NASA faces dearth of mission leaders

When NASA invites proposals in 2013 for its next round of low-cost planetary missions, ideas are sure to be plentiful — but not the leaders crucial to the missions' success. That's the conclusion of a demographic analysis that shows that the number of highly qualified principal investigators (PIs) willing or able to take the driver's seat in NASA's Discovery-class missions is dwindling.

"We have to recognize that this is coming and this is a problem," says Susan Niebur, who presented her analysis on 21 June at an international conference on low-cost missions at Johns Hopkins University's Applied Physics Laboratory in Laurel, Maryland. As a cohort of former PIs nears retirement age, Niebur worries that burn out, budget overruns and missed launch windows will be the result if NASA doesn't find a way to get younger scientists the experience they need to step up into mission-leading roles.

Niebur first encountered the dilemma between 2003 and 2006, when she was the NASA official charged with running the fiercely competitive Discovery programme — the small, scientist-led planetary probes that are often the most innovative in NASA's repertoire. At that time, she says, she kept getting proposals "from the same guys".

Not that they were unqualified. On the contrary, they were precisely the sort of scientists NASA wanted in charge of spacecraft worth hundreds of millions of dollars — people who knew their science but had also dirtied their hands with instrument hardware and experienced the headaches of building a spacecraft. The problem was that there were so few of them — and they were getting older.

Now an independent consultant based in Silver Spring, Maryland, Niebur has been tracking the situation and says that it is getting worse. By 2015, when the winning proposal is chosen, there will be only 14 potential PIs aged 65 and under who have previously been PIs, deputy PIs or project scientists (see 'Planetary shortfall'). This means that many of the roughly 30 proposals that the Discovery programme attracts at every round will be coming from relative rookies.
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Would a New Nuclear Plant Fare Better than Fukushima?

For a world that was on the brink of a major expansion in nuclear power, a key question raised by the Fukushima Daiichi crisis is this: Would brand-new reactors have fared better in the power outage that triggered dangerous overheating at one of Japan's oldest power plants?

The answer seems to be: Not necessarily.

The nuclear industry has developed reactors that rely on so-called "passive safety" systems that could address the turn of events that occurred in Japan—the loss of power to pump water crucial to cooling radioactive fuel and spent fuel. But these designs are being deployed in only four of the 65 plants under construction worldwide. (Four reactors that are in the site-preparation phase and still awaiting regulatory approval in Georgia and South Carolina in the United States would make that eight of 69 plants.)

The vast majority of plants under construction around the world, 47 in all, are considered Generation II reactor designs—the same 1970s vintage as Fukushima Daiichi, and without integrated passive safety systems.

Nuclear plant operators are quick to point out that even if passive safety was not integrated into reactor design at the outset, these and other improvements have been added to existing reactors or to blueprints for ones under construction. For example, at the San Onofre Nuclear Generation Station on the southern California coast, modifications have been made that allow the operators to use a gravity-driven system to circulate the water to cool down the plant for a period of time upon loss of power, according to the Nuclear Energy Institute (NEI), a U.S. industry trade group.

But there are limits to such retrofits. "This is a huge volume of water," says Adrian Heymer, executive director of strategic programs for the NEI. "What happens to that tank in an earthquake?" That's why there's been an effort to integrate a fully passive system from the get-go of the design process, he said.

There is no ready reference list of which plants around the world have been modified with gravity-driven or other safety features. And as for new nuclear plants with integrated passive safety systems, deployment is slow. Nuclear plants require long lead times to gain government approval, obtain financing, and complete planning and construction—making them an anomaly in a world accustomed to lighting-fast changes in technology. In many cases, nuclear plants today are being built with much of the basic technology developed three or four decades ago.
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