Friday, September 23, 2011


There's space news this week! Sometime around mid-day Friday PDT, a NASA satellite the size of a school bus, weighing 6.3 tons, will reenter the Earth's atmosphere, begin to tumble and break up, and then burn up...except for 26 larger pieces that may make it intact to  the surface. NASA and US Strategic Command who track these things, say the surviving bits will land along a 500 mile path. NASA and USSTRATCOM say the largest piece will weigh about 330 lbs.

As I write (5PM Thursday PDT), the impact track is forecast to be over the Pacific Ocean, east of the Philippines Islands.

From my viewpoint, this is one of those Good News/Bad News deals. The good news is those big chunks won't hit anybody (unless there's a sailor out there with really, really bad karma). The bad news is "you can't see it from here!"

As we move into the future, we're looking at a few more years of these reentering space junk episodes. Today, USSTRATCOM is tracking 22,000 objects in Low Earth Orbit that range in size from four inches across to the 900,000 pound International Space Station that's roughly the size of a football field.

Friday's entry in the Space Junk Derby is named UARS, the Upper Atmosphere Research Satellite. It was launched from Space Shuttle Discovery on September 15, 1991, and decommissioned in 2005. UARS studied the upper reaches of the atmosphere with emphasis on the ozone layer.

More recent satellites now in orbit are equipped with reentry guidance controls, theoretically giving the satellite's minders some measure of control upon reentry. The next few years will see the last of the crap-shoot style reentries of these derelict satellites.

You can track the reentry of UARS at the Heavens Above website. Take a little time at Heavens Above to input and save your location data. I have bookmarked three locations at Heavens Above: The DaveCave, The Ancestral Digs, and My Mountain.This makes it a snap to find satellite passes and print them before I head out for the night.

I still get a kick out of watching the ISS pass overhead...I did see two Space Shuttle Reentries, thanks to Heavens Above, and I was able to see Russia's MIR Space Station and the Space Shuttle at the same time just weeks before MIR was deorbited. You can also find astronomical data on the Sun, Moon and Planets as well as comets and meteor showers. Heavens Above has printable sky maps for most observable events, as well as satellite pass info for radio hobbyists.

The internet is tailor-made for events like this one. All the data you need to know of, and view these global events. Even in today's 24/7 CableNews world this event is only getting cursory coverage. This is very different from the first major reentry of the Space Age...

I remember NASA's Skylab fondly, and remember the worldwide media circus surrounding it's reentry. The year was 1979. Being the first big satellite to return to Earth, Skylab was on everybody's radar. In San Francisco both daily papers held contests. The Examiner offered $10,000 for the first piece of Skylab delivered to the Examiner Offices. Not to be outdone, the SF Chronicle offered $200,000 to any subscriber who suffered personal injury or property damage from Skylab's fall.

On the fateful day, my girlfriend and I were in San Francisco. It was Wednesday July 11, 1979. In Union Square we ran into the LIVE Remote of KSAN the FM album rock station.The DJ asked the girlfriend where she wanted Skylab to land. She didn't hesitate to answer: "On the jerk who stole my bicycle!" The small crowd laughed and broke into applause.

Pieces of Skylab did land near Perth, Western Australia. The Examiner Prize was claimed, and a hunk of Skylab debris was displayed on stage at the Miss Universe Pageant which was held in Perth on July 20th. Wikipedia has the whole story and it's a fun read.

Reading the Wiki on Skylab raised some questions. Back in 1979, NASA estimated that the odds of a human being struck by Skylab debris were 1 in 152. Though I can't find the source I that saw this week, today NASA says the odds are 1 in 3200 for the human hit.

OK, I'm no math whiz, but one or both of these odds must be off. Higher odds in 1979 when there were 4.4 billion human targets, but today much better odds of a miss despite almost twice the targets- almost 7 billion people are walking around on Earth now.

Color me where's my Skylab Hard Hat?


  1. What? You are not prepared? What kind of Boy Scout were you?

    My protective satellite junk hat is on the hat rack right next to the metal colander I converted to ward off mind control rays from space aliens.

    A properly deployed colander works just as good as this Thought Screen Helmet --

  2. Protective headgear not a Fluke Digital BS Detector might be in order...NASA says it came down, but claim they don't know where...

  3. I have two Fluke digital multimeters (scored dirt cheap on eBay a few years back and restored to perfect operating condition by yours truly) but neither one has a BS selection on the rotary dial.

    Dagnabit! I must have got the wrong model!