Cassini’s final chapter has begun

The Cassini spacecraft arrived in orbit around Saturn on July 1, 2004.  In just one month, its mission will end forever with a suicidal plunge into the giant planet’s vast atmosphere.  The periapse of Orbit 288 was completed Sunday evening (JPL time; Monday morning UTC), marking the start of the final five orbits.

This periapse was just 1,060 miles above what is arbitrarily described as Saturn’s “surface” — the altitude where the atmospheric pressure is similar to that of Earth at sea level (1 bar).  This is low enough that the spacecraft has now tasted Saturn’s atmosphere directly, using its Ion and Neutral Mass Spectrometer to make the first ever direct measurements of Saturn’s atmosphere.  It’s also low enough the spacecraft may have had to tweak its course with its reaction control thrusters.  Also planned for this orbit are observations of the mysterious streaks in the rings, spectroscopic measurements of the atmosphere, and passive radar observations of Saturn’s atmosphere (observing changes in the carrier signal sent from Earth).

Not long now….

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CRS-12 successfully launched!

A Falcon 9 rocket successfully delivered the CRS-12 Dragon capsule to Earth orbit today, complete with a successful return of the first stage to Cape Canaveral.  It carries 3642 lbs. / 1652 kg of cargo in its pressurized compartment, and the 2773.4 lbs. / 1258 kg CREAM experiment package in the unpressurized “trunk” section.  (At around 10:27 of the following video, you can start to see CREAM in Dragon’s back section, complete with RMS grapple fixtures that will be used to extract it from the trunk later on.)  CREAM, Cosmic-Ray Energetics And Mass, has been flown from stratospheric balloons already; mounting it on the JEM Exposed Facility will give it the opportunity to make far more measurements over a long period of time.  Of more immediate practical return are the experiments in the pressurized compartment, including a crystal growth experiment funded partly by the Michael J Fox foundation to study Parkinson’s Disease, a commercial microsatellite to be deployed later, and an experiment that will grow human lung cell tissue scaffolds to be used in pharmaceutical and biological research.

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Amazon’s eclipse filter recall may need a recall itself

Amazon has started issuing refunds to buyers of filters out of an abundance of caution — they don’t want to get sued, obviously, by injured customers — but their suppliers may end up taking the hit, and not always with cause.

This week, I received a notice from Amazon that they’d be refunding the money I spent on a 9.5″ full-aperture solar filter from a reputable vendor which has been making high quality telescopic equipment for years.  They also said I didn’t have to return it, which made me happy, in that now I have a free solar filter, but also disturbed because it makes me wonder what this will mean for the manufacturer.

I’ve been looking around, and now I’m finding stories that Amazon is casting its net awfully far and wide, advising people not to use perfectly good filters from highly reputable manufacturers (including Orion Telescopes!) just a week before the eclipse when users aren’t likely to be able to actually find any other filters – which means that in addition to harming the vendors, Amazon will also be needlessly ruining the eclipse for a lot of people.

What’s more, the refund notice claims that Amazon has attempted to contact the vendors but received no response, which according to this article is not true.  Vendor AgenaAstro, which sells glasses made by Thousand Oaks and Baader Planetarium (both highly trusted manufacturers), provided documentation to Amazon weeks ago, and received no response.  Then, yesterday, they started to get customer e-mails, and discovered that Amazon was withholding payments to AgenaAstro in order to cover refunds, and sitting on thousands of in-stock glasses  that AgenaAstro now cannot sell before the eclipse.  Since they hired extra staff to cope with volume, this could put them in a precarious financial position.

Now, there actually are counterfeit solar filters running around, and I’ve also read reports of people comparing two different filters bought off Amazon and finding one is blatantly less effective than the other.  But it seems that Amazon is hitting legitimate vendors as well, and I doubt that fact will upset them much.

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The Perseids are peaking!

The Moon is kind of spoiling it a bit, but I’ve been seeing them here in my light-polluted suburb; if you have clear skies where you are, take fifteen minutes or half an hour or so to lie on the lawn and look at the sky.  😉  The Perseids are a fairly spread-out shower, so if tonight is a bust, give tomorrow a go, or even the night after.

Or, if  the weather’s never gonna cooperate, there’s another way to observe them: by listening for the radio echoes as they trail plasma through the upper atmosphere.  Here are a couple of live meteor radio streams you can listen to:

http://spaceweatherradio.com

http://www.livemeteors.com

This one has the radio data represented visually rather than audibly:

http://www.meteorscan.com/meteor-live.html

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Five Years On Mars: Curiosity

Sunday was the fifth anniversary of Curiosity’s landing on Mars.  Like its predecessors, Curiosity has gone on to exceed all of its expectations, and is still going strong despite considerable wheel tread damage.  In honor of the occasion, NASA has released this time-lapse video (with a relaxing musical accompaniment) of all five years, as seen by the rover’s hazard avoidance cameras.  Note the times when it switches to driving backwards, to spread out the wear on its wheels.  😉

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An era fades: the Rotating Service Structure at LC-39A comes down

It’s been kind of fun watching the last few Falcon 9 launches with the Shuttle’s Fixed Service Structure and Rotating Service Structure still in place at the icon LC-39A.  (The structures at LC-39B were removed years ago to return it to its “clean pad” configuration from the Apollo years.)  But that fun has come to an end.  Crews have begun delicately removing the Rotating Service Structure, piece by piece, to avoid damaging the new Falcon 9 structures in place at the pad.  It doesn’t need to be gone right away, but there is a bit of a downtime in the Falcon 9 launch schedule at Merritt Island, so it was a good time to get some progress in.  They expect to have it completely demolished by the end of the year, and the steel hauled off for recycling.

The Shuttle structures won’t be completely gone, though.  The Fixed Service Structure will be retained to support a gantry that will allow crew access once the crewed Dragon flights begin.  That access arm is scheduled to be added this fall, to support flights sometime next year.

There’s a time-lapse video in this article, showing the cranes arriving and beginning to lift down sections:

https://spaceflightnow.com/2017/08/05/shuttle-era-structure-dismantled-piece-by-piece-at-pad-39a/

But, as one era ends, another is beginning.  The loss of Shuttle remains bittersweet, but we’re moving into an exciting era of commercial spaceflight, not just in crewed flights but unmanned as well.  With luck, by the end of the year we’ll also see the launch of some of the Google Lunar Xprize candidates…..

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Vega completes a successful launch of VENµS and OPTSAT-000

Arianespace launched the lightest of their three vehicles on Tuesday (sorry for my late post; it’s been busy) placing two Earth observation spacecraft into orbit: VENµS and OPTSAT-3000. Yes, you read that right — there’s a lower-case mu in the name of the first one.  I think you’re meant to pronounce it “Venus”, but I’m not 100% sure.

VENµS is the Vegetation and Environment monitoring on a New Micro-Satellite (VENµS), which is where the mu comes from — one of the more creative acronyms I’ve seen.  😉  It was built by the Israeli Space Agency and will be operated by France’s CNES, which also supplied one of the instruments, as a cooperative venture between the two nations.  This is Israel’s first major scientific spacecraft, following on from a nanosatellite they flew earlier in the year.  The spacecraft will also test a Hall effect thruster supplied by ISA.

OPTSAT-3000, meanwhile, is Italy’s first optical surveillance spacecraft.  It, too, was built in Israel, but this one is for military purposes.  It joins Italy’s existing fleet of radar surveillance satellites.  OPTSAT-3000 is part of a qui-pro-quo arrangement between the Italian and Israeli governments; in exchange for buying the satellite from Israel, Israel bought a set of Italian fighter jet trainers.  The exact capabilities of OPTSAT-3000 are of course undisclosed, although Italy did indicate it would be comparable to Digital Globe’s best WorldView images.

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