December, 2013Archive for

The Red Planet – pt.3

Saturday, December 28th, 2013

Manned Missions to Mars

For the foreseeable future, the proverbial Holy Grail of astronomy is landing a man on Mars. The last time a human set foot on a world other than our own was Apollo 17, which occurred in December of 1972. A journey to Mars, however, has a slew of additional obstacles to overcome, making it significantly more expensive and dangerous than the Apollo missions to the moon. Nevertheless, there are missions already in the early stages to put men on Mars during our lifetime.

Challenges

The most obvious challenge to going to Mars is the distance. Even with embarking at the optimal time considering the positioning of the two planets, a trip from Earth to Mars will take at least 150 days with current propulsion technology.   While that duration has been surpassed by numerous astronauts and cosmonauts on the ISS and Mir, it has never been attempted in a small spacecraft, and never at such extreme distances from Earth. The mental stability of the crew is a concern, as a round trip journey could take well over a year. Additionally, if anything goes wrong on the journey, there is virtually nothing that can be done on Earth to help rescue the crew.

Perhaps the most difficult challenge currently facing human spaceflight to mars is radiation. Radiation comes from both the Sun as well as deep space. It is very damaging to human tissue in high volumes, and can cause life threatening cancer. In Low Earth Orbit (LEO) where a majority of human spaceflight has taken place, astronauts are protected by Earth’s powerful magnetic shield. Outside of this shield, the radiation is significantly higher. It was calculated that a round trip to Mars would subject astronauts to about .66 Sieverts of radiation, roughly 33 times the maximum acceptable annual radiation by the Department of Energy.

Additionally, a huge obstacle is the sheer cost of a manned mission to Mars. Cost estimates put it at anywhere from $6 billion to $500 billion, depending upon the mission parameters. For reference, the entire operating budget of NASA in 2014 is about $16.6 billion. The cost of a Martian trip is comprised of both the development of the necessary technology, as well as the cost of propelling a spacecraft to the Martian surface and back.

Current Manned Mission Proposals

NASA

Lockheed Martin’s Orion Spacecraft

In 2010 President Obama predicted an orbital mission to Mars in the mid 2030s. This would not put astronauts on the surface, but would get them within reach. Shortly thereafter he predicted a human landing.

NASA is currently developing a spacecraft with Lockheed Martin known as Orion. This craft is built to take astronauts to the Moon, various asteroids, and Mars. The first unmanned test flight is slated for 2014, with the first manned mission expected in the 2020s.

Russia

Russia is currently building a new launch pad which is designed to support missions to the Moon and Mars. It is expected to see its first use in 2018. While there aren’t any details yet on a specific mission to Mars, it is expected that the Russians will team up with the European Space Agency and NASA to build a spacecraft capable of sending humans to Mars

SpaceX Red Dragon Artist Rendering

SpaceX Red Dragon

The Red Dragon is a low cost Mars Lander concept designed by the private company SpaceX. Currently it does not have funding from NASA, but is proposed in budget discussions for 2015. The Red Dragon could launch for testing as early as 2018.

 

Mars One

Mars One Station

Perhaps the most controversial planned mission to mars is referred to as “Mars to Stay” concept. This is utilized by the Mars One program, which plans to send humans to Mars as early as 2024, with the intention of not returning those humans to Earth. This greatly reduces the cost of the trip, because fuel to leave Mars’ gravity and return home is not needed.

The concept is to choose candidates who are willing to live the rest of their lives on Mars, and train them for their mission. After a series of unmanned missions completes to create the initial habitat, four members of the Mars One crew will be sent to the surface. Additional crew and supplies will be sent every two years, expanding the habitat with each mission.

The funding for this project is expected to come primarily from revenue generated by selling television coverage of the mission, including filming the crew on Mars. Additionally, crowd funding sources and the sale of merchandise are anticipated to help contribute to the project’s finances.

This project is heavily criticized for multiple reasons, primarily being the disparity between expected funds and actual cost, and an oversight of the difficult challenges facing a trip and stay on Mars.

Mars Initiative

The Mars Initiative is an international organization to advocate space exporlation, specifically that of a manned mission to Mars. It does so by accepting donations from supporters to provide incentive and generate an additional funding source for the first successful mission, named the “Mars Prize Fund”.

The Facts about Space Exposure

Monday, December 23rd, 2013

Contrary to what Hollywood would have us think, sudden exposure to the vacuum of space (for instance, if an astronaut’s helmet suddenly came off) does not immediately kill you. In fact, it is estimated you could survive a full minute of exposure without permanent damage or death.

Lets start off with evaluating a few misconceptions about this scenario.

Your body would not explode

Exposure to space would have no sudden effects on your head or body in terms of explosions. Your skeletal structure is significantly stronger than the pull of the vacuum of space, which would keep you, for the most part, in tact.

You would not quickly freeze

Space is cold. In fact, on average it is only a few degrees above absolute zero (-273 degrees Celsius). However, space is also a vacuum, which is important in regards to heat transfer. If you are exposed to cold air on Earth, thermal conduction and convection take place which transfers energy from your warm skin to the surrounding less energetic air molecules. This results in your skin temperature rapidly declining. In space, there is nothing to transfer that heat energy to directly, so you retain it. The only way a human body loses heat energy is through thermal radiation, which takes significantly longer.

Your Blood Does Not Boil

This common misconception gets its roots from the concept that the boiling point of a liquid is associated with the air pressure surrounding the liquid. This is why water boils at a lower temperature at higher altitudes. In space, there is no air pressure, so conventional wisdom would state that fluids, such as blood, would instantly boil. While this is correct for exposed fluids, the surface tension of your skin actually provides significant pressure to your internals, thus eliminated the chance of boiled blood.

 

Now lets see what does happen during space exposure:

The Big Exhale

Immediately after exposure, all of the air in your lungs would rapidly be sucked out due to the pressure difference. This actually can cause significant damage to the lungs if you tried to hold in the oxygen. While this alone is not fatal, the de-oxygenated blood will reach your brain in 10-20 seconds, which will cause a loss of consciousness. Most likely “the bends” would occur in a similar fashion.

Pressure Swelling

Another quickly presented symptom of space exposure would be the swelling of most parts of the body, possibly up to twice its normal size. This swelling actually would be relatively painless, and completely reversible once the body is exposed to atmospheric pressure again.

Sunburn

Another dangerous side effect of being exposed to space is not the vacuum itself, but the lack of protection from the Sun’s harmful radiation. This could quickly damage skin in direct exposure, though compared to the dangers of rapid deoxygenation, this effect is less dangerous.

The Red Planet – pt. 2

Saturday, December 21st, 2013

This is part two of a three part series on Mars.

Decedents of Mars

The origin of life on Earth is a hotly debated topic throughout all facets of humanity. Both religiously and scientifically, there are dozens of explanations for how life began on our planet. While most focus on Earth being the cradle of life, there is a theory of the origin of life coming from another celestial body.

Note: This is a scientific theory, and has not been proven.

The Early Solar System

Our sun was formed approximately 4.6 billion years ago, and the planets formed shortly after that. In the early solar system, planets were extremely hot and constantly bombarded with asteroids. Because Mars is about 10 times less massive than the Earth, it was able to cool quicker. In doing so, it may have also formed liquid water earlier than Earth. As we saw in a previous article, water is the key to life, and thus Mars may have been habitable millions of years before Earth.

Extremophiles

Microscopic image of a Tardigrade

Although it is possible that Mars may have been habitable before Earth, it does not necessarily mean any life could travel between the two planets. Space is an extremely hostile environment, with frigid temperatures, fatal doses of radiation, and nearly a complete vacuum. To determine if life could exist in space, we must look at life on Earth today. Even in the harshest conditions on the planet, we find the Earth teeming with life. There is a classification of animals known as “extremophiles” that illustrate this survivability. One particular microscopic animal, known as the Tardigrade, can survive in almost any environment imaginable. They have been shown to live in temperatures a few degrees above absolute zero (−459.67°F), survive harmful doses of radiation, go without food for 10 years, and have even survived in the vacuum of space.

Transportation

Since it is plausible that a microscopic life form can exist in space, all that is needed is the vehicle to travel between planets. As mentioned earlier, the young universe was riddled with asteroids that would often collide into planets. A large enough impact will launch planetary matter with such velocity that it will escape the gravity of that planet and begin its journey into space. It is possible some of this matter on mars may have harbored some extremophiles, and perhaps that matter made its way to Earth, thus seeding life on our own planet. The origin of life on Earth is a hotly debated topic throughout all facets of humanity. Both religiously and scientifically, there are dozens of explanations for how life began on our planet. While most focus on Earth being the cradle of life, there is a theory of the origin of life coming from another celestial body.

The Red Planet – pt.1

Tuesday, December 17th, 2013

This is a part of a three part series on Mars.

The fourth planet from the Sun, Mars has been the focal point of many astronomers for centuries. Recent discoveries from Martian rovers and satellites have shed some light on Mars’ turbulent past, and given us clues as to whether or not it could support life.

Origin

Mars was formed during the same period as earth, about 4.6 Billion years ago. The leading theory is that the entire solar system was once a spinning disk of gas and dust, known as a solar nebula. As gravity took hold, the matter started coalescing at the center to form the sun. Matter escaping the strong gravitational force of the newly formed sun accrued in orbit around it, forming the planets.

Earth and Mars to scale

Statistics

Mars is about half the diameter of Earth, with about 37% of Earth’s gravity at the surface. Its orbital period (a Martian year) is about 687 Earth days, and exists on average about 228,000 km (142,000mi) from the Sun. A day itself on Mars is only slightly longer than that of Earth, about 24 hours and 39 minutes.

Mars’ red color comes from the iron oxide in the soil. It has an atmosphere, albeit a thin one, which is predominantly carbon dioxide.

Real-time animation of Phobos (foreground) eclipsing Demos (background), as seen from the Curiosity rover.

Mars has two natural satellites, Phobos and Demos. Both are relatively small, with Phobos being about 22.5km across, while Demos is only 12.4km across. Both may not have originated from Mars, but may instead be captured asteroids. Phobos is only about 6,000 km (3,700 mi) from the surface of Mars, and is slowly moving closer at a rate of about 1 meter every 100 years, which means in about 50 million years it will either break apart or collide with the planet.

Water on Mars

Mars has water in the form of ice visible on the surface at the north and south poles. It was speculated that liquid water may reside somewhere on the surface, but so far our reconnaissance missions have found no such evidence. This is primarily due to the lack of a significant atmosphere, which in its absence allows liquid water to boil at a very low temperature. However, we have evidence that at some point – perhaps only a few million years ago – water did exists in deep craters.

Recently the NASA rover Curiosity has discovered that Martian soil has as much as 3% water by mass, locked in with other molecules. This could be a vital resource in the future if humans plan on erecting a permanent habitat on the surface.

Life on Mars

Perhaps one of the hottest astrobiological topics of the last 40 years is the possibility of life currently or previously existing on Mars. This was triggered by a meteorite, known as ALH84001, which was found in Antarctica in 1984. This Martian meteorite was particularly interesting because about 25% of its magnetite was found to be similar to biologically generated magnetite on Earth. Also, an electron microscope revealed a bacteria-like structure which launched a debate about its formation.

Bacteria-like structure on the surface of ALH84001

More recently, the NASA rovers currently studying the Martian surface have found key ingredients for the formation of life, including sulfur, nitrogen, hydrogen, oxygen, phosphorus and possibly carbon. The Curiosity rover currently resides in what is suspected to be an ancient lakebed which could have been hospitable for life.

One of the biggest obstacles for Mars supporting current or recent life is the loss of a strong magnetic field, which protected the surface and Martian atmosphere much like Earth’s magnetic field.  Because Mars now has a very weak magnetic field, the atmosphere is subjected to the strong solar wind, causing a majority of it to blow off the planet. Additionally, radiation from the Sun and outer space reach the surface at lethal levels for most life forms found on earth. Scientists are still optimistic life could have once existed on Mars, and plan on using the data collected with the current Martian rovers as well as future expeditions on Mars to continue to hunt for clues of life.