SSTV from the ISS…

Well, it’s not pretty, but I was just using a 17″ whip antenna on my VX-8GR, recorded it with Audacity, and then decoded it with MultiScan on my Macbook. The first bit of the recording is pretty rocky, so I had to start the sync myself. I’ve bean meaning to do some experiments with bad audio and sync recovery, now I have more data.

Oh, in case this was all gibberish to you, the Russians have been running “events” from the International Space Station to honor their cosmonauts by transmitting pictures via slow scan television (SSTV). I received this picture using what most people would call a walkie talkie, a whip antenna, and a laptop.

As decoded by Multiscan:


I thought a second image would have begun later in the pass, but didn’t hear it.

I think an antenna with a little more gain, and/or a preamplifier would help a lot. You really need pretty noise free audio to make a good picture. Still, a fun experiment. I might try the 12:30AM pass tonight.

Addendum: The second pass was also a little rocky. Got the tail end of one transmission fairly cleanly, but the three minute gap to the next one meant it was low. This is what I got.

second pass

SpaceX launch wasn’t as smooth and carefree as it might have seemed…

Yesterday was an important day in the history of space flight: for the first time a commercial entity launched a resupply mission to the International Space Station. I thought it was a pretty big deal, but you’d never have known by watching the news yesterday. ABC news cut away from their coverage of politics and baseball just long enough to show a glowing ball heading skyward, with hardly any commentary. I watched the link via streaming video. It was, despite its historic significance, rather boring. A bright light heading to the sky. A bunch of guys sitting in front of a bunch of monitors. It could have been a LAN party. NASA’s own coverage seemed mundane, especially considering how well they did recently in getting us interested in Curiosity.

But it wasn’t as smooth as we might have been lead to believe.

I was apparently not watching closely enough. At about one minute, nineteen seconds into the flight there was a rather bright flash, and clear signs of debris falling from the rocket. Check it out!

In real time, the flash didn’t seem all that serious, but when you see the 1/10x slow motion version, it looks pretty bad: a bright flash, with all sorts of apparent debris shedding. But perhaps we shouldn’t have worried.

Approximately one minute and 19 seconds into last night’s launch, the Falcon 9 rocket detected an anomaly on one first stage engine. Initial data suggests that one of the rocket’s nine Merlin engines, Engine 1, lost pressure suddenly and an engine shutdown command was issued. We know the engine did not explode, because we continued to receive data from it. Panels designed to relieve pressure within the engine bay were ejected to protect the stage and other engines. Our review of flight data indicates that neither the rocket stage nor any of the other eight engines were negatively affected by this event.
SpaceX Mission Update

In other words, despite how it looks, there wasn’t an explosion on board: the shutdown caused a plan ejection of panels. What we see isn’t the problem: it’s the cure. Pretty nifty bit of engineering. Still, I doubt I’m going to be booking my passage on a Dragon flight anytime soon.

Curiosity down safe on Mars!

Today, around 10:31 Pacific Time, Curiosity successfully landed in the Gale crater on the surface of Mars, and has already sent back a couple of small black and white images. Carman and I were watching it on a combination of Nasa TV on our laptops and the CNN coverage. Thrilling stuff. Here are some of the cool tweets that hit my twitter feed, sampled from some net personalities, as well as just ordinary people that I know.

It once was one small step… now it’s six big wheels. Here’s a look at one of them on the soil of Mars #MSL


Curiosity Rover

Hot damn. Humans are awesome when we reach.


Phil Plait

Pretty awesome (for real definitions of awesome) feat achieved tonight. @ @ #MSL


Roy Eltham

Quick, while everyone is excited…pass some goddam funding legislation for space!


Chris Gammell

From the crowd just before entry: “JPL, baby!” After first picture, it’s a mighty roar of “JPL! JPL! JPL!” #Curiosity


Doug Weathers




If they stick the landing, I say put the @ team on a Wheaties box.


Larry O’Brien

The news business should reflect on the fact that I had to tune into NASA for coverage of the most important space mission of recent times.


Dan Gillmor

Apologies, the blackbird plugin that allows me to inject tweets into WordPress seems to be having difficulties. It may just resolve itself, so if you see tweets above, it got fixed.

Awesome stuff. I’ve previously blogged about how the Apollo program was instrumental in fanning the flames of curiosity and discovery in me when I was just five. I’d like to think that there are a bunch of kids, staying up past their bedtime (with the permission of their parents, naturally), who were inspired to learn about science, engineering and mathematics. What would even be more amazing would be for each of us to consider what we really want to achieve not just as a nation, but as a species. In the words of a former Facebook founder:

“The best minds of my generation are thinking about how to make people click ads. That sucks.”
Jeff Hammerbacher

Let’s reach beyond the limits of our own greed, and work to solve the big problems that the world faces: poverty, hunger, pollution, energy, and intolerance. And let’s try to use science and engineering to learn more about our universe and our place in it.

You made me smile, Curiosity.

50th anniversary of Glenn’s orbit aboard Friendship 7

50 years ago today, American astronaut John Glenn completed three orbits of the earth aboard Friendship 7. Glenn would later become Senator, and would return to space aboard the Space Shuttle Discovery as part of the STS-95 crew, becoming the oldest person to fly into space. These three orbits started fifty years of an American presence in space. Salutations to Senator Glenn, and to NASA.

40th Anniversary of Apollo 11 on AO-51

Tonight the amateur satellite AO-51 made an evening pass that was almost directly overhead, and was sending a congratulatory message for Apollo 11, along with a slow scan TV image. I managed to record it, although not the greatest quality, using my little Yaesu VX-3R and my Arrow antenna. Here are links to the recording as well as the four tries at the SSTV image:

July 20th, 6:40PM recording of AO-51 over CM87

Here was the pass as predicted by my Python code (times are in UTC):

  01:39:06  +0.0° 165.4° ? 12.8°N 115.9°W - AOS 696.4
  01:40:00  +3.6° 165.4° ? 16.1°N 116.6°W -     695.9
  01:41:00  +8.3° 165.5° ? 19.7°N 117.4°W -     695.6
  01:42:00 +14.2° 165.4° ? 23.3°N 118.3°W -     695.6
  01:43:00 +22.4° 165.3° ? 27.0°N 119.1°W -     695.8
  01:44:00 +34.9° 165.0° ? 30.6°N 120.1°W -     696.2
  01:45:00 +55.9° 163.8° ? 34.2°N 121.0°W -     696.9
  01:46:00 +88.1°  99.1° ? 37.8°N 122.1°W -     697.8
  01:46:01 +88.2°  80.1° ? 37.8°N 122.1°W - MAX 697.8
  01:47:00 +57.1° 349.6° ? 41.4°N 123.2°W -     698.9
  01:48:00 +35.9° 348.3° ? 45.0°N 124.4°W -     700.3
  01:49:00 +23.3° 348.0° ? 48.5°N 125.7°W -     701.9
  01:50:00 +15.1° 348.0° ? 52.1°N 127.2°W -     703.7
  01:51:00  +9.1° 348.0° ? 55.7°N 129.0°W -     705.8
  01:52:00  +4.4° 348.1° ? 59.2°N 131.0°W -     708.0
  01:53:00  +0.4° 348.3° ? 62.7°N 133.4°W -     710.4
  01:53:06  +0.0° 348.3° ? 63.0°N 133.7°W - LOS 710.7

And here are the resulting SSTV images as decoded with Multiscan under Mac OS X:





Addendum: I played back the recording with some adjusted settings, and got this picture (somewhat better):


40th anniversary of Apollo 11 landing

201px-Apollo_11_insignia40 years ago today, Neil Armstrong and Buzz Aldrin became the first two astronauts to step out on the surface of the moon, as Michael Collins orbited the moon in the Command Module astronauts Armstrong, Aldrin and Collins launched aboard Apollo 11 on their way to the moon.

I was only five at the time, but NASA and the space program had a strong influence on me. Beyond just being captivated by the prospect of being able to travel into space, I was also fascinated in the math, science and engineering that sent rockets into space. I must admit to only dim memories of the event, but I do remember that the 20th was a Sunday, and that we rushed home from church to watch the coverage of the moon landing. I recall being very excited and impressed.
There are lots of great sites on the web. Start with Wikipedia and browse around.
Apollo 11 – Wikipedia, the free encyclopedia

Some basic footage:

NOAA Satellite Frequencies

I haven’t been goofing around much with receiving APT weather satellite data, but I was going to try to record some passes now that the days are longer and we get more daylight passes over North America. But I hadn’t programmed the frequencies into my radio, and was forced to look them up. So, here they are, all in one place, for future reference:

Satellite Frequency
NOAA 15 137.500 Mhz
NOAA 17 137.620 Mhz
NOAA 18 137.100 Mhz
NOAA 19 137.9125 Mhz

Earlier, I blogged about the collision between Iridium 33 and the defunct COSMOS 2251 satellite. Today, I noticed that Celestrak had orbital elements for 134 fragments resulting from the collision. I was curious what the resulting pattern would look like, so I wrote a bit of code to suck them all in and plot them on a map. Here’s what I got for a particular moment around noon local time.


The labeled points are the tracked location of the main body of the satellite. There are orbital elements for 48 additional fragments of Iridium, and 84 additional fragments of COSMOS. The main body of Iridium 33 was at 785km altitude, while Cosmos is down around 771km. Debris is scattered over quite a wide variety of altitudes, from a low of 284km to a high of 1158km.


It was reported that an Iridium satellite and an “non-functional Russian satellite” collided yesterday. I was curious, so I did a bit of digging, and found out that NASA had reported that it was Iridium 33 and COSMOS-2251. A bit more work uncovered orbital elements for both objects, so I was able to plug in their numbers and determine the location of the collision. A bit more of scripting, and I had GMT generate the following map (click to zoom in some more):


According to my calculations, they passed within 100 meters of one another (but my code gives an uncertainty much greater than that.) Each satellite is travelling about 26,900 km/second hour (sorry for the typo, but the math holds). I don’t have the mass numbers for the satellite, but even if you think they are travelling at perfect right angles, each kilogram of the mass generates about 28M joules of energy. According to this page on bird strikes, a major league fastball is about 112 joules, a rifle bullet is about 5,000 joules, and a hand grenade is about 600,000 joules. This collision generated 28M joules per kilogram of mass. Ouch!

Addendum: It’s been a long time since I took basic physics. If you care, you shouldn’t trust my math, you should do it yourself and send me corrections. 🙂