The Falcon 9 launch that would place Cubesats in orbit and bring a cargo vessel to ISS from last monday was scrubbed due to a leaking helium stage. Therefor KickSAT with the Sprite satellites was also not launched. The launch is postponed until Friday 18 april 2014.
Tomorrow 22-03-2014 there will be a FUNcube-1 (AO-73) Continuous Transponder Test.
FUNcube-1 (AO-73) will be commanded into continuous transponder mode for one or two orbits so we can assess the effect of lower power being radiated by the sat on the battery temperature. We expect the satellite to be put into full time transponder mode (aka amateur mode) during the first morning pass on Saturday, March 22 over the UK, at approximately 0930 UTC.
Please upload as many telemetry frames as possible so the group can analyze the effect on the battery.
Below the Orbitron pass prediction for Western Europe based on CEST (UTC+1)
Time zone : UTC +1:00
Search period : 03-22-2014 00:00:00 - 1 days
03-22-2014 24:00:00
Time Satellite Azm Elv Mag Range S.Azm S.Elv
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03-22-2014 10:31:06 AO-73 90.8 20.1 ? 1406 138.6 31.5
03-22-2014 12:07:53 AO-73 289.9 50.9 ? 764 167.1 38.4
03-22-2014 13:43:20 AO-73 310.5 8.6 ? 2075 197.5 37.8
03-22-2014 19:58:15 AO-73 45.7 6.0 ? 2387 284.4 -10.1
03-22-2014 21:33:29 AO-73 65.6 34.0 ecl 1077 305.0 -23.5
03-22-2014 23:09:55 AO-73 263.9 34.1 ecl 1078 330.1 -33.6
The largest ever launch of 437 MHz satellites is planned for March 16 at 0841 UTC when 200 Sprite satellites will fly on the SpaceX Falcon 9 CRS 3 mission to be deployed into a 325×315 km 51.5 degree inclination orbit. You should be able to watch the launch live on NASA TV.
A Sprite is a tiny, 3.5 by 3.5 cm, single-board spacecraft that was developed by Zac Manchester KD2BHC. Among those involved in the early days of the project was UK radio amateur Michael Johnson M0MJJ. While a visiting scientist at Cornell University he was the first project manager designing the mission and KickStarter campaign.
Each Sprite has a microcontroller, radio, and solar cells and is capable of carrying single-chip sensors, such as thermometers, magnetometers, gyroscopes, and accelerometers.
The 200 Sprites are carried in a 3U CubeSat called KickSat. They are stacked atop a spring-loaded pusher and secured by a nichrome burn wire system.
On reaching orbit KickSat will perform a de-tumble maneuver and establish communication with Cornell University’s ground station. After check-out, the spacecraft will be put in a sun-pointing attitude and spun up to maintain that attitude.
A command signal from the ground station will then trigger the deployment and the Sprites will be released as free-flying spacecraft. After deployment, telemetry and sensor measurements from the individual Sprites will be received through Cornell’s ground station in Ithaca, NY, as well as several other amateur ground stations around the world.
Due to the low orbit Sprites will have a short lifetime before they reenter the atmosphere and burn up. In the best-case scenario the orbital lifetime could be six weeks but realistically it may be considerably shorter depending on atmospheric conditions.
All Sprites operate on a single frequency of 437.240 MHz and use Code Division Multiple Access (CDMA). The transmitter runs 10 mW output of Minimum Shift Keying (MSK) modulated binary data with each data bit modulated as a 511 bit Pseudo-Random Number (PRN) sequence.
The ITU emission designator is 50K0G1D.
The KickSat CubeSat has downlinks on 437.505 MHz and 2401-2436.2 MHz.
Despite earlier messages there are no signals received from Delfi-n3Xt. It seems that the signals that where believed to be Delfi-n3XT where signals from Delfi-C3. Below a message I received from Jasper PC4JB.
Unfortunately, we have not heard anything from Delfi-n3Xt since Thursday 20/02 after our transponder test. During the transponder test we could hear our side beacon at 145.870 MHz and we were still able to switch back to normal transmission an back to transponder again (and also received the beacon the second time). Nothing seemed to be wrong, except for the transponder itself not properly working. The satellite was supposed to return to nominal operations in the next orbit.
We think that a hardware failure occurred either at the second half of the transponder orbit or during the mode switch. Since Friday we have made many attempts to revive the satellite. Since we have an independent radio, there was (and still is some) hope to get the satellite back in transmission. There are however a few points were common mode failures could occur: the phasing circuitry which connects both transmitters and an I2C buffer at the main bus side. We do however still have some hope that only one radio has failed and that we might still be able to command the satellite to use the other. Since all trivial command schemes did not work, next week we will only focus on a specific test to turn the transmitter on for a brief moment. During the weekend we saw some narrow band signal at 10 kHz below 145.870 MHz (+/- Doppler), which might potentially be related to the local oscillator. If we can reconstruct this a few times and clearly correlate this to Delfi-n3Xt (we do have a lot of intermitting noises sources in the neighborhood) we at least know the OBC and one radio is still working and we can commence to next steps.
We appreciate everyone’s help to listen to Delfi-n3Xt to see if there is still some signal left. I think the best changes (besides Delft passes in which we try to command) are when the satellite comes just out of eclipse and is supposed to startup one of the transmitters. Please note that it has become very crowded with CubeSats lately, so any signals which are off in frequency (except for the -10 kHz tone), have a very different bandwidth and/or Doppler shift are very likely to be other satellites in the neighborhood. Today we had for instance Delfi-C3 almost perfectly aligned sending at the same frequency. Delfi-n3Xt will only transmit at about 145.870 MHz.
[PE0SAT Thanks Delfi-n3XT ground station for the above information]