mbed in space

22 Oct 2010

Well, a handful of ARM cores, at least.


This could be replicated without putting your iPhone at risk with an mbed, GPS, and cell phone module.  Maybe you could use a high power XBee module to stream video back to earth in real time rather than have to record it.



22 Oct 2010

That's exactly what I thought when I saw the video via PZ Myers' blog; mbed could do this...

22 Oct 2010

Looks like a fun project!

But, from the datasheet:-

• Throughput data rate (software selectable): 9,600 or 115,200 bps
• RF data rate: 10,000 bps or 125,000 bps

How would one get HDTV down that limited pipe? It's already highly compressed. For 720i MPEG-2 you need 10 to 12MHz, 1080i needs even more. That's probably why they choose to record it. Not to mention the buffetting it got during the ascent, I can't see how you'd get a line of sight transmitter to maintain a link.

22 Oct 2010 . Edited: 22 Oct 2010

(I should first say I have no affiliation with these chaps, but I do admire them, and have met them for chats.)

You can find a lot of practical detail about how to do near-space flights from the Cambridge University CU Spaceflight society. It is a group of undergraduates, who do spaceflight as a hobby, funded by their student loans, with some costs offset by some sponsors.

They have been doing near-space flights for several years, using their own DIY controller cards, an eBay Canon camera running CHDK, and a legal, low power radio system.

I believe it is illegal to fly a powered mobile phone over the UK, so it would need to record and not transmit over the UK.

The CU Spaceflight folks use a very low-power (mW) radio, on a legal waveband. They have have had contact with one of their balloons at 600km, it transmits at about 12 baud (I think), so no video, or even images.

If you dig through the CU Spaceflight Wiki you will find their fully Open Source hardware designs and Open Source Software for their 'flight computers', radio interface, GPS interface, mobile phone interface (they power up the phone when the payloads lands) etc.

You'll also find their software which calculates likely balloon flight path based on wind-speed data retrieved from across the internet, and the payloads continuously broadcast GPS position. There are also a few Google Earth plots of flights.

If you look at the CU Spaceflight Media page you'll see the results of one of their outreach programs. They taught some 'physics of heat' to local school children, then challenged the children to make space suits for small Teddy Bears. The bears were instrumented with temperature sensors, and ascended to over 100,000 feet, above more than 99% of the Earths atmosphere. The Teddy bears were photographed for posterity, instrumented data captured, then retrieved and returned to the school children.

One of the CU Spaceflight projects is to launch a small rocket they are designing and building. The clever part is they will lift their rocket platform on a Helium balloon to approximately 30km, then launch the rocket. The intent is to reach over 100km, i.e. hard space, and probably gain the altitude record over mainland UK. The cost estimate is about £1,000 once perfected. NASA might struggle to arrange meetings to discuss budgeting to review the idea for that level of investment.

I must admit, I am much more impressed and inspired by folks who build hardware and software systems themselves, including software to predict land-fall, and a soft GPS, constrained by European aviation and radio broadcast regulations than someone who uses an off-the shelf phone. But hey, that's just me. It takes all sorts.

I *am* very pleased the father and son did the experiment, and may inspire others to try. I think there is a lot of room for DIY science, technology, engineering and applied maths experimentation and learning using low-cost, modern technology. The microcontroller exemplifying the astoundingly powerful tools we have around us. Faraday, Kelvin, Rutherford, and Turing would be amazed at the facilities a child can access.

I applaud everyone who 'pushes the envelope' and shows us how fabulous the word around us is, with whatever resources they can muster.