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News Article
Site: http://phys.org/space-news/

As part of an international agreement with the Swedish National Space Board (SNSB), the team simulated a flight-vehicle loading operation with LMP-103S Green Propellant at Wallops Flight Facility on Virginia's Eastern Shore. The team demonstrated the proper storage and then loading of the propellant into a flight-like tank provided by the New York-based Moog Inc., an aerospace company interested in green-propulsion technology. This was the first-ever demonstration of its type on a U.S. range, said Henry Mulkey, an engineer at NASA's Goddard Space Flight Center in Greenbelt, Maryland, who led the effort. The demonstration, which took place late in 2015, will be followed this year by two other tests. Goddard's Propulsion Branch is carrying out a fracture test to determine the behavior of a flight tank should it crack while loaded with the propellant. And at the end of 2016, the branch also plans to test fire two Swedish-developed spacecraft thrusters powered by LMP-103S, said Caitlin Bacha, associate head of the center's Propulsion Branch. All tests are designed to show that LMP-103S is a viable, higher-performing, safer, and less-expensive alternative to hydrazine, a highly toxic propellant that requires personnel to don cumbersome, full-body protective gear when handling and loading the propellant into spacecraft. By way of comparison, Mulkey said he mixed LMP-103S wearing just safety glasses and a smock. The propellant, which a Stockholm-based company, ECAPS AB, began developing about two decades ago with SNSB funding, is based on ammonium dinitramide, a high-energy salt. It made its debut about five years ago aboard PRISMA, a Swedish spacecraft equipped with two one-Newton thrusters. (A Newton is a unit of force.) Over the years, 70 LMP-103S-powered thrusters have been built and used in different applications. NASA's Pre-Aerosol, Clouds, and ocean Ecosystem (PACE) mission also is investigating the use of LMP-103S-powered thrusters. "We gained a lot of knowledge and hands-on experience from this pathfinder activity," Mulkey said. "We can take this experience and directly apply it to other flight-loading activities." Goddard's experimentation with LMP-103S is just part of NASA's green propellant story. Goddard, as well as a handful of other NASA centers, also is participating in the Green Propellant Infusion Mission (GPIM). GPIM, which NASA's Space Technology Mission Directorate expects to launch in 2016, will carry 31 lbs. of another green propellant—AF-M315E—developed by the U.S. Air Force Research Laboratory in California. During the demonstration to be carried out by Ball Aerospace & Technologies Corp., of Boulder, Colorado, the spacecraft's five engines or thrusters will burn in different operations, testing how reliably the engines perform. Aerojet Rocketdyne, of Redmond, Washington, built the thrusters. For its part, Goddard carried out fluid testing on GPIM's systems and components, Bacha said. In particular, the test team carried out the first-ever "surge" and flow testing on AF-M315E. Surge is a phenomenon that occurs when an isolation valve opens to allow propellant to rapidly fill empty manifold lines. These pressures, if too high, potentially can damage sensitive flight components downstream. Flow testing, meanwhile, reveals how individual components perform in a system using the propellant. No data of this type existed for the AF-M315E prior to Goddard's surge and flow testing, Bacha said. "We have so many balls in the air with green propellant," she added. "We appreciate the opportunity to get our hands dirty, so to speak, with these propellants." Although the more traditionally used hydrazine will not be completely displaced due to its long heritage and widespread use, the two green propellants do offer compelling advantages. In addition to being easier to handle, they are more tolerant of low temperatures and could bring about less-expensive, more flexible mission designs. Furthermore, both green propellant options are better performing than hydrazine, meaning that a spacecraft could carry out more maneuvers on one tank of propellant or could reduce the needed propellant leaving room for additional flight instruments. "It's beneficial that we understand both," Mulkey said. "The change is coming."


Wallin F.,GKN plc | Olsson J.,ECAPS | Johansson P.P.J.,AB Akronmaskiner | Kruger E.,GKN plc | Olausson M.,GKN plc
Proceedings of the ASME Turbo Expo | Year: 2013

An experimental and numerical investigation of the flow in an s-shaped compressor duct is presented in this paper. The experimental test was conducted in the compressor test facility at STARCS in Bromma, Sweden. The duct was designed based on geometrical properties of corresponding low-speed tests performed at the Universities of Cambridge and Loughborough in the UK in the EU research project AIDA. For the high-speed test, the geometry was scaled to fit the downstream compressor, keeping the non-dimensional characteristics of the duct as similar to the low-speed configurations as possible. Extensive CFD calculations were performed to assist the set-up of the test and to predict the duct performance in detail. The duct was equipped with static pressure taps on hub and shroud as well as on the strut. The duct inlet and exit flowfields were scanned using a miniature five-hole pressure probe that provided total pressure, velocities and flow angles. Two different duct surface finishes were tested at two different compressor operational points. Using the five-hole probe results, the duct loss could be estimated and compared to that of the CFD. For the CFD analysis a surface roughness model was used to account for the different surface finishes of the duct. The results show that using the surface roughness model makes it possible to account for the increase in loss due to a rougher flow surface. The absolute loss values are however under-predicted by approximately 10% in the CFD compared to the experiments. © 2013 ASME. Source


Gohardani A.S.,Springs of Dreams Corporation | Stanojev J.,OHB Sweden | Demaire A.,OHB Sweden | Anflo K.,ECAPS | And 3 more authors.
Progress in Aerospace Sciences | Year: 2014

Currently, toxic and carcinogenic hydrazine propellants are commonly used in spacecraft propulsion. These propellants impose distinctive environmental challenges and consequential hazardous conditions. With an increasing level of future space activities and applications, the significance of greener space propulsion becomes even more pronounced. In this article, a selected number of promising green space propellants are reviewed and investigated for various space missions. In-depth system studies in relation to the aforementioned propulsion architectures further unveil possible approaches for advanced green propulsion systems of the future. © 2014 Elsevier Ltd. Source


Pokrupa N.,OHB | Anflo K.,ECAPS | Svensson O.,ECAPS
47th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit 2011 | Year: 2011

This paper presents the lessons learned from the design, development and in-space demonstration of the novel High Performance Green Propulsion (HPGP) system as implemented on the Prisma spacecraft platform. The opportunity to fly the HPGP system served as means to flight demonstrate the new propulsion technology, but also served as a demonstration of how to incorporate system level aspects to the spacecraft level design. Implementation of the HPGP propulsion system impacts five main system level interfaces namely, thermal, power, shock, vibration and plume effects. This paper presents how these requirements were met by spacecraft design, and quantitatively discusses the interfaces that are to be incorporated in to the spacecraft platform based on design, ground test data and flight test data. © 2011 by OHB Sweden. Source

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