OrbitalHub

Wikipedia dicit:

A rotating detonation engine (RDE) is an engine using a form of pressure gain combustion, where one or more detonations continuously travel around an annular channel. Computational simulations and experimental results have shown that the RDE has potential in transport and other applications.

In detonative combustion, the flame front expands at supersonic speed. It is theoretically more efficient than conventional deflagrative combustion by as much as 25%. Such an efficiency gain would provide major fuel savings.

The basic concept of an RDE is a detonation wave that travels around a circular channel (annulus). Fuel and oxidizer are injected into the channel, normally through small holes or slits. A detonation is initiated in the fuel/oxidizer mixture by some form of igniter. After the engine is started, the detonations are self-sustaining. One detonation ignites the fuel/oxidizer mixture, which releases the energy necessary to sustain the detonation. The combustion products expand out of the channel and are pushed out of the channel by the incoming fuel and oxidizer.

Video credit: NASA’s Marshall Space Flight Center

NASA dicit:

The entire gamma-ray sky is shown as two circular views centered on the north (left) and south poles of our Milky Way galaxy in this 14-year time-lapse of the gamma-ray sky. The central plane of our galaxy wraps around the edges of both circles, suppressing its glow and improving the view of black-hole-powered galaxies in the distant universe. Their gamma rays come from jets produced by supermassive black holes in distant galaxies that point almost directly toward Earth, which enhances their brightness and variability. Over a few days, these galaxies can erupt to become some of the brighest objects in the gamma-ray sky and then fade to obscurity. A moving source, our Sun, can be seen arcing up and down the circles as it appears to move through the sky, a reflection of Earth’s annual orbital motion. Watch for strong flares that occasionally brighten the Sun. In these maps, brighter colors indicate greater numbers of gamma rays detected by Fermi’s Large Area Telescope from Aug. 10, 2008, to Aug. 2, 2022.

Video credit: NASA

Wikipedia dicit:

Features on Mars that resemble dry riverbeds and the discovery of minerals that form in the presence of water indicate that Mars once had a dense enough atmosphere and was warm enough for liquid water to flow on the surface. However, that thick atmosphere was somehow lost to space. Scientists suspect that over millions of years, Mars lost 99% of its atmosphere as the planet’s core cooled and its magnetic field decayed, allowing the solar wind to sweep away most of the water and volatile compounds that the atmosphere once contained.

The goal of MAVEN is to determine the history of the loss of atmospheric gases to space, providing answers about Martian climate evolution. By measuring the rate with which the atmosphere is currently escaping to space and gathering enough information about the relevant processes, scientists will be able to infer how the planet’s atmosphere evolved over time.

Video credit: NASA Goddard

NASA dicit:

NASA is working with several American companies to deliver science and technology to the lunar surface through the Commercial Lunar Payload Services (CLPS) initiative.

These companies, ranging in size, bid on delivering payloads for NASA. This includes everything from payload integration and operations, to launching from Earth and landing on the surface of the Moon. Under Artemis, commercial deliveries beginning in 2023 will perform science experiments, test technologies, and demonstrate capabilities to help NASA explore the Moon as it prepares for human missions. CLPS contracts are indefinite delivery, indefinite quantity contracts with a cumulative maximum contract value of $2.6 billion through 2028.

Video credit: NASA

NASA dicit:

These visualizations show the Moon’s phase and libration at hourly intervals throughout 2024. Each frame represents one hour. In addition, the visualizations show the Moon’s orbit position, sub-Earth and subsolar points, and distance from the Earth at true scale. Craters near the terminator are labeled, as are Apollo landing sites, maria, and other albedo features in sunlight.

Video credit: NASA’s Goddard Space Flight Center/Data visualization by: Ernie Wright (USRA)/Producer & Editor: David Ladd (AIMM)/Music Provided by Universal Production Music: “Go Win It” – Alexander Hitchens

Wikipedia dicit:

Ingenuity, nicknamed Ginny, is a small autonomous helicopter presently operating on the planet Mars. It is part of NASA’s Mars 2020 mission. The helicopter arrived on the Martian surface attached to the underside of the Perseverance rover, which landed on February 18, 2021. The helicopter was deployed to the surface on April 3, 2021. Both the rover and the helicopter began their missions on Mars at the Octavia E. Butler Landing site near the western rim of the 28 mi (45 km) wide Jezero crater.

On April 19 it made the first powered, controlled extraterrestrial flight by any aircraft. During its first flight Ingenuity took off vertically, hovered, and then landed. It flew for a total of 39.1 seconds during that attempt. As of its 66th flight on November 3, 2023 (UTC), Ingenuity had flown a total of 1 hour, 58 minutes and 48 seconds over 928 days.

The flights have demonstrated the helicopter’s ability to fly in the extremely thin atmosphere of Mars, just 0.6% as thick as the air on Earth. It proved that flight was possible on other planets without the direct human control that the finite speed of light makes impractical (depending on the positions of the two planets, radio signals take between 5 and 20 minutes to travel between the Earth and Mars). As a result of this delay Ingenuity must autonomously perform the maneuvers planned, scripted and transmitted to it by its operators.

The helicopter was intended to perform a 30-sol technology demonstration, making five flights at altitudes ranging from 3–5 m (10–16 ft) for up to 90 seconds each. Before Ingenuity’s first flight, Perseverance drove approximately 100 m (330 ft) away to create a safety buffer between itself and the helicopter. The success of Ingenuity’s first flight was confirmed three hours after its completion by JPL, which livestreamed a view of mission control receiving the data. On April 30, 2021, during its fourth flight, Perseverance recorded the sound of Ingenuity during operation, making it the first interplanetary spacecraft whose sound was recorded in situ by another interplanetary spacecraft.

Video credit: NASA Jet Propulsion Laboratory