She was a stray mongrel picked up off the streets of Moscow, and her handlers called her by several names before someone in the budding Soviet space program tagged her as Laika. On Halloween of 1957 she was bundled inside Sputnik 2. Three days later—just one month after Sputnik 1 was launched and started the space race—she became the first living creature in history to leave Earth. That distinction was tragically brief because Laika died only a few hours later, apparently from a combination of stress and overheating, but she lasted long enough to suggest that humans, too, might survive weightlessness and find a future in space. In our current celebrations of the Sputnik golden anniversaries, let us also salute the memory of a very good dog.

In the half a century since then, space programs have seen plenty of other epic triumphs and tragedies. For NASA, the past couple of decades have had an “it was the best of times, it was the worst of times” flavor, with fantastic high points such as the Cassini mission to Saturn and the treks of the Mars rovers but also nadirs such as the shocking losses of the Challenger and Columbia space shuttles. The manned space program in particular has often seemed listless, executing missions in support of an international space station whose raison d'tre has grown shabbier every year.

That has begun to change. President George W. Bush set long-term goals in 2004 for returning to the moon and going to Mars; one may question the wisdom of those targets and their financial impact on science (Scientific American certainly has), but it is nonetheless good to see momentum carrying NASA toward something.

The Constellation program's transportation system, including the new Orion vehicle, is planned to make those coming forays in space possible. A team of NASA and Lockheed Martin engineers involved in developing those craft offers a peek at them in “To the Moon and Beyond,” which makes up one half of this month's special report on the future of space exploration, beginning on page 62.

In the other half, “Five Essential Things to Do in Space,” on page 69, staff editor George Musser weighs what NASA and its counterparts in other nations ought to be doing. Out of the limitless possibilities for study in our solar system, what priorities should space scientists set? Readers may agree or disagree with his choices (and we encourage you to send your preferred list to, but consensus is not the point. Attention to setting the right goals is the best way to keep the space program healthy for another 50 years.

There is also no shortage of crucial choices to make here on Earth about how best to protect imperiled nature. Any desirable future for this planet must be conducive to humans along with the rest of the biosphere. But how to achieve that?

Some past Scientific American articles have championed focusing protection efforts on biodiversity “hot spots.” In “Conservation for the People,” on page 50, however, conservationists Peter Kareiva and Michelle Marvier argue that more good—for both nature and people—will come from saving ecosystems that render valuable services to human communities. Perhaps the only way to convince society to invest more in conservation is by showing how much it already has at stake.