211 research outputs found

    From Lampoldshausen to Orbit: DLR Spin-off GreenDelta and the Development Status of Green Propellant Thrusters Based on H\u3csub\u3e2\u3c/sub\u3eO\u3csub\u3e2\u3c/sub\u3e and N\u3csub\u3e2\u3c/sub\u3eO

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    The German Aerospace Center\u27s Institute of Space Propulsion in Lampoldshausen has more than a decade of experience in green propellant research and green propulsion hardware development. In the frame of internal research projects as well as ESA and third-party projects DLR employees gained a deep and extensive knowledge of propulsion hardware. Based on this knowledge, thrusters and propulsion hardware were developed in-house and the TRL was increased step by step. Currently, the two most promising technologies are: the HyNOx bipropellant technology, based on nitrous oxide and hydrocarbon fuels, as well as the hypergolic HIP_11 technology. The HyNOx bipropellant offers a high Isp, non-toxic components, self-pressurized propulsion systems, easy handling and very low cost. HIP_11 is a patented, hypergolic combination based on hydrogen peroxide and ionic liquid fuels, which offers a comparable Isp, significantly reduced costs, and easy to handle propellants. To commercialize the two propulsion technologies, a DLR spin-off called GreenDelta will be founded in summer 2023. The preparation of the spin-off is currently funded by the Helmholtz Association and DLR. This paper gives an overview on the development of the two technologies and their development status. First thrusters from GreenDelta will be commercially available at Q4 2023

    Predicting the influence of a p2-symmetric substrate on molecular self-organization with an interaction-site model

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    An interaction-site model can a priori predict molecular selforganisation on a new substrate in Monte Carlo simulations. This is experimentally confirmed with scanning tunnelling microscopy on Fre´chet dendrons of a pentacontane template. Local and global ordering motifs, inclusion molecules and a rotated unit cell are correctly predicted

    From Lampoldshausen to Orbit: DLR Spin-off GreenDelta and the Development Status of Green Propellant Thrusters Based on H2O2 and N2O

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    The German Aerospace Center's Institute of Space Propulsion in Lampoldshausen has more than a decade of experience in green propellant research and green propulsion hardware development. In the frame of internal research projects as well as ESA and third-party projects DLR employees gained a deep and extensive knowledge of propulsion hardware. Based on this knowledge, thrusters and propulsion hardware were developed in-house and the TRL was increased step by step. Currently, the two most promising technologies are: the HyNOx bipropellant technology, based on nitrous oxide and hydrocarbon fuels, as well as the hypergolic HIP_11 technology. The HyNOx bipropellant offers a high Isp, non-toxic components, self-pressurized propulsion systems, easy handling and very low cost. HIP_11 is a patented, hypergolic combination based on hydrogen peroxide and ionic liquid fuels, which offers a comparable Isp, significantly reduced costs, and easy to handle propellants. To commercialize the two propulsion technologies, a DLR spin-off called GreenDelta will be founded in summer 2023. The preparation of the spin-off is currently funded by the Helmholtz Association and DLR. This paper gives an overview on the development of the two technologies and their development status. First thrusters from GreenDelta will be commercially available at Q4 2023

    Green Propulsion Demonstrator “The LÄNDer”

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    For future manned and unmanned space missions, landing systems are required, which are able to initiate and carry out soft autonomous landings on extraterrestrial celestial bodies. Development of rapid and robust guidance and control (GNC) systems as well as efficient, controllable and safe thrusters meeting a high level of autonomy and safety is crucial for successful lander missions. To meet those requirements, both component level view such as physico-chemical behavior of the propellants and the transients of the propulsion system itself as well as the system level view of the behavior of the holistic system are of utmost interest. To enable extensive testing and demonstration of new GNC methods and rocket engines, DLR Lampoldshausen has extended its research fields to develop a modular lander platform and a test bench with variable degrees of freedom. The aim is to combine extensive testing of GNC algorithms with sustainable propellant technology

    Failing to hash into supersingular isogeny graphs

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    An important open problem in supersingular isogeny-based cryptography is to produce, without a trusted authority, concrete examples of "hard supersingular curves" that is, equations for supersingular curves for which computing the endomorphism ring is as difficult as it is for random supersingular curves. A related open problem is to produce a hash function to the vertices of the supersingular \ell-isogeny graph which does not reveal the endomorphism ring, or a path to a curve of known endomorphism ring. Such a hash function would open up interesting cryptographic applications. In this paper, we document a number of (thus far) failed attempts to solve this problem, in the hope that we may spur further research, and shed light on the challenges and obstacles to this endeavour. The mathematical approaches contained in this article include: (i) iterative root-finding for the supersingular polynomial; (ii) gcd's of specialized modular polynomials; (iii) using division polynomials to create small systems of equations; (iv) taking random walks in the isogeny graph of abelian surfaces; and (v) using quantum random walks.Comment: 33 pages, 7 figure

    From Lampoldshausen to Space: DLR Spin-off InSpacePropulsion Technologies and the Development Status of Green Propellant Thrusters Based on H2O2 and N2O

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    The German Aerospace Center’s Institute of Space Propulsion in Lampoldshausen has more than a decade of experience in green propellant research and green propulsion hardware development. Over time, thrusters and propulsion hardware were developed in-house and the TRL of the hardware was increased step by step. Currently, the two most promising technologies are: the HyNOx bipropellant technology, based on nitrous oxide and hydrocarbon fuels, as well as the hypergolic HIP_11 technology. To commercialize the two propulsion technologies, a DLR spin-off called InSpacePropulsion Technologies will be founded in summer 2023. The preparation of the spin-off is currently funded by the Helmholtz Association and DLR. This paper gives an overview on the development of the two technologies and their development status

    Bioinformatics tools for cancer metabolomics

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    It is well known that significant metabolic change take place as cells are transformed from normal to malignant. This review focuses on the use of different bioinformatics tools in cancer metabolomics studies. The article begins by describing different metabolomics technologies and data generation techniques. Overview of the data pre-processing techniques is provided and multivariate data analysis techniques are discussed and illustrated with case studies, including principal component analysis, clustering techniques, self-organizing maps, partial least squares, and discriminant function analysis. Also included is a discussion of available software packages

    Measurement of the t(t)over-bar production cross section in pp collisions at root s=7 TeV in dilepton final states containing a tau

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    The top quark pair production cross section is measured in dilepton events with one electron or muon, and one hadronically decaying tau lepton from the decay t (t) over bar -> (l nu(l))((sic)(h)nu((sic)))b (b) over bar, (l = e, mu). The data sample corresponds to an integrated luminosity of 2.0 fb(-1) for the electron channel and 2.2 fb(-1) for the muon channel, collected by the CMS detector at the LHC. This is the first measurement of the t (t) over bar cross section explicitly including tau leptons in proton- proton collisions at root s = 7 TeV. The measured value sigma(t (t) over bar) = 143 +/- 14(stat) +/- 22(syst) +/- 3(lumi) pb is consistent with the standard model predictions

    stairs and fire

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