Thursday, May 24, 2012
Source: SPACE.com: All about our solar system, outer space and exploration
Tuesday, May 22, 2012
And you, young Elon; we shall watch your career with great interest.
No, seriously. This is just a teaser-trailer for what SpaceX has in mind. They are already developing the Falcon Heavy, which will carry twice the payload of the Space Shuttle. And they seem to have every intention of beating NASA to Mars. Good for them! I would love to see NASA get out of the cargo industry and be able to focus on deep space exploration. I'll bet NASA would like that, too.
Sunday, May 20, 2012
Saturday, May 19, 2012
For those who were crazy enough to stay up last night for the launch of the SpaceX Falcon 9 and Dragon space capsule, only to have the launch aborted at (literally) the last second, it's reasonable to be a bit disappointed.
But really, this launch scrub is actually an excellent thing. The monitoring computers caught a potential problem and shut down the launch instantaneously. If commercial space travel is going to succeed, this sort of automatic failsafe is absolutely critical. Because the NASA track record of two catastrophic failures out of five operational vehicles is simply not going to work for regular commercial flights with paying passengers.
Let's look at the numbers here. The entire Space Shuttle program from 1981 to 2011 had a total of 135 flights spread between five vehicles, two of which (Challenger, STS-51-L and Columbia, STS-107) ended catastrophically. In other words, 0ne and a half percent of all Space Shuttle missions were lost.
In 2010 the International Civil Aviation Organisation(ICAO) reported a little over 30 million scheduled commercial airline flights worldwide. If commercial airlines had the same failure rate as the Space Shuttle, that would mean 450,000 airline disasters per year, or 1,233 airline disasters per day, or 51 airline disasters per hour. Or put another way, every minute and ten seconds would see another commercial airliner crashing with 100% fatalities.
Put yet another way, assuming an average payload of 130 passengers plus crew per flight (about average for a Boeing 737), that amounts to nearly 60,000,000 fatalities per year as the direct result of commercial airline disasters. Which is just a little less than 1% of the entire population of the planet. So out of every hundred people on the planet, one would die every year in an airline disaster. Probably if this were the case, nobody would ever fly.
The actual number, incidentally, is more like 1,000 fatalities per year, including all non-military fixed-wing aircraft carrying more than six people. As opposed to 24,000 fatalities per year due to lightning strikes. Really, you are 24 times more likely to die from a lightning strike than you are in an airline crash. Those odds are pretty good,
For commercial space travel to ever become popular and commonplace, a safety record much more like that of commercial air travel will need to be established. It seems that SpaceX is making very significant progress in this direction, many kudos to them for this.
Don't worry, Mr. Musk. We'll stay up late again on Tuesday.
Who needs sleep?
I'm going to be following it here-- http://new.livestream.com/spacex/Launch
But it will also be streaming live on NASA TV.
The weather is not looking especially promising here, but I'll be bringing my sextant with me to work just in case.
Saturday, May 12, 2012
However, earlier this week I was practicing some sunlines with my Astra 3b sextant, and I noticed that the large sunspot group AR 1476 was quite visible. Given that any time Venus is visible (even in broad daylight) it is very easy to see its planetary disk with a 4x40 sextant telescope, and given that during the transit Venus will be about 67,000,000 miles closer to earth than it is during apparent aphelion, it should be very easy to observe the transit using a standard marine sextant with its sun filters in place. If you happen to have a 7x35 scope for your sextant, the viewing will be that much better, but this is not at all necessary.
To use your sextant as a solar telescope, zero the index arm, and ensure that the filters are on both the index mirror and the horizon glass. Then, just look directly at the sun through the sextant telescope. Start with too many filters and then start taking them away until you can see the sun as a crisp disk. Do NOT look at sun unfiltered!! Note that the sextant in the graphic above does NOT have adequate filtering to safely look at the sun; it is a costume piece from a steampunk website, not an actual working sextant.
If you happen to live here in Seattle, you may have the added advantage of having the sun further filtered by dense layers of nimbostratus. Because in Seattle, that's how we roll.
Will be posting more about the transit soon, meanwhile there is much information here (click on image then right click and select "view image" to enlarge):