I study nuclear science/I love my classes/I got a crazy teacher, he wears dark glasses...
The same concept -- perhaps aside from the loving the classes part -- could be said for NASA's STEREO mission, which is currently expected to launch around the end of August. Its purpose isn't music (if that were the case it would be called the IPOD mission).
Rather STEREO -- whose name stands for Solar Terrestrial Relations Observatory -- is in fact going to be studying nuclear science. And it will need the dark glasses, since most of its attention is going to be focused on Coronal Mass Ejections (CMEs)
CME's, more colloquially known as solar flares or even proton storms, are ginormous explosions on the outer surface of the sun that send billions of tons of high energy particles outward from the sun at millions of miles an hour, toward whatever planets might be in the way. Yet while CMEs have been known to fry the odd satellite and take down the occasional power grid, they pose little hazard to earthlings shielded by earth's atmosphere and its magnetic field.
Space travelers discovering the moon and Mars and beyond won't have those advantages though. As a consequence, CMEs and their cousins, cosmic rays -- which are high speed, high energy particles blasted from more distant stars -- pose a hazard to future travelers. Some have speculated that those particle showers could even be showstoppers for long-term trips to Mars and beyond.
The reason goes to the roots of our DNA. All living creatures are composed of cells, and in addition to being the stuff of heredity (and CSI), DNA can also be thought of as the textbook, or operations manual, for those cells. When cells need something, they go to the proper page, read the instructions and follow them.
But the high energy particles that blast out of our star and others plink away at those words and paragraphs, like an adolescent with a BB gun on the last day of school. Some shots won't hit anything. Others will hit words but leave paragraph meanings intact. Others will alter critical parts of the text, ensuring that lessons likely to be forgotten go unlearned instead. Eventually, the text will turn into tatters.
Like students with tattered textbooks, cells with tattered DNA don't do to well. They typically die or become cancerous. The same would be true of unshielded astronauts who tarry too long in space.
And so NASA scientists are working along several lines to avoid putting the "final" into that frontier.
STEREO will be a part of that solution by providing a greater understanding of CME's, the most proximate hazard. So will a variety of experiments that NASA is running on the ground and at the International Space Station that are designed to better understand those particle poisons and possible antidotes.
Better shields are one sure answer, but building them won't be easy. A recent article in Scientific American (March 2006) observed, "cosmic rays pose irreducible risks and dealing with them involves fundamental trade-offs."
One of the most basic trade-offs is between weight and cost. In theory, the easiest way to protect future travelers would be simply to shield the spacecraft with enough layers of something -- water, plastic, items from the J. Peterman Catalogue -- but the costs of doing so in practice are currently prohibitive (even though the Urban Sombreros are reportedly pretty cheap).
So a variety of other measures are being looked at, many of which involve repulsing the charged particles somehow -- using superconducting magnets, electrostatic tethers, or even plasmas. Each of those possibilities also brings their own basic tradeoffs, and so better biology could be at the heart of the best solution. Scientists have begun to search for ways to better repair ripped DNA, or to trim the amount of tattering done in the first place.
NASA knows what it is looking for, but like the band U-2, it still hasn't found it yet. As Jim Adams, of NASA's Marshall Space Flight Center noted, "Shielding solutions need to: Reduce radiation exposure more than is practical with material shielding, be lightweight, safe, practical, and achievable in time for Mars Missions."
Frontiers are inherently hazardous places, and that NASA is searching for such outward bound antidotes is by itself hopeful. Answers may be found -- they should be -- for the frontier never left, it just lifted.
And one day, when scientists find the proper solution for the particle poisons of outer space, the words of Timbuk 3 will again be true, "The future's so bright, I gotta wear shades."
Charles Rousseaux is Senior Speechwriter for Department of Health and Human Services Secretary Mike Leavitt. The starry-eyed views expressed are his own.