The document provides an overview of the ROCKY CubeSat project. The goal is to design and develop a 3U CubeSat to measure lift, drag, magnetic fields, radiation, and GPS performance in low Earth orbit (LEO) and actively control its descent into the atmosphere to maximize time spent in LEO. Key requirements include measuring various phenomena, actively controlling descent from LEO, and including at least one additional science enhancement option. The document outlines subsystem requirements and details partner communications between various universities collaborating on the project. It also discusses relevant past research and technology that could inform project components.

1. ROCKY: RDR BRIEFING
TEAM CD

2. PM
Eric
Powell
LSE
Janelle
Williams
ESTACA
PCE
Nathan
Sandlin
CoC
AE
Qiao
AE
Ricardo
Environment
Austin
Sci Ops
Jeremiah
SCE
Justin
Smith
UTEP
Daniel
Thermal
Andrew
Structure
Hagen
Tuskegee
Khiante”
Team CD

3. ROCKY
Goal: Design and Develop a 3U CubeSat
•Measures lift, drag, magnetic fields, radiation, and GPS Performance in LEO
•Actively controls descent into the atmosphere to maximize duration in LEO
Customer: U.S. Army Space and Missile Defense Command
Process: Agile SE processes

4. Stakeholder: U.S.
Army Space and Missile
Defense Command
Stakeholder
Requirements
for ROCKY
Magnetic
Fields
Lift and Drag
GPS
Performance
in LEO
Radiation
Actively
Controls
Descent into
Atmosphere
from LEO
At lease 1
Science
enhancement
Option

5. REQUIREMENTS
PROJECT
Specifications
● 3U Cubesat < 10kg
DRM:
● 300 km circular orbit @ 28.5°
● 1000 km x 100 km orbit @ 28.5°
● 150 km circular orbit @ 28.5°
Measures:
● Lift & Drag, Magnetic Fields,
Radiation, GPS
Additionally:
● Actively Controls Descent
into Atmosphere from LEO
● At least one science
enhancement option, TBD
FUNCTIONAL
● Sensory
● ADAC
● COMM
● Command and Data
Handling
● Power
● Thermal
● Structural
● Propulsion
ENVIRONMENTAL
● Survivable in LEO Radiation,
magnetic fields and
Temperature fluctuations
● No space debris after 25
years

6. SubSystem Requirements
Thermal
-Thermal subsystem must provide the correct heat distribution across the space craft required
to keep all electrical components within their optimum operation range temperatures.
ADACS
-The attitude determination and control system must perform the duties of stabilizing the space
craft and meet the pointing requirements required by the payload’s mission.
Communications
-Communications must provide reliable communication to a ground station on earth in order to
transmit/receive data and commands.
Structural
-The structural component must provide a secure base for all components to secure to and still
maintain its 3U format size. It must also provide shielding from debris and radiation.

7. Driving Requirements
• Outer structure must be 340.5X100X100 mm
• Must be powered off from time of integration to time of deployment
• CubeSat must have method to constrain deployables
• No pyrotechnics may be used on the CubeSat
• No components can extend past 6.5 mm normal to outer surfaces

8. Requirements-Space Craft
Thermal ADACS Communications Structural Structural (cont’d)
Build materials must adhere to
NASA standards
No pyrotechnics may be used on the
cubeSat
Radio output <= 1.5 at TX antenna input Must have 1 deployment switch on rail
standoff
Rail must have 75% contact with
PPOD rail
Total mass loss <= 1% Propulsion systems must adhere to
AFSPCMAN 91-710 Vol 3.
CubeSat must have 2 independent RF inhibits All parts of structure must remain intact Maximum mass of CubeSat is 10kg
Collected volatile condensable
materials <= .1%
Propulsion systems must have 3 fail
safes to activate system
Operators must be licensed for proper radio
frequencies and have proper documentation
Build materials must adhere to list of
NASA approved materials
CG must be within 2 cm of geometric
center in X and Y direction
Must have battery protection
circuit to prevent cell unbalancing
Must be powered off from time of
integration to time of deployment
Radio systems must adhere to U.S. radio
license agreements and restrictions
Outer structure must be 340.5X100X100
mm
CG must be within 2 cm of geometric
center in Z direction
Thermal vacuum bakeout must
be performed to specs of a
launch provider
Antennas must wait 30 minutes after ejection
from P-POD before deploying
+Z face must be inserted first into PPOD Aluminum 7075, 6061, 5005, 5052
must be used for main structure and
rails.
Radio system cannot generate or transmit
signal from time of integration until 45 mins
after deployment
No components can extend past 6.5 mm
normal to outer surfaces
Rails and standoffs must be hard
anodized aluminum
CubeSat must have method to constrain
deployables
Must perform random vibe test to
specs of the launch provider
Rails must have min width of 8.5 mm,
surface roughness <1.6 mm, and edge
radius of at least 1 mm

9. REQUIREMENT PERTURBATIONS
• Active descent measures will most likely require propulsion
• Sensor suite will require thermal management to stay within its performance
envelope
• Uncertainty factors in measuring lift and drag
• Space debris/Radiation: Any large space debris/radiation could disable/dismember
CubeSat
• External Inertial forces: Excess momentum could overcome the recovery limits of
ADACS system
• Lack of Solar power: Create decreased life cycle for components dependent on
solar power
• Temperature fluctuations: Extreme changes in temperature could cause
flexing/warping

10. CUBESAT SOA TECHNOLOGY
• 2003 AAS Paper on satellite life extension by precision pointing and
orbital maneuvers, i.e. Hohmann Transfer
• 2001 Paper by AIAA on the use of tethers to extend the usable life of
small satellites
• Measuring differential drag by adapting a study by Matthew Horsley

11. PARTNER COMMUNICATION
UTEP TUSKEGEE
None at this
time
ESTACA
None at this
time
College of Charleston
 Contact Established
 Delegation of
responsibilities begun
 integration of personnel
into appropriate
subsystems
 Contact Established
 Rough team structure known
 Research progress update

12. Backup

13. Payload Sensory Subsystem
• Acquires scientific data as well as monitoring the health and progress of the various subsystems of the CubeSat
Instrument Considerations
• the payload sensors subsystem should be light in weight, consume a small amount of power, be high in
sensitivity, and should be able to produce undistorted analog and digital signals
• supplied with required controlling commands from CD&H subsystem
• Output will be transmitted to the ground station through the Communication Subsystem
• Working Closely with the College of Charleston
WBS Definitions

14. Attitude determination and control subsystem
•Measures and controls spacecraft’s angular orientation
•Simplest spacecraft are either uncontrolled or achieve control by passive methods such as spinning or interacting with Earth’s magnetic
or gravity fields
•May or may not use sensors to measure attitude and position
•Capability of attitude control system depends on the number of body axes and appendages to be controlled, control accuracy and
speed of response, maneuvering requirements, and disturbance environment
WBS Definitions cont’d…

15. Command and data handling subsystem
•Distributes command and accumulates, stores, and formats data from spacecraft and payload
•Could be combined with communication to form tracking, telemetry, and command subsystem
•Includes: general processor (computer), data buses, remote interface units, and data storage units
•Data rate and data volume determine size
Power subsystem
•Provides electric power for equipment on spacecraft and payload
•Consists: power source (solar cells, RTG), power storage (battery), power conversion and distribution equipment
•Power needed to operate equipment and power duty cycle determine subsystems’ size
•Must consider power requirements during eclipses and peak power consumption
•Must account for solar cell and battery life limits
•Beginning-of-life (BOL)
•End-of-life (EOL)
WBS Definitions cont’d…

16. WBS Definitions cont’d…
Thermal subsystem
•Controls spacecraft equipment’s temperatures
•Ways
•Passive
•Active
•Passive
•Physical arrangement of equipment
•Thermal insulation and coatings
•Active
•Electrical heaters, high-capacity heat conductors, heat pipes
•Amount of heat dissipation and temperature required for equipment to operate and survive determine size
Structural subsystem
•Carries, supports, and mechanically aligns spacecraft
•equipment
•Cages and protects folded components during boost and
•deploys them in orbit
•Primary structure – load-carrying structure sized by
•Strength needed to carry spacecraft mass through launch accelerations and transient events during launch
•Stiffness needed to avoid dynamic interaction between spacecraft and launch vehicle structures
•Secondary structure – consists of deployables and
•supports for components, designed for compact packaging and convenience of assembly

17. WBS Definitions cont’d…
Propulsion subsystem
• Controls spacecraft orientation
• Actively controls decent with orbital maneuvering
Propulsion types
• Cold Gas - simple and reliable
• MonoPropellant - low thrust, and ineffecient, but reliable
• Resojet - energy demanding
• ION/Hall-effect Thruster - inefficient at small size

18. WBS Definitions cont’d…
Communication Subsystem
•Provides linkage to relay data and send commands
• Information flowing to spacecraft consists of commands and ranging tones
• Information flowing from spacecraft consists of status telemetry, ranging tones, and payload data
• Basics: receiver, transmitter, wide-angle antenna
• Receives and demodulates commands, modulates and transmits telemetry and payload data, and receives and
retransmits range tones
• Data rate, allowable error rate, communication path length, and RF frequency determine size
•Working Closely with UTEP

19. 2003 AAS Paper on satellite life extension by
precision pointing and orbital maneuvers, i.e.
Hohmann Transfer

20. 2001 Paper by AIAA on the use of tethers to
extend the usable life of small satellites

21. Measuring differential drag by adapting
a study by Matthew Horsley