By Bill Arnold â€“ K4IB, June 8, 2013; Edited for web by AK4OL.
Would you like to participate in a first of its kind, Foxhunt in Space? The Foxes are miniature spacecraft, dubbed â€œSpritesâ€ that will be launched into low earth orbit in mid-November 2013 for a limited engagement. Want to find them? . . . .With a few fairly inexpensive parts and rudimentary assembly skills, interested members of AARC can take part in a pioneering experiment in space. Does this grab your attention? If so, read on.
Zac Manchester (KD2BHC) an Aerospace Engineering Graduate Student at Cornell, and his group, chaired by his mentor, Mason Peck, PhD, are preparing to launch several small "KickSat" satellites later this year, piggybacked aboard a SpaceX craft, the prime mission of which is to replenish the International Space Station (see CQ April 2013, pp 74-5). Each KickSat will deploy about 100 solar powered "Sprite Satellites" into low Earth orbit During a recent telephone conversation I had with Zac, he asked us (AARC) to consider joining a growing number of Clubs and Academic Departments who will monitor RF signals transmitted by the satellites.
DETAILS: Each Sprite is a circuit board about the size of two postage stamps, with a mass of 5 grams (that of a U.S. nickel). The board is populated with solar cells, a gyroscope, a magnetometer, a UHF radio transmitter, a micro-controller, a dipole antenna and other components. Individual Sprites will transmit a unique series of characters, usually a few letters, "Like your initials," according to Zac. Currently, three Sprite prototypes are orbiting earth in a Materials Science Experiment Pallet that was mounted on the outside of the ISS in 2011 during the final mission of the Space Shuttle.
All Sprites to be launched this year will transmit a 10mW signal on the same frequency, about 437 MHz. The exact frequency will be determined by the date and time of the launch, so that Zac can coordinate it with the IARU. Signals will be encoded with CDMA technology using PRN spreading codes for unique identification of each Sprite, so that with the proper equipment, ground stations can monitor individual Sprites (see ARRL Handbook 2013 pp 8.15-16). The anticipated life of the Sprites is up to 3 months, although it may be significantly shorter pending the status of the atmosphere.
If you have read this far, you may be interested in building a ground station to monitor the Sprites. The following is a list of components, sent to me by Zac, that when assembled, will be able to carry out this mission.
In Zacâ€™s words,
Here is some info on the ground station stuff:
I’m using this antenna, but basically any yagi will do http://www.arrowantennas.com/arrowii/440-5ii.html
I’m using this Low Noise Amplifier, but again, any decent one will work: http://downeastmicrowave.com/PDF/l-lna.PDF
Here is the USB dongle: http://www.amazon.com/Receiver-RTL2832U-Compatible-Packages-Guaranteed/dp/B009U7WZCA/ref=pd_bxgy_e_img_yor,http://www.nooelec.com/store/software-defined-radio/sdr-receivers/tv28tv2.html#.UYp1_it34ls
It uses a tiny MCX connector, so you’ll probably want an adapter for BNC or
SMA like this one:http://www.amazon.com/Garmin-MCX-BNC-adapter-cable/dp/B0000C5FX5/ref=pd_luc_sbs_02_03_t_lh?ie=UTF8&psc=1
That’s it for the hardware. The software installation info is here:https://github.com/zacinaction/kicksat/wiki/Installing-GNURadio-(Ubuntu)
and here for Windows (less well tested):https://github.com/AndrewBIS/kicksat/wiki/Installing-GNU-Radio-for-Windows-with-Funcube-Dongle
I’m still putting together a full guide. I’ll post on the Kickstarter page when it’s ready.
SELECTED ADDITIONAL REFERENCES:
- 1) Zac Manchesterâ€™s Kickstarter site, devoted to the project, his UPDATES are important: http://www.kickstarter.com/projects/zacinaction/kicksat-your-personal-spacecraft-in-space/
- Excellent article by Mason Peck, PhD about the rationale for creating tiny
- Wikipedia article about Kick Sats http://en.wikipedia.org/wiki/KickSat
- Additional CDMA Details: http://en.wikipedia.org/wiki/Code_division_multiple_access
- BBC News Item:
- Only for those who have read this entire proposal: Many of these references have links to multiple other sources of pertinent information.