PAYLOAD CONCEPT PROPOSAL
VENUS EXPLORER MISSION
More than Meets the Eye
Prepared by: Guntersville High School
May 2014
Payload Concept Proposal
Venus Explorer Mission
1.0 Introduction
The Venus Fly Traps is a team of six engineering students at Guntersville High School
tasked by UAH with designing a payload to be carried aboard an orbiter designed by a team of
Aerospace Engineer majors attending UAH. The payload of the Venus Fly Traps, “Off Kilter”, is
named after the unique nature of the double vortex hurricanes on the South Pole (which have
eyes that are off kilter with one another). “Off Kilter” will be examining the storm on the North
Pole visually, while onboard the UAH orbiter, before conducting its primary mission. The Venus
Fly Traps have thoughtfully designed three payloads that will be deployed into and investigate
Venus’s very unique South Pole storms.
2.0 Science Objective and Instrumentation
The Venus Fly Traps are going to observe, study, and probe the storms on the North and
South Poles of Venus. The North Pole hurricane on Venus has not previously been studied in
detail, and the unusual off kilter, double-vortex hurricane on the South Pole has puzzled
scientists. As Earth’s atmosphere is becoming more like Venus’s atmosphere (due to greenhouse
effects releasing carbon dioxide into the atmosphere and subsequently insulating it),
understanding how storms behave on Venus could be applicable to Earth in the future. Also,
finding out why these unusual storms occur could reveal to us something previously
undiscovered about Venus.
The position and composition of the North Pole storm, and the temperature, pressure, wind
speed, position, and composition of the South Pole storm will be measured. The North Pole
storm will be measured via the visual spectrometer from the orbiter. The South Pole storms will
be measured by instruments on several payloads delving into the storms. (See Table 1 for the
Science Traceability Matrix (STM) and Table 2 for the Instrument Requirements)
Science Objective
Analysis of North
Storm
Analysis of South
Storm
Table 1. Science Traceability Matrix
Measurement
Measurement
Objective
Requirement
Position and
When orbiter is
composition
located over North
Pole
Temperature,
As payload enters into
pressure, wind speed, the hurricane walls or
and composition
eye
Page ‐ 2 Instrument Selected
Visual Spectrometer
Spectrometer,
accelerometer,
thermocouple, and
pressure transducer
Instrument
Mass
Spectrometer
Accelerometer
Thermocouple
Pressure
Transducer
CPU
HFR
Transmitter
Battery
Payload Concept Proposal
Venus Explorer Mission
Table 2. Instrument Requirements
Power
Raw Data
Mass (kg)
Lifetime(s)
(W)
(Mb)
.230
.92-6.3
<2.4
180
Frequency
Duration
Continuous
180
.105
1.32
.36-144
180
Continuous
180
.002
N/A
<.0009
180
Continuous
180
.145
.04
<5
180
Continuous
180
.094
.04
540
Continuous
540
.085
1.7
360
Continuous
360
540
Continuous
540
.00154
3.0 Payload Design Requirements
The atmosphere of Venus has many obstacles that our payload must overcome. The projectiles must be
able to withstand temperatures ranging from -100 to 200°C, pressures up to 75 PSI, and wind speeds in
the hurricane up to 249mph. The launcher must be able to launch the payloads into the hurricane, and the
payloads must be able to send that information to the Venus Explorer Mission (UAH’s orbiter). Other
than environmental requirements, UAH has provided us with several other requirements we must meet.
The payload will be provided 5 kg of mass, 10 watts of continuous power while attached to spacecraft,
volume of 44x24x28, access to data delivery to Earth, and internal temperature of 294 K while upon the
spacecraft, by the Venus Explorer Mission (VEM). The payload must deploy from the VEM spacecraft
and provide its own power without posing any harm to VEM spacecraft. The payload must survive the
environments of space, the atmospheres of Venus, and the South Pole storm. The payload must be able to
gather data through harsh conditions and send data back to Earth.
4.0 Alternative Concepts
Concept 1
Concept 1 consists of a pneumatic launcher, an onboard visual spectrometer, and three
payloads to be deployed into Venus’s South Pole hurricanes. The payloads will be loaded into a
three barreled pneumatic launcher. The payloads will have flaps to slow the payload, which will
be deployed once in Venus’s atmosphere, and provide for a steady more stable measurement
trajectory. Each payload will have a mass spectrometer, accelerometer, thermocouple, and
pressure transducer within it to collect data on the conditions of Venus’s South Pole hurricanes.
The payloads will also have sustaining equipment such as a battery, CPU, and high frequency
transmitter.
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Venus Explorer Mission
Figure 1. Concept 1
Concept 2
To analyze the entirety of the South Pole storm, Concept 2 consists of a payload
containing two small probes will carry out scientific objectives in the entirety of the walls and
eye of the hurricane. In the upper atmosphere of Venus, the two payloads will detach by helium
propulsion to study the outer walls of the hurricane. The center module will continue its
vertically downward spiral into the eye of the hurricane. Instruments aboard the center module
and probes will be a thermocouple, a mass spectrometer, an accelerometer, and a pressure
transducer. See Figure 2.
Figure 2. Concept 2
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Venus Explorer Mission
5.0 Decision Analysis
Table 3. Payload Decision Analysis
Weight Design 1 FOMs 1, 3, or 9 Raw Score Design 2 Weighted Score Raw Score Weighted Score Science Objective 9 9 81 3 27 Likelihood Project Requirement 9 9 81 9 81 Science Mass Ratio 3 3 9 3 9 Design Complexity 3 3 9 1 3 ConOps Complexity 3 9 27 1 3 Likelihood Mission Success 9 9 81 3 27 Manufacturability 1 9 9 9 9 Accuracy 3 3 9 1 3 Data Acquired 3 3 9 3 9 Durability 9 3 27 9 81 342 252 TOTAL 6.0 Engineering Analysis
Concept 1 was chosen due to its simplicity and therefore low possibility of complication or
failure. The mass of the carbon fiber reinforced plastic payload was determined using a density
of 1,800 kg/m3. The mass of the instruments and battery were included in the total mass.
The orbital velocity of the orbiter was determined using the following equation:
where G = 6.67 * 10-11, M is the mass of Venus (4.867 * 1024 kg), and r is the radius of orbit
(6,282,000 km). The orbital velocity was found to be 7,188 m/s.
The muzzle velocity of the projectile was found using the following formula:
2
where the pressure (P) is 91.6 psi (631,591 Pa), the cross-sectional area (A) is 0.00385 m2, the
mass of the projectile (m) is 0.397 kg, the length of the barrel (d) is 0.4 m, and initial velocity
(vi) is 0. The muzzle velocity was found to be 7,320 m/s.
The terminal velocity of the projectile was found using the following formula:
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Venus Explorer Mission
2
where m is the mass of the projectile (0.397 kg), g is the acceleration of gravity on Venus (8.87
m/s2, is the density of the atmosphere (0.594 kg/m3), Cd is the coefficient of drag (0.295), and
S is the cross-sectional area of the projectile (0.0033 m2). The terminal velocity was found to be
110.4 m/s. This velocity was used to determine the time the projectile is in the storm.
The time in the storm was found using time=distance/velocity, and terminal velocity was
applied. The height of the storm used was 65 km.
The mass of the battery was found based on the power usage of the instruments, which was
found to be 0.616 Watts. The mass was calculated using m(battery) =
∗ /
and was found to be 1.54 g.
7.0 Final Design
The Venus Fly Traps have designed a mission that utilizes a visual spectrometer, tri-barrel
launcher, and three independent payloads. The objective for the Venus Fly Traps is to examine
the unique storms inhabiting the poles of Venus. The Venus Fly Traps plan to accomplish this in
two steps.
First, during the Venus Explorer Mission’s orbiter’s elliptical orbit, aerobraking in the South
Pole and rounding the planet at a great distance while over the North Pole, we will employ the
Venus Explorer Mission’s visual spectrometer to record infrared photos of the North Pole storm
in order to get more information about the hurricane that has previously gone unstudied in detail.
Next, the three independent payloads will depart to examine the South Pole hurricanes of
Venus. The three payloads will be ejected from the orbiter by a pneumatic launcher consisting of
three barrels which will house the separate payloads until they are ready to be launched. When
each payload is an optimal distance from its location its destination, the corresponding valve of
the barrel will release 91.6 psi of pressurized helium, provided by the Venus Explorer Mission.
The barrels will be aimed opposite the direction of the orbiter’s travel and will be parallel with
surface of Venus. After the payload is launched out of the barrel at 91.6 psi, with a muzzle
velocity of 70 m/s, the centripetal force will be reduced enough for the gravity of Venus to pull it
out of orbit and toward the ground. After launch, the payload will fall 170 km at terminal
velocity in the negligible top layers of Venus’s atmosphere. 26 minutes and 45 seconds after the
launch the payload will reach 60 km above Venus’s surface, the point at which Venus’s
atmosphere becomes dense enough to consider drag, which is also where the hurricane begins in
the atmosphere. At this point the payload’s flaps will deploy, due to the collision with the denser
atmosphere, to slow the payload for more accurate measurement and the payload’s instruments
will begin measuring and recording data in order to uncover the mysteries of the very unique
phenomenon. The measuring instruments (mass spectrometer, pressure transducer,
thermocouple, accelerometer) will all continue to measure throughout the duration of the descent
through the storm, which will take 3 minutes. At 40 km above the surface of Venus the hurricane
ends, thus the payload will depart the storm. After exiting the storm the measuring instruments
aboard the payload will cease to measure, at which point all data collected will be transmitted to
the orbiter via high frequency radio transmitter. The sustaining instruments (battery, CPU, HFR
transmitter), which will engage upon entering the storm at 60 km, will continue to function after
exiting the storm in order to transmit all collected data to the orbiter during the remaining 6
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Venus Explorer Mission
minutes of the mission. After the 6 min, at which point all the data has been delivered to the
orbiter, the payload will be grounded and will have completed its objective.
Venus’s South Pole holds two massive interlocking hurricanes in which The Venus Fly Trap’s
intend to probe with three payloads. Each payload has a destination that will yield the most
appropriate data for the mission. Payload A and B will be entering the separate eyes of the
interlocking hurricanes. Payload C will be entering the interlocking walls of the hurricanes.
These destinations have been chosen in order to find the most revealing data about Venus’s
mysterious storms.
.Figure 3. Payload Final Design
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Venus Explorer Mission
Table 4. Final Design Mass Table
Function
Deploy
Measure
Collect Data
Provide Power
Send Data
House/Contain Payload
Mass (kg)
.014
1.446
.282
.00462
.255
.00008658
Table 5. Payload Design Compliance
Requirement
Payload Design
No more than 5 kg of mass
2.00171 kg
Fit within 44cm x 24 cm x 28 cm when stowed
40 cm
Survive environment
Durable Carbon Fiber exterior
No harm to the spacecraft
Independent Payloads
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Venus Explorer Mission
Community Engagement Activity Summary
The Venus Fly Traps held an Engineering Day at Guntersville Middle School to inform the
students of UAH’s and NASA’s effort to provide high school students with the opportunity to
participate in a competition that provides vital experience for college and a career. While at the
middle school The Venus Fly Traps presented a rudimentary run through of the mission and
demonstrated several science experiments corresponding with Venus and astrophysics. We
allowed the students to shoot the T-shirt launcher which demonstrates pneumatic launching. We
also demonstrated what happened when you dropped a Mentos into diet Coke, which
demonstrates the Greenhouse effect and how the carbon that once was in the solids of Venus has
diffused into the atmosphere. Also, we demonstrated orbital centripetal force with a bucket of
water. Lastly, we demonstrated the immense pressure of the Venusian carbon dioxide
atmosphere, by sublimating dry ice in a bottle.
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