The NASA “warp drive” project called the EmDrive has everyone excited about the possibility of sending astronauts to Mars within a more reasonable time frame. Unfortunately, even if a NASA warp drive ship were to be built, they face the more practical problem of getting the manned Mars mission to the red planet without going blind or developing Alzheimer’s or cancer.
In a related report by the Inquisitr, a recently published study claims that long-term exposure to cosmic rays can cause brain damage over time. Other reports also claim that the NASA warp drive project breaks the laws of physics.
“Thrust measurements of the EM Drive defy classical physics’ expectations that such a closed (microwave) cavity should be unusable for space propulsion because of the law of conservation of momentum,” wrote José Rodal, Jeremiah Mullikin and Noel Munson for NASA Spaceflight.com. “The concept of an EM Drive as put forth by (Satellite Propulsion Research Ltd.) was that electromagnetic microwave cavities might provide for the direct conversion of electrical energy to thrust without the need to expel any propellant.”
Harold White of the Johnson Space Center said NASA’s warp drive engine could potentially be used in a spaceship designed to reach Mars within 70 days.
“A 90 metric ton, 2 MegaWatt nuclear electric propulsion mission to Mars (would have) considerable reduction in transit times due to having a thrust-to-mass ratio greater than the gravitational acceleration of the sun,” White said.
Even if scientists manage to build a warp drive spaceship, cosmic radiation is still an issue. The moon was only three days away with the old Apollo equipment, and no one knows for certain the effect that long-distance space travel will have on astronauts. The first sighting of these high energy subatomic (HZE) particles were with the Apollo missions, since any particles that could do this would normally be deflected by the Van Allen belts. This natural magnetic field extends over 35 thousand miles above the Earth and protects life from all sorts of cosmic radiation that would otherwise kill us. Astronauts who spend large amounts of time on the International Space Station are also relatively safe since the ISS is located in low-Earth orbit.
Why are cosmic rays so bad for our health? Radiation like x-rays, gamma rays, or microwaves do not contain any mass, while cosmic rays are composed of energetic elements like carbon, oxygen or hydrogen. They can penetrate through walls in space, and when they do so they break molecular bonds. Over time, impacts on the brain and the eye can have a debilitating effect on humans living in space. Cancer is also a concern since cosmic rays can damage the structure of DNA.
Star Trek fans will be delighted since this means NASA’s warp drive project will need to be paired with some sort of shielding in order to make a Mars mission feasible. Surprisingly, you would think some sort of thick metal would do the job, but it turns out plastic is more effective.
“Plastics and other lightweight materials are pound-for-pound more effective for shielding against cosmic radiation than aluminum,” said Cary Zeitlin, of the Southwest Research Institute in Colorado. “The shielding effectiveness of the plastic in space is very much in line with what we discovered from the beam experiments, so we’ve gained a lot of confidence in the conclusions we drew from that work.”
Unfortunately, reports suggest that plastic is only 33 percent effective at blocking cosmic rays, which means heavier materials will have to be built into the design. A ground-based study from 2011 claimed the “best material to shield against these cosmic-ray components is iron, which has the best combination of primary shielding and minimal secondary neutron production.” A layer of lead is also a consideration, but when high speed beta particles hit lead the impact releases X-rays, which are dangerous in of themselves.
This means that in addition to composite physical shielding, some sort of exotic electromagnetic shielding will need to be implemented as well. A patent for such a spacecraft shield was filed in the past, although its energy requirements are fairly high.
“In order to provide an effective shield, the strength of the shield magnetic field at the source is preferably at least 1×10−4 Tesla. To obtain a boundary between the shield magnetic field and a typical solar wind background magnetic field of around 1×10−7 Tesla (perhaps 5×10−8 to 5×10−6Tesla depending on the conditions of the solar wind) at a distance of up to a few hundred metres from the spacecraft a field strength of less than 0.1 Tesla at the magnetic field source will generally be sufficient. Allowing for effects of field persistence in the plasma environment, average electrical power from about 100 W to 10 kW, and more preferably from about 500 W to 5 kW may be provided by the power supply to drive the magnetic field source to generate the shield magnetic field.”
To put these power requirement in perspective, an acre of solar panels provides the International Space Station with 84 kilowatts. In addition, the Engineers at Dartmouth college says providing enough power is just one of the technical challenges of creating effective shielding, since a magnetic shield needs to be “strong enough to deflect GCR particles but weak enough to not harm astronauts.”
Regardless of the technical challenges, reducing the travel time to Mars with NASA’s warp drive engine would definitely help make a manned mission more feasible. As one scientist once said, “Getting in a tin can with a rocket on your back and flying to Mars is never going to be a safe thing to do.”