WEEKLY WHINE

Why space

Earlier this week, we at SEDS received an E/mail message from Eric in Hong Kong, who asked about the potential benefits of space exploration. Here's a response that I sent him.

Subject: Space Exploration
Date: Fri 20 Nov 1998 19:14:54 -0800 (PST)
From: Nathan Brown
To: "Tsang Kong Chau, Eric"
CC: seds@its.caltech.edu

Hi Eric,

First, let me thank you for finding us on the great wide clump of fluff that we call the Internet. It's great to see that we're making friends on the other side of the planet!

Anyway, there are several merits of space exploration. Some have more value than others, and in most cases, people will disagree about how much value each reason has, but regardless, their sum is a substantial argument.

[1] "Because we can".

This argument is analogous to the old argument in favor of climbing a mountain: Because it's there. Space is there, and we're able to explore it, so why shouldn't we? Recently, opinion has shifted; people, especially politicians, seem to say that we shouldn't because it's too expensive. However, given that NASA receives not even 1% of the USA's annual budget, this isn't a problem. Fortunately, there are many other reasons.

[2] Knowledge about the Solar System.

One of the major goals of NASA and all the other space agencies is to find facts about the various bodies that make up the Solar System. To this end, a seemingly endless series of unmanned probes has been sent into interplanetary space. The most ambitious of recent missions has been Cassini [http://www.jpl.nasa.gov/cassini/], launched on 13 Oct 1997. It's currently on its way to Saturn, sixth planet from the Sun and known for its distinctive ring system. When it reaches Saturn in 2004, it will study these rings, as well as the planet's magnetic field and moons. In addition, it will drop the Huygens probe, which will plummet through the atmosphere of Titan, Saturn's largest moon.

Most information gathered about other bodies in the Solar System is also applicable to our own planet. For instance, we're all trying to prevent Earth from being enveloped in greenhouse gases that turn the surface into a pressure cooker. Venus, however, has already succumbed to this effect, so if we are able to determine how it happened to Venus, we should be able to project whether the same thing will happen to Earth, and if so, how we can prevent it.

[3] Direct Observation of Earth

At first, this seems perplexing: why would we study Earth by leaving it? As it turns out, though, this is probably the best way to study Earth. NASA's earth science project [http://www.earth.nasa.gov/] was the first confirmation of the holes in Earth's ozone layer, protecting us from cancer-promoting ultraviolet radiation. Now that we are aware of the danger, most nations have signed a treaty that reduces emissions of CFCs, which are a major cause of ozone depletion. Similarly, changes in ocean temperatures are useful in long-range weather forecasting -- last year's El Nino weather was projected and tracked using oceanic satellites.

[4] Astronomy

The best way to study space is to go there. Even though we can't yet launch probes to the most distant reaches of the Universe, we can turn our telescopes upon faraway galaxies. Of course, the most publicized of such ventures has been the Hubble Space Telescope [http://oposite.stsci.edu/], which has yielded images depicting star formation, evidence for supermassive black holes, and the Hubble Deep Field image that shows more faint galaxies than we could ever guess existed.

[5] Communication

Communication satellites allow us to link remote locations as though they were right next door. In fact, you probably reached our site through a geosynchronous satellite, one that orbits in phase with Earth's rotation. That satellite would transmit data from the Internet's US infrastructure to the mainframe links on the other side of the Pacific. Such satellites can also be used to transmit other forms of information, including television images and pager commands. Satellites also play a key role in the Global Positioning System [GPS], which allows anyone with suitable equipment to calculate precise location on Earth's surface - information that is now being integrated in automobiles so that they help drivers find their way anywhere.

[6] Transportation

Although the Space Shuttle is a rapid and economic method for reaching space, it's not practical enough for ordinary civilians. However, we are approaching the point at which we'll be able to take "space planes" that can fly halfway across the globe within a few short hours; in addition, like Heywood Floyd in Arthur C Clarke's "2001 : A Space Odyssey", there is the potential of reaching orbiting space stations and lunar bases. Perhaps in the far future, colonization of space will be useful for effectively increasing Earth's surface area, allowing further population increases.

[7] More

In addition, there is always the potential for seemingly unrelated advances that reach the private sector. Because of space exploration, we now have Tang, Velcro, hand-held vacuum cleaners, reliable weather forecasting, quartz clocks, faster computers, low resistance metal alloys, and many other items. It's hard to tell what will come down the line, but whatever it is, many of us will be waiting in earnest.

I hope all of this answers your question, and I hope you find all of it interesting. If you've got further questions, feel free to respond to <seds@its.caltech.edu>. It's great to hear from you, and have a wonderful day!

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Nathan Brown, SEDS Excomm
<goober@seds.caltech.edu>

http://www.its.caltech.edu/~seds/
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