“The first task for spacewalkers Mark Vande Hei and Norishige Kanai is to move a Latching End Effector (LEE), or hand, for the Canadian-built robotic arm, Canadarm2, from a payload attachment on the station’s Mobile Base System rail car to the Quest airlock. This LEE was replaced during an Expedition 53 spacewalk in October 2017 and will be returned to Earth to be refurbished and relaunched to the orbiting laboratory as a spare.
Once they have completed that activity, they will move an aging, but functional, LEE that was detached from the arm during a January 23 spacewalk and move it from its temporary storage outside the airlock to a long-term storage location on the Mobile Base System, which is used to move the arm and astronauts along the station’s truss structure.”
“The John F. Kennedy Space Center (KSC) is one of ten National Aeronautics and Space Administration field centers. Since December 1968, Kennedy Space Center has been NASA’s primary launch center of human spaceflight. Launch operations for the Apollo, Skylab and Space Shuttle programs were carried out from Kennedy Space Center Launch Complex 39 and managed by KSC. Located on the east coast of Florida, KSC is adjacent to Cape Canaveral Air Force Station (CCAFS). The management of the two entities work very closely together, share resources, and even own facilities on each other’s property.
Though the first Apollo flights, and all Project Mercury and Project Gemini flights took off from CCAFS, the launches were managed by KSC and its previous organization, the Launch Operations Directorate. Starting with the fourth Gemini mission, the NASA launch control center in Florida (Mercury Control Center, later the Launch Control Center) began handing off control of the vehicle to the Mission Control Center shortly after liftoff; in prior missions it held control throughout the entire mission.
Additionally, the center manages launch of robotic and commercial crew missions and researches food production and In-Situ Resource Utilization for off-Earth exploration. Since 2010, the center has worked to become a multi-user spaceport through industry partnerships, even adding a new launch pad (LC-39C) in 2015.
There are about 700 facilities grouped across the center’s 144,000 acres. Among the unique facilities at KSC are the 525 ft tall Vehicle Assembly Building for stacking NASA’s largest rockets, the Operations and Checkout Building, which houses the astronaut crew quarters, and 3-mile-long Shuttle Landing Facility. There is also a Visitor Complex open to the public on site.”
“Even if rovers, balloons, and airplanes continuously move around and near the surface of Mars one day, we should never judge a planet by its cover. Today’s desert-like Martian surface likely hides the presence of water below ground. To “follow the water” to where it is today, we must go beneath the surface of the planet with subsurface explorers. The subsurface of Mars may resemble some of the colder parts of Earth. For example, in Antarctica or Iceland, we know that water is stored in a layer of permafrost and beneath that, as liquid groundwater. Even if the ancient surface water on Mars evaporated, there may still be substantial reservoirs of water, in either liquid or frozen form, in the subsurface.
The very first subsurface exploration of Mars for NASA will be in partnership with the European Space Agency (ESA) in their Mars Express mission. This spacecraft carries a subsurface radar instrument that will use a 40-meter (130-foot) antenna to detect and map subsurface water. Electric signals will be sent down the antenna, creating low-frequency radar waves. The radar waves will penetrate the Martian surface as deep as five kilometers (three miles) and will be reflected back to the spacecraft by different subsurface features, including water. This data will give us a three-dimensional understanding of where and how much water may be distributed in the Martian subsurface.
A lander on Mars Express called Beagle 2 will also carry the first robotic mole. Mimicking the behavior of the small furry earth-bound creatures that burrow into the ground, robotic moles will drill underground by pulverizing rock and soil, avoiding the need for a complex drill stem. Beagle 2’s mole will only have the ability to penetrate less than a meter (less than 3 feet) below the surface.
A much more capable mole is under development in NASA’s technology program. Weighing about 20 kilograms (44 pounds), it will be capable of drilling hundreds of meters (hundreds of yards) into the ground and possibly deeper at a rate of 10-20 meters (33 – 66 feet) a day. Excavated soil would be moved to the back of the mole and a small tube leading to the surface would help alleviate the pressure from the growing mounds of soil. The tube would also send soil samples back to the surface and carry power to the robotic mole. The samples sent up to the surface would be studied for scientific data such as mineral content and oxidation levels of subsurface soil. A mole drilling at the polar cap would study the layers of ice that tell the story of its history, much like the rings of a tree reveal many things from its past. All of this data would provide clues in the search for ancient, or possibly current, life.
Once we know in more detail where the water lies, the next step is to drill in those locations. To get to the zone where frozen water–and possible dormant life–might be present, we will probably need to drill to a depth of 200 meters (656 feet). Liquid groundwater will be even deeper. That’s no easy feat, but it’s critical for understanding the possibility of past or present life on Mars and for confirming that water resources are available for future human explorers.
Deep subsurface access on Mars will have unique challenges. First of all, unlike on Earth, we will not be able to use a drill to go through mud, water, or probably even gas pressure to carry the cuttings away from the bit. We will need new systems for fluidless drilling. Second, we will need an effective means of keeping the hole open while the drilling proceeds. On Earth, this task is normally done with steel casing, which is very heavy. Engineers are actively seeking alternative ways that don’t require us to send heavy equipment to Mars given the expense. Finally, we will have to develop systems that allow the drill to make operational decisions for itself. On Earth, drills can get stuck very quickly, so a Mars robotic drill or subsurface explorer must know how to recognize, avoid, and solve problems on its own.”
“The Aerojet Rocketdyne RS-25, otherwise known as the Space Shuttle main engine (SSME), is a liquid-fuel cryogenic rocket engine that was used on NASA’s Space Shuttle and is planned to be used on its successor, the Space Launch System.
Designed and manufactured in the United States by Rocketdyne (later known as Pratt & Whitney Rocketdyne and Aerojet Rocketdyne), the RS-25 burns cryogenic liquid hydrogen and liquid oxygen propellants, with each engine producing 1,859 kN (418,000 lbf) of thrust at liftoff. Although the RS-25 can trace its heritage back to the 1960s, concerted development of the engine began in the 1970s, with the first flight, STS-1, occurring on April 12, 1981. The RS-25 has undergone several upgrades over its operational history to improve the engine’s reliability, safety, and maintenance load. Subsequently, the RS-25D is the most efficient liquid fuel rocket engine currently in use.
The engine produces a specific impulse (Isp) of 452 seconds (4.43 km/s) in a vacuum, or 366 seconds (3.59 km/s) at sea level, has a mass of approximately 3.5 tonnes (7,700 pounds), and is capable of throttling between 67% and 109% of its rated power level in one-percent increments. The RS-25 operates at temperatures ranging from −253 °C (−423 °F) to 3300 °C (6000 °F).
The Space Shuttle used a cluster of three RS-25 engines mounted in the stern structure of the orbiter, with fuel being drawn from the external tank. The engines were used for propulsion during the entirety of the spacecraft’s ascent, with additional thrust being provided by two solid rocket boosters and the orbiter’s two AJ-10 orbital maneuvering system engines. Following each flight, the RS-25 engines were removed from the orbiter, inspected, and refurbished before being reused on another mission.”
“Since arriving at Mars in October 2016, the ExoMars Trace Gas Orbiter has been aerobraking its way into a close orbit of the Red Planet by using the top of the atmosphere to create drag and slow down. It is almost in the right orbit to begin observations – only a few hundred kilometres to go! With aerobraking complete, additional manoeuvres will bring the craft into a near-circular two-hour orbit, about 400 km above the plane, by the end of April. The mission’s main goal is to take a detailed inventory of the atmosphere, sniffing out gases like methane, which may be an indicator of active geological or biological activity. The camera will help to identify surface features that may be related to gas emissions. The spacecraft will also look for water-ice hidden below the surface, which could influence the choice of landing sites for future exploration. It will also relay large volumes of science data from NASA’s rovers on the surface back to Earth and from the ESA–Roscosmos ExoMars rover, which is planned for launch in 2020.”
“How can you see the atmosphere? By tracking what is carried on the wind. Tiny aerosol particles such as smoke, dust, and sea salt are transported across the globe, making visible weather patterns and other normally invisible physical processes.
This visualization uses data from NASA satellites, combined with mathematical models in a computer simulation allowing scientists to study the physical processes in our atmosphere. By following the sea salt that is evaporated from the ocean, you can see the storms of the 2017 hurricane season. During the same time, large fires in the Pacific Northwest released smoke into the atmosphere. Large weather patterns can transport these particles long distances: in early September, you can see a line of smoke from Oregon and Washington, down the Great Plains, through the South, and across the Atlantic to England.
Dust from the Sahara is also caught in storms systems and moved from Africa to the Americas. Unlike the sea salt, however, the dust is removed from the center of the storm. The dust particles are absorbed by cloud droplets and then washed out as it rains.”
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