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June was a busy month for space travel buffs, especially those who live in the Free World. Here's an omnibus edition covering all of the missions I caught wind of in the papers or the magazines:



(see the rest at Galactic Journey!)
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Two days ago, there were three active satellites—two Vanguards and one Explorer.

Yesterday, there were two: Vanguard 3 has gasped its last beep.

For 84 days, the last of the Vanguards circled the Earth, returning data from its solar X-Ray detectors, its magnetometer, and its micrometeoroid sensors from an orbit higher than that of its dumber, smaller older brother, Vanguard 1.



Did you know that the Sun emits X-Rays? That's what happens when you heat gasses to millions of degrees Kelvin; such temperatures are common in the solar corona, the bright fringe of gas surrounding the sun's disk that one can see during a solar eclipse. The atmosphere absorbs most extraterrestrial X-Rays, so a satellite is needed to gather comprehensive data. Sadly, all of the energetic particles trapped in the Earth's Van Allen Belts swamped Vanguard 3's detectors, and no useful data were obtained.

On the other hand, Vanguard 3's magnetometer did a heck of a job, returning more than 4000 signals, nearly 3000 of which were of high quality. We have never had such a comprehensive map of our planet's magnetic fields, and it is likely that scientists will be studying these results for years to come, learning how these fields interact with the solar wind to cause phenomena from radio storms to aurorae.

Speaking of radio, if you've ever listened to your shortwave, you might have heard "Whistlers"--those enigmatic sound that calls to mind a skyrocket flying overhead or birds chirping or even a flying saucer. Such signals have been heard since radios were invented, and it is now known that they are emitted by lightning and propagated in the ionosphere. Vanguard 3 was able to "tune in" to Whistler emissions with its magnetometer, which allowed scientists to make some estimates of the density of electrons in the ionosphere. Two for one is a good deal!



No micrometeoroids pierced Vanguard 3's hull for the duration of its mission, but that doesn't mean the satellite didn't run into its share of space junk. The first preliminary estimates from returned data suggest that 10,000 tons of space dust crash into the Earth's atmosphere every day. That sounds like a lot, but considering that it is spread out over the entire surface area of the planet, it's a negligible concern to a small satellite.

With the silence of Vanguard 3, the Vanguard program has come to a virtual end (though Vanguard 1 still keeps beeping away). Three successful launches out of eleven seems like a pretty lousy record. Consider this legacy, however: the bonanza of returned data, the comparative inexpensiveness of the program, the first stage being turned into the Vega second stage booster for other rockets, the second and third stages being used on the Atlas Able and the Thor Able rockets, the Vanguard worldwide signal receiving station pioneering space communications. Vanguard surely must count as a raging success. Moreover, Vanguard set an important precedent by showing that rockets can be used for purely civilian purposes as well as for sending weapons of mass destruction across the globe.

If my epitaph is half as laudatory, I shall be a very happy corpse.

Up next—The Twilight Zone and then... Astounding!

Note: I love comments (you can do so anonymously), and I always try to reply.

P.S. Galactic Journey is now a proud member of a constellation of interesting columns. While you're waiting for me to publish my next article, why not give one of them a read!







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A bit of a stop press on the Space Race as I wade through this months Astounding, which I unwisely saved for last. You should never eat dessert first…

Have you ever noticed how a train’s whistle seems to rise in pitch as the locomotive approaches and then the pitch lowers as the train departs? This is caused by the compression of sound waves as they whistle heads toward your ears followed by a decompression as it heads away. It’s called the Doppler Effect (after the 19th century Austrian scientist, Christian Doppler).

This concept will be used by satellites to provide accurate navigation aids for American military craft and, someday, civilians as well. The idea is that the satellites, called Transit, will broadcast at a fixed frequency. A receiver on the ground can tell from the quality of the Doppler frequency shifts, knowing the satellite’s orbit, where it is to within a small degree of error. Very simple in concept.



Sadly, Transit 1 failed to orbit the day-before-yesterday when its Thor Able booster malfunctioned after liftoff. On the other hand, the Navy (the service that developed the satellite) did get some useful data from the sub-orbital flight, I’m told.

Speaking of the Navy, the final flight of the Navy/civilian Vanguard program ended in success yesterday with the orbiting of Vanguard 3. It is another x-ray, magnetosphere, and micrometeoroid detecting probe along the lines of the Explorers. Its long-lasting orbit and conical shape will also allow the satellite to be used to determine the density of the upper atmosphere for decades to come.

I’ll publish more on the scientific findings of this probe as I hear them. We are beyond the days where just getting the things up is the whole story.

And with that, the Vanguard program comes to an end with three successful flights out of 11. This may sound like a poor record, particularly given the rather vicious coverage given the program by both domestic and foreign media (remember “Flopnik”?)



But Vanguard has enabled the reaping of a tremendous harvest. As a booster, it was remarkably efficient and cheap. The reliable second and third stages have been adopted as supplemental stages on other rockets, and it looks like the first stage will be turned into NASA’s new Vega second-stage system. Thanks to Vanguard, there will be American property in space for the next several hundred years.

Most importantly, Vanguard paved the way for a truly civilian space program. Though it was derived from a Navy proposal, and spin-off technology from the program is being used by the military, the idea of a purely scientific and non-military space endeavor is a powerful and important one. Our new space agency, NASA, owes much to it.


---

P.S. Galactic Journey is now a proud member of a constellation of interesting columns. While you're waiting for me to publish my next article, why not give one of them a read!



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