OrbitalHub

NASA Goddard dicit:

When a new NASA space telescope opens its eyes in the mid 2020s, it will peer at the universe through some of the most sophisticated sunglasses ever designed. This multi-layered technology, the coronagraph instrument, might more rightly be called “starglasses”: a system of masks, prisms, detectors and even self-flexing mirrors built to block out the glare from distant stars — and reveal the planets in orbit around them. Normally, that glare is overwhelming, blotting out any chance of seeing orbiting planets. The star’s photons — particles of light — swamp those from the planet when they hit the telescope.

WFIRST’s coronagraph just completed a major milestone: a preliminary design review by NASA. The instrument has met all design, schedule and budget requirements, and can now proceed to the next phase, b uilding hardware for flight. The WFIRST mission’s coronagraph is meant to demonstrate the power of increasingly advanced technology. As it captures light directly from large, gaseous exoplanets, and from disks of dust and gas surrounding other stars, it will point the way to the future: single pixel “images” of rocky planets the size of Earth. Then the light can be spread into a rainbow spectrum, revealing which gases are present in the planet’s atmosphere — perhaps oxygen, methane, carbon dioxide, and maybe even signs of life.

The two flexible mirrors inside the coronagraph are key components. As light that has traveled tens of light-years from an exoplanet enters the telescope, thousands of actuators move like pistons, changing the shape of the mirrors in real time. The flexing of these “deformable mirrors” compensates for tiny flaws and changes in the telescope’s optics. Changes on the mirrors’ surfaces are so precise they can compensate for errors smalle r than the width of a strand of DNA. These mirrors, in tandem with high-tech “masks,” another major advance, squelch the star’s diffraction as well – the bending of light waves around the edges of light-blocking elements inside the coronagraph.

The result: blinding starlight is sharply dimmed, and faintly glowing, previously hidden planets appear. The star-dimming technology also could bring the clearest-ever images of distant star systems’ formative years — when they are still swaddled in disks of dust and gas as infant planets take shape inside.

The instrument’s deformable mirrors and other advanced technology — known as “active wavefront control” — should mean a leap of 100 to 1,000 times the capability of previous coronagraphs.

Video Credit: NASA Goddard

NASA dicit:

The SpaceX CrewDragon spacecraft parachutes successfully deploy during the latest development test. This test simulated a pad abort, where the vehicle is tumbling at low altitude before parachute deploy, validating SpaceX’s parachute models and margins. As a part of NASA’s Commercial Crew Program, SpaceX has been developing and testing the Crew Dragon parachute system, which is comprised of two drogue parachutes and four main ring-sail parachutes—the same type of parachutes that have been commonly and successfully used for human spaceflight in the past.

Video Credit: NASA

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:

A terrain relative navigation system developed by Draper of Cambridge, Massachusetts, will be tested on a Masten Space Systems Xodiac rocket. The flight is made possible with support from NASA’s Flight Opportunities and Game Changing Development programs. The Draper technology will eventually be ported directly into a NASA-developed descent landing computer for additional testing.

This video shows one of a series of tether tests of the navigation system mounted on the rocket. Tether tests like this ensure the rocket and navigation technology are communicating before the actual suborbital launch and landing.

NASA and commercial partners are relying on the most advanced technology to upgrade navigation for future robotic and crewed missions to the Moon. The agency is developing a suite of precision landing technologies for possible use on future commercial lunar landers.

Video Credit: NASA

Wikipedia dicit:

The Aerojet Rocketdyne RS-25, otherwise known as the Space Shuttle main engine (SSME), is a liquid-fuel cryogenic rocket engine that was used on NASA’s Space Shuttle. NASA is planning to continue using the RS-25 on the Space Shuttle’s successor, the Space Launch System (SLS).

Designed and manufactured in the United States by Rocketdyne (later known as Pratt & Whitney Rocketdyne and Aerojet Rocketdyne), the RS-25 burns cryogenic liquid hydrogen and liquid oxygen propellants, with each engine producing 1,859 kN (418,000 lbf) of thrust at liftoff. Although the RS-25 can trace its heritage back to the 1960s, concerted development of the engine began in the 1970s, with the first flight, STS-1, occurring on April 12, 1981. The RS-25 has undergone several upgrades over its operational history to improve the engine’s reliability, safety, and maintenance load.

The engine produces a specific impulse (Isp) of 452 seconds (4.43 km/s) in a vacuum, or 366 seconds (3.59 km/s) at sea level, has a mass of approximately 3.5 tonnes (7,700 pounds), and is capable of throttling between 67% and 109% of its rated power level in one-percent increments. The RS-25 operates at temperatures ranging from −253 °C (−423 °F) to 3300 °C (6000 °F).

The Space Shuttle used a cluster of three RS-25 engines mounted in the stern structure of the orbiter, with fuel being drawn from the external tank. The engines were used for propulsion during the entirety of the spacecraft’s ascent, with additional thrust being provided by two solid rocket boosters and the orbiter’s two AJ-10 orbital maneuvering system engines. Following each flight, the RS-25 engines were removed from the orbiter, inspected, and refurbished before being reused on another mission.

Video Credit: Aerojet Rocketdyne

Copenhagen Suborbitals dicit:

Adrian guides you through his project of a Reaction Control System for our crewed Spica space capsule. This system will enable our spacecraft to orient and stabilize itself in the vacuum of space.

Copenhagen Suborbitals is the world’s only manned, amateur space program, 100% crowdfunded and nonprofit. In the future, one of us will fly to space on a home built rocket.

Video Credit: Copenhagen Suborbitals