MUSIC: "Our World" theme
This week on "Our World" ... smallpox protection from long-ago vaccinations ... the current state of electric cars ... and unraveling the secret of long-distance animal migration...
LOHMANN: "It just seems impossible that they're able to enter the sea and all by themselves swim around the Atlantic Ocean and then eventually come back to the place where they started out."
Those stories and more, including some words of wisdom from this year's Nobel laureates.
I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."
NASA says next year's scheduled Mars mission will be delayed two years because of some stubborn technical issues, including problems with a motor on a next-generation rover.
The Mars Science Laboratory is designed to see if Mars might now - or in the past - have conditions favorable for life.
NASA Administrator Michael Griffin broke the news to reporters in Washington.
GRIFFIN: "Despite the delay, work on the mission really is progressing well, with the exception of the motor problem, which we just do not yet adequately understand. But we've determined that trying for '09 would require us to assume too much risk, more than, I think, is appropriate for a flagship mission like Mars Science Laboratory."
The NASA chief said that the problems could probably be resolved in a few months, but because of the relative orbits of Earth and Mars, the next favorable launch date won't be until 2011.
The two-year delay will add $400 million to the cost of the mission, bringing it to around $2 billion.
Although smallpox was eradicated in 1977, health officials remain worried that smallpox could be used as a biological weapon. Smallpox vaccinations were halted decades ago, but a new study reports that, should the virus re-emerge, those who had previously been vaccinated should still retain much of their immunity. VOA's Rosanne Skirble reports.
SKIRBLE: Researchers analyzed 50 years of blood chemistry data from 246 participants in the on-going Baltimore Longitudinal Study on Aging.
TAUB: "And what's really unique about this study is we are not looking at one blood point, like bringing them in and drawing blood. We have blood banked for 50 years where we are able to look at two, four, six, eight different time points for an individual over time to see how, if their immune response has changed at all over time."
SKIRBLE: That's Dennis Taub, acting chief of the laboratory of immunology at the National Institute on Aging. He is lead author of the report, published in the December issue of the American Journal of Medicine.
TAUB: "What we found was that 97 percent of the participants actually retain their immunity and that means that they actually retained a level of antibody that was measurable and based on the literature would be deemed to be protective."
SKIRBLE: Taub says the long-term immunity surprised him.
TAUB: "And that's without any re-exposure, natural exposure to the vaccine or to smallpox. That means the immune system has an incredible ability to retain that memory and to continue producing things over an extended time periods."
SKIRBLE: Immunity remained high without booster shots, even for those participants in their 80s and 90s. Taub says the findings can help public officials better distribute vaccines in the event of an attack.
TAUB: "If you have limited supplies they might be more usefully applied to people who have never been exposed than those who have been vaccinated."
SKIRBLE: The supplies would be targeted at people born after 1972, when vaccination against smallpox was terminated. I'm Rosanne Skirble.
The U.S. state of Hawaii this week signed on to a plan to establish a network of electric-car recharging facilities. The plan is spearheaded by a company called Better Place, which has raised $200 million in private financing.
The company's idea is to develop a network of recharging stations, and provide charging services and the cars themselves for a monthly subscription fee that they say will be equivalent to the monthly cost of gasoline.
Better Place has already announced arrangements with Israel, Denmark, and the carmaker Renault-Nissan.
Major auto companies worldwide see electric cars in their future, and a lot of motorists are driving them today, mostly in the form of gas-electric hybrids.
The industry's U.S. trade group met in Washington this week to focus on some of the technical and policy challenges they face.