What's better: manned missions to space or robotic probes?

Sunday, January 18, 2009

VASIMR - Variable Specific Impulse Magnetoplasma Rocket. In French it's "Fusée magnétoplasma à impulsion spécifique variable", so perhaps the Occidental term would be "Magnetoplasma-roquette de variabil specific impulse". Or something like that.

That's basically the subject of an article on space.com from yesterday, which makes the point that we should be relying mostly on unmanned missions considering their much lower cost and higher rate of advance than rocketry. The most interesting part has the following numbers:
Let's look at some numbers. Von Braun's V-2 rockets crossed the English Channel at 1 mile per second. NASA's New Horizons mission to Pluto - the fastest spacecraft ever launched - is headed to this erstwhile planet at 10 miles per second. That's an order-of-magnitude improvement after 70 years.

Now consider one component of our remote sensing capabilities - our ability to "see" what we're exploring. The Mariner 4 spacecraft - the first to snap decent photos of Mars - was fitted with a monochrome TV camera having a resolution of 40 thousand pixels. In the summer of 1965, it sailed by the red planet while imaging craters as small as a few miles across.

Today, the HiRISE camera on NASA's Mars Reconnaissance Orbiter boasts a resolution of 200 million pixels (and shoots in color). It can discern items on the surface as small as a horse.

In other words, in seven decades our rockets sped up by a factor of ten, but in little more than half that time our cameras improved by a factor of five thousand. There's no comparison: probe technology is marching to the beat of a faster drummer.
I agree with the article for the most part. Humans have a natural desire for exploration and there's no way that we won't eventually become a capable spacefaring race (assuming no grand calamities that reduce us to a more primitive state), but at the moment the only place that we can travel to in any sort of comfort is LEO, and everything else is a stretch. As I often write here, I don't believe that we're going to really going to want to explore space until we've found a few locations that resemble our own planet, regardless of whether we can get there in the short term. Simply having a location that we can visit if we can just make it all the way there will turn the area closer to Earth into a kind of training ground for that, and then I expect rocket technology to grow at a much faster rate. That is, right now the only use for better rocket technology is lower cost to make it to LEO and shorter travel time for missions, but that will pale in comparison to attempting to advance our propulsive systems in the hope of one day being able to reach another planet somewhat like our own.

The article already has 167 responses below, so there's quite a bit to read there. Think we're wasting our money on manned exploration when we could be getting a lot more done with robots alone?


Anonymous said...

Yes. What really is the point of sending people up other than that it's kind of neat and prestigious?

hater depot said...

Yes. What really is the point of sending people up other than that it's kind of neat and prestigious?

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