Thursday, February 16, 2012

Nasa struggles even as its science missions bring universe into sharper focus


Life is tough these days at NASA, the space agency that can’t launch anyone into space.

It wrestles with basic questions: Where to go? How to get there? When? And for what purpose?

It killed a plan to return to the moon and now is building a jumbo rocket to go to ... well, it’s unclear. Maybe to an asteroid: a rock to be named later.

NASA is betting that private companies will create a commercial taxi for flights to low Earth orbit. In the meantime, NASA astronauts ride on aging Russian rockets that look increasingly creaky. At any given moment, a few Americans are on the international space station, circling the planet every 90 minutes, nearly as anonymous as they are weightless.

But even as NASA goes through this awkward transition in human space flight, the agency has one bright spot: science. NASA’s scientific missions — robotic probes, telescopes, satellites — are bringing Earth, the sun, the solar system and the universe into sharper focus.

Science at NASA is not without serious problems, a fact expected to be reflected in the Obama administration’s budget request Monday.

The James Webb Space Telescope, the successor to the Hubble, has gone far over budget and is still years from launch. The next Mars rover has also experienced cost overruns. As a result, planetary science, one of the divisions within NASA’s science directorate, will suffer a sharp cut under the new Obama budget, according to scientists familiar with the administration’s plans. Scientists expect that NASA will terminate its collaboration on two European-led robotic Mars missions scheduled for later this decade.

The question is: To what extent will future science missions be squeezed, delayed or terminated by the NASA budget crunch? What’s certain is that NASA has managed in recent years to launch a formidable fleet of scientific instruments.

NASA’s internal chart shows 86 missions, involving 96 spacecraft, either in service or preparation. That doesn’t include the two European Mars missions. It does include other international collaborations, and the extended operations of aging spacecraft that have completed their primary mission and are still blinking away.

One probe, New Horizons, is on its way to Pluto. Another, Messenger, has been orbiting Mercury since March. A lunar orbiter launched in 2009 has mapped the moon in unprecedented detail, and two more NASA spacecraft achieved lunar orbit six weeks ago on a mission to study the moon’s gravitational field and interior structure.

NASA’s Juno spacecraft blasted off in August on a five-year mission to Jupiter. The robotic probe Cassini continues to study Saturn, and in a week will make another close pass of the huge moon Titan.

Kepler, a space telescope launched in 2009, has found 61 planets by last count, with many more candidate planets yet to be confirmed. The longer Kepler observes a small patch of deep space, the more likely it is that it will detect a true Earth twin — a planet that’s both Earth-size and in a propitious orbit that puts it in a star’s “habitable zone.”

NASA is eager to see what happens on the morning of Aug. 6, when the $2.5 billion Mars Science Laboratory, launched in November, lands in a crater and dispatches a souped-up rover, Curiosity, to look for signs that Mars was once warm, wet and teeming with Martian life. The laboratory will land on Mars using a never-before-deployed technology called a sky crane.

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