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Cubesats Deployed from ISS

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Friday February 28 at 0730Z, several cubesats were deployed from the International Space station.litsat deploy

Perhaps of most interest to radio amateurs are Lithuania’s first satellites, LituanicaSAT-1 and LitSat-1.

LituanicaSAT-1 carries an FM repeater with a 145.950 MHz uplink and 435.180 MHz downlink, a 9600 baud AX25 packet system with a 145.850 MHz uplink and 437.550 MHz downlink, and a CW beacon on 437.275 MHz. Detailed information may be found at http://www.kosmonautai.lt/en/satellite/  and https://www.facebook.com/Lituanicasat1

LitSat-1 carries a linear transponder of unknown bandwidth and with a reported uplink of 435.180 MHz and downlink of 145.950 MHz, a AX25 packet system with a 437.550 MHz uplink and 145.850 MHz downlink. Limited additional information can be found at https://www.facebook.com/palydovas and http://www.space-lt.eu/journeyof-thefirstlithuanian-satellites74326-1-541.html#apacia .

UAPSAT is Peru’s third satellite, and will transmit AX25 packet telemetry and an audio message on 145.980 MHz. It is unclear whether there will be a two-way capability. Additional information via Google Translate at http://translate.google.com/translate?hl=en&sl=es&u=http://www.uapsat.info/&prev=/search%3Fq%3Duapsat%26client%3Dfirefox-a%26hs%3DGt9%26rls%3Dorg.mozilla:en-US:official

ArduSat-2 and SkyCube are also included in this deployment.

G. Gould Smith, WA4SXM Steps Down from AMSAT Board of Directors, VP-User Services Positions

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Gould, WA4SXM at the AMSAT Booth at Dayton
Gould, WA4SXM at the AMSAT Booth at Dayton 2012.

G. Gould Smith, WA4SXM of Knoxville, TN has resigned as an AMSAT Board of Directors member as well as his position as VP-User Services on the AMSAT Senior Leadership Team.  Gould notified AMSAT President Barry Baines, WD4ASW of his decision via an e-mail that states in part, “It is with deep regret that I must resign my AMSAT positions of BoD member and VP of User Services.  AMSAT has played a major part in my life over the last 25 years; the incredible people have made it such a great pleasure.”

Gould has persevered despite chronic health issues, but  recent severe medical issues have precluded him from active participation in AMSAT for some time.  Gould noted, “I had hoped that I would be able to contribute this year, but that hasn’t worked out. The organization needs to have contributing people in these positions.”

In his reply to Gould’s notification, Barry responded in part, “I’m sorry to receive your resignation; you have done so much for AMSAT over the years.”

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Update on DELFI-N3XT transponder test

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A follow-up to our previous news on the DELFI-N3XT transponder test was received via e-mail today:

Dear all,

Today we did a first transponder test. We could hear the beacon, but unfortunately did not hear anything back from our calls. Also we were missing the noise floor of the transponder band. Our hypothesis is that our adjustable LO (Si570) which is mixed with the IF band could not be programmed correctly and hence the pass-band goes outside our filtered band (which is a good thing, because we do not want to transmit on illegal frequencies). This LO is adjustable by I2C communication and should be programmed each time at power up (so each time the transponder mode is activated. We will do two attempts more tomorrow at the morning ground passes and even if that doesn’t help we will keep on trying with different settings. If the situation changes I will update you again.

Best regards,

Jasper, PC4JB

DELFI-N3XT update

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delfi-n3xtThe following update was provided today on the DELFI-N3XT satellite launched in November 2013:

Dear radio amateurs,

It has been a while since we have provided an update, so it is time to brief you again.

Delfi-n3Xt Status

The satellite is doing fine and is in healthy shape. We are now almost 3 months in orbit and have fulfilled a major part of the primary mission objectives. This means that we are close to a mission success. This does not mean that everything works flawlessly as there are several subsystems with issues. Given the amount of payloads and new technologies, I can only say that this was to be expected and accounted for in the mission. Delfi satellites are developing platforms and Delfi-n3Xt is an in-orbit test facility. The good thing is that issues encountered are not even a final verdict on the subsystems performance. The attitude determination and control subsystem currently is hampered by a high magnetic noise, but might still be tweaked and tune to see if we can get it to work properly. This however takes some time, so we are glad that the satellite seems to be in healthy state and we can take more time to experiment with it.

DUDe

We are still working on an improved version of DUDe to tackle several issues which we and many of you have discovered and reported. Unfortunately, many of these issues are more difficult to tackle than anticipated and will still take a while before we can release a new solid version of DUDe. One of the main issues is the fact that the software freezes after receiving noise for some time, meaning that DUDe needs to be restarted each time. Attached is a version of DUDe with a dirty fix which resets the PLL every minute. The penalty is that a 1 or 2 frames are lost each minute, so the performance is less than version 5.1. It is however much more convenient for automated ground stations (like our own) and therefore we decided to release this version.

Transponder

We are going to test the transponder functionality of Delfi-n3Xt this week. I have to be honest that this functionality was implemented last minute on the satellite and was only tested briefly in a non-representative setup. I therefore estimate the chance that it will work at 50/50.

Our first test series will be:

Thursday 20-02-2014 at about 10:50 UTC

Friday 21-02-2014 at about 9:50 UTC

Friday 21-02-2014 at about 11:25 UTC

After a few initial tests, and provided that it works, you are free to use the transponder for communication. We will leave it in this mode for the remainder of the sunlit part of the orbit, so only in Europe and Africa it is possible to use this mode for now. If successful we will turn on the transponder more often and for longer periods of time such that everyone can enjoy it.

(Editor’s note : Downlink 145.880 -145.920MHz, Uplink 435.530-435.570MHz, Telemetry on 145.870MHz and 145.930MHz and a high speed downlink on 2405.00MHz)

S-band Transmitter

There seems to be a problem on the S-band transmitter causing the current protection to kick in occasionally. Maybe this is due to charging or some other effect, as the board is not protected by The Onboard Computer leaves the transmitter off after several attempts as part of an internal safety mechanism. We can still turn on the S-band transmitter through telecommand, but this will only last for a few passes. Most cases the S-band transmitter will thus be off and it reporting that we have turned it might not be very effective since it might be off again by the time you read the message. If you are still interested to try and receive the beacon signal of the S-band, please check the regular telemetry in DUDe under ‘Status’à’Satellite Status’à ‘Subsystem Status STX’ to see if it is actually on.

J. (Jasper) Bouwmeester, MSc.

Delfi Nanosatellite Program Manager &

Researcher Small Satellite Technology

Chair of Space Systems Engineering

Delft University of Technology