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Month: March 2015

Pushing the Boundaries of Propelling Deep Space Missions

Engineers at NASA’s Glenn Research Center are advancing the propulsion system that will propel the first ever mission to redirect an asteroid for astronauts to explore in the 2020s.  NASA's Asteroid Redirect Mission will test a number of new capabilities, like advanced Solar Electric Propulsion (SEP), needed for future astronaut expeditions into deep space, including to Mars.

The Hall thruster is part of an SEP system that uses 10 times less propellant than equivalent chemical rockets. In a recent test, engineers from Glenn and the Jet Propulsion Laboratory, using a Glenn vacuum chamber to simulate the space environment, successfully tested a new, higher power Hall thruster design, which is more efficient and has longer life. “We proved that this thruster can process three times the power of previous designs and increase efficiency by 50 percent,” said Dan Herman, Electric Propulsion Subsystem lead.

Hall thrusters trap electrons in a magnetic field and use them to ionize the onboard propellant. The magnetic field also generates an electric field that accelerates the charged ions creating an exhaust plume of plasma that pushes the spacecraft forward. This method delivers cost-effective, safe and highly efficient in-space propulsion for long duration missions. In addition to propelling an asteroid mission, this new thruster could be used to send large amounts of cargo, habitats and other architectures in support of human missions to Mars.

Image Credit: NASA
Michelle M. Murphy (Wyle Information Systems, LLC) via NASA http://ift.tt/1Ex3GzH Amazing.

Hubble Views a Galaxy on Edge

This NASA/ESA Hubble Space Telescope image shows an edge-on view of the spiral galaxy NGC 5023. Due to its orientation we cannot appreciate its spiral arms, but we can admire the elegant profile of its disk. The galaxy lies over 30 million light-years away from us.

NGC 5023 is part of the M51 group of galaxies. The brightest galaxy in this group is Messier 51, the Whirlpool Galaxy, which has been captured by Hubble many times. NGC 5023 is less fond of the limelight and seems rather unsociable in comparison — it is relatively isolated from the other galaxies in the group.

Astronomers are particularly interested in the vertical structure of disks like these. By analyzing the structure above and below the central plane of the galaxy they can make progress in understanding galaxy evolution. Astronomers are able to analyze the distribution of different types of stars within the galaxy and their properties, in particular how well evolved they are on the Hertzsprung–Russell Diagram — a scatter graph of stars that shows their evolution.

NGC 5023 is one of six edge-on spiral galaxies observed as part of a study using Hubble’s Advanced Camera for Surveys. They study this vertical distribution and find a trend which suggests that heating of the disc plays an important role in producing the stars seen away from the plane of the galaxy.

In fact, NGC 5023 is pretty popular when it comes to astronomers, despite its unsociable behavior. The galaxy is also one of 14 disk galaxies that are part of the GHOSTS survey — a survey which uses Hubble data to study galaxy halos, outer disks and star clusters. It is the largest study to date of star populations in the outskirts of disk galaxies.

The incredible sharp sight of Hubble has allowed scientist to count more than 30,000 individual bright stars in this image. This is only a small fraction of the several billion stars that this galaxy contains, but the others are too faint to detect individually even with Hubble.

European Space Agency

Credit: ESA/NASA via NASA http://ift.tt/1aaWXyO Amazing.