OrbitalHub

Wikipedia dicit:

A reaction control system (RCS) is a spacecraft system that uses thrusters to provide attitude control, and sometimes translation. Use of diverted engine thrust to provide stable attitude control of a short-or-vertical takeoff and landing aircraft below conventional winged flight speeds, such as with the Harrier “jump jet”, may also be referred to as a reaction control system.

An RCS is capable of providing small amounts of thrust in any desired direction or combination of directions. An RCS is also capable of providing torque to allow control of rotation (roll, pitch, and yaw).

Reaction control systems often use combinations of large and small (vernier) thrusters, to allow different levels of response. Spacecraft reaction control systems are used for: attitude control during re-entry, stationkeeping in orbit, close maneuvering during docking procedures, control of orientation, or ‘pointing the nose’ of the craft, a backup means of deorbiting, ullage motors to prime the fuel system for a main engine burn.

Because spacecraft only contain a finite amount of fuel and there is little chance to refill them, alternative reaction control systems have been developed so that fuel can be conserved. For stationkeeping, some spacecraft (particularly those in geosynchronous orbit) use high-specific impulse engines such as arcjets, ion thrusters, or Hall effect thrusters. To control orientation, a few spacecraft, including the ISS, use momentum wheels which spin to control rotational rates on the vehicle.

Video Credit: Copenhagen Suborbitals

NASA dicit:

Wherever there are humans, there are microbes, too. Bacteria and fungi live all around us, in our homes, offices, industrial areas, the outdoors – even in space. People literally could not live without these tiny organisms, many of which are beneficial.

The trick is limiting the number of potentially harmful ones, particularly in a contained environment such as a spacecraft. So from the launch of the very first module of the International Space Station, NASA has monitored its microbial community.

Because the station is an enclosed system, the only way that microbes get there is hitching a ride on the contents of resupply spacecraft from Earth and on arriving astronauts. The NASA Johnson Space Center Microbiology Laboratory puts a lot of effort into knowing which microbes ride along.

Video Credit: NASA Johnson

NASA dicit:

Since arriving at near-Earth asteroid Bennu in December 2018, NASA’s OSIRIS-REx mission has been studying this small world of boulders, rocks, and loose rubble – and looking for a place to touch down. The goal of OSIRIS-REx is to collect a sample of Bennu in mid-2020, and return it to Earth in late 2023.

Bennu turned out to be rockier than anticipated, but mission planners have now identified four sites on its surface that are smooth enough for OSIRIS-REx to collect a sample. The mission will down-select to the final two sites – a primary and a backup – in December 2019. Like the mythological Bennu bird for which the asteroid is named, all of the candidate sample sites refer to birds that can be found in Egypt.

Video Credit: NASA Goddard

NASA dicit:

Its size and surface gravity are much larger than Earth’s, and its radiation environment may be hostile, but a distant planet called K2-18b has captured the interest of scientists all over the world. For the first time, researchers have detected water vapor signatures in the atmosphere of a planet beyond our solar system that resides in the “habitable zone,” the region around a star in which liquid water could potentially pool on the surface of a rocky planet.

Given the high level of activity of its red dwarf star, K2-18b may be more hostile to life as we know it than Earth, as it is likely to be exposed to more high-energy radiation. The planet, discovered by NASA’s Kepler Space Telescope in 2015, also has a mass eight times greater than Earth’s. That means the surface gravity on this planet would be significantly higher than on our planet.

Video Credit: NASA

Lockheed Martin dicit:

Space is an important and valuable domain that has changed from a safe environment to one that is congested and threatened. A growing number of satellite system owners and operators need new capabilities to protect their assets and manage their interests in Space. Lockheed Martin’s iSpace software addresses this need by providing command and control and battle management capabilities for customers in all arenas – defense, international, commercial, and civil – that operate in the space domain.

Video Credit: Lockheed Martin

NASA dicit:

This Hubble time-lapse movie shows the orbits of some of Saturn’s icy moons as they circle the planet over an 18-hour period. The video is composed of 33 Hubble snapshots of the planet, taken June 19 to 20, 2019, by the Wide Field Camera 3.

Saturn’s signature rings are still as stunning as ever. The image reveals that the ring system is tilted toward Earth, giving viewers a magnificent look at the bright, icy structure. Hubble resolves numerous ringlets and the fainter inner rings.

This image reveals an unprecedented clarity only seen previously in snapshots taken by NASA spacecraft visiting the distant planet. Astronomers will continue their yearly monitoring of the planet to track shifting weather patterns and identify other changes. The second in the yearly series, this image is part of the Outer Planets Atmospheres Legacy (OPAL) project. OPAL is helping scientists understand the atmospheric dynamics and evolution of our solar system’s gas giant planets.

Video Credit: NASA