Slingshot Day is Here

And so is the September Equinox!

Today OSIRIS-REx will fly to around 11,000 miles / 17,702 km to the Earth at 16:50 UT / 12:50 ET and will get a gravity assist to slingshot it to the near-Earth asteroid Bennu.

Hubble Sees a Binary Asteroid

It’s an asteroid pair and also classified as a main belt comet. Very nice work!

NASA — Hubble was used to image the asteroid, designated 300163 (2006 VW139), in September 2016 just before the asteroid made its closest approach to the Sun. Hubble’s crisp images revealed that it was actually not one, but two asteroids of almost the same mass and size, orbiting each other at a distance of 60 miles.

Asteroid 300163 (2006 VW139) was discovered by Spacewatch in November 2006 and then the possible cometary activity was seen in November 2011 by Pan-STARRS. Both Spacewatch and Pan-STARRS are asteroid survey projects of NASA’s Near Earth Object Observations Program. After the Pan-STARRS observations it was also given a comet designation of 288P. This makes the object the first known binary asteroid that is also classified as a main-belt comet.

The more recent Hubble observations revealed ongoing activity in the binary system. “We detected strong indications for the sublimation of water ice due to the increased solar heating — similar to how the tail of a comet is created,” explained team leader Jessica Agarwal of the Max Planck Institute for Solar System Research, Germany.

The combined features of the binary asteroid — wide separation, near-equal component size, high eccentricity orbit, and comet-like activity — also make it unique among the few known binary asteroids that have a wide separation. Understanding its origin and evolution may provide new insights into the early days of the solar system. Main-belt comets may help to answer how water came to a bone-dry Earth billions of years ago.

The team estimates that 2006 VW139/288P has existed as a binary system only for about 5,000 years. The most probable formation scenario is a breakup due to fast rotation. After that, the two fragments may have been moved further apart by the effects of ice sublimation, which would give a tiny push to an asteroid in one direction as water molecules are ejected in the other direction.

The fact that 2006 VW139/288P is so different from all other known binary asteroids raises some questions about how common such systems are in the asteroid belt. “We need more theoretical and observational work, as well as more objects similar to this object, to find an answer to this question,” concluded Agarwal.

The research is presented in a paper, to be published in the journal Nature this week.

The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington, D.C.

For additional images, visit:

Credits: NASA, ESA, and J. DePasquale and Z. Levay (STScI)


Hurricane Maria Hits Puerto Rico

Puerto Rico has been run-over by a very powerful hurricane. Hurricane Maria hit the island head on with winds at 134 knots.

Reports are saying power is out everywhere and there is widespread damage.   This was a devastating hit.   Hopefully everyone on the island is safe.

No word yet on how the Arecibo Observatory made out.  The observatory made it through Irma, but that was a glancing blow.

Heat Shield Testing

I am trying to figure out how they keep the thermocouple wires to keep from burning off.

NASA – NASA heat shield material that could one day be used on an inflatable aeroshell during atmospheric entry on Mars recently underwent testing at Boeing’s Large Core Arc Tunnel in St. Louis, Missouri.

The inflatable aeroshell, using high temperature advanced flexible material systems, will enable atmospheric entry to planetary bodies and the landing of heavy payloads. The Hypersonic Inflatable Aerodynamic Decelerator (HIAD) project is focused on development of the inflatable aeroshell technology and manufacturing capability at large scale, to support an orbital atmospheric entry flight experiment at Earth and Mars. HIAD overcomes size and weight limitations of current rigid systems by utilizing inflatable soft-goods materials that can be packed into a small volume and deployed to form a large aeroshell before atmospheric entry.

Critical to the development of the technology is development of flexible material systems whose performance must be verified through arc jet testing. During early August testing, small cutouts of the Flexible Thermal Protection System (F-TPS), about 2.5 inches (6.4 cm) in diameter and anywhere from a half-inch (1.3 cm) to 1 inch (2.5 cm) thick, were placed in a supersonic wind tunnel and blasted with jets of superheated plasma gas. The plasma gas hit the cutouts at speeds of Mach 4 or more, and heated the surfaces to temperatures up to approximately 2,700 F. Thermocouples embedded in the samples measured the material’s response to the superheated conditions.

Researchers calibrated tunnel pressure and temperature to be similar to the range of conditions HIADs would face during atmospheric entry on Earth and Mars. The data from these tests will be used to validate mathematical models used for design.

The test team included researchers Steven Tobin, Matt Wells and Andrew Brune of NASA’s Langley Research Center in Hampton, Virginia; and Grant Rossman, a Ph.D. candidate at the Georgia Institute of Technology in Atlanta.

HIAD technology is being developed by researchers at Langley through NASA’s Game Changing Development program, which is part of the agency’s Space Technology Mission Directorate. The program advances space technologies that may lead to entirely new approaches to space missions.

Image: Boeing / NASA

Last Light for Cassini

NASA —  This monochrome view is the last image taken by the imaging cameras on NASA’s Cassini spacecraft. It looks toward the planet’s night side, lit by reflected light from the rings, and shows the location at which the spacecraft would enter the planet’s atmosphere hours later.

A natural color view, created using images taken with red, green and blue spectral filters, is also provided (Figure 1). The imaging cameras obtained this view at approximately the same time that Cassini’s visual and infrared mapping spectrometer made its own observations of the impact area in the thermal infrared.

This location — the site of Cassini’s atmospheric entry — was at this time on the night side of the planet, but would rotate into daylight by the time Cassini made its final dive into Saturn’s upper atmosphere, ending its remarkable 13-year exploration of Saturn.

The view was acquired on Sept. 14, 2017 at 19:59 UTC (spacecraft event time). The view was taken in visible light using the Cassini spacecraft wide-angle camera at a distance of 394,000 miles (634,000 kilometers) from Saturn. Image scale is about 11 miles (17 kilometers).

Vera Rubin Ridge

NASA – This view of “Vera Rubin Ridge” from the Chemistry and Camera (ChemCam) instrument on NASA’s Curiosity Mars rover shows multiple sedimentary layers and fracture-filling deposits of minerals.

Buried layers of what is now a ridge became fractured, and the fractures were filled with mineral deposits precipitated from underground fluids that moved through the fractures.

ChemCam’s telescopic Remote Micro-Imager took the 10 component images of this mosaic on July 3, 2017, during the 1,745th Martian day, or sol, of Curiosity’s work on Mars. The camera was about 377 feet (115 meters) away from the pictured portion of the ridge. The rover’s location at the time, shown in a Sol 1741 traverse map, was west of the place where it began its ascent up the ridge about two months later.

The scale bar at lower right indicates how wide a feature 9 inches (22.8 centimeters) in width would look in the middle portion of the scene.


Return of the Dragon

UPDATE:  The Dragon is home and all is well.

The SpaceX Dragon cargo-ship was scheduled to leave the International Space Station this morning after delivering 2,900 kg / 6,400 lbs of supplies about a month ago.

The departure was scheduled for 08:47 UT / 04:47 ET today (17 Sept 2017) at the end of the Canadarm2 by Expedition 53 Flight Engineer Paolo Nespoli of ESA (European Space Agency) with the assistance of station Commander Randy Bresnik of NASA.

Dragon’s thrusters will be fired to move the spacecraft a safe distance from the station before SpaceX flight controllers in Hawthorne, California, command its deorbit burn. The spacecraft will splash down at about 14:16 UT 10:16 ET in the Pacific Ocean, where recovery forces will retrieve Dragon and approximately 3,800 pounds of cargo. This will include science samples from human and animal research, biology and biotechnology studies, physical science investigations and education activities. The deorbit burn and splashdown will not be broadcast on NASA TV.

NASA and the Center for the Advancement of Science in Space (CASIS), the nonprofit organization that manages research aboard the U.S. national laboratory portion of the space station, will receive time-sensitive samples and begin working with researchers to process and distribute them within 48 hours of splashdown.

In the event of adverse weather conditions in the Pacific, the backup departure and splashdown date is Sept. 20.

With any luck we might get video of the re-entry.

Image: NASA

Earth from Space

ESA’s Sentinel-5P Project Manager Kevin McMullan and Sentinel-5P Mission Manager Claus Zehner join the show to tell us about their roles in the Sentinel-5P mission.

The Last Signals from Cassini

The end of mission activities for Cassini will be here with live commentary from JPL at 11:00 UT/7:00 ET.

Expected LOS is 12:00 UTC / 08:00 EDT

About the image (NASA) – ASA’s Cassini spacecraft gazed toward the northern hemisphere of Saturn to spy subtle, multi-hued bands in the clouds there.

This view looks toward the terminator — the dividing line between night and day — at lower left. The sun shines at low angles along this boundary, in places highlighting vertical structure in the clouds. Some vertical relief is apparent in this view, with higher clouds casting shadows over those at lower altitude.

Images taken with the Cassini spacecraft narrow-angle camera using red, green and blue spectral filters were combined to create this natural-color view. The images were acquired on Aug. 31, 2017, at a distance of approximately 700,000 miles (1.1 million kilometers) from Saturn. Image scale is about 4 miles (6 kilometers) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of Caltech in Pasadena, manages the mission for NASA’s Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.

Image: NASA/JPL-Caltech/Space Science Institute