... Low Polar Orbit . ... Different types of satellite orbits have different uses: while the synchronous orbit is best for communication satellites, Lagrangian point orbits help monitor the solar wind before it reaches Earth. ... Many spacecraft use such orbits, e.g. the US Air Force surveillance satellites of the DMSP series, or the series of French Earth-resources spacecraft SPOT . ... If the satellite then starts near a noon-midnight orbit, it will always pass near noon and near midnight. ...

Different types of satellite orbits have different uses: while the synchronous orbit is best for communication satellites, Lagrangian point orbits help monitor the solar wind before it reaches Earth. A low altitude polar orbit is widely used for monitoring the Earth because each day, as the Earth rotates below it, the entire surface is covered. ... A different choice was made for MAGSAT, orbited 1979-80 to survey the Earth's own magnetic field near its surface. ...

... HST . ... Missions . ... Data . ... Hubble Heritage Project . Future Missions and . ... HST Overview . Overview . ... Cycle 24 Announcement . ... Retrieving HST Data . ... Figure 6.1: - The Hubble Space Telescope and its components. ... Figure 6.2: - The focal plane of HST and the definitions of the V2, V3, U2, and U3 axes in the coordinate system of the spacecraft. Figure 6.3: - Locations of GHRS apertures relative to spacecraft axes. ... Figure 6.4: - Optical Schematic of the GHRS. ...

... May 4, 1999 . Magnetic Mars . Credit: Jack Connerney, Mario Acuna, Carol Ladd, MGS , NASA . Explanation: Mapping Mars from orbit, instruments on the Mars Global Surveyor (MGS) spacecraft have recently revealed banded magnetic field patterns - a startling and unanticipated suggestion that the Red Planet was more Earth-like in its distant past. ... As the crustal plates spread apart along the mid-ocean ridges , they carry a progressive banded record of Earth's changing magnetic field. ...

... The experience of determination of the link between radio sources and dynamical reference frames is presented. To obtain this connection we used a series of very long baseline interferometry (VLBI) observations of the spacecraft Phobos-2 and angularly nearby quasars. ... The dynamical reference frame is determined by equator and equinox of these ephemerides. ... References . ... The relative orientation of the radio and dynamical reference frames can be described by a sequence of three rotations . ...

... Eros Encounter Nears . ... After an unanticipated extra trip around the Sun, the NEAR spacecraft is now politely approaching asteroid 433, Eros, at a respectful relative speed of about 20 miles per hour. ... In the left corner, wearing a red nucleus surrounded by blue spiral arms, is M81. ... Rings Around Beta Pictoris . ... NEAR to Asteroid Eros . ... On December 23, 1998 the Near Earth Asteroid Rendezvous (NEAR) spacecraft flew by asteroid 433 Eros. ... Abell 2218: A Galaxy Cluster Lens . ...

This widget allows you to offset the telescope. ... Offset type : one of "Object Arc", "Object Arc XY" or "Boresight". ... This is motion on the sky or instrument, so don't worry about cos(dec). ... If you want to move that point (e.g. center your object along a different bit of the slit), then use a boresight offset. ... Note that a +X object xy offset will move the sky in the -X direction on the focal plane, because you are centering something in the +X direction on the boresight. ...

... 7 Comments None 3 0.1 1 10 normalized counts/sec/keV Black (qe16) Red (qe17) 1ES0102 REV 0065 MOS2 1 0.2 0.5 -100 -50 0 sign(d-m)*C channel energy (keV) Figure 3: As previous figure, but for MOS2 4 0 10 20 30 40 0.5­2.0 0.6 0.8 1.0 1.2 1.4 statistical basis: 117 observations relative flux in different bands [Joined fit = 1] pn MOS1 MOS2 RGS1 RGS2 xmmsas_20060628_1801­7.0.0_ccf_pub 0 10 20 30 2.0­10.