NASA Moves Closer to Manned Missions to Mars

NASA has moved one step closer to sending astronauts into deep space with the announced development of the Multi-Purpose Crew Vehicle (MPCV).

The MPCV replaces the Orion Crew Exploration Vehicle, commissioned under President Bush and nixed under President Obama due to budgetary constraints. Funds used in the development of the Orion ship had exceeded five billion dollars at the time of the project’s cancellation.

President Obama has instead set goals of a manned mission to a near-earth asteroid in the next twenty years, and a possible manned mission to Mars in the next thirty. NASA hopes the MPCV will help meet these goals. Unlike the Orion, which had been developed with the moon as its only destination, the MPCV will be used as the primary vehicle in the manned exploration of entirely new frontiers, such as asteroids or the Martian moons.

The development of the MPCV was brought about by the 2010 NASA Authorization Act, which shifted NASA’s focus away from the moon and towards a “permanent human presence beyond low Earth orbit.” NASA Administrator Charles Bolden spoke on the Authorization Act and development of the MPCV in a statement released Tuesday.

“We are committed to human exploration beyond low-Earth orbit and look forward to developing the next generation of systems to take us there. The NASA Authorization Act lays out a clear path forward for us by handing off transportation to the International Space Station to our private sector partners, so we can focus on deep space exploration,” he said.

The MPCV will consist of three components – a launch abort system, the crew module, and the service module, though only the crew module will return to Earth. The launch abort system peels off after the successful climb to orbit, while the service module, which generates electricity, stores oxygen, and can deliver scientific payloads, separates from the crew module immediately preceding re-entry.

The spacecraft is expected to be able to carry four astronauts into deep space, on missions lasting up to 21 days. On missions of longer duration, the MPCV would append a larger module, acting in a dormant, supportive capacity. The MPCV will also be capable of standard “in-space” activities, such as extravehicular activity or docking, and will serve as a possible fallback for delivering crew and cargo to the International Space Station.

In total, the volume of the pod-like MPCV will be approximately 690 cubic feet, of which 316 cu ft will be habitable.  The ship will take-off aboard a larger rocket and will splash land off the coast of California. Although reminiscent of the old Apollo spacecrafts, the design of the MPCV maximizes safety – its launches and landings are expected to be ten times safer than those of the space shuttles.

The contract for development of the spacecraft remains with Lockheed Martin Corporation, the primary contractor of the scrapped Orion ship. The decision to stay with Lockheed Martin drew some criticism given the final costs of the Orion project. SpaceX, a private company, has also indicated it can develop a similar ship for significantly lower costs.  However, NASA officials were careful to point out that budgetary considerations remain paramount.

“This selection does not indicate a business as usual mentality for NASA programs,” stated Douglas Cooke, an associate administrator with the NASA Exploration Systems Mission Directorate. “The Orion government and industry team has shown exceptional creativity in finding ways to keep costs down through management techniques, technical solutions and innovation.”

The announcement of the development of the MPCV comes a little over a month before the final launch of the space shuttle Atlantis. Scheduled for liftoff in early July, Atlantis’ completion of the STS-135 mission will signify the end of the shuttle program.

Photo Credits: NASA

First Possibly Habitable Exoplanet Found

A group of French researchers with the Laboratoire de Métrologie Dynamique (CNRS/UPMC/ENS/Ecole Polytechnique) at the Institut Pierre Simon Laplace in Paris have posited Gliese 581d as the first exoplanet possibly able to sustain life.

The team utilized a new atmospheric model, similar to the climate models currently employed to study the Earth’s atmosphere. The team’s findings have indicated that due to its location in the “Goldilocks zone” – that distance from a star where temperatures on a planet allow for the presence of liquid water – the planet may be habitable.

Gliese 581d’s atmosphere, believed to consist primarily of carbon dioxide, is thought to allow for features and weather phenomenon akin to those seen on Earth, such as liquid oceans, clouds and rain.

Discovered in 2007, the rocky Gliese 581d is one of six planets thought to orbit the star Gliese 581.  Located approximately 20.3 light years away in the constellation Libra, Gliese 581 is a red dwarf star. Although the most common type of stars in the galaxy, red dwarfs can be more volatile than their larger cousins – because of the variance created by star spots and flares, their energy outputs can vary from almost half their normal average to twice their normal average, sometimes for months at a time. Gliese 581 is a typical red dwarf star, with a mass one third that of our Sun. Unlike the Sun, however, the light emitted by Gliese 581 is generally in the infrared spectrum.

Gliese 581d orbits its star outside its planetary neighbor, Gliese 581g, which was originally considered a stronger candidate for possible habitation. Also thought to be a rocky world, Gliese 581g was discovered in September of 2010, and was believed to be three times larger than the Earth. Gliese 581g’s discovery caused a great deal of excitement, as it orbits in the middle of Gliese 581’s “Goldilocks zone”. However, as other astronomers have had difficulty independently verifying the planet’s existence, there is now some debate regarding the methodology used to find Gliese 581g, raising questions as to whether the planet exists at all.

Physically, although Gliese 581d is twice the Earth’s size, its mass is seven times larger than that of our planet. Gravity’s effect on the face of Gliese 581d would therefore be double that of Earth. Also, although Gliese 581d is closer to its star, it receives only one third of the energy from its star that the Earth receives from the Sun.

Scientists had previously discounted Gliese 581d for a number reasons. First, the planet was considered too far from its red dwarf star, and therefore its temperatures too cold to sustain liquid water. Secondly, Gliese 581d may be tidally locked to its star, meaning it’s always day on one side of the planet and always night on the other. The possibility of the planet being tidally locked seemed to preclude the existence of a moderate climate – any atmosphere significant enough to warm the planet would probably freeze off completely on the night side.

The new model, however, posits that a greenhouse effect – the circulating of warm temperatures on the sunlight side to the dark side by the atmosphere – combined with a thick, carbon atmosphere could allow for temperatures warm enough to maintain liquid water.           

Despite being in close cosmic proximity to Earth, however, Gliese 581d’s distance renders it too far for human visitation in the near future. Utilizing current Earth technology, it would take almost a third of a millennium to reach the planet.

Even studying the rocky world has proven difficult, as current telescopes are not powerful enough to observe the planet in sufficient depth. However, as telescope technology improves, Gliese 581d will remain a prime candidate in our quest for exoplanets capable of sustaining life. 

Photo Credit: Lynette Cook

Mysterious Gamma Ray Bursts Stun Scientists

The otherwise steadfast Crab Nebula has stunned scientists by emitting a huge burst of gamma rays, the source of which remains a mystery. According to NASA’s Fermi Gamma Ray Space Telescope (formerly the Gamma Ray Large Area Telescope, or GLAST), the burst emitted was up to 30 times the nebula’s normal output of gamma rays, and five times more powerful. 

The Crab Nebula is located  in the constellation Taurus, approximately 6,500 light years from Earth. It is comprised primarily of the remnants of a supernova – the explosion of a dying star. The light from the supernova which formed the Crab Nebula reached Earth and was recorded by astronomers at the time in the year 1054 AD.

What’s left of the core of the star, located in the center of the iconic gas cloud, is a spinning neutron star, or pulsar. Each of the neutron star’s 30-second rotations blasts huge beams of radiation outward. Referred to as a “constant candle”, the Crab Nebula has long since been considered a steady emitter of light, radio, and high-energy radiation, making the recent bursts of gamma rays particularly singular.

Of all the waves in the electromagnetic spectrum, gamma rays have the smallest wavelengths and the highest energy. Gamma ray bursts release significantly more energy than traditional stars.  

“An individual gamma ray burst can release in a matter of seconds the same amount of energy that our Sun will radiate over its 10-billion-year lifetime,” stated NASA scientist Neil Gehrels.

While waves of visible light or radio emissions permeate through our atmosphere, gamma rays are absorbed before they reach the Earth’s surface. This is beneficial for organisms on Earth, as gamma rays can be fatal for living cells.

However, this also makes gamma rays more difficult to study, requiring highly sensitive equipment, like the Fermi Telescope, often placed in the upper reaches of or above the Earth’s atmosphere.   

Speaking with the BBC, scientist Rolf Buehler explained part of the mystery surrounding the Crab Nebula’s sudden gamma ray bursts.  “If you look in optical light, the Crab is very steady,” he stated.  “In radio emission, it’s very steady; in very, very high-energy gamma rays it’s very steady. Only in this part between do we see it varying.”

The Fermi Telescope, which through its GLAST Burst Monitor (GBM) specifically studies gamma ray bursts, was able to record the first burst on April 12th, 2011. The GBM has the capacity to detect as many as 200 gamma rays bursts annually.

“It’s amazing that gamma-ray bursts are so powerful that a small detector you could hold in one hand can observe them from distances of billions of light-years,” stated GBM Principal Investigator Charles Meegan of NASA’s Marshall Space Flight Center.

The information was discussed at the Third Fermi Symposium in Rome, which ended yesterday.  Fermi’s observations were corroborated by similar findings on the AGILE, the Italian Space Agency’s satellite.

Speaking on the gamma ray flares, NASA’s Goddard Space Flight Center’s Alice Harding stated, “These superflares are the most intense outbursts we’ve seen to date, and they are all extremely puzzling events.”

Theories do exist as to the source and nature of the gamma-ray bursts. Scientists with NASA believe that the flares are a result of restructuring of the pulsar’s magnetic field, which can accelerate particles to very near the speed of light. 

Gamma ray bursts are thought to arise from the consequent interaction of these high-speed particles, like electrons, with the pulsar’s magnetic field. While scientists estimate that the emitting region must be within a third of a light year from the pulsar and approximately as large as our solar system, the exact source of the bursts remain unclear.

Photo credit: NASA/DOE/Fermi LAT/R. Buehler, ESA, J. Hester, A. Loll (ASU)

Penultimate Space Shuttle Launch Delayed Again Until End of Week

The launch of the NASA space shuttle Endeavour was scrubbed three hours before lift-off, due to problems with one of the shuttle’s three auxiliary power units. The auxiliary power units provide hydraulic power, used by the shuttle for steering purposes during ascent and re-entry.

The astronauts, led by Commander Mark Kelly, were already in the Astrovan when the launch was scrubbed.

A heater in the first auxiliary power unit (APU-1) has stopped working. The heater is one of two on APU-1, and is used to prevent the APU’s hydrazine fuel from freezing once the shuttle reaches orbit. NASA technicians have been systematically checking the thermostat associated with the APU-1 fuel line.

Though the thermostat is still not operational, NASA technicians have yet to determine whether the issue lies simply with the thermostat, or with an electrical switchbox or shorted wire. According to NASA, no decision on the feasibility of a Monday launch will be made until Sunday morning, at the earliest. The target launch time for the Endeavour shuttle is currently set for Monday at 14:34 eastern time.

Speaking on the decision to scrub the launch, Mission Management Team Chair and Shuttle Launch Integration Manager, Mike Moses stated, “It was pretty straight-forward scrub today. The team made a very good call.”

Endeavour’s external fuel tanks were drained Saturday. The draining of the “rocket fuel” – 500,000 gallons of liquid oxygen and  liquid hydrogen, is necessary for NASA technicians to safely reach the aft of the shuttle, from which they will attempt to diagnose the issue.   

The failure of the Endeavour launch was described as “disappointing” by shuttle launch director Michael Leinbach.

“A disappointing day for Team Endeavour and the astronauts, but as we always say in this business, ‘we will not fly this machine until it’s ready’ and today it was not ready’, ” he said.

The Endeavour mission is scheduled to bring a $2.1 billion dollar payload to the International Space Station, including the Alpha Magnetic Spectrometer (AMS-02) and spare parts. The AMS-02 is a particle physics detector which will search for dark matter and antimatter.

Sponsored by the United States Department of Energy, it was built and is operated by an international consortium spanning 16 countries and 56 institutes, and will be the first magnetic spectrometer to operate in space.

The launch was of particular historical importance. The mission, STS-134, was to be Endeavour’s last, and the penultimate space shuttle mission before the space shuttle program is discontinued. Built in 1992, the Endeavour is the youngest orbiter, and has successfully completed 35 previous shuttle missions.  It has orbited the Earth 4,429 times, and has spent over 280 days in space.

The Endeavour will spend two weeks in orbit. Following its re-entry in May, plans have been made for the shuttle to be displayed in a California museum.

The mission has also received additional attention due to the presence of Arizona Congresswoman Gabrielle Giffords, the wife of Commander Kelly.  Congresswoman Giffords was shot during a public meeting with constituents in January, and is currently undergoing physical rehabilitation in Texas.  She was on site to watch Friday’s launch from a private area reserved for the astronauts’ families.

President Obama was also present to watch the shuttle’s scheduled launch on Friday. He met with the astronauts and Congresswoman Giffords.  Following the launch’s scrubbing, the President took a tour of the Kennedy Space Center with his family.

On Sunday, the launch was again scrubbed because engineers had to replace a switch box in the engine compartment. The new target launch date is later this week.

As the space shuttle program draws to a close, attendance at the launches has grown significantly. Police have estimated that as many as 750,000 people were expected to watch the Endeavour launch from the surrounding roads and beaches.

Space shuttle Atlantis, scheduled for launch June 28th, 2011, will be the last orbiter to fly before the 30-year shuttle programs ends. The shuttle will carry the Raffaello multipurpose logistics module and spare parts to the International Space Station.

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