Startram the Maglev train: Destination low earth orbit (LEO)

Getting into space is one of the harder tasks to be taken on by humanity.

The present cost of inserting a kilogram (2.2 lb) of cargo by rocket into Low Earth Orbit (LEO) is about US$10,000.

A manned launch to LEO costs about $100,000 per kilogram of passenger (except in China) but who says we have to reach orbit by means of rocket propulsion alone?

Instead, imagine sitting back in a comfortable magnetic levitation (maglev) train and taking a train ride into orbit.

Dr George Maise invented the Startram orbital launch system along with Dr James Powell, who is one of the inventors of superconducting maglev - for which he won the 2002 Franklin Medal in engineering. Startram is in essence a superconducting maglev launch system.

The system would see a spacecraft magnetically levitated to avoid friction, while the same magnetic system is used to accelerate the spacecraft to orbital velocities, just under 9 km/sec (5.6 miles/s).

Maglev passenger trains have carried passengers at nearly 600 kilometers per hour (373 mph) - spacecraft have to be some 50 times faster, but the physics and much of the engineering is the same.

The scope of the project is challenging.

A launch system design for routine passenger flight into LEO should have rather low acceleration - perhaps about 3 g's maximum, which then requires 5 minutes of acceleration to reach LEO transfer velocities. In that period, the spacecraft will have traveled 1,000 miles (1,609 km).

The maglev track must be 1,000 miles in length - similar in size to maglev train tracks being considered for cross-country transportation.

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High dietary phosphate intake may promote skin cancer formation

A high dietary intake of phosphate promotes tumour formation in an animal model of skin cancer, researchers at Emory University School of Medicine have found.

The results, published in the journal Cancer Prevention Research, suggest that a high intake of phosphates may promote tumour development and contribute to tumour growth in skin cancer, while restricting phosphate intake may help prevent cancer.

The researchers applied dimethylbenzanthracene, a carcinogen found in cigarette smoke, to the skins of mice, followed by another chemical that stimulates cell growth.

Feeding these mice a high phosphate diet (1.2 percent by weight) increased skin papilloma number by 50 percent compared with a low phosphate diet (0.2 percent).

Skin papillomas are the initial stage of skin cancer development, which may progress to full carcinoma.

"This is a very well established model for the initiation and progression of cancer, and the effects of many physiological conditions on cancer initiation have been measured this way," says senior author George Beck, PhD, assistant professor of medicine (endocrinology). Beck is also a member of the Winship Cancer Institute, Emory University.

Phosphate is an essential nutrient forming both the physical support for bones, when complexed with calcium, and the chemical backbone of DNA. Phosphate chemical bonds provide the energy currency in the cell, in the form of ATP (adenosine triphosphate).

In addition, many oncogenes, the motors driving cancer cells to divide relentlessly, are regulatory enzymes that attach phosphate chemically to other proteins, turning their activity up or down depending on the protein target.

Altered levels of phosphate could be tipping the balance of these chemical reactions in complex ways, Beck says.

Public health researchers say that phosphate dietary intake has increased over the last 30 years and also may be underestimated because of the increasing contribution of food additives.

Phosphate is added to a variety of processed foods such as meats, baked goods and soft drinks to improve texture and durability.

The authors calculate that the human dietary equivalent of a mouse's high phosphate diet is 1,800 milligrams per day, an intake level that many humans match or exceed.

The high-phosphate diet did not have a corresponding increase in calcium, which would reflect the equivalent of a dairy-rich diet. A low-phosphate diet in the mice corresponds to 500 milligrams per day for humans.

"Another way to look at it is that a low-phosphate diet may help prevent cancer," Beck adds.

Sunny Delight - High in Sugar

Sunny D may contain a full day's supply of vitamin C, as its bottle says, but as with all Cola and Soda drinks, the tangy orange drink is drowning in sugar — 27 g per glass.

Better choice: Milk. Skip Sunny D and pour your kid a glass of skim milk. It's full of calcium and essential vitamins without the sugar.

Space Radiation Reaches an all time High

Like a wounded Starship Enterprise, our solar system's natural shields are faltering, letting in a flood of cosmic rays. The sun's recent listlessness is resulting in record-high radiation levels that pose a hazard to both human and robotic space missions.

Galactic cosmic rays are speeding charged particles that include protons and heavier atomic nuclei. They come from outside the solar system, though their exact sources are still being debated.

Earth dwellers are protected from cosmic rays by the planet's magnetic field and atmosphere. But outside Earth's protective influence, cosmic rays can play havoc with spacecraft electronics – they may be responsible for some recent computer glitches on NASA's Kepler spacecraft, which temporarily halted its planet-hunting observations. They can also damage astronaut DNA, which can lead to cancer.

Now, the influx of galactic cosmic rays into our solar system has reached a record high. Measurements by NASA's Advanced Composition Explorer (ACE) spacecraft indicate that cosmic rays are 19 per cent more abundant than any previous level seen since space flight began a half century ago.

Solar minimum
"The space era has so far experienced a time of relatively low cosmic ray activity," says Richard Mewaldt of Caltech, who is a member of the ACE team. "We may now be returning to levels typical of past centuries."

The sun's magnetic field normally blocks some of the cosmic rays, preventing them from entering the solar system. But that protection has weakened of late. The solar wind, which helps project the sun's magnetic field out into space, has dropped in pressure to a 50-year low. And the strength of the magnetic field in interplanetary space is down to just 4 nanoTesla, compared to the more typical 6 to 8 nanoTesla.

The recent weakening of the shield is due to cycles in solar activity. The sun is at a minimum in its 11-year cycle of magnetic activity, and this particular dip is deeper than any other seen in nearly a century.