iwf graz … 1 report at midterm meeting april 11 2006 meltingprobe midterm meeting: 11-04-2006...
TRANSCRIPT
1
IWF G
raz
…IWF G
raz
…Report at Midterm Meeting April 11 2006
Melt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
Melt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
Development of a melting probe for Mars and Europa
Norbert I. Kömle
Project overview
2
IWF G
raz
…IWF G
raz
…Scientific Goals Scientific Goals
Melt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
Melt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
Explore vertical layering of deep ice sheets under low pressure conditions
CompositionTextureDust contentTraces of organics
Reconstruct geological history and climate evolution
of planetary bodies
Thermal propertiesOptical propertiesElectrical propertiesDensityPressure
Geocryology for icy moons and planets
Overview Overview M
elt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
Melt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
•Administration
•Characterization of targets
•Scientific requirements
•Technical requirements
•Payload candidates
4
IWF G
raz
…IWF G
raz
…Administration Administration
Melt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
Melt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
September 06 2005
Kickoff Meeting IWF Graz
November 2005
ESTEC contract signed by all parties (ÖAW, ESTEC)
Dr. Erika Kaufmann 100 % working contract funded from project (current funding period: 12 months)
November 2005 -April 2006
Draft documents created:
TARGET CHARACTERIZATION, SCIENTIFIC REQUIREMENTS AND PAYLOAD CANDIDATES
MECHANICAL AND THERMAL DESIGN
ELECTRONICS DESIGN
February 06 2006 First melting test in vacuum with existing probe
April 11 2005 Midterm Meeting IWF Graz
5
IWF G
raz
…IWF G
raz
… Targets Targets
diameter 6794 km
mass 0.108 ME
solar distance 1.52 AU
max. solar radiation 591 W/m2
gravitational acceleration
0.38 g
Melt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
Melt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
MARS
EUROPA diameter 3138 km
mass 0.008 ME
solar distance 5.20 AU
max. solar radiation 51 W/m2
gravitational acceleration
0.134 g
6
IWF G
raz
…IWF G
raz
…Target description: MARS Polar Areas Target description: MARS Polar Areas
Melt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
Melt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
North perennial ice cap South perennial ice cap
7
IWF G
raz
…IWF G
raz
…Target description: EUROPA 1 Target description: EUROPA 1
Melt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
Melt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
Interior structure
8
IWF G
raz
…IWF G
raz
…Target description: EUROPA 2 Target description: EUROPA 2
Melt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
Melt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
Triple bands and ice cracks
9
IWF G
raz
…IWF G
raz
…Target description: EUROPA 3 Target description: EUROPA 3
Melt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
Melt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
Suspicion: Around ice cracks ice layer may be thin
Access to subsurface oceanby means of a melting probe?
10
IWF G
raz
…IWF G
raz
…Technical requirements for first prototype Technical requirements for first prototype
Melt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
Melt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
Use of standard components for electronics: Cross section not too small, chosen dimensions: diameter 6 cm, length 20 cm
Length of tether: ca. 30 m (long enough to test functionality of tether deployment and internal power dissipation
Power supply: 28V, 70W maximum (to avoid use of high voltage components in laboratory testing
Payload: Simple strawman payload, A/D conversion of sensor data inside probe and data transfer through power cable
11
IWF G
raz
…IWF G
raz
…Payload Candidates Payload Candidates
Melt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
Melt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
Temperature sensors
housekeeping and natural temperature profile during non-heating periods (evaluation of thermal properties)
Tilt sensorshousekeeping (reconstruct path of probe in the ice)
ISFET chemical sensorsPH-value of meltwater, trace elements
Miniature mass spectrometer (Open University)
elemental composition
Miniature TOF mass spectrometer (Physikalisches Institut, Uni Bern)
elemental composition
CBD-densitometer
(Open University)
material density around by measuring Compton backscattering of a gamma source
Optical/IR sensorsalbedo variations along melt path as indicator for contaminations
12
IWF G
raz
…IWF G
raz
…Present status of prototype construction Present status of prototype construction
Melt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
Melt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
Item Status
Mechanical design drawings ready
Electronics design under consideration, partially ready
Mechanical parts for prototype ordered
Electronics parts for prototype ordered, partially available
Components for tether partially available
Heater foils (MINCO) available
PT100 sensors (MINCO) available
ADXL tilt sensor available
ISFET PH sensor available
13
IWF G
raz
…IWF G
raz
…First melting test at IWF: 06-02-2006 First melting test at IWF: 06-02-2006
Melt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
Melt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
Temperature evolution of different parts of melting probe
and ice sample during the experiment
14
IWF G
raz
…IWF G
raz
…Test results Test results
Melt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
Melt
ing
pro
be M
idte
rm M
eeti
ng
: 11-0
4-
2006
Heating power: 60 W
Ice temperature: -30°CHot tip temperature when in contact with ice: 30°CHot tip temperature after loss of ice contact: > 130°CTemperature of probe rear end (still outside ice): 80°C
Power of 70 W appropriate for 6 cm cross sectionLaunch pad must be improvedRear end may become too hot as long as probe not fully inside ice
Lessons from test: