CubeSat Deorbit DeviceFinal Report

MAE 435Fall 2013

435 Team Members

Sahil Dhali Christopher Quarles

Michael Foch Brockton Baskette

Kyle Wade Cian Branco

Advisor: Dr. Robert Ash, P.E.

Introduction

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

Overview

De-orbit Device Project is multidepartment effort between the Mechanical and Electrical Engineering Departments

MAE 435 Group’s goal to build the prototype

Team Gantt Chart

Benzoic Acid

Sublimation at room temperature

Inflation Requirements

Sounding Rocket Altitude: 160kms.

Pressure for sublimation@160kms: 1.42*10-6

Temperature for sublimation@160kms: -41’C

Large Vacuum Chamber

Difficulties

Unknown leak in large vacuum chamber

Extensive man hours spent troubleshooting and brainstorming solutions

Ultimately had to resort to using small vacuum chamber

Small Vacuum Chamber

Small Chamber Cont.

The small chamber reaches minimum pressure around 3 minutes

Preliminary Heating Element

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.

Preliminary Heating Element Cont.

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.

Pros/Cons

Materials readily available Inexpensive Easy to modify design

Difficult to control heat output Power runs out quickly Requires Direct Contact

New Heating Element: E-Cigarette

• 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

Our E-Cig Heating Element

Fig 1

Fig 2Fig 3

• 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.

Pros/Cons of Using E-Cig Atomiser

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

Conclusion: Heating Element 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.

Final Steps

Design remote activation for heating element

Fit all the parts together for one final test before launch.

ODU Satellite Ground Station

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.

Balloon Airbrake

Material - Aluminized Mylar for its strength and reflectivity. (DuPont Films)

Target Cross-sectional area – 1 m2

The inflation medium will be benzoic acid.

Constraints

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

Mylar Inflatable Status

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 Storage

Benzoic acid stored in a washer with a screen.

Epoxied (cold welded) to inflatable.

Located on the inner surface of balloon.

Inflatable Prep

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

Inflatable Prep

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.

Balloon Chamber

Provides a pressurized zone to house the balloon.

Contains a valve mounted in the bottom surface. Current prototype does not account for

camera mounting

Chamber Testing

Single layer of Kapton failed.

Punctured by sharp corners of chamber cap

Chamber Testing Cont.

More Testing

5 mil Mylar holds pressure with 2 gaskets

There are multiple points of deformation in membrane

Remaining Challenges

Mounting doors on pins

Locking mechanism to keep the doors closed

Conclusion

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?

Questions? Comments? Concerns?

Thank you!