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Showing posts with label Space Science. Show all posts
Showing posts with label Space Science. Show all posts

Monday, July 11, 2011

Future of U.S. manned spaceflight looks bleak


When Atlantis takes off from Kennedy Space Center, it will be the last time NASA launches astronauts aboard a government-built spacecraft for perhaps the rest of this decade.
Space shuttle Atlantis astronauts conduct a launch
dress rehearsal at Kennedy Space Center in Florida. |
Red Huber/Orlando Sentinel/MCT


The agency that put Apollo in the history books faces the biggest crisis since its formation in 1958. Plans to replace the shuttle with a government-run rocket are beset by budget and design issues. Attempts to bring commercial-rocket companies into the game are promising but far from certain.

And a country once willing to put 4 cents out of every federal dollar into NASA now spends about half a cent, as America struggles with more-earthbound concerns such as unemployment and health care.

"After a half-century of remarkable progress, a coherent plan for maintaining America's leadership in space exploration is no longer apparent," Apollo astronauts Neil Armstrong, Jim Lovell and Gene Cernan wrote in an op-ed this spring.

The reasons-NASA mismanagement, congressional parochialism and an influential aerospace industry-are not new. These problems have plagued NASA for years, but they're magnified by the end of the 30-year-old shuttle program.

Consider what happened to Constellation, the program President George W. Bush and NASA chose to replace the retiring shuttle and return U.S. astronauts to the moon by 2020.

Its intent was "safe, simple, soon," and the design reflected as much: an Apollo-like capsule atop what amounted to a bigger version of a shuttle booster rocket.

But the project was not either simple or soon. Its problems ranged from cost overruns to technical troubles such as violent shaking of the rocket - and last fall Congress and President Barack Obama canceled Constellation after five years and about $13 billion spent.

The result was nothing new to NASA.

According to an analysis by former NASA official Scott Pace, now at George Washington University, NASA has spent more than $21 billion during the past two decades on space-transportation programs, such as the X-33 space plane and Constellation.

"If you look at the pattern as a whole, it's a failure of leadership," said Pace, who added that the blame lies with administrations going back to Bill Clinton's.

Another space expert, Howard McCurdy of American University, said the constant failures speak to the difficulty of keeping a multiyear program going as Republicans and Democrats-with different budget priorities and industry allies- trade control of the White House.

Between administrations, these things get reconsidered to death," McCurdy said. "We spend our time redesigning the problem rather than building" a space vehicle.

Equally cumbersome is the influence of Congress, where NASA policy is dominated by lawmakers who have a vested interest in protecting their home states and industries.

As part of the deal to cancel Constellation, lawmakers settled on a new rocket intended to protect workers in Texas, Alabama and Florida while helping regular NASA contractors in the aerospace industry.

The new plan all but requires NASA to reuse pieces of the shuttle and Constellation to build a new rocket-benefiting established companies such as Lockheed Martin and Alliant Techsystems while essentially ruling out competition or the use of newer technology.

"You are always going to have that parochial problem," said former U.S. Rep. Bart Gordon, D-Tenn., former chairman of the House science committee. "It's hard to ask someone from Houston or Canaveral to vote against the interests or their constituents ... but you can't let it drive the train, or you wind up undermining the agency."

Under the current direction, NASA will continue building the capsule it aimed to complete under Constellation while flying it on a vehicle that will resemble the current shuttle configuration - minus the planelike orbiter.



But despite this reliance on decades-old technology, NASA has said that the money set aside - $14 billion during the next five years - isn't enough to build a rocket capable of flying to the International Space Station by the 2017 deadline set by Congress.

NASA's budget issues stand in the way.

For example, a presidential commission in 2009 noted that Constellation failed in part because it didn't get the funding it was promised. But NASA also has a long history of busting budgets and deadlines. The Government Accountability Office, a congressional watchdog, has kept the agency on its list of "high-risk" budget violators since 1990.

NASA advocates worry that this track record and increased austerity in Washington mean NASA could get even less money in the future, as tea-party-backed lawmakers push for greater cuts, especially with the shuttle no longer there as a shield to protect the agency's budget from being raided.

The House appropriations subcommittee with oversight of NASA introduced legislation this week that would set NASA's 2012 budget at $16.8 billion - nearly $2 billion less than Obama's request and at least $1 billion less than what NASA has received in recent years.

As it stands, NASA will fly its astronauts to the space station aboard Russian spacecraft until it can develop an alternative - government-run or otherwise.

One scenario, pushed by the Obama administration, would have NASA contract with commercial companies, such as SpaceX and Sierra Nevada, to fly crew and cargo to the station.

But though there have been some early successes - SpaceX in December became the first private company to launch a capsule into space and return it safely to Earth-a commercial company has yet to deliver cargo to the station.

A GAO report this year noted that NASA's commercial-cargo plans are almost two years behind schedule and will cost $300 million more than expected.

The problems aren't lost on NASA Administrator Charles F. Bolden.

In an email to staff last week, he wrote that "some say that our final shuttle mission will mark the end of America's 50 years of dominance in human spaceflight." These critics, he added, "must be living on another planet."

But he offered little to counter those critics, other than: "At NASA, failure is not an option."

A recent poll by the Pew Research Center noted that support for NASA still remains high; nearly 60 percent said it was essential for the U.S. to be a world leader in space exploration.

But these polls over time have reflected support a mile wide and an inch deep, and it remains to be seen how NASA would stack up against other budget priorities.

In Florida, the future of NASA isn't simply a matter of national pride. About 7,000 shuttle workers will lose their jobs once the program ends, and the prospects of many of these positions quickly returning is grim.

Rep. Bill Posey, R-Fla., who represents many Kennedy Space Center workers, attributed the erosion of NASA to public and a lack of leadership in the White House. But like Bolden and others, he has few solutions other than a bill urging NASA to return to the moon by 2022.

"It's something we take for granted, like our freedom," said Posey, who put the onus on Obama to fix the situation. "We need leadership in space. . . . If NASA is going to survive, it's going to need more-spirited outreach to Congress and the public."

Obama largely has stayed above the fray, although he has visited Kennedy Space Center twice during his presidency.

Most recently, in late April, he and his family got a guided tour from Janet Kavandi, a veteran of three shuttle missions. Afterward, Kavandi said the first family was very inquisitive-particularly Obama's daughter Sasha, then 9.

Monday, April 6, 2009

Young Pulsar Shows Its Hand


This graphic demonstrates the difference in physical size between the nebula around the pulsar B1509-58 and its more famous cousin, the Crab Nebula, seen on the left. The Crab was generated when a star collapsed, as seen in 1054 A.D. Since then, the nebula its pulsar created has increased in size to some 10 light years. In contrast, astronomers think the B1509-58 system is about 1,700 years old, yet its nebula now covers some 150 light years. The discrepancy in these sizes may be due to the different environment each pulsar was born into. (Credit: NASA/CXC/SAO/P. Slane et al.)

A small, dense object only twelve miles in diameter is responsible for a beautiful X-ray nebula that spans 150 light years.

At the center of a new image made by NASA's Chandra X-ray Observatory is a very young and powerful pulsar, known as PSR B1509-58, or B1509 for short. The pulsar is a rapidly spinning neutron star which is spewing energy out into the space around it to create complex and intriguing structures, including one that resembles a large cosmic hand.


In the new image, the lowest energy X-rays that Chandra detects are red, the medium range is green, and the most energetic ones are colored blue. Astronomers think that B1509 is about 1,700 years old and is located about 17,000 light years away.


Neutron stars are created when massive stars run out of fuel and collapse. B1509 is spinning completely around almost 7 times every second and is releasing energy into its environment at a prodigious rate -- presumably because it has an intense magnetic field at its surface, estimated to be 15 trillion times stronger than the Earth's magnetic field.


The combination of rapid rotation and ultra-strong magnetic field makes B1509 one of the most powerful electromagnetic generators in the Galaxy. This generator drives an energetic wind of electrons and ions away from the neutron star. As the electrons move through the magnetized nebula, they radiate away their energy and create the elaborate nebula seen by Chandra.


In the innermost regions, a faint circle surrounds the pulsar, and marks the spot where the wind is rapidly decelerated by the slowly expanding nebula. In this way, B1509 shares some striking similarities to the famous Crab Nebula. However B1509's nebula is 15 times wider than the Crab's diameter of 10 light years.


Finger-like structures extend to the north, apparently energizing knots of material in a neighboring gas cloud known as RCW 89. The transfer of energy from the wind to these knots makes them glow brightly in X-rays (orange and red features to the upper right of the image). The temperature in this region appears to vary in a circular pattern around this ring of emission, suggesting that the pulsar may be precessing like a spinning top and sweeping an energizing beam around the gas in RCW 89.


NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass.


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Saturday, January 31, 2009

NASA invites public to choose Hubble's next discovery




To commemorate the international Year of Astronomy, NASA has invited the public to vote for one of six candidate astronomy-related objects for the Hubble Telescope to observe. The options, which Hubble has not previously photographed, range from far-flung galaxies to dying stars. Votes can be cast online March 1 at youdecide.hubblesite.org, and the final images will be released from April 2 to 5.


Thursday, October 16, 2008

Life from Space


Introduction
Growing evidence suggests that life on earth may have been seeded from outer space.


Podcast

Life from Space

Transcript

1. Nucleobases from Space

DNA components from space. I'm Bob Hirshon and this is Science Update.

Life on earth may have been jump-started by a special delivery from outer space. This according to a new report from an international team of scientists.

The researchers identified key chemical components of DNA and RNA—components called nucleobases—in a meteorite that landed in Australia in 1969. Lead author Zita Martins of University College London says nucleobases have been found in other meteorites too, but it wasn't clear how they got there.

Martins:

Our study really proved that in fact they are extraterrestrial.

That's because they contain a heavy isotope of carbon that forms only in outer space. The findings add to a growing body of evidence that the first building blocks of life came from meteorites and comets: an attractive theory, because the primitive earth appears unlikely to have formed them spontaneously. I'm Bob Hirshon for AAAS, the Science Society.

2. Molecular Space Cloud

Seeds of life in space. I'm Bob Hirshon and this is Science Update.

There's growing evidence that life on earth may have started with organic chemicals from outer space. Now, scientists are using the massive Green Bank Telescope to find these molecules in our Milky Way today.

Anthony Remijan of the National Radio Astronomy Observatory says they're studying a rich cloud of gas and dust, like the one that formed our solar system long ago.

Remijan:

There must have been complex organic molecules in that cloud in order to seed the molecular complexity we see in the solar system today. We just haven't had the instruments yet to detect these large molecules until now.

They're surveying the cloud across a wide range of radio frequencies. Then they'll look through the data for distinct radio signatures that are unique to each organic molecule. I'm Bob Hirshon for AAAS, the Science Society.



Making Sense of the Research
How did life arise on earth? It's a question that scientists have asked since the dawn of science. These studies address the very earliest stages of evolution, before actual life even existed.

According to current models, the earth formed about 4.6 billion years ago, and the oldest known fossils are about 3.5 billion years old. Sometime in between—no one knows exactly when—microscopic life began. But before you even get to the origin of life, you have to explain the origin of complex organic chemicals: chemicals that are the building blocks of all living things.

Those chemicals wouldn't have been abundant on a brand-new earth, which had a very different and much simpler chemical composition than today's planet. No one knows for sure what the early earth was like, but evidence suggests that it began as a ball of hot molten rock, surrounded by a thin atmosphere of hydrogen and helium. Later, as the surface cooled, volcanic eruptions would have released heavier gases into the atmosphere, like ammonia, methane, and water vapor.

Some scientists believe that the first building blocks of life, perhaps early forms of the genetic molecules DNA and RNA, were formed by chemical reactions in this early earth environment. Others believe that these molecules came directly from space, by hitching a ride on comets or meteorites that slammed into the planet's surface. There is evidence supporting both sides, but these two studies focus on the second hypothesis, which was once considered far-fetched but has been gaining favor over the past decade.

One reason that many scientists have doubted the life-from-space hypothesis (sometimes called panspermia or exogenesis) is that comets and meteorites burn as they enter the earth's atmosphere. Some scientists have argued that the extreme heat would destroy any organic molecules on the comets or meteorites before they hit the ground. Martins' study, however, claims to have found important organic molecules inside meteorites that could only have come from space, based on the chemical signature of the carbon in those molecules.

While the meteorites Martins studied fell to earth just forty years ago, the findings suggest that the same thing could easily have happened four billion years ago. Furthermore, evidence suggests that the early earth got smacked with meteorites a lot more than today. More meteorites means more chances for those nucleobases to collect on earth in large enough quantities to get life going.

Remijan's work is just getting started, but instead of looking on earth, he'll look in outer space for signs of organic compounds. His team will use a new, powerful radiotelescope to look at a cloud of space dust that resembles the cloud that formed our own solar system. They will base their search on the fact that all molecules emit radio waves as they rotate and vibrate, and that each molecule gives off a distinctive radio signature. By pointing the telescope at the cloud and sifting through these radio frequencies, they should be able to identify the types of chemicals in the cloud. Finding organic molecules in that cloud would lend further support to the idea that life may have been seeded from space.

Now try and answer these questions:
  1. What are two basic explanations for the origin of organic compounds on earth?
  2. Why is it important to explain the origin of these chemicals?
  3. What are nucleobases? How did Martins establish that the nucleobases in the Australian meteorites came from space?
  4. How will Remijan's work add to our understanding of the origin of organic molecules?
  5. What limits our scientific understanding of the origins of life on earth?

Saturday, April 5, 2008

India to launch remote sensing satellite this month


BANGALORE, India (AFP) — India will later this month launch a remote sensing satellite equipped with high-resolution cameras and advanced scientific instruments, space agency officials said here.

Cartosat-2A, as the all-weather, reconnaissance satellite is called, will be used to plan urban and rural development projects. It can also be used for intelligence gathering, the officials said Friday.

"The tentative launch date is April 28," Indian Space Research Organisation chairman G. Madhavan Nair told reporters in Bangalore where the agency is based.

"The exact date and time will be finalised in a fortnight after factoring weather and other relevant data," he added.

Identical to the mapping satellite Cartosat-2, which was launched in January 2007, the 680-kilogram (1,500-pound) Cartosat-2A will be placed in a polar orbit at an altitude of 630 kilometres (391 miles).

The satellite will be launched by the Indian-developed rocket, the Polar Satellite Launch Vehicle, from the Sriharikota space station in southern India.

India started its space programme in 1963, and has since developed and put several of its own satellites into space. It has also designed and built launch rockets to reduce its dependence on overseas space agencies.

Space agency chairman Nair said the body has finalised a project report concerning a manned mission by 2014-15.

"The report is being submitted to the government for approval and budgetary allocation," he said. "The Space Commission, headed by Prime Minister Manmohan Singh, will meet next week or so to review the report and take a decision."

Thursday, March 13, 2008

Mysterious Meteorites Stymie Scientists


A pair of mysterious meteorites discovered in Antarctica is baffling scientists who are struggling to determine the origin of the space rocks. The meteorites, dubbed GRA 06128 and GRA 06129, were found in the Graves Nunataks region of Antarctica in 2006

The rocks were oddly rusty and salty and smelled like rotten eggs, its discoverers said.

Initially, a team at the University of New Mexico (UNM) caused a stir when its analysis hinted that the pair may hail from Venus or the moon.

But other teams then hurried to get pieces of the space rocks for analyses of their own—and for the most part, they disagree.

GRA 06128 looks like rocks retrieved from the lunar highlands by the Apollo 16 astronauts in 1972, but it contains much more sodium, research has shown.

The rock is also much older than the Venusian surface, according to the newer analysis, thereby eliminating that possibility.

The identity of the meteorites' source remains exciting and mysterious, said Allan Treiman, a scientist with the Lunar and Planetary Institute in Houston who led one of the recent investigations of the rocks.

"From what has been reported so far, it's pretty clear that the meteorite is not from the Earth, or the moon, or Venus, or any of the common sources of meteorites," he said. "It's much harder to know where it is from."

Both teams—along with three others—are presenting findings about the meteorites at the 39th Lunar and Planetary Science Conference in Houston this week.

Not of This World?

GRA 06128 and its mate are slab-shaped, gray rocks containing bits of black glass.

Mysterious Meteorites Stymie Scientists


One of the first teams to get a sample of the meteorites was led by UNM's Chip Shearer. The researchers analyzed chemical signatures called isotopes and initially determined that the meteorites came from Earth or the moon, a position they've since retooled.

"Although initial oxygen isotopic compositions are consistent with an origin in the Earth-Moon system, numerous observations appear to eliminate both bodies," Shearer and his team write in an abstract presented at this week's meeting.

Doug Rumble from the Carnegie Institution and his colleagues will also present an analysis of GRA 06128 and 06129 at the conference.

He said the New Mexico researchers initially studied a "tiny crumb that fell off the outside" of GRA 06129, but they didn't wash the outer layer to remove any Earthly weathering agents that might alter the findings.

"The UNM analytical results reflect only imperfectly the actual extraterrestrial composition of the meteorite, because UNM also analyzed rust that formed as the meteorite lay exposed to Earth's atmosphere," he said.

Rumble's own analysis puts the meteorites "right in the range of values expected for rare meteorites called brachinites," he said.

Brachinites are believed to be the remnants of planets that once orbited between Mars and Jupiter

"So now we are all meeting in Houston to hang our heads a little and admit to one another that maybe we were a little too hasty," Rumble said, "and got too excited over an unwashed meteorite."

Unsettled Debate David Kring, a visiting scientist at Houston's Lunar and Planetary Institute and a co-author on Treiman's paper, said there's still work to be done to nail down the exact nature of the meteorite pair.

The chemical and mineral compositions of the rocks are similar to brachinites and another type of meteorite called chondrites, he said.

Chondrites, leftovers from the formation of asteroids, are the most common meteorites. But the pair doesn't match either category exactly, Kring said.

The rocks are partially melted, which is not characteristic of chondrites.

And they contain high levels of the mineral feldspar, which is not typically associated with the short-lived planets between Mars and Jupiter.

"Thus there are two mysteries," Kring said. "What is the parent planet for the rock, and what type of geologic activity on that planet produced the unusual mineral assemblage?"

There is no shortage of new ideas to account for the disparity.

"My preferred working hypothesis is that [the meteorites] actually represent a piece of crust from an asteroidal body—the surface of another planet, if you like," offered James Day, a geologist at the University of Maryland.

Day has joined the other researchers at this week's meeting to puzzle over the rocks.

Treiman added that it would take a very large asteroid or a dwarf planet to cause the melting seen in the meteorites.

Whether or not its home is discovered, GRA 06128 is a "pretty puzzle, and will help us understand how asteroids form and how they evolve to become planets," he said.