Transcript The team: Agata Białek, Anthony Donohoe, María Fernández-Jiménez, Barbara Frasl, Antonio Gurciullo, Andreas Kleinschneider, Robert-Jan Koopmans, Anna Losiak, Thurid Mannel, Iñigo Muñoz Elorza,

The team:
Agata Białek, Anthony Donohoe, María Fernández-Jiménez, Barbara Frasl,
Antonio Gurciullo, Andreas Kleinschneider, Robert-Jan Koopmans, Anna Losiak,
Thurid Mannel, Iñigo Muñoz Elorza, Daniel Nilsson, Marta Oliveira, Paul Magnus
Sørensen-Clark, Ryan Timoney, Iris van Zelst

central question:
◦ Why has Venus evolved so differently from Earth?

science questions we would like to answer:
◦ Is Venus’ internal structure and composition similar to
Earth’s?
◦ Is Venus tectonically active and on what time scale?

main payload items:
◦ SAR
◦ gradiometer
◦ IR + UV cameras

a balloon and orbiter will be used for this mission
orbiter science phase,
May 2033
launch,
December 2032
Hohmann transfer,
117 days
aerobreaking,
20 days
dedicated balloon phase,
25 days
5 years
operation
Interactive content
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
orbiter
payload
balloon
transfer
timeline
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Venus
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Despite similarities between Earth and Venus…
Earth
Venus
5.97
4.88
6371.0
6051.8
density [kg/m3]
5514
5243
surface gravity [m/s2]
9.81
8.87
mass [1024 kg]
mean radius [km]
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
…there are some striking differences.
Earth
Venus
year [Earth days]
365.26
224.70
day [Earth days]
1
243.02
1.01325
92
15
464
surface pressure [bar]
surface temperature [°C]
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
The aim of the mission is to investigate why Venus has evolved so differently from
Earth. This will not only answer questions about how our solar system formed, but
also contrain models on planetary formation in general, including exoplanets.
In ESA’s Cosmic Vision and NASA’s Visions and Voyages this has been recognised as
important topics.
For the Hesperos mission the following scientific questions and subquestions are
asked:

Is Venus’ internal structure and composition similar to Earth’s?
1. What is the core size and phase?
2. How do mantle processes drive surface activity?

Is Venus tectonically active and on what time scale?
3. Is there plate movement on Venus and what are its characteristics?
4. Is there volcanic activity on Venus and to what extent?
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
measurement
quantity
1. core size
2. mantle
processes
spin rate / J2-effect /
moment of inertia
SAR (O)
SAR (O)
topography changes
SAR (O)
gravity field
cold atom
gradiometer (O)
3. plate
movement
4. volcanoes
SAR (O)
SAR (O)
cold atom
gradiometer (O)
acoustic waves
sounding device
(A)
sounding device
(A)
sounding device
(A)
magnetic field
magnetometer (A)
magnetometer (A)
magnetometer
(A)
heat signature
IR + UV
spectrometer and
IR camera (O)
(noble) gas isotopes
mass spectrometer
(A)
atmospheric dust
surface emissivity
sounding device
(A)
nephelometer (A)
IR + UV
spectrometer (O)
(O) refers to measurements from orbit; (A) refers to measurements in the atmosphere.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
For measurements that need to take place in the atmosphere a so called phase
change double aeroshell balloon will be used. The working fluids are water and
helium. By means of evaporation and condensation of water the buoyancy of the
balloon can be changed. In this way the altitude of the balloon can be varied.
The whole structure consists of a:

front and back shall for protection during
descent into the atmosphere

a parachute system for decelaration

Balloon, including gondola, aeroshell and
tanks for helium and water

S/C adapter
The balloon will be at an altitude between
40 and 60 km and gradually drift to one of
the poles.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Key features of the orbiter are:
 8 m2 of radiators for cooling of the satellite
 16 heater lines to keep temperature within limits during eclipse
 3 m2 of body mounted Ga-Ar solar panels for power generation
 3 m diameter steerable X-band High Gain Antenna
 S-band Medium Gain Antenna
 UHF link for comunication with the balloon
3m Steerable X-Band Antenna
Mounted Solar Panels
Radiator Panel
Fairing Interface Mount
Balloon Re-entry Module
500N Apogee Motor
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
To detect changes in surface topology, the orbiter should repeat the same track at
least three times. Furthermore, to determine the mass distribution of Venus the
orbiter should cover as much of Venus as possible. These contraints result in an
orbit with the following characteristics:
 altitude of 250 km
 eccentricity of 0 (circular orbit)
 inclination of 85°
These basic orbital parameters result in a orbital period of 92 minutes. The track is
repeated every 2 Venus days.
The nominal mission duration is 7 Venus days or about 5 years.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Balloon Release, April 2033
Aerobraking, May 2033
5 years mission
Orbiter
Phase I
Orbiter
Phase II
Orbiter
Phase III
Orbiter
Phase II
25 days
4 Venus day
1 Venus day
2 Venus day
Balloon
Phase
25 days
Phase I: IR+UV Spectrometer/IR Camera
Phase II: SAR, IR+UV Spectrometer/IR Camera
Phase III: Gradiometer
Venus final orbit, May 2033
Checkout & Commissioning, 2 weeks
Extended
Phase
Explanation about science objectives and
observables.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Despite similarities between Earth and Venus…
Earth
Venus
5.97
4.88
6371.0
6051.8
density [kg/m3]
5514
5243
surface gravity [m/s2]
9.81
8.87
mass [1024 kg]
mean radius [km]
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
…there are some striking differences.
Earth
Venus
year [Earth days]
365.26
224.70
day [Earth days]
1
243.02
1.01325
92
15
464
surface pressure [bar]
surface temperature [°C]
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
The aim of the mission is to investigate why Venus has evolved so differently from
Earth. This will not only answer questions about how our solar system formed, but
also contrain models on planetary formation in general, including exoplanets.
In ESA’s Cosmic Vision and NASA’s Visions and Voyages this has been recognised as
important topics.
For the Hesperos mission the following scientific questions and subquestions are
asked:

Is Venus’ internal structure and composition similar to Earth’s?
1. What is the core size and phase?
2. How do mantle processes drive surface activity?

Is Venus tectonically active and on what time scale?
3. Is there plate movement on Venus and what are its characteristics?
4. Is there volcanic activity on Venus and to what extent?
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Doppler tracking by the Magellan and Pioneer Venus missions has resulted in
an estimated second harmonic potential number, or Love number, of 𝑘2 =
0.295 ± 0.066. Models predict a value of 0.23 < 𝑘2 < 0.29 for a liquid iron core and
𝑘2 = 0.17 for a solidified iron core1. Here it is assumed that the internal
structure/viscosity is similar to Earth’s.
Furthermore, Venus’ moment of inertia factor, characterising the radial mass
distribution, is unkown. Hence, the size of the core is unkown.
?
1
A. Konopliv and C. Yoder, Geophysical Research Letters 23 (1996) 1857-1860
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Measuring a magnetic field would be a strong hint that at least part of the core is
solid. Several past missions have not been able to detect any magnetic field. To
further constrain the models on the phase of the core magnetic field measurements
have to be done at a higher resolution, a lower altitude or, ideally, a combination of
the two.
To constrain the moment of intertia
factor, Venus’ spin rate has been
accurately determined in the past.
However, the measurements do not
agree with each other and suggest a
variable spin rate2. This would in turn
also tell something about the internal
structure of Venus.
2
N. Müller et al., Icarus 217 (2012) 474-483
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
As the radius of Venus is known, constraints on the size of the core also
constraints the size of the mantle, but does not tell anything about the structure
and dynamics of the mantle.
On Earth the mantle structure and dynamics are closely linked to surface
processes. Understanding these on Venus would link the internal structure with
what is observed at the surface and in the atmosphere.
The structure of the mantle and its variation over time can best studied by
performing gravity gradient measurements.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Surface dating of Venus has revealed that the surface is relatively young (~750
Ma). This suggests that Venus has some form of plate tectonics. There are
currently three theories for this:

stagnant lid theory3,4
Here heat accumulation in the mantle results in periodic catastrophic
resurfacing of large parts of the planet. Periods in between these events show
hardly any activity. According this theroy tectonic plates do not exist.
 tectonic plates disimilar from Earth5,6
Here it is assumed that tectonic plates exists but are different from Earth’s.
Large scale tectonic and volcanic activity should be expected.
 mantle plumes7
In this theory mantle plumes cause resurfacing on a smaller scale than the
stagnent lid theory.
3
4
5
6
7
D. Turcotte, Journal of Geophysical Research 98 (1993) 17061-17068
A. Basilevsky and J. Head, Journal of Geophysical Research 105 (2000) 24583-24611
G. Schubert and D. Sandwell, Icarus 117 (1995) 173-196
R. Ghail, Journal of Geophysical Research 107 (2002) 4.1-4.7
C. Johnson and M. Richards, Journal of Geophysical Research 108 (2003) 5058
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Gravity & topography
The tectonic system can be investigated by combining the gravitational field with
detailed topographic data. This would reveal uneven mass distributions in the
crust and would allow to estimate the crustal thickness. In this way subsurface
structures can be detected.
Rift-like structures have been observed on Venus. Their size is comparable with
rift structures found on Earth. However, subduction zones have not been
detected so far.
For rifts and subduction zones to be detected variations in the gravity field with
an accuracy of 5 mgal and spatial resolution of <100 km need to be measured.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Seismic waves
Tectonic activity on Earth is clearly noticeable by earthquakes. Earthquakes can
also be detected by pressure waves in the atmosphere as the the interior is
seismically coupled with the atmosphere8. Given the pressure and density on
Venus the coupling is tighter. At similar altitude the amplitude of the waves is
about 600 times higher9.
Sound detected
from volcanoes on
Earth
8
9
H. Kanamori et al., Journal of Geophysical Research 99 (1994) 21947-21961
R. Garcia et al., Geophysical Research Letters 32 (2005) L16205
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Outgassing
The level of outgassing of Venus can also be used as an indication for the overal
tectonic activity. The level of outgassing can be determined by measuring
radiogenic noble gasses in the atmosphere.
Venera 11 and 12 have measured the 40Ar/36Ar ratio to be 1.19 ± 0.07, which was
confirmed by measurements of Pioneer Venus (1.03 ± 0.04)10. This suggests a
very low level of outgassing which would be consistent with the stagnant lid
theory. However, to better constrain the model at least also the 3He/4He ratio
should be determined.
10
B. Fegley, Global Earth Physics (1995) 320-345
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Volcanoes are a clear indication of a dynamic interior of Venus. The Venus
Express recently showed strong hints for volcanic activity on Venus.
11
E. Shalygin et al., LPSC (2014) 2556
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Volcanic activity can be detected in several ways.

volcanic gasses such as SO2 and HCl from orbit
The atmospheric windows of Venus’ atmosphere allow the determination of
these gasses by means of spectroscopy.

thermal imaging of the surface
Due to the higher temperature of lava, thermal imaging can reveal active lava
flows/volcanoes.

volcanic gasses such as SO2 in the atmosphere
Atmospheric measurements allow the determination of isotopic ratios to
confirm volcanic origin of these gasses.

volcanic ash in the atmosphere
From Earth based volcanoes it is known that ash can vary in size from less
than 10 µm to about 2 mm. The heavier particles have a residence time of
less than a day, but smaller particles can be measured for several days.
11
E. Shalygin et al., LPSC (2014) 2556
Explanation about science questions.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Doppler tracking by the Magellan and Pioneer Venus missions has resulted in
an estimated second harmonic potential number, or Love number, of 𝑘2 =
0.295 ± 0.066. Models predict a value of 0.23 < 𝑘2 < 0.29 for a liquid iron core and
𝑘2 = 0.17 for a solidified iron core1. Here it is assumed that the internal
structure/viscosity is similar to Earth’s.
Furthermore, Venus’ moment of inertia factor, characterising the radial mass
distribution, is unkown. Hence, the size of the core is unkown.
?
1
A. Konopliv and C. Yoder, Geophysical Research Letters 23 (1996) 1857-1860
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Measuring a magnetic field would be a strong hint that at least part of the core is
solid. Several past missions have not been able to detect any magnetic field. To
further constrain the models on the phase of the core magnetic field measurements
have to be done at a higher resolution, a lower altitude or, ideally, a combination of
the two.
To constrain the moment of intertia
factor, Venus’ spin rate has been
accurately determined in the past.
However, the measurements do not
agree with each other and suggest a
variable spin rate2. This would in turn
also tell something about the internal
structure of Venus.
2
N. Müller et al., Icarus 217 (2012) 474-483
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
As the radius of Venus is known, constraints on the size of the core also
constraints the size of the mantle, but does not tell anything about the structure
and dynamics of the mantle.
On Earth the mantle structure and dynamics are closely linked to surface
processes. Understanding these on Venus would link the internal structure with
what is observed at the surface and in the atmosphere.
The structure of the mantle and its variation over time can best studied by
performing gravity gradient measurements.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Surface dating of Venus has revealed that the surface is relatively young (~750
Ma). This suggests that Venus has some form of plate tectonics. There are
currently three theories for this:

stagnant lid theory3,4
Here heat accumulation in the mantle results in periodic catastrophic
resurfacing of large parts of the planet. Periods in between these events show
hardly any activity. According thsi theroy tectonic plates do not exist.
 tectonic plates disimilar from Earth5,6
Here it is assumed that tectonic plates exists but are different from Earth’s.
Large scale tectonic and volcanic activity should be expected.
 mantle plumes7
In this theory mantle plumes cause resurfacing on a smaller scale than the
stagnent lid theory.
3
4
5
6
7
D. Turcotte, Journal of Geophysical Research 98 (1993) 17061-17068
A. Basilevsky and J. Head, Journal of Geophysical Research 105 (2000) 24583-24611
G. Schubert and D. Sandwell, Icarus 117 (1995) 173-196
R. Ghail, Journal of Geophysical Research 107 (2002) 4.1-4.7
C. Johnson and M. Richards, Journal of Geophysical Research 108 (2003) 5058
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Gravity & topography
The tectonic system can be investigated by combining the gravitational field with
detailed topographic data. This would reveal uneven mass distributions in the
crust and would allow to estimate the crustal thickness. In this way subsurface
structures can be detected.
Rift-like structures have been observed on Venus. Their size is comparable with
rift structures found on Earth. However, subduction zones have not been
detected so far.
For rifts and subduction zones to be detected variations in the gravity field with
an accuracy of 5 mgal and spatial resolution of <100 km need to be measured.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Seismic waves
Tectonic activity on Earth is clearly noticeable by earthquakes. Earthquakes can
also be detected by pressure waves in the atmosphere as the the interior is
seismically coupled with the atmosphere8. Given the pressure and density on
Venus the coupling is tighter. At similar altitude the amplitude of the waves is
about 600 times higher9.
Sound detected
from volcanoes on
Earth
8
9
H. Kanamori et al., Journal of Geophysical Research 99 (1994) 21947-21961
R. Garcia et al., Geophysical Research Letters 32 (2005) L16205
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Outgassing
The level of outgassing of Venus can also be used as an indication for the overal
tectonic activity. The level of outgassing can be determined by measuring
radiogenic noble gasses in the atmosphere.
Venera 11 and 12 have measured the 40Ar/36Ar ratio to be 1.19 ± 0.07, which was
confirmed by measurements of Pioneer Venus (1.03 ± 0.04)10. This suggests a
very low level of outgassing which would be consistent with the stagnant lid
theory. However, to better constrain the model at least also the 3He/4He ratio
should be determined.
10
B. Fegley, Global Earth Physics (1995) 320-345
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Volcanoes are a clear indication of a dynamic interior of Venus. The Venus
Express recently showed strong hints for volcanic activity on Venus.
11
E. Shalygin et al., LPSC (2014) 2556
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Volcanic activity can be detected in several ways.

volcanic gasses such as SO2 and HCl from orbit
The atmospheric windows of Venus’ atmosphere allow the determination of
these gasses by means of spectroscopy.

thermal imaging of the surface
Due to the higher temperature of lava, thermal imaging can reveal active lava
flows/volcanoes.

volcanic gasses such as SO2 in the atmosphere
Atmospheric measurements allow the determination of isotopic ratios to
confirm volcanic origin of these gasses.

volcanic ash in the atmosphere
From Earth based volcanoes it is known that ash can vary in size from less
than 10 µm to about 2 mm. The heavier particles have a residence time of
less than a day, but smaller particles can be measured for several days.
11
E. Shalygin et al., LPSC (2014) 2556
Explanation about instruments.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
measurement
quantity
1. core size
2. mantle
processes
spin rate / J2-effect /
moment of inertia
SAR (O)
SAR (O)
topography changes
SAR (O)
gravity field
cold atom
gradiometer (O)
3. plate
movement
4. volcanoes
SAR (O)
SAR (O)
cold atom
gradiometer (O)
acoustic waves
sounding device
(A)
sounding device
(A)
sounding device
(A)
magnetic field
magnetometer (A)
magnetometer (A)
magnetometer
(A)
heat signature
IR + UV
spectrometer and
IR camera (O)
(noble) gas isotopes
mass spectrometer
(A)
atmospheric dust
surface emissivity
sounding device
(A)
nephelometer (A)
IR + UV
spectrometer (O)
(O) refers to measurements from orbit; (A) refers to measurements in the atmosphere.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
The SAR can be used to help
formulate
answers
to
and/or
constrain models for all scientific
questions.
It does so by measuring the spin rate,
establishing detailed topographical
maps and monitor changes in the
topography.
To
establish
topographical
the
surface should be mapped at least
twice. The first pass is to establish a
reference map. During the second
pass the surface is mapped again but
at a different angle. Now the
topography can be derived.
To monitor changes in topography a
third scan has to be made.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Studying mantle processes requires
detailed topographical maps. Current
available
geographical
maps
from
Venus, obtained during the Magellan
mission, has a spatial resolution of 1020 km and a vertical resolution of 50100 m12. A higher spatial resolution of
1-2 km and vertical resolution of about
50 m is available for 20% of the
surface13.
The figure shows known the size
distribution of known features on the
surface of Venus. Mapping the surface
with a spatial resolution of 500 m and a
vertical resolution of 25 m is required to
capture all the known features.
In addition, with this resolution it is
possible
to
detect
topographical
changes caused by volcanoes rated as
VEI 3 or higher.
12
13
P. Ford and G. Penttengill, Journal of Geophysical Research – Planets 97 (1992) 13103-13114
R. Herrick et al., EOS Transaction 93 (2012) 125-126
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Venus was extensively researched by the
former Soviet Union. The Venera
programme included 8 landers (Venera 7
to Venera 14). These landers managed to
survive the harsh conditions for up to
about two hours.
Although not active anymore, the radar
signature of these landers can easily be
detected from orbit. Especially, because
their location is known to at least within
150 km. As such, the landers can be
used as fixed points for accurate spin
rate determination of Venus.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Studying mantle processes requires detailed
gravitational and topographical maps. Ideally,
resolution of gravitational maps should be such that
all surface features can be studied in relation to
mantle processes. Currently, Venus‘ gravity field is
known with a spatial resolution of about 700 km14,
which would only allow Tesseras to be studied.
With a cold atom gradiometer, currently under
development, this resolution can be increased to
about 100 km depending on the orbit of the
satellite.
The working principle of this instrument can be
summarised with the following steps:
1. A cloud of atoms is cooled and trapped by a
laser
2. Upon release the atoms accelerate along the
local gravity gradient
3. The position of the atoms is measured by atom
interferometry from which the local gravity
gradient can be deduced
14
A. Konopliv et al., Icarus 139 (1999) 3-18
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Detecting seismic activity and volcano eruption by acoustic waves has been
successfully tested on Earth. Given the stronger coupling between the surface of
Venus and the atmosphere, it is expected that a similar phenomenon is present
on Venus as well15. To detect such waves two arrays of infrasonic sounding
devices are placed at the bottom of the balloon. To estmate the origin of acoustic
waves, a wind speed and direction meter is added as well.
Sound detected
from volcanoes on
Earth
15
J. Johnson and M. Ripepe, Journal of Volcanology and Geothermal Research 206 (2011) 61-69
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
None of the missions to Venus have deteceted an existing magnetic field. However,
using magnetometers with a higher resolution than on past missions and by flying it
much closer to the surface it will be possible to further constrain any models about
Venus‘ interior.
Two magnetometers will be fixed on a boom attached to the balloon. The
magnetometers will be placed as far away as possible from other instruments to avoid
any interference.
Goddard Space
Flight Center
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
A hot spot detected by Venus Express11
For monitoring SO2, H2O and HCl
abundances in the atmosphere over
long periods of time, an IR and UV
spectrometer will be employed. This is
very similar to the SPICAV instrument
flown on Venus Express. The required
spectral range is 0.11-0.31 µm,
resolution is 0.8 nm, resolving power is
300 and FoV of 55x8.7 rad.
To detect hot spot, possibly indicating
volcanoes, an IR camera will be used.
This instrument is based on the SPICAV
and VIRTIS instruments flown on Venus
Express. The required spectral range is
0.7-5 µm, resolution is 0.8 nm,
resolving power is 100-200 and FoV of
64x64 rad.
11
E. Shalygin et al., LPSC (2014) 2556
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
A spectrometer and nephelometer attached to the balloon will be used for
investigation of gasses and dust in Venus‘ atmosphere.
The 40Ar/36Ar have been independently measured during previous missions. The
isotope ratio of at least one other noble gas, such as 3He/4He, will be measured to
further constrain the degree of outgassing of Venus. Furthermore, to confirm the
volcanic origin of the volcanic gasses, the isotopic ratio of SO2, H2O and HCl will
be measured as well. The spectrometer required for this should have an accuracy
of ±1%, sensitivity of 0.1 ppb, mass resolution of 0.1 AMU and mass range of 2150 AMU.
A nephelometer will be employed
to measure volcanic ash in the
range of 0.1-10 µm and an
accuracy of 0.1 µm.
Explanation about instruments.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
The SAR can be used to help
formulate
answers
to
and/or
constrain models for all scientific
questions.
It does so by measuring the spin rate,
establishing detailed topographical
maps and monitor changes in the
topography.
To
establish
topographical
the
surface should be mapped at least
twice. The first pass is to establish a
reference map. During the second
pass the surface is mapped again but
at a different angle. Now the
topography can be derived.
To monitor changes in topography a
third scan has to be made.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Studying mantle processes requires
detailed topographical maps. Current
available
geographical
maps
from
Venus, obtained during the Magellan
mission, has a spatial resolution of 1020 km and a vertical resolution of 50100 m12. A higher spatial resolution of
1-2 km and vertical resolution of about
50 m is available for 20% of the
surface13.
The figure shows known the size
distribution of known features on the
surface of Venus. Mapping the surface
with a spatial resolution of 500 m and a
vertical resolution of 25 m is required to
capture all the known features.
In addition, with this resolution it is
possible
to
detect
topographical
changes caused by volcanoes rated as
VEI 3 or higher.
12
13
P. Ford and G. Penttengill, Journal of Geophysical Research – Planets 97 (1992) 13103-13114
R. Herrick et al., EOS Transaction 93 (2012) 125-126
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Venus was extensively researched by the
former Soviet Union. The Venera
programme included 8 landers (Venera 7
to Venera 14). These landers managed to
survive the harsh conditions for up to
about two hours.
Although not active anymore, the radar
signature of these landers can easily be
detected from orbit. Especially, because
their location is known to at least within
150 km. As such, the landers can be
used as fixed points for accurate spin
rate determination of Venus.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Studying mantle processes requires detailed
gravitational and topographical maps. Ideally,
resolution of gravitational maps should be such that
all surface features can be studied in relation to
mantle processes. Currently, Venus‘ gravity field is
known with a spatial resolution of about 700 km14,
which would only allow Tesseras to be studied.
With a cold atom gradiometer, currently under
development, this resolution can be increased to
about 100 km depending on the orbit of the
satellite.
The working principle of this instrument can be
summarised with the following steps:
1. A cloud of atoms is cooled and trapped by a
laser
2. Upon release the atoms accelerate along the
local gravity gradient
3. The position of the atoms is measured by atom
interferometry from which the local gravity
gradient can be deduced
14
A. Konopliv et al., Icarus 139 (1999) 3-18
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Detecting seismic activity and volcano eruption by acoustic waves has been
successfully tested on Earth. Given the stronger coupling between the surface of
Venus and the atmosphere, it is expected that a similar phenomenon is present
on Venus as well15. To detect such waves two arrays of infrasonic sounding
devices are placed at the bottom of the balloon. To estmate the origin of acoustic
waves, a wind speed and direction meter is added as well.
Sound detected
from volcanoes on
Earth
15
J. Johnson and M. Ripepe, Journal of Volcanology and Geothermal Research 206 (2011) 61-69
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
None of the missions to Venus have deteceted an existing magnetic field. However,
using magnetometers with a higher resolution than on past missions and by flying it
much closer to the surface it will be possible to further constrain any models about
Venus‘ interior.
Two magnetometers will be fixed on a boom attached to the balloon. The
magnetometers will be placed as far away as possible from other instruments to avoid
any interference.
Goddard Space
Flight Center
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
A hot spot detected by Venus Express11
For monitoring SO2, H2O and HCl
abundances in the atmosphere over
long periods of time, an IR and UV
spectrometer will be employed. This is
very similar to the SPICAV instrument
flown on Venus Express. The required
spectral range is 0.11-0.31 µm,
resolution is 0.8 nm, resolving power is
300 and FoV of 55x8.7 rad.
To detect hot spot, possibly indicating
volcanoes, an IR camera will be used.
This instrument is based on the SPICAV
and VIRTIS instruments flown on Venus
Express. The required spectral range is
0.7-5 µm, resolution is 0.8 nm,
resolving power is 100-200 and FoV of
64x64 rad.
11
E. Shalygin et al., LPSC (2014) 2556
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
A spectrometer and nephelometer attached to the balloon will be used for
investigation of gasses and dust in Venus‘ atmosphere.
The 40Ar/36Ar have been independently measured during previous missions. The
isotope ratio of at least one other noble gas, such as 3He/4He, will be measured to
further constrain the degree of outgassing of Venus. Furthermore, to confirm the
volcanic origin of the volcanic gasses, the isotopic ratio of SO2, H2O and HCl will
be measured as well. The spectrometer required for this should have an accuracy
of ±1%, sensitivity of 0.1 ppb, mass resolution of 0.1 AMU and mass range of 2150 AMU.
A nephelometer will be employed
to measure volcanic ash in the
range of 0.1-10 µm and an
accuracy of 0.1 µm.
Explanation about the balloon.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
For measurements that need to take place in the atmosphere a so called phase
change double aeroshell balloon will be used. The working fluids are water and
helium. By means of evaporation and condensation of water the buoyancy of the
balloon can be changed. In this way the altitude of the balloon can be varied.
The altitude of the balloon will vary between
40 and 60 km and gradually drift to one of
the poles as a consequence of the prevailing
wind direction.
The balloon is made of Teflon-Mylar-Vectran
layers which is capable of surviving the harh
atmosphere of Venus. A full-scale test has
already successfully been performed16.
During a two-week test the He leakage was
zero and the Teflon outer layer showed
exellent resistance against sulfuric acid.
16
K. Baines et al., 5th International Interplanetary Probe Workshop (2007)
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
The entry probe consists of a:

front and back shell for protection during
descent into the atmosphere

parachute system for decelaration

balloon, including gondola, aeroshell and
tanks for helium and water

S/C adapter
For entering Venus’ atmosphere the balloon
and payload is stowed away in a protective
shell. The front and back shell have a carbon
phenolic thermal protection layer, which can
withstand heat fluxes up to 300 MW/m2. A
maximum deceleration of 60 g is expected.
At 70 km the front shell will be seperated and
the back shell will act as a drogue chute, which
pulls the main parachute. The balloon will start
inflating. Once finished, the parachute and He
tank will be released.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Once fully inflated, a 4.5 m boom will be released to which the magnetometers
are fixed as well as the atmospheric sounding module. This means that only one
instrument at the time can be switched on to avoid interference.
The diameter of the He balloon will be 4.1 m and of the inner balloon containing
H2O vapour 1.05 m. The structure has an estimated mass of 213 kg.
The expected atmospheric temperature will vary between -30 and +130°C. For
an acceptable temperature of the payload the gondola uses a passive thermal
control system consisting of MLI enclosure and surface finish.
The overall power consumption of the balloon will be 104 W of which 70 W is
dedicated to the payload. Power will be provided by four Lithium-Monofluoride
batteries and one Lithium-Suphur Dioxide battery.
Communication between the balloon and the orbiter will be provided by UHFband; similar to the Venera landers17. For this two 0.12 m UHF antennas will be
used.
17
M. Keldysh, Icarus 30(4) (1977) 605-625
Explanation about the orbiter.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
A schematic view of the orbiter is shown below. Main drivers of the orbiter design
are:
 the high solar flux around Venus combined with a high albedo of Venus’
atmosphere
 the large power and data rate requirements for the SAR
 high stability for accurate gravity gradient measurements
3m Steerable X-Band Antenna
Mounted Solar Panels
Radiator Panel
Fairing Interface Mount
Balloon Re-entry Module
500N Apogee Motor
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
The solar flux around Venus is about 2.6 kW/m2. It’s albedo is 0.8 and via IR
radiation another 0.15 kW/m2 is added. The worst-case incoming heat flux is
estimated to be 2.8 kW/m2. This requires passive as well as active thermal control
systems to ensure that the temperature of the payload and subsystems stays within
the operational limits.
MLI
Passive thermal control is provided by:
 MLI consisting of 23 layers of Kapton
 high-reflectivity coating on exposed surfaces
(CryoSat-2 heritage)
Active thermal control is provided by:
 2 x 8 m2 of radiators for cooling of the satellite
 16 heater lines to keep temperature within limits
during eclipse
Radiators with the louvers
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
An X-band High Gain Antenna (HGA) sends the science data gathered by the orbiter
as well as the balloon back to Earth. As the SAR produces a large amount of data a 3
m steerable dish antenna will be used. In addition, when the orbiter is close to Earth
an S-band Medium Gain Antenna (MGA) will be used wenn the HGA cannot be pointed
accurately enough and no high data rate is required. The 35 m dishes of ESA’s Deep
Space Antennas are selected as groundstation.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Including margins the orbiter is expected to require about 1.3 kW of power. This is
provided by:
 3 m2 of body mounted Ga-Ar solar panels assuming an efficiency of 0.2
 2 batteries, Lithium-Thionyl Chloride


moderate lifetime < 4 hours
170-440 Wh/kg
The solar panels are body mounted as depoyable solar panels would introduce
vibrations to the orbiter. This would have a detrimental effect on the measurements
performed by the gradiometer.
The orbiter dry mass is roughly 1500 kg.
Explanation about how to get there.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Launch from Kourou by Ariane 5 and entry into Ground Transfer Orbit by
launcher on December 2032. The estimated total launch mass (orbiter, balloon
and propellant) is 4100 kg.
Launch window: 25/2/2032 to 22/9/2033
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
ΔV1
Earth
orbit
Hohmann transfer to Venus sphere of
influence in a hyperbolic trajectory.
Hohmann
transfer
RV
ΔV2
RE
Initially, the satellite satellite will be
injected into an elliptical orbit during
which the balloon will be released.
Due to the elliptic orbit, the balloon
will be visible for the orbiter for the
largest part for the largest part of the
orbit.
The required Δv = 2.7 km/s and will
be provided by a 500 N MMH-NTO
apogee kick motor.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
After the balloon phase the orbiter will go into a circular orbit. To save fuel this will
be achieved by using the atmosphere of Venus to lower the apoapsis.
To ensure that the orbiter does not enter the atmosphere a Δv of 1 m/s applied at
the periapsis is required.
The procedure has successfully been applied to Venus Express.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Key orbital parameters:
Altitude:
Eccentricity:
Orbital period:
Inclination:
Repeat pattern:
Maintenance Δv:
250 km
0
92 min
85°
every 2 Venus days
10 m/s per year
Explanation about the mission timeline.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Launch,
December 2032
Hohmann transfer,
117 days
Aerobreaking,
20 days
Balloon Checkout, 10 days
Balloon Release
Balloon Phase, 25 days
Venus final orbit,
May 2033
5 years
operation
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
A dedicated balloon phase at the beginning of the mission
significantly reduces the required amount of propellant.
Balloon Release, April 2033
25 days balloon mission
Balloon Phase A
Magnetometer, Nephelometer, Stereo & Meteo Station
End
of balloon
mission
25 days
Balloon Phase B
Mass Spectrometer
2.1 days
Mass spectrometer most important,
therefore at the beginning of balloon mission.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Balloon Phase A
Magnetometer, Nephelometer, Stereo & Meteo Station
25 days
55
45
35
0
50
100
150
200
250
300
350
400
450
500
550
time (hours)
Balloon Phase B
Mass Spectrometer
2.1 days
65
60
altitude (km)
altitude (km)
65
Sampling point for mass spectrometer
55
50
45
40
35
0
10
20
30
time (hours)
40
50
600
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Balloon Release, April 2033
Aerobraking, May 2033
5 years mission
Orbiter
Phase I
Orbiter
Phase II
Orbiter
Phase III
Orbiter
Phase II
25 days
4 Venus day
1 Venus day
2 Venus day
Balloon
Phase
25 days
Phase I: IR+UV Spectrometer/IR Camera
Phase II: SAR, IR+UV Spectrometer/IR Camera
Phase III: Gradiometer
Venus final orbit, May 2033
Checkout & Commissioning, 2 weeks
Extended
Phase
We would like to thank FFG and ESA for organising the Alpbach Summer School and
the post-Alpbach week. We would also like to thank our supervisors from the postAlpbach week Günther Gargl, Richard Ghail, Manuela Unterberger and Olivier Baur.
Thanks for your attention!!
back to main menu
The team:
Agata Białek, Anthony Donohoe, María Fernández-Jiménez, Barbara Frasl,
Antonio Gurciullo, Andreas Kleinschneider, Robert-Jan Koopmans, Anna Losiak,
Thurid Mannel, Iñigo Muñoz Elorza, Daniel Nilsson, Marta Oliveira, Paul Magnus
Sørensen-Clark, Ryan Timoney, Iris van Zelst
Explanation about the balloon.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
For measurements that need to take place in the atmosphere a so called phase
change double aeroshell balloon will be used. The working fluids are water and
helium. By means of evaporation and condensation of water the buoyancy of the
balloon can be changed. In this way the altitude of the balloon can be varied.
The altitude of the balloon will vary between
40 and 60 km and gradually drift to one of
the poles as a consequence of the prevailing
wind direction.
The balloon is made of Teflon-Mylar-Vectran
layers which is capable of surviving the harh
atmosphere of Venus. A full-scale test has
already successfully been performed16.
During a two-week test the He leakage was
zero and the Teflon outer layer showed
exellent resistance against sulfuric acid.
16
K. Baines et al., 5th International Interplanetary Probe Workshop (2007)
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
The entry probe consists of a:

front and back shell for protection during
descent into the atmosphere

parachute system for decelaration

balloon, including gondola, aeroshell and
tanks for helium and water

S/C adapter
For entering Venus’ atmosphere the balloon
and payload is stowed away in a protective
shell. The front and back shell have a carbon
phenolic thermal protection layer, which can
withstand heat fluxes up to 300 MW/m2. A
maximum deceleration of 60 g is expected.
At 70 km the front shell will be seperated and
the back shell will act as a drogue chute, which
pulls the main parachute. The balloon will start
inflating. Once finished, the parachute and He
tank will be released.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Once fully inflated, a 4.5 m boom will be released to which the magnetometers
are fixed as well as the atmospheric sounding module. This means that only one
instrument at the time can be switched on to avoid interference.
The diameter of the He balloon will be 4.1 m and of the inner balloon containing
H2O vapour 1.05 m. The structure has an estimated mass of 213 kg.
The expected atmospheric temperature will vary between -30 and +130°C. For
an acceptable temperature of the payload the gondola uses a passive thermal
control system consisting of MLI enclosure and surface finish.
The overall power consumption of the balloon will be 104 W of which 70 W is
dedicated to the payload. Power will be provided by four Lithium-Monofluoride
batteries and one Lithium-Suphur Dioxide battery.
Communication between the balloon and the orbiter will be provided by UHFband; similar to the Venera landers17. For this two 0.12 m UHF antennas will be
used.
17
M. Keldysh, Icarus 30(4) (1977) 605-625
Explanation about the orbiter.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
A schematic view of the orbiter is shown below. Main drivers of the orbiter design
are:
 the high solar flux around Venus combined with a high albedo of Venus’
atmosphere
 the large power and data rate requirements for the SAR
 high stability for accurate gravity gradient measurements
3m Steerable X-Band Antenna
Mounted Solar Panels
Radiator Panel
Fairing Interface Mount
Balloon Re-entry Module
500N Apogee Motor
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
The solar flux around Venus is about 2.6 kW/m2. It’s albedo is 0.8 and via IR
radiation another 0.15 kW/m2 is added. The worst-case incoming heat flux is
estimated to be 2.8 kW/m2. This requires passive as well as active thermal control
systems to ensure that the temperature of the payload and subsystems stays within
the operational limits.
MLI
Passive thermal control is provided by:
 MLI consisting of 23 layers of Kapton
 high-reflectivity coating on exposed surfaces
(CryoSat-2 heritage)
Active thermal control is provided by:
 2 x 8 m2 of radiators for cooling of the satellite
 16 heater lines to keep temperature within limits
during eclipse
Radiators with the louvers
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
An X-band High Gain Antenna (HGA) sends the science data gathered by the orbiter
as well as the balloon back to Earth. As the SAR produces a large amount of data a 3
m steerable dish antenna will be used. In addition, when the orbiter is close to Earth
an S-band Medium Gain Antenna (MGA) will be used wenn the HGA cannot be pointed
accurately enough and no high data rate is required. The 35 m dishes of ESA’s Deep
Space Antennas are selected as groundstation.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Including margins the orbiter is expected to require about 1.3 kW of power. This is
provided by:
 3 m2 of body mounted Ga-Ar solar panels assuming an efficiency of 0.2
 2 batteries, Lithium-Thionyl Chloride


moderate lifetime < 4 hours
170-440 Wh/kg
The solar panels are body mounted as depoyable solar panels would introduce
vibrations to the orbiter. This would have a detrimental effect on the measurements
performed by the gradiometer.
The orbiter dry mass is roughly 1500 kg.
Explanation about how to get there.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Launch from Kourou by Ariane 5 and entry into Ground Transfer Orbit by
launcher on December 2032. The estimated total launch mass (orbiter, balloon
and propellant) is 4100 kg.
Launch window: 25/2/2032 to 22/9/2033
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
ΔV1
Earth
orbit
Hohmann transfer to Venus sphere of
influence in a hyperbolic trajectory.
Hohmann
transfer
RV
ΔV2
RE
Initially, the satellite satellite will be
injected into an elliptical orbit during
which the balloon will be released.
Due to the elliptic orbit, the balloon
will be visible for the orbiter for the
largest part for the largest part of the
orbit.
The required Δv = 2.7 km/s and will
be provided by a 500 N MMH-NTO
apogee kick motor.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
After the balloon phase the orbiter will go into a circular orbit. To save fuel this will
be achieved by using the atmosphere of Venus to lower the apoapsis.
To ensure that the orbiter does not enter the atmosphere a Δv of 1 m/s applied at
the periapsis is required.
The procedure has successfully been applied to Venus Express.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Key orbital parameters:
Altitude:
Eccentricity:
Orbital period:
Inclination:
Repeat pattern:
Maintenance Δv:
250 km
0
92 min
85°
every 2 Venus days
10 m/s per year
Explanation about the mission timeline.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Launch,
December 2032
Hohmann transfer,
117 days
Aerobreaking,
20 days
Balloon Checkout, 10 days
Balloon Release
Balloon Phase, 25 days
Venus final orbit,
May 2033
5 years
operation
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
A dedicated balloon phase at the beginning of the mission
significantly reduces the required amount of propellant.
Balloon Release, April 2033
25 days balloon mission
Balloon Phase A
Magnetometer, Nephelometer, Stereo & Meteo Station
End
of balloon
mission
25 days
Balloon Phase B
Mass Spectrometer
2.1 days
Mass spectrometer most important,
therefore at the beginning of balloon mission.
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Balloon Phase A
Magnetometer, Nephelometer, Stereo & Meteo Station
25 days
55
45
35
0
50
100
150
200
250
300
350
400
450
500
550
time (hours)
Balloon Phase B
Mass Spectrometer
2.1 days
65
60
altitude (km)
altitude (km)
65
Sampling point for mass spectrometer
55
50
45
40
35
0
10
20
30
time (hours)
40
50
600
1. Main – 2. Summary – 3. Venus – 4. Payload – 5. Balloon – 6. Orbiter – 7. Transfer – 8. Timeline
Balloon Release, April 2033
Aerobraking, May 2033
5 years mission
Orbiter
Phase I
Orbiter
Phase II
Orbiter
Phase III
Orbiter
Phase II
25 days
4 Venus day
1 Venus day
2 Venus day
Balloon
Phase
25 days
Phase I: IR+UV Spectrometer/IR Camera
Phase II: SAR, IR+UV Spectrometer/IR Camera
Phase III: Gradiometer
Venus final orbit, May 2033
Checkout & Commissioning, 2 weeks
Extended
Phase