Wednesday, March 16, 2011

Soyuz lands

I stayed up to watch the NASA TV coverage of the Soyuz landing last night. Scott Kelly posted this last spacegeo contest yesterday that showed the part of Kazakhstan where they would be landing. Thanks to one of the comments giving the latitude and longitude I was able to study the terrain closely in Google Earth in summer conditions. It's an interesting place; salt flats and sand dunes as well as grass and little mountains. They didn't have video of the landing site or much of what was happening on NASA TV, just the horribly noisy audio with steady heavy breathing. Apparently they don't have automatic mic mixers in the Soyuz. After reentry started they just had reports of telemetry reporting separation. Helicopters reported seeing the drogue chute deploying. All good signs. According to the article on Spaceflight Now today they followed the preferred non-ballistic entry path but still skidded 25 years (sic) dragging their parachute before coming to a full stop.

I wish we could just all go to the MKS system and stick with it. Meters, kilograms, and seconds. And please can we straighten out if we mean years or yards, seconds or meters? I can see mixing up yards and meters, but time and distance seem more fundamentally different. I still can't figure out if the Soyuz really fires the soft landing rockets 1 second off the ground or 1 meter off the ground, which would be much less than a second. I find articles that say at 2 seconds before impact the rockets fire 0.8 meter above the ground and slow it to 1.5 m/s. That just makes no sense. It would go 0.8 meters in less than a second at 1.5 m/s. What happens the other half of the time?

Anyway, it doesn't matter because skidding for 25 *units* dragging the parachute means it didn't take advantage of soft landing rockets in any kind of symmetrical way.

But they made it back intact and I trust they all passed their physicals. Scott Kelly is probably nearly back to Houston already since he was due to fly straight back there after the flight surgeon cleared him. When the rescue crews extracted them from the capsule it was in the 20s, which I assume is degrees F in that article since 20s C wouldn't be so snowy. Texas is nice today, in the 70s. Fahrenheit. So welcome home, CDR Kelly!


  1. MKS? That's a bit old-school isn't it? The rest of the world uses SI.

  2. You're right. SI is the official name of what was originally MKS. I was just being specific that I meant meters, kilograms, and seconds with the implied cadre of amperes, degrees kelvin, candela, and moles. Just not the centimeter, gram, second thing that I still see sometimes and definitely not the inches, pounds, seconds, degrees Fahrenheit they use on the American news. Pounds isn't even mass! It should at least be inches, slugs and seconds but absolutely NOBODY uses slugs. It makes me cringe to hear them describe the size of things on the International Space Station in pounds.

  3. Sorry if I came across as a bit narky, I must have been in a picky mood yesterday.

    Slugs, eh? I always thought that "pounds" was mass and "pounds force" was force. You learn something every day. But I haven't had to deal with imperial units since 1970, when Australia went metric.

    Thanks for an entertaining blog!