NASA astronaut Peggy Whitson trains underwater for a spacewalk at the Neutral Buoyancy Laboratory (NBL) at Johnson Space Center in Houston. Whitson is scheduled to launch to the International Space Station in late 2016 as part of Expedition 50/51.
Dr. Whitson first traveled to the space station as a crew member of Expedition 5, launching aboard the space shuttle STS-111 mission and returning six months later on STS-113. She was named the first NASA Science Officer during her stay, and she conducted 21 investigations in human life sciences and microgravity sciences as well as commercial payloads. Whitson became the first woman to command the International Space Station in October 2007, leading Expedition 16 during a six-month stay on the orbiting laboratory.
Image Credit: Bill Brassard (NBL)
Last Updated: Feb. 11, 2016
Editor: Sarah Loff
This image, taken by the NASA/ESA Hubble Space Telescope, shows a peculiar galaxy known as NGC 1487, lying about 30 million light-years away in the southern constellation of Eridanus.
Rather than viewing it as a celestial object, it is actually better to think of this as an event. Here, we are witnessing two or more galaxies in the act of merging together to form a single new galaxy. Each galaxy has lost almost all traces of its original appearance, as stars and gas have been thrown by gravity in an elaborate cosmic whirl.
Unless one is very much bigger than the other, galaxies are always disrupted by the violence of the merging process. As a result, it is very difficult to determine precisely what the original galaxies looked like and, indeed, how many of them there were. In this case, it is possible that we are seeing the merger of several dwarf galaxies that were previously clumped together in a small group.
Although older yellow and red stars can be seen in the outer regions of the new galaxy, its appearance is dominated by large areas of bright blue stars, illuminating the patches of gas that gave them life. This burst of star formation may well have been triggered by the merger.
Image credit: ESA/Hubble & NASA, Acknowledgement: Judy Schmidt
Text credit: European Space Agency
Maximum Take-Off Weight (MTOW) 575,000 kg (1,268,000 lb).
The maximum takeoff weight (MTOW) or maximum takeoff mass (MTOM) of an aircraft is the maximum weight at which the pilot of the aircraft is allowed to attempt to take off, due to structural or other limits.
MTOW is the heaviest weight at which the aircraft has been shown to meet all the airworthiness requirements applicable to it. MTOW of an aircraft is fixed, and does not vary with altitude or air temperature or the length of the runway to be used for takeoff or landing. A different weight the “maximum permissible takeoff weight”, or “regulated takeoff weight”, varies according to flap setting, altitude, air temperature, length of runway and other factors. It is different from one takeoff to the next, but can never be higher than the MTOW.
Certification standards applicable to the airworthiness of an aircraft contain many requirements. Some of these requirements can only be met by specifying a maximum weight for the aircraft, and demonstrating that the aircraft can meet the requirement at all weights up to, and including, the specified maximum. These requirements include:
At the MTOW, all aircraft of a type and model must be capable of complying with all these certification requirements.
Among large airliners, the same model of aircraft can have more than one MTOW. An airline can choose to have its airliner certified for an increased weight at an additional cost. Some airlines which do not require a high MTOW choose to have a lower MTOW for that particular aircraft to reduce costs (Landing and air traffic control fees being MTOW based).
In many circumstances an aircraft may not be permitted to take off at its MTOW. In these circumstances the maximum weight permitted for takeoff will be determined taking account of the following:
The maximum weight at which a takeoff may be attempted, taking into account the above factors, is called the maximum permissible takeoff weight, maximum allowed takeoff weight or regulated takeoff weight.
Expedition 46 flight engineer Tim Peake of ESA captured this photo on Jan. 29, 2016 from the International Space Station, as the robotic arm in Japan’s Kibo laboratory successfully deployed two combined satellites from Texas universities. The pair of satellites — AggieSat4 built by Texas A&M University students, and BEVO-2 built by University of Texas students — together form the Low Earth Orbiting Navigation Experiment for Spacecraft Testing Autonomous Rendezvous and Docking (LONESTAR) investigation.