What do they mean by missile tracking satellites? can you give more details about it.
Answer
This is a bit out of my area. Actually, quite a bit out of my area of understanding. NASA does not build or operate missle tracking satellites.
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Editor
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Question
From time to time scientists announce fears of a possible Near Earth Object hitting Earth in the years and decades to come. What is NASA doing about this and how real is this danger?
Answer
NASA was recently tasked by the U.S. Congress to assess the effort required to identify Near Earth Objects. The Agency issued a report that describes a program to survey the skies for objects that might pose a threat to Earth.
The full report is available on the NASA web site, www.nasa.gov, in the section for media.
In summary, the report says that 90 percent of all potentially hazardous objects greater than 140 meters in size whose orbits pass within .05 AUs of Earth could be identified by 2020 in cooperation with other government agencies.
A number of telescopes and other instrumentation would be required.
Different methods are discussed for diverting a threatening object, including nuclear "standoff" explosions and other ways to push the object into a different orbit.
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charles murphy
- United States
Profession
oilfield
Question
Is there a Surat in the in THE HOLY QUR-AN about space travel. thank you
Answer
I do not know the answer to this one. Perhaps you could direct that question to one of the other guests. Thank you.
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Editor
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With all the satellites and space junk hovering in orbit around the Earth, when do you expect that action would need to be taken to clear up Earth's perimeter before a space disaster happens?
Answer
Regarding space debris, this is a very serious problem that threatens all orbiting spacecraft, mostly in Low Earth Orbit. This debris comes mostly from other spacecraft whose used booster stages have exploded, or in some cases from spacecraft which have been intentionally exploded in space. Other debris ranges in size from small chips of paint and items the size of sand grains up to large rocket bodies weighing tons.
Even a small piece weighing a few grams can cause serious, even devastating damage to other spacecraft because of the speeds at which these items move. Objects in low Earth orbit move around 17,000 miles per hours. Tests have shown that a small plastic pellet moving at high speed can put a large hole in something even as tough as a reinforced fuel tank.
As to the issue of clearing the items from orbit, there is very little that can be done. In time, most objects will eventually re-enter the atmosphere. Unfortunately, in the higher orbits, that process can take many years.
The main challenge is to reduce the new debris that is added to the existing junk.
Name
Hend
- Egypt
Profession
Information projects
Question
I always wanted to know why do all the scientists decide that there is no possibility of life on a plant if it has no Oxygen? Can’t aliens breath anything else!
Answer
Very good question. Of course, not all life "breathes" as we do, but life on our planet uses oxygen as part of the chemical process that is central to life as we know it.
It is very interesting to speculate about the other forms that life might take on other worlds. We should never assume that only those things familiar to us can exist elsewhere. Even on our own planet, life forms exist in extreme environments where it might seem impossible. Living things have an amazing ability to adapt to their conditions, given enough time. We should keep an open mind to all possibilities.
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Editor
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The thrust to reach the moon in the 1960's came mainly from the cold war environment. What is the thrust for the current plans to return to the moon, and is it strong enough to undertake the feat?
Answer
There are many viewpoints as to the main reasons for human exploration of space. Those that sound the most logical include scientific research or the potential economic benefits of expanding human presence into the solar system.
But the more inspiring reasons have to do with the nature of humanity. In my opinion, the reasons we go into space, especially when we attempt to go far beyond Earth, relate to our desire to achieve great things. Throughout history, even in dark times when human kind suffered from war, disease and hunger, there has been a desire to express the better part of our nature.
Whether it was building great objects such as the pyramids of Egypt, creating beautiful structures for religious purposes, or going on great quests of exploration and discovery, there has always been a part of humanity that needs to express that spirit of achievement.
I believe that is still the driving force behind space exploration and I hope we humans never lose the will to achieve great things.
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Editor
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Following up on that question about space junk, how do rockets and spaceships (not to mention the space station and space walking astronauts) avoid these objects as they travel in orbit or as they launch and re-enter the Earth's atmosphere?
Answer
That's a very tough thing to do. The short answer is that they can't avoid all such objects. Many times the Space Shuttle has returned with minor damage such as small pits in the windows, apparently from impact with very tiny material. I'm sure there must have been other damage that we haven't clearly identified as coming from orbital debris, simply because there are a number of other things that cause apparent damage such as the impact of ice during launch. So it's not easy to tell which damage came from a certain source.
We do track orbiting objects of a certain size, something you could hold in your hand, and on many occasions we have changed the orbit of the Shuttle or the Space Station to avoid these. We call those changes "collision avoidance maneuvers" and they are fairly common.
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Editor
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What is the best science that has come out of the continuous inhabitance of the International Space Station? Have scientific experiments on board been trickling down to everyday life on Earth?
Answer
There have been many benefits to building and operating the International Space Station.
Much of the science is in the category of basic research, the type of experiments that add to our basic understanding of something but that usually don't result in a new product or an immediate cure for a disease.
Experimental work on animal systems, observing such things as how bones heal in the microgravity enviromment, or how different types of cells such as kidney cells or cancer cells develop, add to our basic knowledge. As with mush science of this type, the results become part of the published work available to the general science community and add to our understanding.
One area of focus is a large set of experiments that measure how humans adapt to the space enviroment. Over the years, this has included studies of vision, balance, nutrition, muscular adaptation and other areas that will help us make sure people can survive long space missions.
Another important benefit of having the International Space Station has been as a technology test bed. Vital systems such as those for generating oxygen and purifying the air must be well developed and completely dependable before we undertake a mission to Mars. It is much better to find the weaknesses in our life support and other systems when we are only hours from returning home instead of months away as we would be on Mars.
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Editor
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Question
In recent years, and perhaps partly because of the Ansari X PRIZE, a number of companies have been set to launch space tourists to the edge of space.
Do you think that private enterprise is ready, both technologically and safety wise, to take responsibility of none professionals beyond Earth's atmosphere? How successful do you expect these ventures to be?
Answer
We at NASA are very excited to see the growth of private sector space activity and we have been cooperating with private space companies to encourage their efforts. NASA also has offered a prize to encourage private technology development such as a lunar lander capability. Competitors came close to winning it several months ago.
Having said that, going into space, even near-Earth space and keeping your passengers and crew alive during the trip is a monumental challenge. So far, private companies are taking on the first step in that effort -- aiming to carry people on sub-orbital trips for only around 20 minutes or so up to the "edge" of space. That's pretty much a quick up and down experience and it is a much greater leap to be able to go into sustainable orbit for days at a time, then successfully re-entering the atmosphere from 17,000 miles per hour.
I personally believe that the private companies will successfully achieve the sub-orbital "hops" very soon. But the larger task of sustained flight in orbit and succcessful return is probably much farther away.
Name
Ibrahimovic
- Russian Federation
Profession
Question
I wonder why space exploration has such huge budgets. I mean what's the point of it all? Why not use that money to stop wars and end epidemics?
I'm not against what you're doing...but there is this question that I can't find an answer for:
What good has come from SE since it all started other than launching spy satellites?
Answer
Another excellent question and one that I hear often.
Undeniably, there are great needs here on Earth that more funding could help. Scientific research into the causes and cures of our worst diseases is one of my top favorites.
I can only speak about the U.S. space program since that's where I work, so I leave it to others to comment on their nation's program.
Many people believe that a large fraction of the national budget is spent on the space program. In reality, less than one percent of the federal budget of the United States is spent on NASA's activities. Of course, that is separate from the military budget for space which supports reconnaisance satellites and other work.
The money spent by NASA goes for a variety of projects including scientific research in fields such as astronomy (Hubble and other space telescopes) and planetary study (the Mars rovers and robotic explorers in the outer solar system). It also goes for aeronautical research, advancing the design of aircraft to increase fuel efficiency, performance and safety.
Our study of human adaptation to space has led to some important improvements in medicine including a role in the development of a small device to help people with failing hearts and another machine that significantly improves our ability to study cancer cells.
The largest piece of the budget is for human exploration of space. That money is spent, of course, in paying the scientists and engineers who develop the rockets and plan the missions, train the astronauts, etc. The money that they are paid goes back into our economy as they purchase goods and services, creating jobs for others both here in the U.S. and from the countries whose imports we buy.
I encourage you to go to our website, www.nasa.gov, to learn more about how the money is spent. There is much more than I can offer in my short answer here.
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Host
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Finally, we would like to thank our guest Mr. Steve Nesbitt for joining us. We would also like to thank those who participated with their questions in this live dialogue.
Please check back with us regularly as the Health & Science section continues its coverage of space sciences and exploration.
