NASA PhoneSat
Thric
Posts: 109
So I recently attended a Small Sat Conference in Utah and I was talking to some researchers at the NASA Ames Research Laboratory when they mentioned that they are going to use a propeller up in space on the EDSN project. Apparently they are using it as a data managing hub handling data between the Nexus phone processor, arduino, and radio. Thought people here would appreciate such a neat use of a propeller.
Comments
Amazing. It would be great if there were a little paper or write up on line somewhere.
I wish that the next bird our lot are planning to use has a lot of propeller(ants). It another cheaper inclined orbit ...
Alan
http://www.nasa.gov/directorates/spacetech/small_spacecraft/phonesat.html
No specific mention of the prop. Parallax might be interested in verifying that a prop was actually used and, if it was, how and why it was selected.
There was a discussion of rad hardness in another thread which I can't find now.
Sandy
Van Allen's belt will beat it senseless.
I guess it didn't because the experiment was completed successfully in 2013. I started digging and found out the following:
- According to M.K. Borri's profile on LinkedIn, the PhoneSat electronic design and firmware were developed by him while he worked at NASA.
- Here's the kicker! The prop code he wrote is available in the OBEX! Search for Serial Router.
I remenber there being some discussion of radiation hardness of the prop in another thread but can't find the thread now. I believe the outcome of some testing that was done was that it was surprisingly durable. I believe the reason given had something to do with the feature size.
Sandy
Either my friend was full of it, or the satellites were never exposed to harmful radiation.
For all the talk of radiation in space it seems to be quiet survivable for astronauts over long periods. And quite survivable for the commercial grade laptops and whatever they are taking with them to the space station for example.
I don't see why a Propeller built with "big" semiconductor process technology should be any more susceptible than a lot of other things that have been used up there.
Secondary emissions?
But in this case I'd suspect the entire electronics packages are being heavily shielded.
Rather than just the components?
Because there is no way anything outside our atmosphere "doesn't get exposed".
Apparently not!
Sandy
(to a certain degree.)
Thank you Thric.
The soft error problem in early chips was traced to the presence of an alpha emitting contaminant in the ceramic. I actually went to the International Science Fair in that era by placing radiation sources on my computer's memory chips to try to induce soft errors, and extrapolating that they were surprisingly insensitive to gamma radiation.
M.K.Borri and the NASA stuff was a big inspiration. I switched focus from a stand-alone propforth terminal (which worked but didn't have much room for anything else) to using an android device as terminal and network services, and a linux node for crunchng and storage, for our prop systems. Instead of an arduino, were are planning to use a WiFi router, and we can talk to our props using WiFi or as well as bluetooth.Kind of neat that it can be wireless at both ends, and the whole internet can lie in between. Its not NASA grade, but its still kind of cool.
Wow, I think you have just resolved a decades old mystery for me.
Back in the early 1980's I worked with custom designed mini-computers used as embedded processors for military radar systems. Their memory cards, all of a few K's of 24 bit words or something, all had parity checking. Even a red LED on the card edge to indicate a parity error.
It was explained to me that this was impart designed to catch random errors due to cosmic rays and back ground radiation. I only ever saw those LEDs light up when the memory card was busted though.
Then for years their was much written about ever shrinking transistors and memory cells and how all this radiation was going to cause big problems with "bit rot" and how w all needed error correcting systems in our memory arrays.
Despite the dire warnings, memory density went up my orders of magnitude over the following years and I noticed that most PCs did not have error correcting memory. Also it seemed not to be a problem for anyone.
How could that be? Was then the mystery.
Seems you have at least a partial answer with that alpha emitting ceramic package idea. For sure there are not many ceramic packages around any more.
However did hear a presentation, from Google I think, describing their use of fault tolerant techniques to keep everything running. A major outage was described that was traced to a single bit error in some message that go propagated around the system and how they now apply checksums to everything that is stored or transmitted.
It's all kind of worrying. A single bit change in a document can totally change it's meaning with out the reader ever being aware of it. I don't recall that there are any checksums on a web page for example. Or that email you send. What about pdfs or Word documents etc.