SEDSAT-2 Payload Selection Study
From SEDSWiki
Contents |
Primary Payloads
Earth imaging
This solution got baselined following the vote at Protoforge.
This idea has been recommended by the Payload team as a possible primary or secondary
payload for SEDSAT-2. Reason: Getting photos of the Earth does not seem like a very ambitious undertaking, yet
produce a nice result.
Pro: Modest requirements. Con: Relies on attitude control to a certain extent.
Purpose: To take visible-wavelength photos of the Earth.
Conclusion
Earth imaging is a viable mission. It can be done almost regardless of focal length and camera resolution - even attitude control is not really necessary, provided spin/tumble rate is not extreme. Instead any attitude control can be exploited to decide what to take pictures of, while the optics can be engineered to specifications to get the most interesting/useful results attainable within the resource budget.
SWOT - Analysis:
| Strenghts | Weaknesses |
|---|---|
| - modest requirements - presentable output for media - further usages derivable
| - Relies on attitude control to a certain extent
- will not surprise general public ("yet another earth-picture-taker group") - has been done by other CubeSat groups |
| Opportunities | Threats |
| - we could manage to increase quality and resolution - possibility to modify image spectrum | - possible malfunction because of radiation (?) |
Questions arising:
- Can we create something radically more sophisticated than previous missions had?
- Can we demonstrate something special with our photos? (eg weather phenomena?)
Rating:
- scientific usefullness: medium
- public relations and media attention: medium
- success probability (estimate the risk of non-working systems): high
- innovativeness: low-medium
- educational benefit for our team members: high
- procurement complexity: medium
Using a PAL-lens for imaging and ADS
This solution did NOT get baselined in the vote at Protoforge.
This idea has been recommended by the Payload team as a possible primary or secondary payload
for SEDSAT-2. Reason: PAL photos could be interesting compared to ordinary photos because of
their 360 degree view. Could be used for attitude determination at some extra processing cost.
Pro: Novel images. Con: Requires moving parts.
PAL - Conclusion
Since the PAL lens must protrude the outer casing of the CubeSat because of it's FOV, and since nothing may protrude the CubeSat before 15 minutes after POD deployment - moving parts are required. The PAL system could be a good addition to ADS, together with providing us panoramic views. Because of it's FOV, we would be able to capture different objects, like the sun, moon and other planets.
SWOT - Analysis:
| Strenghts | Weaknesses |
|---|---|
| - Innovative and little known approach - Good for PR | - System requires moving parts - The inner areas of the image has lower resolutions - Relatively heavy lens |
| Opportunities | Threats |
| - The PAL system can be used for ADS - System can deliver panorama images - Can be used to look at different objects | - Complexity increases general risk of malfunction. - Will require onboard processing for ADS |
Questions arising: ...
Rating:
- Scientific usefullness: High
- Public relations and media attention: High
- Success probability (estimate the risk of non-working systems): Low-Medium
- Innovativeness: High
- Educational benefit for our team members: High
- Procurement complexity: High
Comments:
I belong to system team. Some time ago I was working with 360x360 pictures. There are some technologies to make this kind of photos but one of the easiest is using two fisheye lenses focused to opposite sides. We should analyze if we could find some so tiny lenses for this purpose.
>>Some people have been asking what a PAL image would look like:
example of an image taken using a PAL lens
Secondary Payloads
Thermal Imaging
This idea has been recommended by the Payload team as a possible secondary payload for SEDSAT-2. Reason: Getting infrared images could possibly be done using the primary imaging device without alteration (if supported). Pro: Modest requirements. Con: Focus will not be optimal.
Purpose: To observe the earth through the infra-red spectrum.
Conclusion
This is a feasible concept, it would not be a complex module to implement, it would also be suitable due to the fact that it would not use any more mass or weigth than an any other cmos chip.
SWOT Analysis
| Strenghts | Weaknesses |
|---|---|
| ... | ... |
| Opportunities | Threats |
| ... | ... |
Rating:
- scientific usefullness: (low, medium, high) - public relations and media attention: (low, medium, high) - success probability (estimate the risk of having non-working systems): (low, medium, high) - innovativeness: (low, medium, high) - educational benefit for our team members: (low, medium, high) - procurement complexity: (low, medium, high)
Deployment Imaging
This idea has been recommended by the Payload team as a possible secondary payload for SEDSAT-2. Reason: Getting photos of the launch vehicle or other cubesats would be cool. Pro: Might be done as a "bonus" without adding much complexity to an Earth imaging payload. Con: Will require use of power before satellite status can be determined.
Purpose: To take visible-wavelength photos shortly after separation from the P-POD.
Conclusion
Successfully photographing the launch vehicle seems plausible. If the camera has a short focal length, giving it a relatively wide field of view, and a picture is taken once a second from 3 to 30 seconds after separation, the yield would in theory be three successfull photos.
SWOT Analysis
| Strenghts | Weaknesses |
|---|---|
| ... | ... |
| Opportunities | Threats |
| ... | ... |
Rating:
- scientific usefullness: (low, medium, high) - public relations and media attention: (low, medium, high) - success probability (estimate the risk of non-working systems): (low, medium, high) - innovativeness: (low, medium, high) - educational benefit for our team members: (low, medium, high) - procurement complexity: (low, medium, high)
Radiation detection
Reason: Radiation detection can be done on a very limited resource budget, and would provide data that might be useful to others. Pro: Modest requirements. Con: Is an entire, extra payload.
Purpose: To measure the radiation exposure of the spacecraft.
This secondary concept should be possible to implement without any major impacts on the primary imaging payload, and does not add a lot to the complexity of the payload system, as long as there is a minimum surplus of power/space to implement the detector circuit. This data might be usefull both to future cubesat missions and to sucessor missions to the SEDSat-2.
SWOT Analysis
| Strenghts | Weaknesses |
|---|---|
| ... | ... |
| Opportunities | Threats |
| ... | ... |
Rating:
- scientific usefullness: (low, medium, high) - public relations and media attention: (low, medium, high) - success probability (estimate the risk of non-working systems): (low, medium, high) - innovativeness: (low, medium, high) - educational benefit for our team members: (low, medium, high) - procurement complexity: (low, medium, high)
Forwarded Payloads
| Payload Selection Study |
|---|
| Baselined primary: Earth imaging |
| Recommended primary: Earth imaging • PAL imaging ("doughnut") |
| Recommended secondary: Deployment imaging • Thermal imaging • Radiation detection |
| Forwarded to other teams: Telecom relay • Electric propulsion • ACS |
| Not recommended: Object imaging • ISS beacons • Radio emission detection • Sun/star imaging • Self-imaging • Video |
| The ideas were evaluated at this meeting The voting took place on Protoforge |
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