Barred Spiral Galaxies SBA

Edwin Hubble classified spiral galaxies of this type as "SB" (spiral, barred) in his Hubble sequence and arranged them into sub-categories based on how open the arms of the spiral are. SBa types feature tightly bound arms, while SBc types are at the other extreme and have loosely bound arms. SBb-type galaxies lie in between the two. SB0 is a barred lenticular galaxy. A new type, SBm, was...

SpaceX Dragon Space Vehicle

On 23 February 2009, SpaceX announced that its chosen phenolic-impregnated carbon ablator heat shield material, PICA-X, had passed heat stress tests in preparation for Dragon's maiden launch. The primary proximity-operations sensor for the Dragon spacecraft, the DragonEye, was tested in early 2009 during the STS-127 mission, when it was mounted near the docking port of the Space Shuttle Endeavour...