2011-02-06
2010-04-08
New Rocket engine could reach MARS in 40 Days
By Jeremy Hsu
SPACE.com Contributor
Future Mars outposts or colonies may seem more distant than ever with NASA's exploration plans in flux, but the rocket technology that could someday propel a human mission to the red planet in as little as 40 days may already exist.
A company founded by former NASA astronaut Franklin Chang-Diaz has been developing a new rocket engine that draws upon electric power and magnetic fields to channel superheated plasma out the back. That stream of plasma generates steady, efficient thrust that uses low amounts of propellant and builds up speed over time.
"People have known for a long time, even back in the '50s, that electric propulsion would be needed for serious exploration of Mars," said Tim Glover, director of development at the Ad Astra Rocket Company.
The rocket technology could drastically cut down the amount of time a spacecraft needs to send astronauts on Mars missions. Instead of half a year, a spacecraft could make the trip in just over a month using the engine and a large enough power source, according to an Ad Astra mission study.
NASA's recent course change has freed up some funding for new propulsion technologies. And the U.S. space agency has not lost sight of the red planet, NASA administrator Charles Bolden told Congress as he presented a new budget last month.
"While we cannot provide a date certain for the first human visit, with Mars as a key long-term destination we can identify missing capabilities needed for such a mission and use this to help define many of the goals for our emerging technology development," Bolden said.
Familiar chemical rockets that burn solid or liquid chemical propellants won't get humans to Mars fast because they would require too much propellant. They can create a huge boost for several minutes at the cost of huge inefficiency — not unlike a speed demon with poor gas mileage.
Slow but steady push
Some satellites and spacecraft already rely upon electric propulsion in their ion engines that create thrust based on energized gas. Similarly, Ad Astra's Variable Specific Impulse Magnetoplasma Rocket (VASIMR) ionizes gases such as xenon or hydrogen to create superheated plasma stream for thrust.
But VASIMR also has the advantage of relying upon electromagnetic waves to create and energize the plasma, rather than physical electrodes that get worn down due to contact with the superheated plasma. That translates into greater reliability over time and allows for a very dense plasma stream to create more thrust.
VASIMR can also adjust its thrust to speed up or slow down, and even has an "afterburner" mode that provides a temporary high-speed boost at the cost of efficiency.
"Our technology is different," Glover told SPACE.com. "It's one possibility. We certainly think it has the most potential at high power levels."
Yet even the most efficient rocket engine needs a power source. VASIMR may use gas as the propellant, but it also requires an electric power source that can ionize the gas to create its plasma.
I need more power!
A mission trajectory study estimated that a VASIMR-powered spacecraft could reach the red planet within 40 days if it had a 200 megawatt power source. That's 1,000 times more power than what the current VASIMR prototype will use, although Ad Astra says that VASIMR can scale up to higher power sources.
The real problem rests with current limitations in space power sources. Glover estimates that the Mars mission scenario would need a power source that can produce one kilowatt (kW) of power per kilogram (kg) of mass, or else the spacecraft could never reach the speeds required for a quick trip.
Existing power sources fall woefully short of that ideal. Solar panels have a mass to power ratio of 20 kg/kW. The Pentagon's DARPA science lab hopes to develop solar panels that can achieve 7 kg/KW, and stretched lens arrays might reach 3 kg/KW, Glover said. That's good enough for VASIMR to transport cargo around low-Earth orbit and to the moon, but not to fly humans to Mars.
Ad Astra sees nuclear power as the likeliest power source for a VASIMR-powered Mars mission, but the nuclear reactor that could do the job remains just a concept on paper. The U.S. only ever launched one nuclear reactor into space back in 1965, and it achieved just 50 kg/kW.
SPACE.com Contributor
Future Mars outposts or colonies may seem more distant than ever with NASA's exploration plans in flux, but the rocket technology that could someday propel a human mission to the red planet in as little as 40 days may already exist.
A company founded by former NASA astronaut Franklin Chang-Diaz has been developing a new rocket engine that draws upon electric power and magnetic fields to channel superheated plasma out the back. That stream of plasma generates steady, efficient thrust that uses low amounts of propellant and builds up speed over time.
"People have known for a long time, even back in the '50s, that electric propulsion would be needed for serious exploration of Mars," said Tim Glover, director of development at the Ad Astra Rocket Company.
The rocket technology could drastically cut down the amount of time a spacecraft needs to send astronauts on Mars missions. Instead of half a year, a spacecraft could make the trip in just over a month using the engine and a large enough power source, according to an Ad Astra mission study.
NASA's recent course change has freed up some funding for new propulsion technologies. And the U.S. space agency has not lost sight of the red planet, NASA administrator Charles Bolden told Congress as he presented a new budget last month.
"While we cannot provide a date certain for the first human visit, with Mars as a key long-term destination we can identify missing capabilities needed for such a mission and use this to help define many of the goals for our emerging technology development," Bolden said.
Familiar chemical rockets that burn solid or liquid chemical propellants won't get humans to Mars fast because they would require too much propellant. They can create a huge boost for several minutes at the cost of huge inefficiency — not unlike a speed demon with poor gas mileage.
Slow but steady push
Some satellites and spacecraft already rely upon electric propulsion in their ion engines that create thrust based on energized gas. Similarly, Ad Astra's Variable Specific Impulse Magnetoplasma Rocket (VASIMR) ionizes gases such as xenon or hydrogen to create superheated plasma stream for thrust.
But VASIMR also has the advantage of relying upon electromagnetic waves to create and energize the plasma, rather than physical electrodes that get worn down due to contact with the superheated plasma. That translates into greater reliability over time and allows for a very dense plasma stream to create more thrust.
VASIMR can also adjust its thrust to speed up or slow down, and even has an "afterburner" mode that provides a temporary high-speed boost at the cost of efficiency.
"Our technology is different," Glover told SPACE.com. "It's one possibility. We certainly think it has the most potential at high power levels."
Yet even the most efficient rocket engine needs a power source. VASIMR may use gas as the propellant, but it also requires an electric power source that can ionize the gas to create its plasma.
I need more power!
A mission trajectory study estimated that a VASIMR-powered spacecraft could reach the red planet within 40 days if it had a 200 megawatt power source. That's 1,000 times more power than what the current VASIMR prototype will use, although Ad Astra says that VASIMR can scale up to higher power sources.
The real problem rests with current limitations in space power sources. Glover estimates that the Mars mission scenario would need a power source that can produce one kilowatt (kW) of power per kilogram (kg) of mass, or else the spacecraft could never reach the speeds required for a quick trip.
Existing power sources fall woefully short of that ideal. Solar panels have a mass to power ratio of 20 kg/kW. The Pentagon's DARPA science lab hopes to develop solar panels that can achieve 7 kg/KW, and stretched lens arrays might reach 3 kg/KW, Glover said. That's good enough for VASIMR to transport cargo around low-Earth orbit and to the moon, but not to fly humans to Mars.
Ad Astra sees nuclear power as the likeliest power source for a VASIMR-powered Mars mission, but the nuclear reactor that could do the job remains just a concept on paper. The U.S. only ever launched one nuclear reactor into space back in 1965, and it achieved just 50 kg/kW.
2010-02-17
Few Extreme Planet Facts
Source: www.space.com
Mercury
As the planet nearest the sun, the surface of Mercury can reach a scorching 840 degrees F (450 degrees C). However, since this world doesn't have enough atmosphere to entrap any heat, at night temperatures can plummet to -275 degrees F (-170 degrees C), a more than 1,100 degrees F temperature swing that is the greatest in the solar system.
Venus
Although Venus is only the planet second nearest the sun, its dense, toxic atmosphere traps heat in a runaway version of the greenhouse effect that warms up the Earth. As a result, temperatures on Venus reach 870 degrees F (465 degrees C), more than hot enough to melt lead.
Earth
It might seem a bit like navel-gazing to point out how special Earth is — after all, we live here. Although Earth is covered in oceans of water, Mars could have once hosted seas as well. But nowhere else in the solar system can one find atmospheres loaded with free oxygen, which ultimately proved vital to one of the other unique features of Earth — us.
Mars
The red planet is home to both the highest mountain and the deepest, longest valley in the solar system. Olympus Mons is roughly 17 miles (27 kilometers) high, about three times as tall as Mount Everest, while the Valles Marineris can go as deep as 5 to 6 miles (8 to 10 kilometers) in some places and runs for roughly 2,500 miles (4,000 kilometers), which is close to the width of Australia or the distance from Philadelphia to San Diego.
The dust storms of the Mars are the largest in the solar system, capable of blanketing the entire red planet and lasting for months. One theory as to why dust storms can grow so big on Mars starts with airborne dust particles absorbing sunlight, warming the Martian atmosphere in their vicinity. Warm pockets of air flow toward colder regions, generating winds. Strong winds lift more dust off the ground, which in turn heats the atmosphere, raising more wind and kicking up more dust.
Jupiter
The most extraordinary feature on Jupiter's surface is undoubtedly the Great Red Spot, a giant storm seen for more than 300 years. At its widest diameter, the Great Red Spot is roughly three times as wide as Earth. Every now and again, the spot fades entirely.
Saturn
Saturn is most famous for its spectacular rings. One ring, too faint to be seen from Earth and discovered just in 2009, measures at least 200 times the diameter of the planet — a billion Earths could fit inside the ring.
A mysterious hexagon shape on Saturn, which was captured by cameras aboard NASA's Cassini spacecraft, spans about two Earths and is likely created by the path of a jet stream.
Uranis
Unlike other worlds, Uranus is tilted so far that it essentially orbits the sun on its side, with the axis of its spin nearly pointing at the star. Many astronomers believe this unusual orientation might be due to a collision with an Earth-sized planet soon after it was formed.
Neptune
On Neptune, one can find jet stream winds traveling at more than 1,500 mph. It remains a mystery as to how it gets the energy to drive the fastest planetary winds seen in the solar system, despite it being so far from the sun — at times farther from the sun than Pluto — and having relatively weak internal heat.
Mercury
As the planet nearest the sun, the surface of Mercury can reach a scorching 840 degrees F (450 degrees C). However, since this world doesn't have enough atmosphere to entrap any heat, at night temperatures can plummet to -275 degrees F (-170 degrees C), a more than 1,100 degrees F temperature swing that is the greatest in the solar system.
Venus
Although Venus is only the planet second nearest the sun, its dense, toxic atmosphere traps heat in a runaway version of the greenhouse effect that warms up the Earth. As a result, temperatures on Venus reach 870 degrees F (465 degrees C), more than hot enough to melt lead.
Earth
It might seem a bit like navel-gazing to point out how special Earth is — after all, we live here. Although Earth is covered in oceans of water, Mars could have once hosted seas as well. But nowhere else in the solar system can one find atmospheres loaded with free oxygen, which ultimately proved vital to one of the other unique features of Earth — us.
Mars
The red planet is home to both the highest mountain and the deepest, longest valley in the solar system. Olympus Mons is roughly 17 miles (27 kilometers) high, about three times as tall as Mount Everest, while the Valles Marineris can go as deep as 5 to 6 miles (8 to 10 kilometers) in some places and runs for roughly 2,500 miles (4,000 kilometers), which is close to the width of Australia or the distance from Philadelphia to San Diego.
The dust storms of the Mars are the largest in the solar system, capable of blanketing the entire red planet and lasting for months. One theory as to why dust storms can grow so big on Mars starts with airborne dust particles absorbing sunlight, warming the Martian atmosphere in their vicinity. Warm pockets of air flow toward colder regions, generating winds. Strong winds lift more dust off the ground, which in turn heats the atmosphere, raising more wind and kicking up more dust.
Jupiter
The most extraordinary feature on Jupiter's surface is undoubtedly the Great Red Spot, a giant storm seen for more than 300 years. At its widest diameter, the Great Red Spot is roughly three times as wide as Earth. Every now and again, the spot fades entirely.
Saturn
Saturn is most famous for its spectacular rings. One ring, too faint to be seen from Earth and discovered just in 2009, measures at least 200 times the diameter of the planet — a billion Earths could fit inside the ring.
A mysterious hexagon shape on Saturn, which was captured by cameras aboard NASA's Cassini spacecraft, spans about two Earths and is likely created by the path of a jet stream.
Uranis
Unlike other worlds, Uranus is tilted so far that it essentially orbits the sun on its side, with the axis of its spin nearly pointing at the star. Many astronomers believe this unusual orientation might be due to a collision with an Earth-sized planet soon after it was formed.
Neptune
On Neptune, one can find jet stream winds traveling at more than 1,500 mph. It remains a mystery as to how it gets the energy to drive the fastest planetary winds seen in the solar system, despite it being so far from the sun — at times farther from the sun than Pluto — and having relatively weak internal heat.
2010-01-21
Almost-close encounter
By Paul Duggan
Washington Post Staff Writer
Thursday, January 21, 2010
Much later, after the hole in the roof had been fixed and the debris cleaned up, after the cause of the damage finally had become clear, Frank Ciampi wondered: What are the odds?
He is a doctor. He has worked for 18 years in the two-story building in Lorton that houses the Williamsburg Square Family Practice, in the 9500 block of Richmond Highway. He spends his days walking in and out of examining rooms, seeing patients.
What are the chances, as he goes about his routine, that he'll get hit by a meteorite?
Not impossible.
It almost happened.
"I was in my office doing charts," Ciampi recalled. It was Monday, a little after 5:30 p.m. He was on the building's second floor. "And I heard a loud boom, almost like a small explosion."
At first, he said, he thought a bookcase had toppled nextdoor. "So I ran toward the office. And then I saw all the debris in the hallway," he said.
The floor just outside examination room No. 2 -- about 10 feet from where Ciampi had been doing paperwork -- was littered with small pieces of wood, plaster and insulation. Upon inspection, more debris lay inside the room. He saw three chunks of stone on the floor that together formed a rock about the size of a tennis ball, with a glassy-smooth surface. Then he saw a hole about the size of the rock in the tile ceiling, and a tear in the maroon carpet where the rock had landed.
"The first thing we thought was maybe something had fallen from a plane," Ciampi said.
For most of the day, the 10 examination rooms used by Ciampi and two other medical professionals in the practice had been occupied by patients. Had the falling object crashed through the ceiling a little earlier, it might have killed someone.
"I thank God," Ciampi said.
Later, he said, "I was up all night, wondering what it was." No one else in the practice could figure it out, either. Then on Tuesday, the office manager, Rhonda Lawrence, offered a suggestion from her husband Jeffrey, who has a background in geology.
Washington Post Staff Writer
Thursday, January 21, 2010
Much later, after the hole in the roof had been fixed and the debris cleaned up, after the cause of the damage finally had become clear, Frank Ciampi wondered: What are the odds?
He is a doctor. He has worked for 18 years in the two-story building in Lorton that houses the Williamsburg Square Family Practice, in the 9500 block of Richmond Highway. He spends his days walking in and out of examining rooms, seeing patients.
What are the chances, as he goes about his routine, that he'll get hit by a meteorite?
Not impossible.
It almost happened.
"I was in my office doing charts," Ciampi recalled. It was Monday, a little after 5:30 p.m. He was on the building's second floor. "And I heard a loud boom, almost like a small explosion."
At first, he said, he thought a bookcase had toppled nextdoor. "So I ran toward the office. And then I saw all the debris in the hallway," he said.
The floor just outside examination room No. 2 -- about 10 feet from where Ciampi had been doing paperwork -- was littered with small pieces of wood, plaster and insulation. Upon inspection, more debris lay inside the room. He saw three chunks of stone on the floor that together formed a rock about the size of a tennis ball, with a glassy-smooth surface. Then he saw a hole about the size of the rock in the tile ceiling, and a tear in the maroon carpet where the rock had landed.
"The first thing we thought was maybe something had fallen from a plane," Ciampi said.
For most of the day, the 10 examination rooms used by Ciampi and two other medical professionals in the practice had been occupied by patients. Had the falling object crashed through the ceiling a little earlier, it might have killed someone.
"I thank God," Ciampi said.
Later, he said, "I was up all night, wondering what it was." No one else in the practice could figure it out, either. Then on Tuesday, the office manager, Rhonda Lawrence, offered a suggestion from her husband Jeffrey, who has a background in geology.
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