## Príspevky

### Pravdepodobnosť, že v skupine sa nachádzajú dve osoby s rovnakým dátumom narodenia

Mirek Rokyta otvoril tento  problém vo videu
https://youtu.be/cuBbmeLwZGg

Riešenie:
Pm = 1-365!/365^x/(365-x)!

pocet osôb v skupinepravdepodobnosť Pm20,00330,00840,01650,02760,04070,05680,07490,095100,117110,141120,167130,194140,223150,253160,284170,315180,347190,379200,411210,444220,476230,507 ...
750,9997

### Boeing CST-100 Starliner

On 22 December 2019 at 6:55 AM EST, Starliner was cleared to reenter the Earth's atmosphere. A 55 second deorbit burn started at 7:23 AM EST. Service module separation occurred at 7:26 AM EST and entered Earth's atmosphere at 7:41 AM EST.The heat shield jettisoned and the drogue-chutes deployed at 7:53 AM EST main parachutes deployed at 7:54 AM EST.[citation needed] The Starliner touched-down at White Sands Missile Range successfully at 7:58:02 AM EST.

### Halo orbit

A halo orbit is a periodic, three-dimensional orbit near the L1, L2 or L3 Lagrange point in the three-body problem of orbital mechanics. Although the Lagrange point is just a point in empty space, its peculiar characteristic is that it can be orbited. Halo orbits can be thought of as resulting from an interaction between the gravitational pull of the two planetary bodies and the Coriolis and centrifugal accelerations on a spacecraft. Halo orbits exist in any three-body system, e.g., the SunEarth–Orbiting Satellite system or the Earth–Moon–Orbiting Satellite system. Continuous "families" of both Northern and Southern halo orbits exist at each Lagrange point. Because halo orbits tend to be unstable, stationkeeping is required to keep a satellite on the orbit.

Most satellites in halo orbit serve scientific purposes, for example as space telescopes.
https://en.wikipedia.org/wiki/Halo_orbit

### Nodal precession Precesia uzlov

Nodal precession is the precession of the orbital plane of a satellite around the rotational axis of an astronomical body such as Earth.Rate of precession The rate of precession depends on the inclination of the orbital plane to the equatorial plane, as well as the orbital eccentricity. For a satellite in a prograde orbit around Earth, the precession is westward (nodal regression), the node and satellite move in opposite directions.[1] A good approximation of the precession rate is {\displaystyle \omega _{\mathrm {p} }=-{\frac {3}{2}}\cdot {\frac {{R_{\mathrm {E} }}^{2}}{\left(a\left(1-e^{2}\right)\right)^{2}}}J_{2}\omega \cos i} where ωp is the precession rate (in rad/s)RE is the body's equatorial radius (6378137 m for Earth)a is the semi-major axis of the satellite's orbite is the