MakerSat

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Creator:
Spacefelix
Status:
In Planning
Born On:
14:03, 28 July 2010 (CDT)
Last Updated:
11:32, 19 November 2010 (CDT)

Overview

This page is for the MakerSat project. Makers Local 256's spaceflight effort to put a satellite in space. In collaboration with HAL5's Project HALO.

Calendar

To Dos

  1. Ask Bill Brown on recommendations for broadcast frequency and power. Last we spoke on 9/2/2010, he recommended a frequency of 900 mHz and 1 Watt. Let's confirm this with him.
  2. High-Altitude Balloon test flight of a radio tracker to determine required broadcast range and reception capability.

Status

  • 11/13/2010 - Discussion with Makers Local 256 members on satellite construction and design. Got recommendations on design for satellite electronics for signal broadcasting and power. Have developed an inital concept for the satellite.
  • 10/16/2010 - Spacefelix spoke to some guys at PhreakNIC 14 about building a space-capable satellite. Strick referred to his friend Charlie ([1]), who works with satellites. He gave recommendations on how to harden against vibration, radiation and thermal extremes.
  • 9/3/2010 - Discussed with Makers Local 256 members on satellite concepts. Came up with bird tracker concept from CrashCart.
  • 9/2/2010 - Discussed with Bill Brown about transmitting from space and recieving on ground.
  • 7/19/2010 - Bendersgame and Spacefelix discussed some setups for operating a CubeSat. Bendersgame will also try to contact the Indian Space Research Organization (ISRO) for information on the cost of launching cubesats since they have a history doing so. Bendersgame also made the recommendation that we start this project with the TubeSat option since we can gain design, build and fly experience on the cheap before we try the more expensive CubeSat.
  • 6/2010 - Have gathered information and resources on satellite and launch options and costs (monetary and technical).

Current Concepts

  • Goal - To put a satellite in orbit for a period of time per the N-Prize Rules. It will be a simple Broadcast Satellite.
  • Current Satellite Configuration:
    • Small analog or digital transmitter broadcasting a circularily polarized signal over two dipole antennas 90-degrees out of phase from each other. It will broadcast intermittently to save power. It will store power onboard in a supercapacitor or battery and will be powered either by a battery, solar power or electromagnetic induction due to flight through the Earth's magnetic field. The entire unit will be potted in high-temperature epoxy to protect it from vibrations, temperature extremes and radiation. A polyethylene coating may be added for additional radiation protection.
  • Current Mission:
    • Broadcast - Broadcast custom pre-recorded signals over Ham Radio frequencies so anyone can tune in to our flight. <- This is the simplest and lowest-cost mission. We will have our first hackersat fly this one.
  • Notes:

Old Concepts

  • Old Satellite Options:
    • TubeSat - Will be in a decaying LEO (Low Earth Orbit). It will only stay up for a couple of months. But it will only cost $8,000 to buy kit and launch. The best option for us to start out and learn about satellites and spaceflight.
    • CubeSat - Will be in LEO for an indefinite period of time. Cost to build and launch can be up to $50,000. Due to high cost, it would be beneficial to get sponsorships and have other hackerspaces come on board and contribute. We could part out space and mass slots in the satellite for the other spaces to build and integrate their own projects. The option for more capacity, capability and mission duration.
  • Former Suggested Missions:
    • Real-Time Imaging From Space - Webcast a live real-time video or pictures from the satellite. Give an Overview Effect.
    • Biological Payload - Something akin to an EcoSphere or other biological specimens. Would need a way to remotely observe them. Potential science project collaboration.
    • Time/Data Capsule - Put up a record of something that a future spacefarer may find and decode to understand our culture.

Challenges

  • Technical
    • Launch Environment - Heating due to supersonic flight through the atmosphere, g-loads of ascent and manuevering, vibration of vehicle.
      • Pot the electronics by encasing them in epoxy, especially the electrical connections. The thermal protection for the space environment ought to be sufficient to take supersonic flight heating.
    • Space Environment - Cosmic radiation, space debris, temperature extremes between light and shadow (temperature difference of up to 275 degF). Shielding, radiation and temperature hardening and thermal control will be important.
      • Most vulnerable parts to cosmic radiation would be the microprocessors. Hardened/milspec versions of chips and parts recommended. Will be able to take temperature extremes and radiation. Is it also possible to use a polymer that has a high atomic density for radiation sheilding such as polyethylene.
      • Will need to test in high-radiation and extreme temperature environments. Ratmandu and HAL5's Project HALO have access to high and low-temperature ovens. Alternatively from [User:Preauxphoto|Preauxphoto], we can use dry ice or liquid nitrogen. Bill Brown also recommends high-altitude balloon flights to test gear in radiation.
    • Satellite Attitude Control - Launch vehicle and satellite ascent and flight dynamics could induce undesired motion in the satellite by the time it reaches orbit. This would make broadcasting a signal difficult.
      • The signal can be circularily polarized and broadcast over two 1/4-wavelength dipole antennas out of phase by 90 degrees so that signal will be broadcast in all directions. Therefore the satellite is indifferent to tumbling and orientation.
    • Tracking/Transmitting From Space & Ground Reception
      • Directional vs. Omnidirectional transmission - Directional broadcasting requires less power, but will require the satellite to hold a specific attitude with respect to the Earth's horizon. The omnidirectional broadcast will require more power, but no specific attitude required.
      • Broken Trace had the idea of broadcasting to the AMSAT/OSCAR ham radio communications satellites. This would be a distance of 1000-800 nm sat-to-sat. Would be possible with omnidirectional broadcasting.
      • Bill Brown recommends that we broadcast sideways rather than straight down to make signal acquisition easier. Most ground-based HAM towers side transmit and recieve. Also, due to the speed of the satellite, a straight down connection will be hard to achieve since it will only see a point straight down for a very short time. Side transmission gives more time to connect and recieve from the satellite. He also is able to provide a high-gain antenna array on the ground for tracking. The approximate maximum distance we will be transmitting over is 100 nm sat-to-ground. He recommends high-altitude balloon flights as a means to test broadcast range to ground stations, satellites, etc.. As a balloon flight would put us above 99% of the Earth's atmosphere, atmospheric attenuation would be mostly accounted for in such a test. To test this further, we can manually attenuate the signal from the satellite to see how low the power can be before our communication elements can't pick it up. It would also allow for testing what orientations give the best signal pickup for various tracking methods.
      • Observing the specifications of Sputnik 1, they broadcast their signal at a power of 1 Watt and at 20.005 and 40.002 MHz. Ratmandu stated that the lower the frequency, the lower the power required to broadcast over a given distance under given conditions. This would assist with reducing the power requirement and therefore mass of the satellite.
      • If all else fails, make a huge radar target (right angle radar reflector) from aluminized mylar that could be inflated like a balloon. Ask organization and people who operate space radars if they can track it. May be difficult to obtain, therefore radio tracking would be preferable.
      • Visual tracking is not a very viable option due to the very specific positions (during dusk or dawn) in which a satellite is visible.
    • Space and Weight Limitations - Projects must be lightweight, compact and must consume minimal resources. Bare-bones parts and architectures a must.
      • Mog stated that the simplest thing we can do is all-analog architechture. Confirmed by Ratmandu, a specific signal as well as timing could be hardwired in such an architechture. On the other hand, a digital architechture would have more capability, but may increase weight and power needed.
      • Reduce Power Usage - Use energy harvesting from solar power or induction off the Earth's magnetic field (we are going to be moving 8 km/s through the Earth's magnetic field) to eliminate the weight of batteries and/or have intermittent broadcasts to save power. Strages recommends the use of supercapacitors as an alternative to batteries for energy storage. It would also be possible to operate intermittently to save power.
    • Long-Distance Troubleshooting - Once it's up there, you can't fix it. You must make it robust and/or allow for remote troubleshooting.
  • Financial
    • High Cost of Spaceflight - Achieving orbit on a 1g planet with an atmosphere is a wonder in of itself given the energy required. Getting to orbit on a barely-controlled explosion is always expensive. Therefore, partnerships with people who work with small satellites on the amature level (AMSAT, an amature radio club and a local University CubeSat group) and sponsorships are a must.
      • If there is space on the satellite to put up something (a special object or data), we could charge people/groups to have a slot on the satellite. An example would be if we had a digital architechture for the broadcaster, it could contain custom messages from various people/groups.

People

Resources

TubeSat

CubeSat

Hardware

Etc.

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