Final Presentation

advertisement
MAE 435
Fall 2013
Sahil Dhali
Christopher Quarles
Michael Foch
Brockton Baskette
Kyle Wade
Cian Branco
Advisor: Dr. Robert Ash, P.E.

Space debris are a serious hazard to
continued Space exploration

Dead CubeSats are hard to track

De-Orbit Device Project aimed at Prototype
for 1U CubeSats

De-orbit Device Project is multidepartment
effort between the Mechanical and Electrical
Engineering Departments

MAE 435 Group’s goal to build the prototype

Sublimation at room temperature

Sounding Rocket Altitude: 160kms.

Pressure for sublimation@160kms: 1.42*10-6

Temperature for sublimation@160kms: -41’C

Unknown leak in large vacuum chamber

Extensive man hours spent troubleshooting
and brainstorming solutions

Ultimately had to resort to using small
vacuum chamber

The small chamber reaches minimum
pressure around 3 minutes

Design required to fit inside small chamber at
minimal cost

Prototype: Steel wire wound around itself in
the shape of a Fermat’s Spiral.

Operates on 4 AA batteries.

The element can achieve temperatures between 60’C to 85’C

The spiral grill was designed to create a flat surface area with as much
contact with the plate holding the benzoic acid.






Materials readily available
Inexpensive
Easy to modify design
Difficult to control heat output
Power runs out quickly
Requires Direct Contact
• Default temperature:65-80 ‘C
• Potentially can go up to 180’C
with appropriate voltage.
• Made of 4 major parts:
• The LED light cover
• The lithium battery
• The Atomizer (heating
element)
• The mouth piece
• Fig 1 shows the mouth of the piece where the
airbrake would be attached with the epoxy.
• Fig 2 shows the top view of the heating
element. The benzoic acid crystal would be
secured on the screen over the heating coil.
• Fig 3 shows the battery pack we used to perform
the experiment. It attches to the bottom of the
element and powers to heat the coil visible in
fig.2.
Fig 3
Fig 1
Fig 2
Extremely light weight; usually Al alloy;…..
Weight Constraint: Check
 Safe and easy to use and store;…..
Storing and lasting Constraint: Check
 Power efficient; Works on a 3.1V – 6.7V to achieve max
heating capabilities;…..
Power Constraint: Check
 Size is significantly smaller than previous design, but needs
to be more compact…..
Space Constraint: Not Check
 Bowl on which acid to be secured cannot hold all the acid
required for complete deployment…..
Container Volume Constraint: Not Check





Meets our temperature requirements, which
was our main concern.
The on board lithium battery should be
enough to power our heater.
This device is powered by a button which has
to be manually pressed
Now all that is needed for the heating
element is a bigger bowl to store the
complete amount of the acid, securing it in
the mylar.

Design remote activation for heating element

Fit all the parts together for one final test
before launch.
Operates mission specific transceivers,
antennas, transmission lines, amplifiers
and digital signal processing.
 Intended to communicate with orbiting
weather satellites and amateur radios to
obtain earth images and current
prevailing weather conditions.
 Designed to receive data from NOAA
weather satellites.
 OUR PURPOSE: Use the SGS to keep
constant communication with our
CubeSat to obtain its position coordinates
and signal to deploy the airbrake on
command.


Material - Aluminized Mylar for its strength
and reflectivity. (DuPont Films)

Target Cross-sectional area – 1 m2

The inflation medium will be benzoic acid.

Benzoic Acid Pressure
 Pmin > 0.1813 Pa (greater than environment @ 90 km)

Partial Pressure of Air
 Ambient air in balloon is to be removed to prevent
premature inflation

Benzoic Acid Placement
 Must absorb enough heat from heating element to
reach sublimation

New material from (Coated Product Sales)
was ideal for sealing.

Rectangular Cross-Section (Pillow shape) was
used.

Cross-sectional area may need to be reduced
due to chamber volume.

Benzoic acid stored in a washer with a screen.

Epoxied (cold welded) to inflatable.

Located on the inner surface of balloon.
 Vacuum Seal-Off Fitting – Oerlikon Leybold
product
▪ Predesigned to seal off during vacuuming, solid heat
conduction, low weight and small profile
▪ Vacuum seal-off fitting was press-fit into the bottom of
chamber
▪ Balloon will be epoxy sealed to the fitting

During removal of ambient air, the material
was sucked into the valve exhaust creating a
seal.

Did not allow for all ambient air to be
evacuated.

Solutions included folding the balloon before
pumping, a pump with a throttle and/or
collapsible stent.

Provides a pressurized zone to house the
balloon.

Contains a valve mounted in the bottom
surface.
 Current prototype does not account for camera
mounting

Single layer of
Kapton failed.

Punctured by
sharp corners of
chamber cap

5 mil Mylar holds
pressure with 2
gaskets

There are multiple
points of
deformation in
membrane

Mounting doors on pins

Locking mechanism to keep the doors closed

Prototype in current state reduces chance for waste

Overall Goal to pass working prototype to current
434 students at end of the semester has been met

Hand-off to occur next week
Questions? Comments? Concerns?
Thank you!
Download