STENNIS - NASA plans to begin testing RS-25 engines for its new Space Launch System (SLS) in the fall of 2014, and the agency's Stennis Space Center in Mississippi has a very big -- literally -- item to complete on the preparation checklist.
Fabrication recently began at Stennis on a new 7,755-pound thrust frame adapter for the A-1 Test Stand to enable testing of the engines that will provide core-stage power for NASA's SLS. The stand component is scheduled to be completed and installed by November 2013.
"We initially thought we would have to go offsite to have the equipment built," said Gary Benton, RS-25 test project manager at Stennis. "However, the Stennis design team figured out a way to build it here with resulting cost and schedule savings. It’s a big project and a critical one to ensure we obtain accurate data during engine testing."
Each rocket engine type requires a thrust frame adapter unique to its specifications. On the test stand, the adapter is attached to the thrust measurement system. A rocket engine then is attached to the adapter, which must hold the engine in place and absorb the thrust produced during a test, while allowing accurate measurement of the engine performance.
The J-2X equipment installed on the A-1 Test Stand now cannot be used to test RS-25 engines since it does not match the engine specifications and thrust requirements. For instance, the J-2X engine is capable of producing 294,000 pounds of thrust. The RS-25 engine will produce approximately 530,000 pounds of thrust.
NASA and the Lockheed Martin Test Operations Contract Group team worked together in designing the new adapter to make sure such requirements were met. They also communicated closely with the Jacobs Technology welding and machine shop teams to make sure what was being designed actually could be built.
The design had to account for a number of considerations, such as specific stresses on the equipment as an engine is fired and then gimbaled (rotated) during a test; what type and strength of bolts are needed to fully secure the equipment; and what materials can be used to build the adapter.
"This is a very specific process," Benton said. "It is critical that thrust data not be skewed or compromised during a test, so the adapter has to be precisely designed and constructed."
The fabrication process itself involves handling and shaping large segments of certain material, which required welders to receive specialized training. In addition, shop personnel had to create a welding procedure for dealing with the chosen construction material. For instance, the area of material being welded must maintain a heat of 300 degrees in order to ensure welds bond properly. That procedure and other specifications are being incorporated into Stennis standards.
"It's a challenging project," said Kent Morris, RS-25 project manager for Jacobs Technology. "It's similar to the J-2X adapter project, but larger. It will take considerable man hours to perform the welding and machining needed on the material. The material used for the engine mounting block alone is 32 inches in diameter and 20 inches thick."
Physically, the adapter is the largest facility item on the preparation checklist for RS-25 testing, but it is far from the only one, Benton said. Additional modifications will be made to the test stand configuration and equipment once J-2X gimbal testing is complete this summer.
Once testing begins, engineers and test team personnel at Stennis will draw on a wealth of engine testing experience. The RS-25 engines, previously known as the space shuttle main engines were tested at Stennis for more than three decades.
PARIS - ESA’s fourth Automated Transfer Vehicle, Albert Einstein, completed a flawless rendezvous with the International Space Station on 15 June when it docked smoothly with orbital outpost at 14:07 GMT (16:07 CEST). The Automated Transfer Vehicle (ATV) is now connected to the Space Station.“Bravo Europe, bravo ESA, bravo ATV. Thank you Member States, thank you industry, thank you CNES, thank you Russian partner,” commented Jean-Jacques Dordain, Director General of ESA.
“With the fourth ATV now ready to support and supply the Space Station with essential supplies and scientific experiments, ESA again proves itself to be a reliable partner in the international station upon which the future can be developed.”
The 20-tonne ferry, the heaviest spacecraft ever launched by Europe, flew autonomously and docked with the 420-tonne complex with a precision of a few cm as both circled Earth at 28 000 km/h.
“Such a gentle contact between a spacecraft the size of a double-decker bus and a Station 20 times larger is an amazing achievement, highlighting the impressive level of control achieved by this European space system developed by our industry under ESA’s direction,” said Thomas Reiter, ESA’s Director of Human Spaceflight and Operations.
“These impressive technological capabilities will live on in the service module of NASA’s upcoming Orion crew vehicle.”
The rendezvous and docking were performed autonomously by ATV’s own computers, closely monitored by flight controllers from ESA and France’s CNES space agency at the ATV Control Centre in Toulouse, France, and by Luca Parmitano and his crewmates on the Station. Like its predecessors, ATV-4 is much more than a simple supply vessel: it is a space tug, a tanker, a freighter and a temporary habitation module.
To compensate for the natural decay in altitude of the Station’s orbit caused by atmospheric drag, it is loaded with 2580 kg of propellant to perform regular reboosts. It can even move the entire space complex out of the path of hazardous space debris. ATV also provides attitude control when other spacecraft are approaching the Station.
In its tanks, it carries 860 kg of propellant, 100 kg of oxygen and air, and 570 kg of drinking water, all to be pumped into the Station’s tanks. In its pressurised cargo module, it carries more than 1400 items packed into 141 bags, including 2480 kg of dry cargo such as scientific equipment, spare parts, food and clothes for the astronauts.
During its four months attached to the Station, ATV will provide 45 cubic metres of extra crew quarters. On previous missions, the addition was welcomed by the astronauts as “the quietest place in the Station” and was often the preferred area for working.
At the end of its mission, scheduled for 28 October, ATV-4 will separate from the Station, packed with waste bags. The following day, it will be directed to burn up safely in the atmosphere during reentry over the South Pacific Ocean.
PARIS - The module carrying the telescope and scientific instruments of ESA’s Euclid ‘dark Universe’ mission is now being developed by Astrium in Toulouse, France. Euclid will be launched in 2020 to explore dark energy and dark matter in order to understand the evolution of the Universe since the Big Bang and, in particular, its present accelerating expansion.Dark matter is invisible to our normal telescopes but acts through gravity to play a vital role in forming galaxies and slowing the expansion of the Universe.
Dark energy, however, causes a force that is overcoming gravity and accelerating the expansion seen around us today.
Together, these two components are thought to comprise 95% of the mass and energy of the Universe, with ‘normal’ matter, from which stars, planets and we humans are made, making up the remaining small fraction. Their nature remains a profound mystery.
“Euclid will address the cosmology-themed questions of ESA’s Cosmic Vision 2015–25 program with advanced payload technologies, enabling Europe to become a world leader in this field of research,” says Thomas Passvogel, Head of the Project Department in ESA’s Directorate of Science and Robotic Exploration.
Astrium will deliver a fully integrated payload module incorporating a 1.2 m-diameter telescope feeding the mission’s two science instruments, which are being developed by the Euclid Consortium.
The two state-of-the art, wide-field instruments – a visible-light camera and a near-infrared camera/spectrometer – will map the 3D distribution of up to two billion galaxies and the associated dark matter and dark energy, spread over more than a third of the whole sky.
By surveying galaxies stretched across ten billion light-years, the mission will plot the evolution of the very fabric of the Universe and the structures within it over three-quarters of its history.
In particular, Euclid will address one of the most important questions in modern cosmology: why is the Universe expanding at an accelerating rate today, rather than slowing down due to the gravitational attraction of all the matter in it?
The discovery of this cosmic acceleration in 1998 was rewarded with the Nobel Prize for Physics in 2011 and yet there is no accepted explanation for it.
By using Euclid to study its effects on the galaxies and clusters of galaxies across the Universe, astronomers hope to come much closer to understanding the true nature and influence of this mysterious dark energy.
“We are excited that Euclid has reached this important milestone, allowing us to progress towards launch in 2020, and bringing us ever closer to uncovering some of the Universe’s darkest secrets,” says Giuseppe Racca, ESA’s Euclid Project Manager.
PASADENA, Calif. -- Researchers using NASA's Mars Reconnaissance Orbiter have found that temperatures in the Martian atmosphere regularly rise and fall not just once each day, but twice.
"We see a temperature maximum in the middle of the day, but we also see a temperature maximum a little after midnight," said Armin Kleinboehl of NASA's Jet Propulsion Laboratory in Pasadena, Calif., who is the lead author of a new report on these findings.
Temperatures swing by as much as 58 degrees Fahrenheit (32 kelvins) in this odd, twice-a-day pattern, as detected by the orbiter's Mars Climate Sounder instrument.
The new set of Mars Climate Sounder observations sampled a range of times of day and night all over Mars. The observations found that the pattern is dominant globally and year-round. The report is being published in the journal Geophysical Research Letters.
Global oscillations of wind, temperature and pressure repeating each day or fraction of a day are called atmospheric tides. In contrast to ocean tides, they are driven by variation in heating between day and night. Earth has atmospheric tides, too, but the ones on Earth produce little temperature difference in the lower atmosphere away from the ground. On Mars, which has only about one percent as much atmosphere as Earth, they dominate short-term temperature variations throughout the atmosphere.
Tides that go up and down once per day are called "diurnal." The twice-a-day ones are called "semi-diurnal." The semi-diurnal pattern on Mars was first seen in the 1970s, but until now it had been thought to appear just in dusty seasons, related to sunlight warming dust in the atmosphere.
"We were surprised to find this strong twice-a-day structure in the temperatures of the non-dusty Mars atmosphere," Kleinboehl said. "While the diurnal tide as a dominant temperature response to the day-night cycle of solar heating on Mars has been known for decades, the discovery of a persistent semi-diurnal response even outside of major dust storms was quite unexpected, and caused us to wonder what drove this response."
He and his four co-authors found the answer in the water-ice clouds of Mars. The Martian atmosphere has water-ice clouds for most of the year. Clouds in the equatorial region between about 6 to 19 miles (10 to 30 kilometers) above the surface of Mars absorb infrared light emitted from the surface during daytime. These are relatively transparent clouds, like thin cirrus clouds on Earth. Still, the absorption by these clouds is enough to heat the middle atmosphere each day. The observed semi-diurnal temperature pattern, with its maximum temperature swings occurring away from the tropics, was also unexpected, but has been replicated in Mars climate models when the radiative effects of water-ice clouds are included.
"We think of Mars as a cold and dry world with little water, but there is actually more water vapor in the Martian atmosphere than in the upper layers of Earth's atmosphere," Kleinboehl said. "Water-ice clouds have been known to form in regions of cold temperatures, but the feedback of these clouds on the Mars temperature structure had not been appreciated. We know now that we will have to consider the cloud structure if we want to understand the Martian atmosphere. This is comparable to scientific studies concerning Earth's atmosphere, where we have to better understand clouds to estimate their influence on climate."
JPL, a division of the California Institute of Technology in Pasadena, provided the Mars Climate Sounder instrument and manages the Mars Reconnaissance Orbiter project for NASA's Science Mission Directorate, Washington.
Beijing – The Shenzhou-10 crew, who successfully launched out of the Jiuquan Satellite Launch Center yesterday aboard a modified Long March 2B booster, spent their first full day in space today offering the country Dragon Festival (Chinese New Year) greetings from within the spacecrafts descent module. Astronauts Nie Haisheng, Zhang Xiaoguang and Wang Yaping appeared on camera around 1pm local time today to thank those who were stuck working because they were in orbit and to send greetings to the rest of the country.
"We wish all Chinese around the world a happy Dragon Boat Festival," the astronauts said while holding a banner reading "Happy Dragon Boat Festival." Within the next day or two the crew should reach their destination – the Tiangong-1 space laboratory. Chinese technicians describe Tiangong-1 as a “mini Space Station”, a uniquely Chinese construction where Chinese astronauts can begin honing their skills before graduating to a full sized space station before the year 2020.
Tiangong 1 is 35 feet long and is 11 feet in diameter at its widest part. It weighs just 8.5 tons (compare that to the first Russian space station which weighed 25 tons). It is made up of two major modules. At the front is a docking port. Tiangong 1 has been fitted with a modified APAS-89 docking unit. The same unit currently used by Russia and the United States to dock with the International Space Station. It is believed that the Chinese chose this system deliberately in order to make their spacecraft compatible with ISS.
From the docking port, a cone shaped adapter leads to the first module known as the “experiment” module. This is a two steeped pressurized module with the back half being slightly larger than the front. This is the area in which the crew will do most of their work. The experiment module is connected to the second module, known as the resource module, via a second cone like structure. The resource module is a cylinder which contains all of the crew’s life support systems as well as all of the mechanical systems and fuel. Power is generated using two foldable solar panels that attach to the module. There are also at least two maneuvering engines in the back. It is entirely possible that this section is a modified Shenzhou service module. This would be similar to how the Russians used modified Soyuz service modules on their early space stations.
Shenzhou – 10 is the first operational flight of a Shenzhou spacecraft. Up to this point, the Chinese have been using each manned mission to develop certain key technologies. First was to simply fly a man in space, then to fly a crew into space, next was to conduct a spacewalk, and after that was to dock with an orbiting lab (Tiangong-1). Now they are seeking to utilize these key technologies to begin living and working in space.
High on the priority list for Shenzhou-10 will be docking operations. In fact this is mission critical objective. Once Shenzhou-10 reaches Tiangong-1 the crew will attempt to dock with it. This will be done autonomously from the ground. If Shenzhou-10 fails to dock the mission will be over. Upon docking the crew will enter Shenzhou-10’s orbital module. Unlike the Russian Soyuz and the American Space Shuttle, which normally stay passive during docked operations, Shenzhou-10 will play a very active roll. One of the Unique capabilities of the Shenzhou system is the fact that the orbital module can function independent of the rest of the spacecraft. It acts like a third module housing the kitchen, bathroom, and a single sleep station (two more are on the lab). It is interesting to note that on this particular mission the crew will be using a new and improved toilet as well as testing out new food.
Once the post docking checks are complete the crew will open the hatch and one of them, most likely the commander, will enter the lab. The first thing he will do is give the interior a thorough look over. Tiangong-1 has been in space now for over 600 days, during this time it has only been visited once. Early Russian space stations that were left un-occupied so long were often found to have mold or slime growing on the walls by the next crew. Chinese scientists believe that they have that problem under control but they want to make sure. Following his inspection the commander will invite the other two astronauts inside where they will hold a brief news conference before beginning work.
Over the course of the next few days the crew will work to resupply the station (something the Chinese have never done before) and begin work on science experiments. Earth observations and observations of China’s farm lands will be conducted using a special hyperspectral camera that has been installed inside the experiment module. The camera will enable scientists to monitor such things as heavy metal pollution, pesticide residue, and plant disease. In addition to the camera, the spacecraft comes equipped with facilities to study photonic crystals, a material that is expected to revolutionize information technologies here on Earth, and other experiments involving life sciences.
Taking a que from NASA, the crew plans to host a live broadcast with school children in China. Astronaut Wang Yaping plans to give Chinese primary and middle school students on Earth a lesson in the effects of the zero-gravity environment. This is intended to inspire them to pursue careers in science or mathematics.
After a period of time the crew will once again enter Shenzhou-10 and un-dock from the station. After performing a series of maneuvers meant to simulate relocating a spacecraft from one station port to another, the crew will re-dock with the station only this time they will do it manually.
The crew will spend the rest of the mission finishing up their experiments and packing away the results. During the time between the last Shenzhou visit and this one, the station has been working autonomously so there is a lot of data to collect. The crew will then return to Earth. The entire mission is expected to last 15 days.