AirSpaceMag.com

Well-earned retirement: Atlantis heads into the hangar after its last spaceflight.

For the Memorial Day weekend, an assortment of news from the world of air and space:

►  The field of hypersonic flight has a new record: The Air Force’s X-51A Waverider reached Mach 5 in a 200-second scramjet engine burn over the Pacific on Wednesday. Video below:

►  What looked at first like a small asteroid circling the sun may in fact be an old Soviet rocket stage from the failed Luna 23 sample return mission in 1974. It may come back to hit us in 2036 (the nerve!) but it’s too small to do anything but burn up in the atmosphere.

►  The Stratospheric Observatory for Infrared Astronomy (SOFIA), an airborne telescope created by NASA and the German Aerospace Center, registered “first light” Wednesday night. Here’s a video of some of the pre-flight preparations and the takeoff. And here’s a shot of Jupiter taken during the flight.

► Tomorrow is the 23rd anniversary of 19-year-old Mathias Rust’s daring (dumb?) landing in Red Square, still one of the most talked-about aviation stunts in history.

►  And after racking up more than 120 million miles during 32 orbital flights over 25 years, the space shuttle Atlantis came back to Earth for the last time on Wednesday, capping the STS-132 mission to the International Space Station. Commander Ken Ham made a particularly soft touchdown:

Eyjafjallajökull the Unpronounceable, as seen by GeoEye's IKONOS satellite.

The risk to airplanes from the recent eruption of Eyjafjallajökull volcano in Iceland was more than just the danger of jet engines shutting down in flight. The ash could also have led to long-term damage that’s harder to spot. After a NASA DC-8 flew through a volcanic ash cloud in 2000, researchers found that:

…some of the particles we flew through were less than one micron in diameter, and even at those limits we didn’t experience any engine parameter failures or any indications whatsoever, but the engine manufacturer who did the work specified that we probably would have started seeing performance degradation in some of the engines in as little as 100 flight hours because of the loss of cooling and other things…

Read more about the 2000 research flight here.

U.S. Air Force PT uniform, circa 2006.

Ah, uniforms. People either love ‘em or hate ‘em. One could argue that the U.S. military has a good number of attractive uniforms: think of the Marine Corps dress uniform, the blue Army service uniform, the Navy’s full dress whites, and the Air Force flightsuit.

But it seems that our illustrious military cannot seem to master the physical training uniform. Note the Air Force PT uniform, left, which was redesigned in 2006. Complaints abounded over the outfits, which were supposedly an improvement over the existing gear. Dislike of the “MC Hammer” pants and “swishy suits” (so-called because of the noisy nylon fabric) meant that as of this year, another redesign is in the works.

In a 2009 Air Force Times article by Sam LaGrone, when asked “What are the dumbest rules in the Air  Force?” hundreds of airmen listed the Air Force’s 162 pages of uniform regulations as their top complaint.

Scorn of the PT uniform is not limited to our flying brethren, however. When presented with a look at the new Navy PT garb, hundreds of sailors posted comments. “This is a joke, they are just messing with us right?” asked one dismayed guest. Another poster commented, “I do not trust Master Chiefs to pick out clothing that looks good. I seriously doubt that they would mandate [the uniform] to be worn in the gym. If they do I will pay to go to a gym out of town.”

“Well the rain exploded with a mighty crash, as we fell into the sun…” As a kid, when I heard Paul McCartney sing those words, I sort of envisioned this:

An artist's concept of WASP-12b, the hottest planet known. Image: NASA, ESA, and G. Bacon (STScI)

Now astronomers using the Hubble Space Telescope have envisioned something like this happening to a planet orbiting a star 600 light-years away. But there’s no rain to be found on this eerie world.

The planet, WASP-12b, about 1.4 times the size of Jupiter, is steadily losing mass to its host star, which, like our sun, is a yellow dwarf. Discovered in 2008 by a team led by Carole Haswell of the Open University of Great Britain, WASP-12b orbits just one stellar radius from the blistering surface of the host—much closer than tiny Mercury, the innermost planet in our solar system, orbits the sun. Mercury completes an orbit every 88 Earth days. WASP-12b circles its star in 26 hours. “If you were on the outskirts of the planet,” says Haswell, “the star would pretty much fill your view of the sky.”

She says “outskirts,” because the planet is basically a roiling, football-shaped (due to tidal forces) ball of gas heated to 2,800 degrees Fahrenheit—the hottest world yet discovered. Each time WASP-12b passes in front of the star, which dims the star’s light a bit, Hubble’s Cosmic Origins Spectrograph detects heightened levels of aluminum, tin, manganese, and other elements, which means they exist in the planet’s atmosphere. Within 10 million years, possibly, the planet will basically evaporate. Or it may go gulp, right into the fire, before then.

What will that look like? Well, says Haswell, “My conscience is clear if I give you the caveats.” First off, it may not really be what we think of as a planet; just an opaque mass that passes in front of the star once a day, surrounded by a tenuous gas cloud of almost three Jupiter radii. That cloud is so expanded from the star’s heat that it is being gradually slurped away by the star. “The opaque planet is bigger than models of gas giant planets predict,” she says. “If there is a hard metal core, this tends to make the radius of the planet smaller.”

Theoretical work published last winter by Shu-lin Li of Peking University predicted that the planet’s tidal distortion makes the interior so hot that it greatly expands the outer atmosphere, which has now been confirmed by Hubble. “Since we suspect, after the work of Li [and his team] that this planet is inflated by tidal heating,” says Haswell, “there could be a hard metal core.” At some point, that metal core would begin to boil. “But this depends on whether the evolution causes the separation between the star and planet to increase or decrease. It’s fair to say we don’t have a complete picture of it yet.” The angular momentum would determine whether the planet eventually falls inward or drifts outward. But if it stays where it is, it will continue losing “atmosphere” to the star.

The planet could at some point get gulped into the star like an oyster, or smeared onto the stellar surface. If Earth-bound astronomers are around in 10 million years to watch this happen, what might they see? With current technology, says Haswell, astronomers would note no further dip in the light from the star, or the “Doppler wobble” caused by the planet’s mass tugging on the star, as it transits each day.

But 10 million years is a pretty long time—maybe by then we’ll watch it through some future telescope in high-resolution, or be out there in a starship for the occasion.

Artwork: Wright Patterson AFB.

The Air Force’s X-51A Waverider is being readied for its first hypersonic test flight on Tuesday, May 25. If all goes well, the scramjet-powered vehicle will fly for five minutes and hit Mach 6 before coming down into the ocean off the California coast. Project engineers hope to collect lots of data, while breaking the previous record for a scramjet flight, just 10 seconds, set by NASA’s X-43 in 2004.

Update on the April 22 HTV-2 hypersonic test: No joy—the vehicle stopped transmitting data nine minutes into its flight.