Requirements Document
Version 4 (J. Simmons, 10/28/2013 01:29 pm) → Version 5/6 (Jeremy Wright, 01/28/2014 01:42 pm)
h1. Ground Sphere Requirements v0.1
{{toc}}
h2. Technical Requirements
h3. TR 1.1 Enable users to receive "space tweets"
h4. TR 1.1.1 Predict SkyCube flyover opportunities
The *Ground Sphere* will include software which predicts when the SkyCube satellite will flyover the ground station and be within signal reception range
h4. TR 1.1.2 Receive radio signals on 915 MHz
The *Ground Sphere* will receive radio signals on 915 MHz with sufficient gain to enable decoder software to decode the "space tweet" text message
h4. TR 1.1.3 Decode "space tweet" message from SkyCube
Decode BPSK-modulated, unencrypted AX.25 data packets sent at 9600 baud
h4. TR 1.1.4 Account for Doppler shift
The *Ground Sphere* needs to account for Doppler shift during satellite flyovers
h3. TR 1.2 Be easy to assemble from kit components
h4. TR 1.2.1 Time to assemble
The *Ground Sphere* will take no longer than 60 minutes (threshold)/30 minutes (objective) to assemble by an average maker
h4. TR 1.2.2 Tools for assembly
The *Ground Sphere* will only require simple tools (screw drivers, pliers, wrenches, etc) for assembly
h3. TR 1.3 Have low shipping costs for the packaged kit
The *Ground Sphere* kit will cost no more than $15 (threshold)/$7.50 (objective) to ship by ground across the USA.
h3. TR 1.4 Operate using a modern Windows PC
h4. TR 1.4.1 Software must run on Windows
The *Ground Sphere* software must run on Windows 7 or Windows 8 (32bit or 64bit)
h4. TR 1.4.2 Software must be easy to install
The *Ground Sphere* software must ship in a Windows installer
h4. TR 1.4.3 Hardware must connect to PC using standard port(s)
The ground station radio must connect to the ground station computer through a commonly available port (for example: USB)
h3. TR 1.5 Hardware must be robust
The *Ground Sphere* hardware should minimize the opportunity for mechanical failures (from things such as broken connectors or a lack of strain relief)
h2. Project Requirements
h3. PR 1.1 Number to produce
The *Ground Sphere* design must enable the production of at least 30 +/- 5 v1.0 kits by volunteers in one or more makerspaces
h3. PR 2.1 Budget
h4. PR 2.1.1 Unit cost
The materials cost must be under $100 per kit.
h4. PR 2.1.2 Development cost
The project budget (covering three prototypes) must be no more than $500 (threshold)/$400 (objective)
h3. PR 3.1 Timeline
Version 1.0 of the *Ground Sphere* will be ready for kit production no later than Feb Jan 14, 2014. 2013.
{{toc}}
h2. Technical Requirements
h3. TR 1.1 Enable users to receive "space tweets"
h4. TR 1.1.1 Predict SkyCube flyover opportunities
The *Ground Sphere* will include software which predicts when the SkyCube satellite will flyover the ground station and be within signal reception range
h4. TR 1.1.2 Receive radio signals on 915 MHz
The *Ground Sphere* will receive radio signals on 915 MHz with sufficient gain to enable decoder software to decode the "space tweet" text message
h4. TR 1.1.3 Decode "space tweet" message from SkyCube
Decode BPSK-modulated, unencrypted AX.25 data packets sent at 9600 baud
h4. TR 1.1.4 Account for Doppler shift
The *Ground Sphere* needs to account for Doppler shift during satellite flyovers
h3. TR 1.2 Be easy to assemble from kit components
h4. TR 1.2.1 Time to assemble
The *Ground Sphere* will take no longer than 60 minutes (threshold)/30 minutes (objective) to assemble by an average maker
h4. TR 1.2.2 Tools for assembly
The *Ground Sphere* will only require simple tools (screw drivers, pliers, wrenches, etc) for assembly
h3. TR 1.3 Have low shipping costs for the packaged kit
The *Ground Sphere* kit will cost no more than $15 (threshold)/$7.50 (objective) to ship by ground across the USA.
h3. TR 1.4 Operate using a modern Windows PC
h4. TR 1.4.1 Software must run on Windows
The *Ground Sphere* software must run on Windows 7 or Windows 8 (32bit or 64bit)
h4. TR 1.4.2 Software must be easy to install
The *Ground Sphere* software must ship in a Windows installer
h4. TR 1.4.3 Hardware must connect to PC using standard port(s)
The ground station radio must connect to the ground station computer through a commonly available port (for example: USB)
h3. TR 1.5 Hardware must be robust
The *Ground Sphere* hardware should minimize the opportunity for mechanical failures (from things such as broken connectors or a lack of strain relief)
h2. Project Requirements
h3. PR 1.1 Number to produce
The *Ground Sphere* design must enable the production of at least 30 +/- 5 v1.0 kits by volunteers in one or more makerspaces
h3. PR 2.1 Budget
h4. PR 2.1.1 Unit cost
The materials cost must be under $100 per kit.
h4. PR 2.1.2 Development cost
The project budget (covering three prototypes) must be no more than $500 (threshold)/$400 (objective)
h3. PR 3.1 Timeline
Version 1.0 of the *Ground Sphere* will be ready for kit production no later than Feb Jan 14, 2014. 2013.