This paper describes guidance algorithms that use numerical predictor-corrector techniques to guide the spacecraft to the proper objectives. The precision landing objective is to deploy a parachute within 10 km of the target, and the aerocapture objective is to use a single atmospheric pass instead of an orbit insertion burn, with the requirement of being within 0.1° of the desired inclination ...

A precise analytic model for the relative motion of a group of satellites in slightly elliptic orbits is introduced. With this aim, we describe the relative motion of an object relative to a circular or slightly elliptic reference orbit in the rotating Hill frame via a low-order Hamiltonian, and solve the Hamilton-Jacobi equation. This results in a first-order solution to the relative motion id...

Receivers able to track satellites belonging to different GNSSs (Global Navigation Satellite Systems) are available on the market. To compute coordinates and velocities it is necessary to identify all the elements that contribute to interoperability of the different GNSSs. For example the timescales kept by different GNSSs have to be aligned. Receiver-specific biases, or firmware-dependent bias...

Taiji-1, which is the first experimental satellite for space gravitational wave detection in China, relies on key technologies include laser interferometer, reference sensor (GRS), micro-thruster and platform. Similarly to Laser Interferometer Space Antenna (LISA) pathfinder, except science optical bench (OB) of Taiji-1 contains test mass (TM) interferometers. Limited by lower mechanical streng...

suppose $g$ is a split connected‎ ‎reductive orthogonal or symplectic group over an infinite field‎ ‎$f,$ $p=mn$ is a maximal parabolic subgroup of $g,$ $frak{n}$ is‎ ‎the lie algebra of the unipotent radical $n.$ under the adjoint‎ ‎action of its stabilizer in $m,$ every maximal prehomogeneous‎ ‎subspaces of $frak{n}$ is determined‎.

Abstract The differential code biases (DCBs) of the global positioning system (GPS) receiver onboard low-Earth orbit (LEO) satellites are commonly estimated by a local spherical symmetry assumption together with known GPS satellite DCBs from ground-based observations. Nowadays, more and LEO equipped receivers for precise determination, which provides unique chance to estimate both without any g...

We present the first proper motion study of M10 (NGC 6254). Absolute proper motions of about 532 stars in the field of the globular cluster M10 were determined with respect to Hipparcos and ACT reference stars. In addition to photographic plates of Bonn and Shanghai also wide field CCD observations as second epoch plates were used. The wide field CCD observations show an accuracy comparable to ...

The key limitation of existing Real-Time Kinematic (RTK) systems is the service distances between reference stations and user receivers due to the impact of distance-dependent biases such as orbit error, and ionospheric and tropospheric signal delay. In current Network-RTK implementations, the inter-station distance is typically 70km to 90km. If coverage were to be extended to the whole Queensl...

Low-thrust transfers between given orbits within the two-body problem are considered; the thrust is assumed power limited. A simple method for obtaining the transfer trajectories based on the linearization of the motion near reference orbits is suggested. Required calculation accuracy can be reached by means of use of a proper number of the reference orbits. The method may be used in the case o...

The EnviSat altimeter, RA-2, is intended to continue an uninterrupted series of measurements of sea-level and ice-sheet elevation started by ERS-1 in 1991. To fully exploit these measurements, an absolute reference in the time series, and a distinction between instrumental artifacts and significant geophysical signals, is necessary. Therefore, the range bias and instrument drift shall be determ...