Friday, August 11, 2017

AO-85 SSTV

This has been fairly well communicated across the Satellite community, buy hey, I'm always a bit late to the party :)

From Andrew KO4MA:

With the recent popularity of Slow Scan Television (SSTV) from the
ISS, AMSAT Operations is bringing back Experimenter’s Wednesday to AO-
85.

On a trial basis, we invite users to exchange pictures using Robot
36 SSTV mode via the FM repeater on AO-85 during UTC Wednesdays.
Please identify prior to beginning transmissions, and only send when
the uplink is clear.

Stations are requested to only uplink if they have a reasonable
expectation of maintaining a full-quieting signal for the duration of
the image transmission.

Smaller stations are encouraged to focus on receiving the images.

Please don’t send questionable or provocative images. If in doubt,
pick another one.

Expect all ages to be participating.

Feedback is encouraged, and comments may be directed via email to: ko4ma at amsat dot org.

=====================

This past Wednesday, I did manage to snag a couple of noisy pics... interesting to listen
to the FM QSOs coming in between SSTV images on the pass.







Wednesday, August 09, 2017

Just Another Science Blog: Ham Radio at the South Pole!

Just Another Science Blog: Ham Radio at the South Pole!: As I think I have mentioned, I am involved in amateur or ham radio. My callsign is AI4LX for the those who are interested. It is a hobby I h...

Wednesday, August 02, 2017

A Slovak Satellite

Somewhere in Slovakia, outside of Bratislava, I still have some relatives... common descendants from my grandparent's family's.

Perhaps someone I'm related to, worked on the skCube, who knows? :D

But to listen for this satellite, Robo OM1LD gave some great info:

Watch digipeater mode on telemetry packet COM (DK3WN sw decoder)
If zero than digi is OFF. Any value is ON. Value is a time to end (minutes).
Take Your packet immediately after rx COM packet

AX.25 GMSK 9k6 (g3ruh) UI frame
Unproto CQ
TXdelay 15 to 25 (by the tcvr, short is better)

Uplink and downlink for DIGIMODE is a 437100kHz +/- doppler

swl report and more info
http://www.skcube.sk/skcube/swl-skcube-report/

Digipeater is switch on demand or follow this source.

https://twitter.com/OM3KAA
https://www.facebook.com/OM3KAA/
https://www.qrz.com/lookup OM9SAT

73!
Robo 

... I also went to the skcube web site direct and (with the help of google translate) found this:


First Slovak satellite is great success especially for young researchers: Slovak president
Source: Xinhua| 2017-07-04 21:19:30|Editor: Yurou Liang

BRATISLAVA, July 4 (Xinhua) -- Slovakia's first satellite skCUBE is a remarkable success for the young people who took part in launching and operating it. Slovak President Andrej Kiska announced at a briefing here on Tuesday.

The skCube has successfully operated more than ten days and has fulfilled its tasks.

"It's a great success for the young people who have contributed towards the fact that we have our first satellite. I'm happy, as I heard that we'll have a first Slovak selfie taken by the Slovak satellite - it'll take a picture of Slovakia from above," stressed Kiska.

The skCUBE satellite was launched into space on June 23. It's now orbiting the Earth at 7.8 kilometres per second at an altitude of more than 500 kilometres.

Its mission is to perform various experiments in radio communications, to send back pictures of the Earth, to measure various phenomena in high orbit and the magnetosphere and to test the effects of radiation on its onboard components.

KEY WORDS:Slovak

http://www.skcube.sk/faq/ (via google translate... although slovak is my heritage :) )

Q?
Why did you decide to build a satellite?
A.

Because we love flying into the universe! Astronauts, rockets, satellites - these are, in particular, cutting-edge technology, new insights and a huge adventure of discovering new worlds. In addition, space exploration brings mankind to new technological innovations for everyday life - just remember the GPS satellite navigation you have on your phone. And small and relatively inexpensive CUBESAT satellites present today a very modern direction, often serving to quickly test new technology concepts, such as solar sailboats. In the near future, the Cubes will also fly to the Moon or even to other planets. Would not you like to send something that you own?
Q?
When and how will skCUBE fly into space?
A.

The launch of skCUBE into orbit around the Earth is provided by the Dutch company Innovative Space Logistics. The launch of the satellite has been postponed several times due to the problems of Falcon 9 rocket American SpaceX. The current scheduled start window is set for the second quarter of 2017.
Q?
Is the satellite on the racket alone?
A.

The launch of the rocket that will take place in the space of the skCUBE satellites takes place mainly for the purpose of rendering the large Taiwanese satellite Formosat 5 together with more than 80 smaller satellites from all over the world, including the Slovak skCUBE satellite.
Q?
How long will the satellites run around the Earth?
A.

This is the so-called " "Sun-synchronous orbit," ie a polar run at a height of 450-720 km above the Earth's surface, with a slope of about 98 degrees to the Earth's equator. The satellite on this track enters the Earth about once every 90 minutes, flying at a speed of 28,000 km / h (7.8 km / s). Although this route was determined by the primary customer of the Formosat 5 launch, it is very well suited to the scientific purpose of the first Slovak skCUBE satellite.
Q?
Why does not the spacecraft fall back from Earth?
A.

Basically, it holds inertia in the orbit. As the satellite targets the Earth at a high speed, The first cosmic, moreover in an environment where it does not have to stop it (at a given height of 450-720 km, Earth's atmosphere almost does not exist), the satellite collides with the free fall of the planet below.

You can imagine this too: say you stand on a high tower from which you throw golf balls. If you strike weakly, the ball will fall near the tower. If you hit harder, it will fly further, but eventually it will fall back to the ground. If you continue to increase the speed of the strike (and you do not feel the atmosphere), you would be steadily going further - to the neighboring state, to the suburban continent, until you reach a speed of about 8 km / s when the ball can not fall back - it would get into its own orbit around the planet.

This idea was formulated as the first Sir Isaac Newton in 1728.
Q?
How long will skCUBE be in the universe?
A.

The satellite itself is designed to operate in the universe for about two to three years, although it can last even longer. However, the satellite's internal batteries, which are up to 16 times charged and discharged daily, are probably the first to fail. The number of these charging cycles is limited to about 10,000. After the satellite shuts down, it will continue to ring around the Earth like a dead body. The residual Earth's atmosphere (a few molecules per cubic kilometer) will continue to slow down the satellite very slowly, thereby losing the satellite at its height. In the course of a decade, satellite below 100 km will drop into the more intense layers of Earth's atmosphere, which will naturally worsen as a meteor.
Q?
What are the risks for spacecraft in the universe?
A.

The space over the earth's atmosphere is very cruel. There is a deep vacuum, temperatures are floating from -170 to +125 ° C, and they do not protect you from direct sunlight, including dangerous X-rays or UV rays. But the launch of the rocket itself is not without risk. The satellite must survive the following conditions in the racket:

- Overloading 6 to 8.5 G
- sine vibrations of about 100 Hz,
- Acoustic vibrations of up to 131 dB,
- stochastic shocks and, in particular, shock waves with forces of up to 1000 G (at the time of first missile separation)


If the rocket explode or otherwise does not fail when placed cargo into orbit, where spacecraft survives rough start missiles, become jammed in the discharge container, neupečie her radiation from the sun and misses it or micrometeorite or other piece of space debris, we hopefully expect that the signal capture Some of our ground stations.
Q?
What tasks will skCUBE do in space?
A.

The satellite is designed to contribute in addition to technical and Vedek experiments and popularization of space research in Slovakia. It has multiple experiments. A satellite camera will scan the Earth and we would like to take pictures of Slovakia, respectively. Central Europe. For the general community radio amateurs will be opportunity to tune into the frequency and listen to the broadcast in Morse code. It will also be able to send a satellite to its own report, which followed repeated satellite (degepeater) to