Under the new plan NASA's focus would be the development of systems that would carry men and equipment outside of low-Earth-orbit (LEO) and successfully land them on other objects in the solar system. Missions to LEO would be handled by space craft developed in private industry. This is especially key now that President Obama has extended the life of the International Space Station (ISS) to 2020 or beyond. (The ISS was scheduled to retire long before then under the Bush Administration's plan.)
The problem with this, is that the Constellation Program was exactly this kind of replacement. Though, admittedly, it was being designed to have the flexibility to conduct LEO missions as well. With the initial cancellation of the program, the heavy lift rockets that would be need to make the craft outside of LEO were cancelled as well. However, as the new plan has been debated in Congress, it appears that elements of the rockets will continue to be developed.
It is becoming apparent that at least elements of the Constellation Program will survive, if for not other reason it will be necessary to achieve the goals set forth by the President. In addition to the needed rockets and boosters, it also appears that the Orion Crew Module will receive a reprieve from the scrap heap.
Ultimately it is still unclear by what means man will explore the Universe outside of LEO; it may look very similar to the original Constellation Program designs, or it may go in a whole new direction. It seems that it is all coming down to funding and the price Congress is willing to pay for a manned space program.
Where Will Man Go Next?
Assuming that everyone can get on the same page, and a new vehicle for leaving LEO is developed, where will man visit next? It seems likely that one of the first destinations will be, well, nowhere.There are points in space known as Lagrange points. These are positions in space where the gravitational pull from object is completely balanced by the gravitational attraction of another. There are five such points between Earth and the Moon (designated L1 through L5 as one moves away from Earth), and even more between the Earth and Sun (though it can become even more complicated once other massive objects -- like planets -- enter the equation as well). Traveling to the L1 point between the Earth and Moon -- about 5 million miles from the Earth -- would allow the space craft to sit in space for an extended period of time while consuming relatively little energy.
It would also allow scientists to study the effects of having astronauts outside of the protective shield of Earth's magnetosphere for extended periods of time. Then NASA would probably consider sending astronauts to a nearby asteroid, perhaps as early as 2025. Landing on an object roughly the size of a football stadium (or even smaller) would have multiple benefits. Obviously, there is just the experience of conducting such a logistically difficult space flight. But there are also considerable scientific reasons for such a mission.
This would give NASA the opportunity to develop and test deflection systems that could redirect a potentially hazardous asteroid threatening Earth. Also, it would provide new information about the origin of the solar system.
Then, by the 2030s, NASA hopes to be able to send astronauts to orbit Mars, and ultimately land on the Red Planet. With this as the ultimate goal, NASA has to consider the time it would take to travel there (which will depend on the advancement of engine technology). How does one supply such a mission? How do you protect the astronauts from the high levels of radiation emitted form the Sun? These are questions that need answers before man can step out into the solar system.
As the plan for human space exploration takes shape, there is a lot to consider. And of course, this all depends on the continued funding for such programs. The next 30 years will see a lot of activity on the space exploration front, and the hope is that man will continue to push the boundaries of human ability. By John P. Millis, Ph.D
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