OrbitalHub

NASA dicit:

Cameras outside the International Space Station captured dramatic views of Hurricane Zeta at 12:50 p.m. Eastern time Wednesday October 28, 2020 as the storm churned 200 miles south-southwest of New Orleans packing winds of 90 miles an hour.

Zeta is expected to make landfall near New Orleans later in the day Wednesday October 28 as a Category 2 hurricane before accelerating to the northeast.

Video credit: NASA

SpaceX dicit:

On Saturday, October 24, 2020, SpaceX completed its 100th successful flight since Falcon 1 first flew to orbit in 2008. Over the course of these flights, SpaceX landed Falcon’s first stage booster 63 times and re-flew boosters 45 times.

Video credit: SpaceX

NASA dicit:

The Sun is stirring from its latest slumber. As sunspots and flares, signs of a new solar cycle, bubble from the Sun’s surface, scientists are anticipating a flurry of solar activity over the next few years. Roughly every 11 years, at the height of this cycle, the Sun’s magnetic poles flip — on Earth, that’d be like the North and South Poles’ swapping places every decade — and the Sun transitions from sluggish to active and stormy. At its quietest, the Sun is at solar minimum; during solar maximum, the Sun blazes with bright flares and solar eruptions. In this video, view the Sun’s disk from our space telescopes as it transitions from minimum to maximum in the solar cycle.

Video credit: NASA’s Goddard Space Flight Center/Joy Ng (USRA): Producer/Tom Bridgman (GST): Data Visualizer/Maria-Jose Vinas Garcia (Telophase): Support/Pedro Cota (ADNET Systems): Support

NASA dicit:

NASA’s Neil Gehrels Swift Observatory tallied the water lost from an interstellar comet as it approached and rounded the Sun. The object, 2I/Borisov, traveled through the solar system in late 2019.

Comets are frozen clumps of gases mixed with dust, often called “dirty snowballs.” As a one approaches the Sun, frozen material on its surface warms and converts to gas.

When sunlight breaks apart water molecules, one of the fragments is hydroxyl, a molecule composed of one oxygen and one hydrogen atom. Swift detects the fingerprint of ultraviolet light emitted by hydroxyl using its Ultraviolet/Optical Telescope (UVOT). Between September and February, Swift made six observations of Borisov with Swift. It saw a 50% increase in the amount of hydroxyl — and therefore water — Borisov produced between Nov. 1 and Dec. 1, which was just seven days from the comet’s closest brush with the Sun.

At peak activity, Borisov shed eight gallons (30 liters) of water per second, enough to fill a bathtub in about 10 seconds. During its trip through the solar system, the comet lost nearly 61 million gallons (230 million liters) of water — enough to fill over 92 Olympic-size swimming pools. As it moved away from the Sun, Borisov’s water loss dropped off — and did so more rapidly than any previously observed comet.

Swift’s water production measurements also helped show that Borisov’s minimum size is just under half a mile (0.74 kilometer) across. The team estimates at least 55% of Borisov’s surface was actively shedding material when it was closest to the Sun. That’s a large fraction compared to most observed solar system comets.

Video credit: NASA’s Goddard Space Flight Center/Scientific Visualization Studio/Scott Wiessinger (USRA): Lead Producer/Jeanette Kazmierczak (University of Maryland College Park): Lead Science Writer/Scott Wiessinger (USRA): Lead Animator/Dennis Bodewits (Auburn University): Scientist/Zexi Xing (University of Hong Kong): Scientist/Francis Reddy (University of Maryland College Park): Science Writer

NASA dicit:

NASA’s first asteroid sample return mission, OSIRIS-REx, will make a daring attempt to “TAG” asteroid Bennu on October 20 – touch its surface and collect a sample for return to Earth. Experience the sample collection event in 360 and watch as OSIRIS-REx contacts the rocky surface of sample site Nightingale on Asteroid Bennu.

Video credit: NASA’s Goddard Space Flight Center/James Tralie (ADNET): Lead Producer, Narrator/Jonathan North (USRA): Animator/Walt Feimer (KBRwyle): Animator/Michael Lentz (USRA): Art Director/Kel Elkins (USRA): Lead Visualizer/Aaron E. Lepsch (ADNET): Technical Support/ Music is “Fight for the Kingdom” from Enrico Cacace and Lorenzo Castellarin

Wikipedia dicit:

Rehearsals will be performed before the sampling event, during which the solar arrays will be raised into a Y-shaped configuration to minimize the chance of dust accumulation during contact and provide more ground clearance in case the spacecraft tips over (up to 45°) during contact. The descent will be very slow to minimize thruster firings prior to contact in order to reduce the likelihood of asteroid surface contamination by unreacted hydrazine propellant. Contact with the surface of Bennu will be detected using accelerometers, and the impact force will be dissipated by a spring in the TAGSAM arm.

Upon surface contact by the TAGSAM instrument, a burst of nitrogen gas will be released, which will blow regolith particles smaller than 2 centimetres (0.8 in) into the sampler head at the end of the robotic arm. A five-second timer will limit collection time to mitigate the chance of a collision. After the timer expires, the back-away maneuver will initiate a safe departure from the asteroid.

OSIRIS-REx will then halt the drift away from the asteroid in case it is necessary to return for another sampling attempt. The spacecraft will use images and spinning maneuvers to verify the sample has been acquired as well as determine its mass and verify it is in excess of the required 60 grams (2.1 oz). In the event of a failed sampling attempt, the spacecraft will return for another try. There is enough nitrogen gas for three attempts.

In addition to the bulk sampling mechanism, contact pads on the end of the sampling head will passively collect dust grains smaller than 1 mm, upon contact with the asteroid. These pads are made from tiny loops of stainless steel.

After the sampling attempt, the Sample-Return Capsule (SRC) lid will be opened to allow the sampler head to be stowed. The arm will then be retracted into its launch configuration, and the SRC lid will be closed and latched preparing to return to Earth.

Video credit: Lockheed Martin