Posts Tagged ‘Jet Propulsion Laboratory’

Ion Propulsion

March 9, 2013

Improved designs in ion engines may be the ticket for making trips to the outer solar system quicker and more feasible both for unmanned probes and (I hope) manned spacecraft. I haven’t been keeping up with space exploration as much as I used to, so I am glad to find this article in Gizmag which explains a little about ion engines and how scientists have been making them better.

The phrase “engage the ion drive” still has the ring of a line from Star Wars, but these engines have been used in space missions for more than four decades and remain the subject of ongoing research. Ion engines have incredible fuel efficiency, but their low thrust requires very long operating times … and therein lies the rub. To date, erosion within such an engine seriously limits its operational lifetime. Now a group of researchers at NASA’s Jet Propulsion Laboratory (JPL) has developed a new design that largely eliminates this erosion, opening the gates for higher thrust and more efficient drives for manned and unmanned missions to the reaches of the Solar System.

There are many varieties and more proposals (the VASMIR engine comes to mind), but the operating principle is quite simple. There are two basic styles of ion engines, electrostatic and electromagnetic.

An electrostatic ion engine works by ionizing a fuel (often xenon or argon gas) by knocking off an electron to make a positive ion. The positive ions then diffuse into a region between two charged grids that contain an electrostatic field. This accelerates the positive ions out of the engine and away from the spacecraft, thereby generating thrust. Finally, an neutralizer sprays electrons into the exhaust plume at a rate that keeps the spacecraft electrically neutral.

An electromagnetic ion engine also works by ionizing a fuel. In this case a plasma is created that carries current between the ionizing anode and a cathode. The current in turn generates a magnetic field at right angles to the electric field, and thereby accelerates the positive ions out of the engine via the Lorentz force – basically the same effect on which railguns are based. Again a neutralizer keeps the spacecraft electrically neutral.

There are many varieties and more proposals (the VASMIR engine comes to mind), but the operating principle is quite simple. There are two basic styles of ion engines, electrostatic and electromagnetic.

 

There is a lot more in the article.

Even Scotty would be impressed by this.

Though, what we really need is warp drive. Anyone doing research on that?

 

Advertisements

Mars Time

August 21, 2012

 

 

The Martian day, called a “sol” is 24 hours and 39 minutes, making it 39 minutes longer than an Earth day. In order to properly monitor a Mars rover‘s mission, many of the scientists and engineers involved switch to Mars time, at least for the first three months. A forty minute longer day may not seem like much of an adjustment, but that daily forty minutes adds up and before too long you are out of sync with Earth’s day and night. Here is the story from AP about a whole family that is trying the adjustment out.

Since the landing of NASA’s newest Mars rover, flight director David Oh’s family has taken the unusual step of tagging along as he leaves Earth time behind and syncs his body clock with the red planet.

Every mission to Mars, a small army of scientists and engineers reports to duty on “Mars time” for the first three months. But it’s almost unheard of for an entire family to flip their orderly lives upside down, shifting to what amounts to a time zone change a day.

Intrigued about abiding by extraterrestrial time, Oh’s wife, Bryn, could not pass up the chance to take their kids – 13-year-old Braden, 10-year-old Ashlyn and 8-year-old Devyn – on a Martian adventure from their home near the NASA Jet Propulsion Laboratory where the Curiosity rover was built.

“We all feel a little sleepy, a little jet-lagged all day long, but everyone is doing great,” Bryn Oh said, two weeks into the experiment.

Days on Mars last a tad longer. Earth rotates on its axis once every 24 hours – the definition of a day. Neighbor Mars spins more lazily. Days there – known as sols – last 39 minutes and 35 seconds longer than on Earth. The difference may not seem like much each day, but it adds up.

To stay in lockstep, nearly 800 people on the $2.5 billion project have surrendered to the Martian cycle of light and dark. In the simplest sense, each day slides forward 40 minutes. That results in wacky work, sleep and eating schedules. Many say it feels like perpetual jet lag.

The Oh family broke in slowly. A sign on their front door warns: “On Mars Time: Flight Director Asleep. Come Back Later.”

Days before Curiosity’s Aug. 5 touchdown, the children stayed up until 11:30 p.m. and slept in until 10 a.m. In the beginning, it wasn’t much different from a typical day on summer vacation. As the days wore on, they stayed up later and later, waking up in the afternoon and evening.

One day last week, the family ate a 3 p.m. breakfast, 8 p.m. lunch, 2:30 a.m. dinner and 5 a.m. dessert before heading off to bed.

To sleep when the sun is out, their bedroom windows are covered with aluminum foil or cloth to keep out any sliver of light. In the hallway, a handmade calendar keeps track of the days and schedules are written on an oversized mirror. A digital clock in the master bedroom is set to Mars time.

The article goes on about the various troubles the family has in essentially rotating their day and nights forward about a time zone every day. I wonder what effect the slightly longer Martian day might have on any colonists. They wouldn’t have the trouble of having to contend with Earthly time cues, such as sunrise and sunset, or with human activities, which on Mars would be in accord with the Martian day. I don’t think the extra forty minutes would be too hard to adjust to, if everyone in the colony were on the same time.

They would have to do something about their clocks. Would they divided a Martian day into 24 slightly longer Martian hours? What about minutes and seconds? The Martian year is about 687 Earth days. Would Martian colonists measure time by Earth years or Mars years? If I lived on Mars, would I be able to get away with saying I am 20 (Martian) years old?

It will be interesting to see how they figure these sorts of things out. I hope I live to see a colony on Mars.

 

 

The Good, the Bad, and the Ugly

August 6, 2012

First the good. The rover Curiosity landed safely on Mars. Perhaps that doesn’t seem so big a deal, but each time a Mars probe succeeds in landing safely is a technological miracle. Reaching Mars is easy enough, but landing on a planetary surface is difficult, especially when you have no control over the spacecraft and there is about an eighteen minute delay in communications. Here is more from Foxnews.

 In a show of technological wizardry, the robotic explorer Curiosity blazed through the pink skies of Mars, steering itself to a gentle landing inside a giant crater for the most ambitious dig yet into the red planet’s past.

Cheers and applause echoed through the NASA Jet Propulsion Laboratory late Sunday after the most high-tech interplanetary rover ever built signaled it had survived a harrowing plunge through the thin Mars atmosphere.

“Touchdown confirmed,” said engineer Allen Chen. “We’re safe on Mars.”

Minutes after the landing signal reached Earth at 10:32 p.m. PDT, Curiosity beamed back the first black-and-white pictures from inside the crater showing its wheel and its shadow, cast by the afternoon sun.

“We landed in a nice flat spot. Beautiful, really beautiful,” said engineer Adam Steltzner, who led the team that devised the tricky landing routine.

It was NASA’s seventh landing on Earth’s neighbor; many other attempts by the U.S. and other countries to zip past, circle or set down on Mars have gone awry.

The arrival was an engineering tour de force, debuting never-before-tried acrobatics packed into “seven minutes of terror” as Curiosity sliced through the Martian atmosphere at 13,000 mph.

President Barack Obama lauded the landing in a statement, calling it “an unprecedented feat of technology that will stand as a point of national pride far into the future.”

Over the next two years, Curiosity will drive over to a mountain rising from the crater floor, poke into rocks and scoop up rust-tinted soil to see if the region ever had the right environment for microscopic organisms to thrive. It’s the latest chapter in the long-running quest to find out whether primitive life arose early in the planet’s history.

The voyage to Mars took more than eight months and spanned 352 million miles. The trickiest part of the journey? The landing. Because Curiosity weighs nearly a ton, engineers drummed up a new and more controlled way to set the rover down. The last Mars rovers, twin Spirit and Opportunity, were cocooned in air bags and bounced to a stop in 2004.

Right after that, President Obama reminded the engineers at the Jet Propulsion Laboratory that they didn’t build Curiosity all on their own. Someone else made it happen.
This is exciting and the only thing that would have made it perfect would be if it had been a manned mission. I would really like to see a human on Mars in my lifetime.
Now the bad. Yesterday,  a man named Michael Page shot and killed 6 people at a Sikh temple in Milwaukee. The motive is unclear since Page himself was killed by the police. He appears to have been involved with white-supremacist groups.

The children were downstairs, in Sunday school.

The women were in the kitchen nearby, cooking the weekly meal that is free to all.

And the gunman was striding into the wide-open Sikh Temple, bent on killing as many people as he could.

Then came the shots, ripped off, according to a weapons instructor who lives nearby, “as fast as you can pull the trigger.”

By the time the shooter was done, six people lay dead or mortally wounded in what Oak Creek police said was being treated as a domestic terrorist incident – if so, one without precedent in Wisconsin.

Counting the gunman – fatally shot by an Oak Creek police officer – the death count stands at seven.

“This,” a temple leader said later, “is insanity.”

It is also the most deadly U.S. attack on Sikhs – who often have been mistaken for Muslims and targeted in hate crimes – in recent memory.

Within three hours of the mass slaying at the five-year-old temple, built on S. Howell Ave. to accommodate the Milwaukee area’s growing Sikh community, a task force of federal, state and local law enforcement officers was gathering on the scene.

Sikhism is a monotheistic religion, which is, in some ways, a blend of Islamic and Hindu traditions. It was founded by Guru Nanak in the Punjab about 500 years ago. Although Sikhism has spread throughout the world, the majority of Sikhs still live in the Punjab. People in in that region are generally considered to be Caucasians or white, so I am not sure why a white supremacist would target them, unless they weren’t white enough for him. Then again, a lot of those people hate Jews, who look as white as anyone. Maybe he meant to kill Muslims. Sikhs have been targets for hate crimes by the ignorant since 9/11. His motivation will have to remain as something of a mystery since he apparently didn’t leave behind any notes or manifestos.

And now the ugly. As one might expect, much of the ugliness in today’s discourse comes from the tolerant Left, the ones who incessantly lecture the rest of us about civility. I won’t bother to mention some of the vandalism directed at Chick-fil-A, this past week. Here are two stories I read today. First, Anti-hunting mob urges Team USA shooter Corey Cogdell to shoot herself

Corey Cogdell is a Trap Shooter who won a bronze medal at the 2008 Olympic Games in Beijing and competed in the 2012 Olympic Games in London.

She also participates in trophy hunting (hunting of wild game animals).

After Cogdell published photos on Facebook of herself posing alongside animals she killed, anti-hunting activists took to Twitter to express their strong displeasure.

Natascha Bracale @TaschaB13

@CoreyCogdell pity the bus didn’t crash. You are a waste of oxygen and an embarassment to the human race.Karma is a bitch.

Konejira @Konejira

@CoreyCogdell please go shoot yourself in the knees. YOU ANIMAL MURDERER!! you’re a disgusting human being.
@pablito_honas

@CoreyCogdell I hope that someone someday shoot your whole familly just practicing.—
Pablo Honney (@pablito_honas) August 02, 2012

Nice people.

Then there is the latest action by the tolerant Atheist community.

26-foot tall cross emblazoned with the message “Jesus Saves” has become the center for more First Amendment debate in Indiana.

The cross stands on a public plot of land in the small Hoosier State community of Dugger, and has Americans United for Separation of Church and State threatening to sue.

“It’s a pretty flagrant display of the government saying ‘this is a Christian town,'” Gregory Lipper, the group’s senior counsel, told FoxNews.com. “Everyone gets freedom of religion …just because Christianity is this country’s religious majority doesn’t mean that they get to put their thumb on the scale and use taxpayer dollars.

“It doesn’t matter what religion the government is endorsing … it’s a clear violation of the Constitution.”

The land that the cross sits on is valued at about $3,000, and the little 955-person town cannot afford legal fees to save such a small spot of land.

“We’ve given the church 60 days to make a decision,” Dwight Nielsen, Dugger Town Board president, told FoxNews.com. “We may sell the land to a group of [churches].”

The cross was erected two years ago on behalf of the town’s Faith Community Church. The fixture sits on town-owned property near a high school baseball field, but the town approved the build.

“We wanted people to be able to see what the message of the cross represents and get it out to the world in need,” Shawn Farris, head pastor at the Faith Community Church, told FoxNews.com.

Farris does not believe that the town made a religious endorsement by letting the church put up the cross:

“We knew it was okay because when you look at the separation between church and state, it’s just a fact that the government couldn’t tell people how to worship … it would be the same if they allowed a crescent moon to be put up,” he continued.

The town will soon hold a meeting to discuss and finalize the future plans of the cross, officials said.

Religious freedom means they cannot put up a cross? How is anyone hurt by this? Would anyone object if some other religious symbol were erected? Why don’t the people at the Americans United for Separation of Church and State get a life, and stop harassing people?

 


%d bloggers like this: