April 17, 2014

Life in the Astro-Blogosphere: On Vigilance and the One That Got Away

Look! There it is!

Credit-The Virtual Star Party.

Now the story can be told.

You just never know when the universe is going to dangle a discovery right in front of your eyes. We amateur astronomers often pride ourselves on being “visual athletes,” patient steely-eyed observers who let little slip by us.

But we too can fall into the trap of routine. Just such a discovery was ours to lose a few weeks ago during the weekly Virtual Star Party held every Sunday night hosted by CosmoQuest and Universe Today on Google+. [Read more...]

January 2014-Life in the Astro-Blogosphere: Bizarro Astronomy

Our (Familiar?) Moon…

Photo by author

Weirdness is where you look for it. This was drove home to me while observing the Transit of Venus back in June 2012. While we strugged to grab a few brief views of the event through the pervasive cloud cover, we noted that life around us was going on pretty much as usual.

What else would we expect? Cars honked, dogs barked, kids played, all while a dim celestial event transpired just overhead, if you only knew where to look for it. [Read more...]

Astro-Vid Of the Week: Eclipse-Rise over KSC

Eclipse-Rise+VAB. (Photo by author).

Yesterday, we told the tale of our adventures in eclipse-chasing along the Florida Space Coast. The morning of Sunday, November 3rd 2013 found us on the Parrish Park causeway outside of Titusville, Florida shooting a frame of the eclipse every few seconds. We were fortunate that we had only a low cloud deck from the front that had passed through the day before, which provided us with just enough lingering clouds to be photogenic.   [Read more...]

November 2013-Life in the Astroblogosphere: Chasing the Saros

Eclipse-Sign! (Photos by Author).

It started with a tweet.

Towards the end of 2012, our thoughts turned, as they always do in the month of December, toward the top 100 astronomical events of the coming year. Eclipses always make this compilation, and we duly noted that totality for 2013 would only occur during the brief hybrid eclipse of Sunday, November 3rd. [Read more...]

July 2013-Life in the AstroBlogosphere: Who’s Who in the AstroTwitterverse

Astrophoto-shoot take 2;

note inclusion of AstroLab!

Recently, we wrote up an article on The New Social Face of Astronomy for the August 2013 issue of Sky &Telescope. Among the many cyber-corners and crannies of ye ole Internet that we explored was the world of Twitter. Twitter is a great source of fast breaking information, tailor made for certain aspects of astronomy such as meteorite falls, satellite reentries, new comet discoveries and nova flare-ups. [Read more...]

Life in the Astro-Blogosphere May 2013: They’re Out There, Man…

Why yes, we HAVE seen the ISS!

You just never know when you’ll come face-to-face with Woo.

We recently wrote about Comet ISON on Universe Today and how conspiracy crackpots are already lining up to capitalize on the projected “Comet of the Century.” It’s really win-win for them; if the comet lives up to expectations, there’ll be lots to hype, and if it’s a fizzle, hey, NASA’s “secret mission” must’ve taken it out…

[Read more...]

April 2013: Life in the Astro-Blogosphere: Astronaut or Rockstar?

1st band in space? (Credit: NASA/STS-110).

What did you want to be when you grew up? Of course, this tired old saw of a question assumes that you’re already a mortgage-paying, car-pooling adult who has had those childhood dreams tempered by reality. Hey, we all know that one guy or gal in our home town that got exactly what they wished for. For example, I knew a friend in high school that spent every waking hour drawing, designing and talking about car stereo boxes… and guess what? That’s what he does to this day. (Hopefully, the whole Ipod thing didn’t ruin his grandiose business schemes). [Read more...]

March 2013 Life in the Astro-Blogosphere: Living the NASASocial Experience.

Smartphones in Action!

(All photos by author.)

Ah, the romantic life of a free-lance science writer. Writing offers you the freedom to set your own hours and wake up slowly when you feel like it; it also earns one the right to “sing for their supper” and starve feral and in the wild, often on their very own time table. But along with the triumphs and tragedies that go with modern day writing online, you also tend to miss human interaction and that convergence of like-minded souls. [Read more...]

Exploring the Roper Mountain Science Center & the Charles E. Daniel Observatory.

The Daniel Observatory open & ready for

action!

(All photos by Author except as noted).

We love telescopes, old and new. Recently, we had a chance to explore a gem of an observatory nestled in the foothills just outside of Greenville, South Carolina. As we reported in Week 3 of our journey throughout the U.S. southeast, Greenville is the heart of all that is hip in western South Carolina. Located on the outskirts of the city, the Roper Mountain Science Center and the Charles E. Daniel Observatory houses a fine piece of astronomical history. [Read more...]

Week 6: Homeward Bound.

Sights near & far!

(All photos by Author).

Home. As Mad Max might say, “wherever you go, well, there you are,” but in the end, it’s great to come back into your own domain. Well, at least until you look at the pile of mail and backed up writing projects (such as finishing this six week article) that lies ahead. But just as Batman has his Batcave and Superman has his Fortress of Solitude, we too have Astroguyz HQ, wherever on this Big Blue Marble it might currently be located. The last week of 2012 saw us make the pilgrimage from South Carolina across Georgia and back into the great state of Florida. [Read more...]

Week 5: Down the (Future) Path of Totality.

The author & friends at the DoubleTree Hotel in

downtown Charleston, South Carolina!

(All pics by author).

It’s never too early to start planning, especially when it comes to solar eclipses. Week five of our southeastern sojourn saw us travel down the same path that the 2017 total solar eclipse will take over the Carolinas. We left the solitude and dark skies of the Appalachians as chronicled in Week 4 of the great American Road trip and headed back into civilization… and what a welcome it was!

[Read more...]

Week 4-The Quest for Dark Skies: Into the Appalachians.

A very slender Moon…

(All photos by Author).

The mountains always beckon. In the end, all astronomers must heed the call of dark, pristine skies and head into the foothills beyond the suburban lowlands in search of the universe only hinted at from our backyards. This past week we did just that in our week four installment of the great American Road Trip as we explored the U.S. Southeast and beyond. And, hey, we arrived under pristine skies just in time for this year’s Geminid meteor shower!

One Geminid of MANY seen!

Sunday saw a breakfast that couldn’t be beat at the Nosedive Bar and our departure from Greenville, South Carolina. As reported in week three of our 4-state spanning sojourn, we thoroughly enjoyed this town, a hip Portlandia-esque oasis in the South.

An armillary sphere-spotting at the Red Horse Inn!

A short drive saw us posed to hop across the North Carolina border in Landrum, South Carolina. Actually, we crisscrossed the border twice into “The North,” hitting the two outstanding wineries of Green Creek & the remarkable Overmountain Vineyards. We stayed at the charming Red Horse Inn in Landrum, where we consumed our days’ booty (a bottle of wine) under the stars in the hot tub adjoining our cabin. The Red Horse Inn would make an excellent star-gazing destination, as a short trip down the road finds you in total darkness away from the cottage lights… this would also make a fine group astronomy expedition area, especially as a good jumping off point for the graze line of the August 2017 total solar eclipse passing over the Mountain Bridge Wilderness Area just to the west.

Mmmm… beer… line ‘em up!

For our next adventure we headed northward into Asheville, North Carolina. If Greenville is the Portland (Oregon) of the South, Asheville is its Seattle, set long before Grunge became a name brand. We stayed at the enormous Grove Park Inn, a massive hotel complex perched just outside the city. Asheville itself is a wonderful, rambling city sprawling over dozens of foothills that put us in mind of Amman, Jordan, repleate with art spaces and breweries instead of mosques and sheesha bars. The Arts District alone was fascinating, as was the encaustic work of Constance Williams. Hey, we’d never even heard of encaustic in our High School Art I & II days! The Moog factory was also a fascinating stop. Based in Asheville, Moog has been the proud manufacturer of keyboards and synthesizers since 1978. And hey, who knew that they still make the theremin? Sheldon would be glad know… check out the action on Moog’s YouTube and Twitter feeds!

At Moog, where the theremin still reigns!

After hitting the local Asheville  Brewing Company and a fine Tapas meal at Cúrate, it was off to Mars Hill, North Carolina and the Scenic Wolf Resort for a night of dark sky observing. Located at about 4,000 feet elevation in the shadow of Mount Mitchell (the highest peak in the Appalachians) our cabin afforded a fine view of the 2012 Geminid meteors. And this was none too soon, as BBC 5 Live called us up that very night for a Skype interview! With a limiting magnitude of +5.5, I’d say that the Geminids put on one of the best displays in recent memory, with dozen several meteors seen gracing the sky before midnite!

The skies over Mars Hill, North Carolina.

But alas, we had to depart the beloved darkness for light-polluted climes all too soon. Having reached the northernmost apex of our journey, our ingress into society saw a brief stop in exotic Lincolnton, North Carolina… more to come next week!

 

Astro-Challenge: The Stars of Apollo 1.

Apollo 1 & the mission patch that never flew. (Credit: NASA).

What’s in a name? When it comes to stars in astronomy, a curious and often confusing system has arisen over the years; many stars are known by multiple designations from numerous surveys and catalogs done over the centuries, while many of the brighter stars have familiar designations handed down from Arab astronomers that remain fixed in our cultural lexicon. Say the name “Alpha Virginis” and you many get quizzical stares at the next star party, but everyone knows good ‘ole Spica as the brightest star in the constellation Virgo, even if few of us recall its obscure translation as the “ear of wheat”. Interestingly, even murkier stellar names seem to be making a comeback as various GOTO telescopes know exhort us to slew to “Cursa” or center “Thuban”…

This week, I’d like to draw your attention to three stellar names honoring a crew of brave pioneers that have made their way into the modern lexicon and even publication on some star maps. 45 years ago this week on January 27th, 1967, astronauts Roger Chaffee, Edward White, and Virgil “Gus” Grissom perished in a fire that engulfed the cabin of their Apollo 1 spacecraft during a training simulation. The tragedy was the worst that NASA had experienced up until that time. In fact, the argument has been made that the resolve and safety overhaul that resulted from the fire was what allowed NASA to step back, reassess, and make that ultimate drive towards the Moon. The final week of January into early February has also marks two other tragedies in the history of NASA, with the loss of Space Shuttle Challenger and her crew during launch on January 28th, 1986 and the destruction of Columbia and her gallant crew upon re-entry on February 1st, 2003. Space travel is a hazardous business, and the very fact that we as a nation and a species were able to pick up and press on marks the resolve embodied by these brave men and women.

Over the years, these astronauts have been memorialized by the naming of schools, landmarks, and more. In the case of the Apollo 1 astronauts, craters on the Moon and hills on Mars are named in their honor, as well as a plaque entitled the “Fallen Astronaut” containing their names along with those of Russian cosmonauts that perished in Soyuz 1, 11, and training accidents that was placed at Hadley Rille by Apollo 15 astronauts. But another quiet tribute rests in the springtime sky, one with a fascinating tale…

The Fallen Astronaut Memorial on the Moon (Credit: NASA/Apollo 15).

Astronauts used stellar targets to find their way during their missions to the Moon, much like ancient seafaring mariners. This enabled them to get an accurate fix on their position in time and space. This method also gave astronauts the autonomy to navigate without the help of ground control and  would have been crucial in an emergency situation if communications had been damaged. Much of this celestial training was conducted at the Morehead Planetarium in Chapel Hill, North Carolina in 1966. The story goes that Command Pilot Gus Grissom conspired to have the crew of Apollo 1′s names inserted for 3 of the more obscure 36 target stars in the flight navigation manual. A November 1966 checklist later surfaced depicting the ‘revisions’ and backing up the story!

A common mis-conception is that these three stars were named in honor of the Apollo astronauts, but in fact, they themselves placed their reversed monikers among the stars, which then came into common use after the Apollo 1 fire. Astronauts can even be heard on later mission tapes referring to the Apollo 1 “stars” by their names, and they have also found their way into various star charts. The good news is that late northern hemisphere winter into early spring is a fine time to find these three modern wonders of astronomical lore; all three shine at easy naked eye visiblibility threshold in the evening skies;

Navi, a finder chart. (Graphics created by the Author using Starry Night).

Right Ascension: 00 Hours 56’ 43”

Declination: +60° 43’ 00”

The northernmost Apollo star is “Navi,” backwards for “Ivan” as in Virgil “Ivan” Grissom. Located in the central “pivot” of the “W” asterism in the constellation Cassiopeia, this star is also referred to as Gamma Cassiopeia or “Tish” in Chinese, meaning “The Whip”. Navi is an eruptive variable star with a close spectroscopic white dwarf or neutron star companion. Earlier in the 20th century Navi attained a peak brightness of magnitude +1.6 in 1936, outshining the other stars of Cassiopeia. Navi rides high in February skies immediately after sunset.

Dnoces rising!

Right Ascension: 08 Hours 59’ 12”

Declination: +48° 02’ 30”

Dnoces” as in “Second” backwards for Edward White “The Second,” is located in the constellation Ursa Major and is also referred to as Iota Ursa Majoris or Talitha, meaning “The third leap” in Arabic. Dnoces is an interesting close multiple star system first noticed by John Herschel in 1820. The  magnitude +3.12 A component has a 9th magnitude B component that was at 10” arc seconds of separation on discovery that closed down to 4.4” and closing as of 1969. The B component in turn has a faint 10 magnitude companion on a 39.7 year orbit that will reach a maximum separation from the primary of 0.9” (tiny but perhaps just spilt-able with a large scope under excellent seeing!) in 2020. The entire system is about 48 light years distant. Dnoces rises around 10 PM for middle northern latitudes in February and earlier during the following months.

Suhail… or do you say Regor?

Right Ascension: 08 Hours 09’ 32”

Declination: -47° 20’ 12”

Regor” The southernmost of the three Apollo 1 stars, is also known as Gamma Velorum in the constellation Vela. This star also has the obscure name of Suhail and is one of the brighter stars in the southern sky shining at +1.7th magnitude. Regor is a Wolf-Rayet variable star and one of the most massive known at 10 times the mass of our own Sun. The system is also a complex one comprising no less than 6 stars, tying Castor for the title of most stars in one system. Gamma Velorum is a binocular double, with a blue-white +4.2 magnitude sub-giant companion about 41” arc seconds distant. A telescope will tease out further companions C (+8 magnitude, sep 62”) and D and E (magnitudes +9 & +13 respectively) 2” apart and 94” from the primary. The entire complex system is about 800 light years distant along the galactic plane.  From our 28° degree north latitude vantage point here at Astroguyz HQ in Hudson, Florida, Regor has a maximum elevation of about 16° degrees on the meridian at midnite local on February 1st, then progressively earlier in the evening as spring arrives.

Apollo 1 astronauts during a test checkout of the spacecraft. (Credit: NASA).

What I really love about the Apollo 1 stars is the wry thought put into naming them that the astronauts obviously gave; “Regor, Dnoces, and Navi” all sound suitably cryptic and simply sound “stellar”… one could image a pedantic astronomy professor utilizing them, or a sci-fi flick entitled “Invaders from Regor!!!” As we mark the anniversary of the fire that marred the Apollo program and shaped NASA, make a point to get out and spot these stars that pay tribute to these fine brave men and the legacy that they gave us!

 

Constellations of Yore.

Hunting Cerberus…

(From Johann Bode’s 1801 Uranographia, in the Public Domain).

Sure, you’re familiar with the constellations of Orion and Ursa Major. Or perhaps you even know the difference between a constellation and an asterism such as the “Teapot” or the “Sickle” of Leo, or maybe you can even successfully pronounce such tongue-twisting names as Vulpecula or Camelopardalis… But have you ever heard of Gallus the Rooster or  Polophylax the “Pole Keeper?” [Read more...]

No Nukes?-What the Plutonium Stoppage Means to the Space Program.

MMMmmmm….Plutonium cake… (Credit: Department of Energy).

(Editor’ s Note: We’d like to thank fellow backyard astronomer Clay M. Davis with giving us the “Nuclear Physics 101″ help embedded in this post!)

Amidst the impending decade of transition for the United States space program, a quiet fact is slowly rearing its ugly head, one that will have wide implications for the future of manned & unmanned space exploration. Specifically, NASA is running out of juice to explore the solar system. And that’s not a figurative or political metaphor, but we mean “juice” in terms of real, honest-to-goodness fuel in the form of plutonium-238. But first, a little background/history of this often maligned substance and its role in space;

When leaving our fair planet, mass is everything. Space being a harsh place, you must bring nearly everything you need, including fuel, with you. And yes, more fuel means more mass, means more fuel, means… well, you get the idea. One way around this is to use available solar energy for power generation, but this only works well in the inner solar system. Take a look at the solar panels on the Juno spacecraft bound for Jupiter next month… those things have to be huge in order to take advantage of the relatively feeble solar wattage available to it… this is all because of our friend the inverse square law which governs all things electromagnetic, light included.

To operate in the environs of deep space, you need a dependable power source. To compound problems, any prospective surface operations on the Moon or Mars must be able to utilize energy for long periods of sun-less operation; a lunar outpost would face nights that are about two Earth weeks long, for example. To this end, NASA has historically used Radioisotope Thermal Generators (RTGs) as an electric “power plant” for long term space missions. These provide a lightweight, long-term source of fuel, generating from 20-300 watts of electricity. Most are about the size of a small person, and the first prototypes flew on the Transit-4A & 5BN1/2 spacecraft in the early 60’s. The Pioneer, Voyager, New Horizons, Galileo and Cassini spacecraft all sport Pu238 powered RTGs. The Viking 1 and 2 spacecraft also had RTGs, as did the long term Apollo Lunar Surface Experiments Package (ALSEP) experiments that Apollo astronauts placed on the Moon. An ambitious sample return mission to the planet Pluto was even proposed in 2003 that would have utilized a small nuclear engine.

New Horizons in the laboratory with the RTG (on left) attached. (Credit: NASA).

This is not without risks; for example, the aborted Apollo 13 mission had to ditch their Lunar Module Aquarius in the Pacific Ocean near Fuji along with its nuclear fueled payload on return to Earth reentry (which by the way survived intact as intended and is somewhere in the deep ocean where it can do no harm). Pu238 has a half life of 87.7 years and a 55 kg mass can power a spacecraft like the Pluto-bound New Horizons mission for decades. The next spacecraft headed for Mars, the SUV sized Mars Science Laboratory, will also contain an RTG as it explores the environs of Gale crater, and doubtless this launch slated for late 2011 will draw a scattering of protesters as did the Galileo, New Horizons, and Cassini missions…

Yes, plutonium is nasty stuff. It is a strong alpha-emitter and a highly toxic metal. If inhaled, it exposes lung tissue to a very high local radiation dose with the attending risk of cancer. If ingested, some forms of plutonium accumulate in our bones where it can damage the body’s blood-forming mechanism and wreck havoc with DNA. NASA had historically pegged a chance of a launch failure of the New Horizons spacecraft at 350-to-1 against, which even then wouldn’t necessarily rupture the RTG and release the contained 11 kilograms of plutonium dioxide into the environment. Sampling conducted around the South Pacific resting place of the aforementioned Apollo 13 LM re-entry of the ascent stage of the Lunar Module, for example, suggests that the reentry of the RTG did NOT rupture the container, as no plutonium contamination has ever been found. The same went for another failure, that of the nuclear powered Nimbus B-1 weather satellite in 1968, in which case the RTG was recovered intact. Yes, the Soviets have had a few release failures historically (see below), but NASA knows its business and has a long standing track record of safely handling nuclear material. RTG’s are designed to withstand intact uncontrolled re-entry, spacecraft explosion, booster explosion, and a host of other high energy events without releasing the contents of the fuel package.  Of course, all stats are highly speculative. The black swan events such as Three Mile Island, Chernobyl and Fukushima have served to demonize all things nuclear, much like the view that 19th century citizens had of electricity. Never mind that coal-fired plants put many times the equivalent of radioactive contamination into the atmosphere in the form of lead210, polonium214, thorium and radon gases, every day. Safety detectors at nuclear plants are often triggered during temperature inversions due to nearby coal plant emissions… radiation was part of our environment even before the Cold War and is here to stay. To quote Carl Sagan, “Space travel is one of the best uses of nuclear weapons that I can think of…” Whether it is as use as a thermal electric power plant, a nuclear propulsion engine, or even an Orion style bomb-propelled spacecraft, nuclear fission and the energy it produces provides us a way to get out into the solar system, now. Ideas such as fusion engines and Bussard ramjets are all well and good and should be researched, but for now are on the drawing board only. The joke is that contained fusion capability is always “20 years down the road” and may remain there for some time.

Any science fiction “space ark’ will likely include an RTG or two…(Amazing Stories cover/In the Public Domain).

And therein, as they say, lies the rub. But first let’s look at some basic nuclear physics. We promise, it will only hurt for a little bit…

Plutonium is an artificial element that does not occur in nature. First produced by Glen Seaborg and friends in 1940, plutonium is created in the modern day laboratory by the beta decay process which occurs when uranium238 is bombarded with neutrons and decays into unstable neptunium and then plutonium239, the “weapons grade” isotope of the stuff. If neptunium-237 is used as target (fertile material) instead of U238 in a “fast” reactor the product is plutonium238. Likewise, bombard uranium-238 with deuterium (2x hydrogen nuclei) in an accelerator and the decay result is Plutonium-238 Pu-238 produces 560 watts per kg of decay heat, 280x times that of Pu239. The United States ceased production of plutonium in 1989 as the Cold War ground to an end, (more on the political aspect in a moment) and starting that production train back up would be no easy process.  The United States and Russia have tiny dwindling reserves, and at best NASA has enough for one more Cassini-style mission and perhaps a small scout style mission like New Horizons past the launch of the Mars Science Laboratory. And as you can see, utilizing the pre-existing weaponized Pu239/240 would do little good beyond perhaps as part of an Orion-style propulsion system, as the energy of decay or the specific power yielded is just too low.  Reading the writing on the cosmic wall, things look pretty grim for the recent Planetary Exploration Decadal Survey published earlier this year; a Uranus probe, Titan blimp, and Enceladus or Europa orbiter plus lander would all require RTGs, as would the shelved Jupiter Icy Moons Mission. Contrast the problems the spunky Mars Rovers had with “dusty solar panels,” as well as the eventual lack of solar power that did the Mars Phoenix polar lander in…

One of the RTGs that flew on the Voyager spacecraft. (Credit: NASA).

Are there alternatives in the nuclear area? Yes, but not without cost; for example, there are difficulties with the use of thorium isotopes. Relatively abundant in the Earth’s crust compared to uranium, the preferable thorium232 & thorium230 isotopes have a low abundance and a relatively low specific power in comparison to plutonium, again, making it a very poor heat source. In addition, thorium232 is bread to uranium233, which is nasty stuff and emits a very penetrating dose of gamma radiation as it decays further to thallium208. (Remember the Hulk?) Weaponized plutonium 239/240 also has too low a specific power, creating a huge mass penalty for outgoing spacecraft with its very short 30 year half-life. Strontium90 can be used as a RTG, but also at a great mass penalty. Same goes for any prospects of a pulsed fission reactor. In the 50’s through 70’s, NASA and the Department of Energy looked into the possibility of building a nuclear engine via Project Rover. This phases included Kiwi, Phoebus, and Pewee engines which were tested at the Nevada Test Site Area 25 desert complex facility… several extreme high altitude nuclear detonations where also conducted, most notably the Starfish Prime project in 1962. The Limited Test Ban Treaty of 1967 put the lid on further weapons testing in space, along with the prospects for a development of a nuclear propulsion engine.

Small high power solid core fission reactors have been used in space as the heat source for turbo-electric high power applications (primarily Soviet radar-satellites for intelligence purposes). One accidently returned to Earth landing in Canada in the 1970’s causing much political uproar and very little environmental damage. Solid core propulsion reactors have been designed and tested in both the United States (NERVA) and Russia and have a solid theoretical and practical engineering foundation. None have been tested in space. This concept still stands as our best bet to get humans quickly to Mars.

 

Nuclear-fueled & ready to roll; the Mars Curiosity Rover. (Credit: NASA JPL/CalTech).

Currently, NASA faces a dilemma that will put a severe damper on outer solar system exploration in the coming decade. As mentioned, current plutonium reserves stand at about enough for the Mars Science Laboratory Curiosity, which will contain 4.8kilograms of plutonium dioxide, and one last large & and perhaps one small outer solar system mission. MSL utilizes a new generation MMRTG (the “MM” stands for Multi-Mission) designed by Boeing that will produce 125 watts for up to 14 years. But the production of new plutonium would be difficult. Restart of the plutonium supply-line would be a lengthy process, and take perhaps a decade. Other nuclear based alternatives do indeed exist, but not without a penalty either in low thermal activity, volatility, expense in production, or short half life.

The implications of this factor may be grim for both manned and unmanned space travel to the outer solar system. Juxtaposed against at what the recent 2011 Decadal Survey for Planetary Exploration proposes, we’ll be lucky to see many of those ambitious “Battlestar Galactica” –style outer solar system missions come to pass. A mission like Juno headed to the environs around Jupiter gets around this somewhat by utilizing huge solar panels; Juno is scheduled to leave the pad at Cape Canaveral next month on August 5th and this will mark the first non-nuclear powered mission to the outer solar system. This will occur, however, at a huge cost; Juno must drag its panels along for the ride and will only operate in a wide 11-day Jovian orbit. This is necessary to keep Juno exposed to the Sun and will preclude exploration of the Jovian moons during its projected 32-orbit life span. The three solar arrays on Juno also equal an area of 650 sq ft, a large target for any debris in the Jovian system that makes engineers cringe. Solar cells are also sensitive to high radiation fields such as those encountered in Jupiter space. This is one of the factors behind Juno’s short mission life.

Landers, blimps and submersibles on Europa, Titan, and Enceladus will all operate well out of the Sun’s domain and will need said nuclear power plants to get the job done… contrast this with the European Space Agency’s Huygens probe, which landed on Titan after being released from NASA’s Cassini spacecraft in 2004, which operated for scant hours on battery power before succumbing to the -179.5 C° temps that represent a nice balmy day on the Saturnian moon.

 

One of the “other” uses for plutonium; Fat Man on Tinian. (Credit: US Govt image in the Public Domain).

Part of what has always complicated matters is what is known as the Outer Space Treaty, or in its long-form, The Treaty on Principles Governing Activities of States in the Exploration and the Use of Space. Signed and ratified by the U.S., U.K. and the Soviet Union on January 1967, this treaty seeks to curb the militarization of space and specifically the use of space-based nuclear weapons as well as nuclear detonations in space.  This has formed the basis of a broad amalgam of what been termed over the years as “Space Law” which covers such things as the international use of space, salvage rights and claims, and the non-recognition of any territorial claims on a celestial body. And while “Space Court” hasn’t become filler for afternoon or late-night cable TV, the Treaty did largely keep nuclear weapons out of space during the Cold War. Some of the ideas for an “EMP shield” over the US from the 50’s are slightly frightening to read about today, as we would be now reaping the environmental consequences. While said treaties never specifically limited the use of fissile material for deep space exploration, the very concept and stigma of “Nukes in Space” made it suffer by extension. Whenever a launch with an RTG occurs, a small band of protesters gather outside the gates and grab the media spotlight until the payload has cleared Earth orbit. Modern day fears of all things nuclear can be likened to the 19th century suspicion of electricity, which to date has taken far more victims than the peaceful use of radioactive isotopes in space.

So, what’s a space-faring civilization to do? Certainly, the “not going into space” option is not one we want on the table, and warp or Faster-Than-Light drives ala every bad science fiction flick are nowhere in the immediate future. In our highly opinionated view, NASA has the following options;

3. Exploit other RTG sources at penalty. As mentioned previous, other nuclear sources in the form of Plutonium, Thorium, and Curium isotopes do exist and could be conceivably incorporated into RTGs; all, however, have problems. Some have unfavorable half-lives; others release too little energy or hazardous penetrating gamma-rays. Plutonium238 has high energy output throughout an appreciable life span, and its alpha particle emissions can be easily contained.

 

MER’s curium-containing spectrometer. (Credit: NASA/JPL).

2. Design innovative new technologies. Solar cell technology has come a long way in recent years, making perhaps exploration out to the orbit of Jupiter is do-able with enough collection area. The plucky Spirit and Opportunity Mars rovers (which did contain Curium isotopes in their spectrometers!) made do well past their respective warranty dates using solar cells, and NASA’s Dawn spacecraft currently orbiting the asteroid Vesta sports an innovative ion-drive technology. Solar sails have made their debut on JAXA’s IKAROS spacecraft in the inner solar system, and perhaps a technology employing the use of space-based lasers could do double duty propelling spacecraft through the outer solar system like something out of a Larry Niven novel. Fusion of deuterium or helium3 resources could also provide a powerful light weight energy source, but of course this is all strictly drawing board stuff… the standing joke is that controlled fusion stated above is that its always “20 years away,” which leads us to option #3;

1. Push to restart plutonium production. Again, it is not that likely or even feasible that this will come to pass in today’s financially strapped post-Cold War environment. Other countries, such as India and China are looking to “go nuclear” to break their dependence on oil, but it would take some time for any trickle-down plutonium to reach the launch pad. Also, power reactors are not good producers of Pu238. The dedicated production of Pu238 requires either high neutron flux reactors or specialized “fast” reactors specifically designed for the production of trans-uranium isotopes. Going along with such specialized reactors are adequate safe facilities for the separation, concentration, and preparation of the final product. Since the end of the Cold War, the United States and Russia have closed and decommissioned the vast majority of their plutonium production facilities and reactors. The reconstitution of these cold war process plants is as of this writing beyond reasonable consideration. The huge plants at Hanford Washington and Savanna River South Carolina made sense during the Cold War, where Pu238 was a minor byproduct in the production of many tons of weapons grade plutonium. Practically, specialized research reactors at Oak Ridge Tennesse and Idaho National Laboratory can breed Pu238 and special separation and processing facilities there could produce gram per cycle quantities. However about 5kg/yr would be required to meet anticipated needs requiring a retool of currently available reactors and processing labs. Such a mission deviates critical research facilities from their primary missions that are themselves vital to understanding materials for spacecraft. Construction of new reactors and facilities for the production and processing of fissile materials is also fraught with significant funding, environmental, treaty, and local / national opposition hurdles. This can lead to very significant increases in cost over initial estimates and multi-decade delays prior to construction or production. Based on the realities of nuclear materials production the levels of funding for Pu238 production restart are frighteningly small. NASA must rely on the DOE for the infrastructure and knowledge necessary and solutions to the problem must fit the realities within both agencies.

And that’s the grim reality of a brave new plutonium-free world that faces NASA; perhaps the solution will come as a combination of some or all of the above. The next decade will be fraught with crisis and opportunity… plutonium gives us a kind of Promethean bargain with its use; we can either build weapons and kill ourselves with it, or we can inherit the stars.

 

The Early Astronomers: A Brief History of Astronomy.

Ye ‘ole telescope…(Photo by Author).

(Editor’s note: The following is an essay wrote by yours truly in the quest for a science teaching degree. Now that said degree has come to fruition, our writing can be immortalized forever in a re-vamped blog format).

Astronomy is one of man’s earliest pursuits for knowledge. Once we began living in organized communities and brute survival and safety wasn’t a constant and overriding concern, we began to look up and ponder our place in the cosmos and contemplate the workings of the heavens above us. [Read more...]

A Look at the Earth’s Interior.

Eruption! Our active planet as seen from the Aqua satellite… (Credit: NASA).

(Note: The essay that follows it part of a series of papers I wrote in my quest for my science teaching degree… I always hate the fact that school writing only makes it to two sets of eyeballs, mine and the graders, so I re-worked my writing a bit for the blog format…)

The Earth is the only terrestrial planet that we have the availability to reach out and examine up close. By use of painstaking scientific processes, we can monitor the inner workings of our world and create a model of its interior structure that presents a high degree of accuracy with what is observed. Still; while we live on its surface, we have never penetrated the shell of even its outer crust or sampled its deep interior… just how do we know what’s within?

To map the Earth’s interior perhaps no tool is more essential than the seismograph. Also sometimes referred to as the seismometer, this device is essential for recording and monitoring seismic waves in the Earth’s crust and their passage through the interior. This device usually consists of an internal inertial mass that is deflected relative to an external frame, usually anchored to the surrounding bedrock. As the device is shaken, the mass is moved as waves pass through it, deflecting a needle against a scrolling spool of paper marking the passage of time. Early detectors were constructed during the Chinese Han Dynasty. Modern detectors may be on the classic needle deflection type or digital and utilize the precise measurement of laser beams or a mass magnetically suspended generating a negative feedback loop. Key waves detected are P, or primary waves, S, or secondary waves, and surface seismic waves.  P waves are the initial “push-pull” waves of an earthquake. These are the fastest waves, and thus the first recorded during a seismic event. An elastic wave, P waves can travel through any medium, be it solid, liquid or gaseous. These waves are compressional and can also vary with the subsurface depth of the earthquake. Next waves to arrive are the S, or shear waves. Also known as transverse waves, these are slower moving and can only travel through solid material. Finally, the surface waves are the last to arrive at a given detector, as they are slower moving and generally cause the most damage. If these waves can be recorded by three separate detectors spaced out on the Earth’s surface, a precise epicenter can be pinpointed. Also, the fact that an Earthquake shadow zone is generated where only P waves are seen is prime and well documented evidence that the Earth’s outer core is not solid, but molten. Indeed, the magnetic shear or torsion generated by the interplay of Earth’s iron-nickel solid core, and liquid molten outer core, is further evidenced by our relatively strong magnetic field. In comparison to the Moon and other terrestrial or rocky planets, the interior of the Earth is a dynamic place, and seismology helps us understand this differentiated structure.

(Created by Author).

Elements of seismograph construction may include a digital strong-motion accelerograph or several inter-connected seismometers working to create one coherent output. A classic earthquake will first register on a seismogram as a series of short spikes marking the initial P-waves. Minutes later, the first S-waves will arrive spanning a slightly longer period of time. Finally, the largest and most damaging surface waves arrive. As seen on a seismograph, the timing and spacing recorded at an individual station may vary depending on the depth and distance of the earthquake epicenter.

The science of seismology is crucial to understanding the interior structure of the Earth as well as predicting where damaging earthquakes or tsunamis are likely occur. This study is vital to the whole Earth model because although we cannot directly sample interior layers of the Earth, we can model them by examining the speed and types of waves that transverse the crust, silica rich mantle, and inner and outer cores.

The outer surface of the Earth is composed of tectonic plates that either converge, or subduct one under another, diverge or separate, or strike slip or grind past one another. This type of surface material recycling drives what’s known as the rock cycle. The outer-most rigid crust is known as the lithosphere, which is comprised of the crust and a layer of brittle and solid rock about 100 km thick. This crust is thickest on the continents, and thinnest underneath the oceans. Of special interest is a separation known as the Mohorovi?i? Discontinuity, first discovered in 1909. This boundary between the crust and the Earth’s mantle was deduced by studying the refraction pattern of earthquakes by shallow p-waves.

Farther down, the lithosphere rides along top of the flexible and molten asthenosphere. This layer extends down to a depth of about 400 miles and is mechanically detached from the deep lower mantle. Again, only P-waves can travel through molten regions of the inner Earth; S-waves cannot. This key fact is prime evidence that the outer core of the Earth is fluid, or molten. Likewise, the refraction and reflection of seismic waves can also provide us with a “look” inside the Earth to probe its interior.

But beyond the probing of Earth’s interior, the study of seismology is crucial to other applications, both scientific and economic. The study and conduction of seismic waves can be applied to locating large fossil fuel deposits as well as prime aquifers or areas of potential sink hole activity. Again, this utilizes our understanding of the transmission, reflection, and refraction of P- and S- waves through solid versus liquid and gaseous material. Seismology is also used to detect nuclear weapons testing, and to assure compliance with test ban treaties. The liquid outer core is further evidenced by the creation of Earth’s magnetic field. When we look at smaller, cooler bodies such as the Moon and Mars, little evidence for a magnetic field is seen; in fact, the low density of the Moon versus its size is prime evidence that it was once part of the Earth’s crust and mantle ejected by a massive impact. Igneous basaltic rocks brought back from the Moon by Apollo astronauts support this theory. Finally, seismology demonstrates evidence for plate tectonics by showing observational proof that the plates of the lithosphere are active and in motion. Plates snapping back into place or grinding past each other all generate massive amounts of seismic waves in what we know as earthquakes. Over time, these cause the raising of great mountain ranges such as the Himalayas or massive earthquakes such as were recently witnessed in Haiti, Chile and Japan.

In conclusion, seismology and the study of seismic waves are key examples of how we can study something in science without directly examining it. Beyond just scientific interest, this has given us such benefits as the Pacific Tsunami Warning Center that has saved countless lives. As we move out and study other planets in our solar system, knowledge of the interior structure of the Earth will give us some insight into comparative planetary science and just how common or rare a dynamic place like Earth truly is.

Declassified: The True Tale of Project Orion.

Artist’s conception of an Orion vessel about to depart from Mars orbit. (Credit: NASA).

Ever wondered if man will ever head to the stars? Certainly, the magnitude of the issues that need solving for interstellar travel are many times more difficult than a simple spin around the block in our solar neighborhood… radiation exposure, sustainability of resources, and the effects of time dilation would all come into play. And yes, in these troubled times, we’re finding it exponentially difficult to even leave low Earth orbit… but did you know that the U.S. government once seriously researched the feasibility of interstellar transportation using current technology? Let me tell ya’ a story…. [Read more...]