  I 1  Dr. S c h w e i t z e r  
DFVLR Koln 
U. G i e s s e n  
Krupp F I  E s s e n  
DFVLR Koln  
DFVLR Koln 
DFVLR Koln 
MTU Munchen 
U .  C l a u s t h a l  
Krupp F I  Essen 
llTU Munchen 
Ten payloads for future flights in the Get Away Special Prgram 
are in various stages of preparation and a listing of the 
experiment titles and the resonsible Principal Investigators is 
given in Table 2. A condensed form of the scientific objectives 
follows below. 
T a b l e  2: Summary 
MAUS P a y l o a d  
M i s i i o n  i ;;. 
4- 1 9 , 2 0  
of MAUS P a v l o a d s  i n  P r e p a r a t i o n  
E x p e r i m e n t  T i t l e  I C a r r i e r  
GAS 
GAS 
C r i t i c a l  Marangon i  C o n v e c t i o n  
O s c i l l a t o r y  Marangon i  C o n v e c t i o n  
C h e m i c a l  I n s t a b i l i t i e s  
C02 D i s s o l u t i o n  i n  Glass  Melts 
Dr. B e w e r s d o r f f  DFVLR K61n 
D r .  A v n i r  I 
P r o f .  F r i s c h a t  Univ.  C l a u s t h a l  - 
32 
Critical Marangoni Convection: 
Marangoni convection in this experiment is achieved by a 
temperature gradient between two circular plates which can also 
be rotated. The following goals are considered: Documentation 
of the influence of iso-rotation on the steady and oscillatory 
Marangoni convection; evaluation of the shape stability of the 
floating zone configuration during rotation; determination of 
the influence of higher Marangoni numbers on the hydrodynamic 
stability of Marangoni convection by variation of the 
temperature gradient. Convection is made visible in silicone 
oil by dispersed particles. Observation is by a laser cut 
technique in a defined plane which is recorded by a movie 
camera. 
Oscillatory Marangoni Convection: 
The goal of this experiment is to investigate Marangoni 
convection and to determine the critical Marangoni number at 
which the convection becomes oscillatory. Oscillations (about 1 
Hz) are observed by means of a thermo-couple within the liquid 
zone. The material to be investigated is NaN03. In addition to 
previous successful MAUS investigations the length of the 
column will be increased giving access to a different aspect 
ratio. 
Pool Boiling: 
Pool Boiling (nucleate boiling) and forced convection are the 
most effective heat transfer mechanisms. From the many fluid 
physics phenomena which are observed in boiling kinetic heat 
and mass transport by evaporation and condensation is 
independent of gravity. This experiment will lead to a physical 
separation of the gravity driven parameters and therefore to a 
better understanding of the boiling process. A platinum wire 
immersed in Freon 12 will be used to initiate boiling. The 
bubble behavior will be recorded simultaneously by two cameras 
with different recording frequencies. 
Gas Bubbles in Glass Melts: 
Fining is one of the most important processes on technical 
glass fabrication.The removal of gass bubbles from glass melts 
can be achieved in two ways: Rising of the bubbles controlled 
by buoyancy (which is not possible in microgravity) and 
dissulution by diffusion. The shrinking of a He-bubble at 
around 1100 O C was successfully recorded in a previous MAUS 
experiment. This investigation will be performed at the higher 
temperature of 1300' C to complement data on the diffusion in a 
wider temperature range. The convectional influence is expected 
stronger and a larger difference between earth and space 
33 
experiment will result. In a follow-up experiment the 
objectives will be extended towards technically relevant 
glasses like the dissolution of CO, in silicate glass melts. 
Ostwald Ripening: 
The phenomenon of Ostwald ripening is represented in a 
dispersion by growth of larger droplets on the expense of 
smaller ones. For this kind of studies metallic alloys with a 
miscibility gap in the liquid state are well suited like the 
system aluminum-indium. Samples which are already in a 
dispersed state will be heated into the miscibility gap but not 
above. With a series of samples Ostwald ripening and related 
interfacial phenomena will be studied. The experiment will 
require furnaces with long-term temperature stability and a 
regulating accuracy of smaller than 1' C. 
Reaction Kinetics in Glass Melts: 
The interdiffusion between two silicate glasses (potassium and 
rubidium silicate) and the corrosion behavior of SiO, glass by 
alkali halogenide is observed. Transport mechanisms in glass 
melts will be derived and a theroretical model for this case 
defined. Disturbing buoyancy forces are avoided by microgravity 
conditions. 
Chemical Instabilities: 
The spontaneous formation of three-dimensional structures may 
occur in systems far from thermodynamic equilibrium. This 
process must involve transport of matter by convection and/or 
diffusion. To clarify the mechanism of pattern formation a 
space experiment will be performed to exclude gravity driven 
convection. The photochemical reaction will be activated by 
ultraviolet light in microgravity and pattern formation with 
its consecutive development photographed by an optical camera. 
Interconnected MAUS Payloads: 
In this MAUS 10 mission two containers will be interconnected 
to transfer data and electrical power. This feature is very 
important to meet the challenge of future advanced payloads. 
Preliminary studies in this direction have already been 
performed. However, the scientific experiments for these 
missions have not yet been selected. 
34 
3. Instrument Technolocry 
ORIGINAL PAGE IS 
OF POOR QUALITY 
The basic design of a MAUS-Payload consists of the standard 
experiment mounting structure (EMS), the battery (Ag-Zn, Ni-Cd) 
the standard electronics for experiment control and data 
acquisition, the housekeeping system, and the experiment 
hardware including experiment dedicated electronics. The past 
10 MAUS-experiments have been flown with this standard 
configuration, which has been presented in detail in former 
GAS-Symposia. The experience gained during the past MAUS 
missions showed that in connection with progress in technology 
experiments supposed to be accomodated in the Spacelab could 
well be flown as an outonornous payload in the GAS-program. 
As an example of such a complex payload MAUS-payload DG-504 
will be presented (Fig. 3.1). The experiment modification 
needed to suit the requirements of that payload will be 
discussed. 
Fig. 3.1: MAUS-Payload DG 504 
To reach the scientific goal, this payload requires the 
following resources (the nominal ones of a standard 
MAUS-payload are given in parenthesis): 
o Mass: 42.2 kg (20 kg) 
o Energy: 1.36 kWh (1.04 kWh Ag-Zn-battery with 46 cells 
instead of 80) 
o Command: 26 (16) 
o Data: 24 Mbit (10 Mbit) 
35 
The comaand and data requirements could be fulfilled using one 
analog output to generate 10 additions and by using thinner 
tapematerial and reducing tapespeed. The optimized experiment 
hardware without interface electronics requires almost the 
total volume available. Thus, the interface electronics could 
not be acconaodated on the experiment platforms. The only 
solution was to construct a' new adapter ring (Fig. 3.2) 
allowing the accommodation of an interface electronics box 
containing up to fourteen cassetts of experiment dedicated 
electronics. 
The voltage regulators as well as the clock unit of MAUL 
experiment DG 504 could not be assembled in one cassette each, 
if conventional electronic components were used. Therefore, the 
units were partly manufactured by using SMD (Surface-Mounted- 
Device) technology resulting in a high packing density 
especially by applying multilayer techniques. Fig. 3 . 3  shows 
the voltage regulator unit. 
Fig. 3.2: Card with SMD's 
Further advantages of SMD technology are: 
- higher mechanical stability concerning vibration and shock 
- parasitic capacities and inductivities are drastically 
reduced 
36 
ORIGINAL PAGE IS 
OF POOR QUALITY 
Due to the accomodation of the interface electronics on the new 
adapter ring, the available space for the battery is reduced to 
almost 50 % .  Consequsntly the mass available for experirnent 
hardware increases of approximately 12 kg. Further mass 
reduction of the standard system is achieved by us i .ng  a dc/dc 
converter to supply standard electronics as well a s  by 
reduction of structure mass, e.g. open spaces in platforms. 
These modifications also lead to a reduction of t h e  available 
energy to almost 50 % .  But to perE0r-n. a reasonable experi;?c:nt 
from the sci2ntific point of view 1.36 kWh are needed .  Thcr:. only 
solution is a change in battery type froni Ag-Zr-1 to Li-S02 Iicn 
-rechargeable batteries, both produced by the co:rrlpany SILBER- 
K R A F T .  
Li-SO, battery packages have already be?n an :i f a (7 t 11 r c: d 
according to the safety rc-quirerients of t-he S T S - p r o y u a i ?  
(Fiy.3.3). The advantages of these batteries are: 
o alrrDst unlimited lifetlme (no problsp with d e l a y s  of 
STS-missions) 
o safety features 
- reverse-save ct-1 Is 
- diode-quat safety conczpt 
- temperature / current f u s ~ s  
o compared to other battery systen: 
- low cost of cells 
- high energy / mass ratio 
Fig. 3.3 Engineering Model of Li-SO, Battery C e l l  Packages 
together with the Distribution and Fuse Box. 
37 
Up to now, for each up MAUS-payload a thernal analysis has been 
performed. In a mathematical node-?.odel the thermal properties 
were imitated. The optimal insulation can be ca lcu la t c=d  for 
critical components. 
I _ _  ~ _ _ _ _  - ~ _ _  . ~ ~ _----_J 
Fig. 3.4: Temperature vs Time, Experiment DG 504 
From the ten flown MAUS-payload it turned out that a passive 
thermal control system was sufficient to meet acceptable 
tenperature values. 
MAUS payload DG 324 "Gas Bubbles in Glass Melts" will be 
reflight of MAUS payload DG 318 but with a different experiment 
profile (higher temperature, longer duration). With an average 
power consumption Of 300 W for 3 . 7  hours, the thermal analysis 
showed that this experiment needs additional thernal eqaipment 
to avoid overheating of hardware xounted in the vicinity of the 
furnace. 
Assuming the experiment rnounting plate of the GAS-can to be 
used as a radiator, the heat transport form the upper experi- 
ment platform to the radiator has to be increased. A changa of 
the post material from V A-steel to aluminum turned o u t  not to 
be sufficient. Only the integration of heatpipes can provide 
the required conductive heat path. The detailed 1ayc)ut of the 
heat-pipes and further thermal analysis is currently under 
development. 
38 


Ten past and ten future GAS/MAUS-payloads

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