Project:HackSat One

File:Hacksat1-mission-patch.png

See https://flux.org.uk/projects/hacksat/ for latest info. Dev board should be going to board house imminently. Flux will update the wiki shortly.

HackSat1 will be a sprite: a tiny independent satellite. It's due to launch in 2013 as part of the KickSat swarm. The primary goal of the project is to receive signals from HackSat1 at a ground station in the London Hackspace, Hoxton. In the longer term we hope to design and launch our own hardware.

All the sprites in the KickSat swarm will have the same hardware design. So focus is on the software and ground station. Speak to Flux if you're interested in getting involved.

Current Activities

• Messing around with a TI LaunchPad and learning the basics of MSP430. See also MSP430 Mac Howto.
• Working out the payload
• Working out what's needed for Hoxton Space Centre (ground station)

Sprite Hardware

We don't get to design the hardware on this mission, just program it. The current KickSat code is available on GitHub. Development of HackSat specific code is due to being summer 2012.

• MSP430 controller: CC430F6137 (16-Bit Ultra-Low-Power MCU, 32KB Flash, 4KB RAM, CC1101 Radio, AES-128, 12Bit ADC, USCI, LCD driver)
• sensors: temperature + one other TBC (KickSat are taking suggestions)
  • According to a kickstarter update, the latest dev boards have a magnetometer and a gyro onboard. No mention of the temperature sensor. (The MCU has a temperature sensor build-in)
• radio: we can transmit what and when we like (subject to solar power) but data rate is only a few bits per second
  • Signals cannot be sent to the sprite: communication is strictly one way (from sprite to ground station)

"For sensors, basically they have to be packaged in a tiny SMT chip and not use too much power (no more than a few mW). We don't have a list yet, but one example of something that would work is this magnetometer: http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Sensors/Magneto/HMC5883L-FDS.pdf"

The Launch

July 2013 on Space X Falcon 9 rocket as part of ELaNa 5 / CRS 3.

The Orbit

"While we don't know the orbit, we're aiming for a circular low altitude LEO - around 300 km. altitude. That would mean a roughly 90 minute orbit with several daylight passes per day (usually 3 or 4 over any given location). Each pass would be somewhere around 5 minutes long."

At that (low) a height - the orbit repeat cycle would really matter quite a bit; i.e. how many days before it passes within line of sight of a given ground station; and is there enough power to survive across such cycles; or if not - is there enough to be 'on' when doing an overpass (in daylight). The basic concept that as it circles earth in a bit over 90 minutes; each pass is a couple of degrees westward (on the illuminated side of earth usually) - returning to roughly the same orbit after a couple of days/weeks. Key is then having (had) enough power to charge any batteries to be able to power up the transmitter (and generally not having enough time/power to establish position - so you need to do this a lot - in a hit and run mode looking for the elusive ground station and then offload your wares quickly -- within the 10's of seconds you have (left).

B.t.w. "Criteria and Trade-offs for LEO Orbit Design" in IEEE Xplore has a pretty good overview.

Useful Resources

• Tracking satellites with an Arduino
• Building a Distributed Satellite Ground Station Network - A Call To Arms

Mission patch created by Nick Cramp.