Microscope in orbit calibration procedure for a test of the equivalence principle at 10(-15)

The scientific objectives of the MICROSCOPE space mission impose a very fine calibration of the on-board accelerometers. However the required performance cannot be achieved on ground because of the presence of high disturbing sources. On-board the CHAMP satellite, accelerometers similar in the concept to the MICROSCOPE instrument, have already flown and analysis of the provided data then allowed to characterise the vibration environment at low altitude as well as the fluctuation of the drag. The requirements of the in-orbit calibration procedure for the MICROSCOPE instrument are demonstrated by modelling the expected applied acceleration signals with the developed analytic model of the mission. The proposed approach exploits the drag-free system of the satellite and the sensitivity of the accelerometers. A specific simulator of the attitude control system of the satellite has been developed and tests of the proposed solution are performed using nominal conditions or disturbing conditions as observed during the CHAMP mission.     

Body orientation and center of mass control in microgravity

The control of the body orientation and the center of mass position with respect to the feet was investigated under normo- and microgravity (space flight Altair), during erect posture and at the end of a forward or backward upper trunk movement.

It was observed that during erect posture, the trunk orientation with respect to the vertical was inclined some 6 ° forward in both subjects under microgravity, whereas it was vertical or slightly backward oriented under normogravity. Under microgravity, on the contrary, the initial position CM changed either backwards or forwards. This result suggests that the inclined trunk posture might be due to misevaluating the vertically under microgravity and that different control mechanisms are involved in orienting the trunk and placing the CM.

It was also noted that the final position of the CM at the end of the movement did not differ markedly between microgravity and normogravity. This result suggests that the kinematic synergies which stabilize the CM during uppertrunk movements may result from an automatic central control which is independent from the gravity constraints.     

The search for companions to Epsilon Eridani

The authors review efforts to examine the star Epsilon Eridani and determine the possibility for the existence of an Earth-like planet. Early data indicated that there must be a habitable ecosphere about 82.5 million Km from the primary. Research into the existence of another planetary system determined that Epsilon Eridani was a binary star with an Oort cloud system, indicating the possibility of planet formation. A review of the evidence suggests that the presence of the small red Dwarf companion star precludes the existence of a planetary system surrounding Epsilon Eridani. It is suggested that observations continue to provide further data about the formation of binary systems.     

RESEARCH ON THE LOCAL BLOCKAGE OF A TRANSPORTATION NETWORK AND ITS MINIMUM FLOW CAPACITY

ＲＥＳＥＡＲＣＨＯＮＴＨＥＬＯＣＡＬＢＬＯＣＫＡＧＥＯＦＡＴＲＡＮＳＰＯＲＴＡＴＩＯＮＮＥＴＷＯＲＫＡＮＤＩＴＳＭＩＮＩＭＵＭＦＬＯＷＣＡＰＡＣＩＴＹＮｉｎｇＸｕａｎｘｉ（ＩｎｄｕｓｔｒｙａｎｄＢｕｓｉｎｅｓｓＣｏｌｌｅｇｅ，ＮＵＡＡ２９ＹｕｄａｏＳ...     

A CONCISE M-METRIC LEAST SQUARE FORMULA FOR POLYNOMIAL ANALOGY

ＡＣＯＮＣＩＳＥＭ－ＭＥＴＲＩＣＬＥＡＳＴＳＱＵＡＲＥＦＯＲＭＵＬＡＦＯＲＰＯＬＹＮＯＭＩＡＬＡＮＡＬＯＧＹ￥ＰａｎＸｉａｏｓｕ（ＣｏｌｌｅｎｇｏｆＳｃｉｅｎｃｅ，ＮＵＡＡ２９ＹｕｄａｏＳｔｒｅｅｔ，Ｎａｎｊｉｎｇ２１００１６，Ｐ．Ｒ．Ｃｈｉｎａ）Ａ...     

RESEARCH ON THE BLOCKING FLOW IN A TRANSPORTATION NETWORK──THE GENERAL CONCEPTS AND THEORY OF THE BLOCKING FLOW

ＲＥＳＥＡＲＣＨＯＮＴＨＥＢＬＯＣＫＩＮＧＦＬＯＷＩＮＡＴＲＡＮＳＰＯＲＴＡＴＩＯＮＮＥＴＷＯＲＫ──ＴＨＥＧＥＮＥＲＡＬＣＯＮＣＥＰＴＳＡＮＤＴＨＥＯＲＹＯＦＴＨＥＢＬＯＣＫＩＮＧＦＬＯＷ￥ＮｉｎｇＸｕａｎｘｉ（ＩｎｄｕｓｔｒｙａｎｄＢｕｓｉｎｅｓ...     

NUMERICAL SIMULATION OF THREE DIMENSIONAL INTERACTING TURBULENCE FLOW FIELD OVER PROJECTILE WITH LATERAL JETS

INTRODUCTIONIn recent years,the study of lateral jets hasaroused more interest of aerodynamicist all overthe world.On the one hand,the interacting flowfield caused by lateral jet includes complicatedshock wave patterns and has important values tostuding flow phenomena.It has been not veryclear to this day and it is very difficult for nume-rical simulation.On the other hand,lateral jethas important applications for the field of aero-nautics,astronautics and weapons:for example,lateral jet …     

AN INVESTIGATION OF HOT FILM SIGNALS ON LOCATING BOUNDARY LAYER TRANSITION

ＡＮＩＮＶＥＳＴＩＧＡＴＩＯＮＯＦＨＯＴＦＩＬＭＳＩＧＮＡＬＳＯＮＬＯＣＡＴＩＮＧＢＯＵＮＤＡＲＹＬＡＹＥＲＴＲＡＮＳＩＴＩＯＮＷａｎｇＴｉｅｃｈｅｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＡｅｒｏｄｙｎａｍｉｃｓ，ＮＵＡＡ２９ＹｕｄａｏＳｔｒｅｅｔ，Ｎａｎｊｉ...     

ACTIVE VIBRATION CONTROL OF A CANTILEVER BEAM USING PIEZOELECTRIC SENSORS AND ACTUATORS

讨论了利用压电片作为传感器和驱动器对悬臂梁进行主动振动控制问题，针对模态频率差距较大的系统，提出了分组建模和控制的方法。使用滤波器消除观测溢出。文中还讨论了传感器／驱动器配置问题。实验结果验证了所述方法的有效性。     

The Urey instrument: an advanced in situ organic and oxidant detector for Mars exploration

The Urey organic and oxidant detector consists of a suite of instruments designed to search for several classes of organic molecules in the martian regolith and ascertain whether these compounds were produced by biotic or abiotic processes using chirality measurements. These experiments will also determine the chemical stability of organic molecules within the host regolith based on the presence and chemical reactivity of surface and atmospheric oxidants. Urey has been selected for the Pasteur payload on the European Space Agency's (ESA's) upcoming 2013 ExoMars rover mission. The diverse and effective capabilities of Urey make it an integral part of the payload and will help to achieve a large portion of the mission's primary scientific objective: "to search for signs of past and present life on Mars." This instrument is named in honor of Harold Urey for his seminal contributions to the fields of cosmochemistry and the origin of life.