17 October 2012

The End of an Era - A Personal Look Back at the Shuttle

Shuttle Endeavour leaves Houston on its final transcontinental flight, September, 2012

The transfer of shuttle Endeavour to California this past month, including several flyovers in Houston I  witnessed and videoed, signals the last "flight" of the Space Shuttle era.  For us late Baby Boomers and beyond, the Shuttle was a continuous element of our adult lives from its inception.  It has also been linked indirected with my own career more than once.  The flyovers and public viewing in Houston last month were perhaps not so surprisingly emotive personally, given the link professionally and the link through time.  What follows is a personal retrospective on Shuttle history, a reflection on the journey we all, as individuals and as a nation, have taken with the Shuttle for the past 4 decades.

Endeavour flies past the Mercury-Redstone at JSC on its last trip - September 2012

Much of Shuttle history derives directly from its origins.  The shuttle program was founded in 1972 as the space agency fought for some sort follow-up to Apollo, lest exploration of space die on the Moon.  The high adventure of the Apollo moon landings gave flight to some fanciful and wild dreams for the future of manned space exploration, including orbiting stations, shuttles to orbit, deep space probes to the planets . . .   Articles in 1969 frequently featured subterranean Moon-bases and orbital infrastructure not far removed from what we saw on the big screen the year before in 2001: A Space Odyssey. Many of these visions had their roots in much earlier dreams, especially those from the 1950's following the War and capture of the german rocket scientists, the chief of those being Werner von Braun.  Dreams of space conquest were famously captured in the paints of Chesley Bonestal, and others and in articles in Collier's.  The shuttle was hoped to be the beginning of this next era, but the future in space did not quite follow this path.  Neither Congress nor Nixon were in a spending mood in space.  The result was a vehicle built from compromise, perpetually struggling to justify it existence from the day of its inception.

optimistic tho faded clip from a Buffalo newspaper July 12, 1969 . . . 

Despite its triumphant and anguished history, Americans are justifiably proud of their men and women on the Space Shuttle, and we tend to invest a lot of national pride in them, even when flights seemed to be routine, reduced to the mundane of lofting cargo to the Space Station.  We often tend to neglect that pride.  The Shuttle program took us on a powerful ride to places we didn't anticipate, from exhilaration to despair.  It is fitting to pause to reflect on some of those moments.

September 17, 1976
Enterprise Rollout
Four years after funding start, the first test Shuttle, Enterprise, rolls out of the assembly building, joined by the cast of Star Trek.  Destined for flight and landing tests, it would represent the fleet at the Air and Space Museum until Shuttle retirement 35 years later.  It's only trips to the launch pad were integration and structural tests at KSC and the later abandoned Vandenberg Shuttle launch facility in California.

August 12, 1977 
Approach and Landing Tests (Enterprise)
Enterprise was taken airborne by its 747 carrier and cut loose for several free-flight and landing tests in southern California.  Now largely forgotten, the first of these 5 flights was telecast live on several networks (in the days before Cable, the Internet, cell phones, etc.).  The landing tests went very well and there was genuine enthusiasm but development problems continue, especially concerning loose heat shield tiles on the underbelly and with the main engines.  The first launch was initially scheduled for 1979.  Skylab's orbit decayed, and the Shuttle was not ready to save the laboratory before it entered the atmosphere and crashed into the Australian desert in 1979.  Meanwhile the first launch of Columbia slipped, and slipped . . .

April 12, 1981
First Shuttle launch 
STS-1 (Columbia)  
The launch had been scheduled for April 10 but halted at T-9 minutes when the on-board computers failed to chat properly.  Disappointed, we all geared up again for the 7 am (EDT) liftoff two days later, now coinciding with the 20th anniversary of the first manned orbital flight by the Soviet Union's Yuri Gagarin.  We watched with curiosity and amazement.  This was something new, though far riskier than we knew at the time.  We were just coming out of the unsettling 1970's, the oil crises, gas lines, Iranian hostages, Soviet Afganistan invasion, job losses in steel and other key industries . . .  The Reagan administration was only a few months old, but the hostages had been released, he had just survived an assassination attempt 2 weeks before (the low point of his popularity swing in 1982 was yet to come), Disco was finally dead, and the 6 year hiatus in manned spaceflight highlighted by continual reports of shuttle construction difficulties was finally almost over.  As a happy accident of timing, the shuttle launch became part of a national reawakening out of the angst of the prior decade (the crushing debt load incurred as part of that rebirth would have to be dealt with later).
I was in first year at graduate school in Illinois and listened on the radio during the 7 am launch, disappointed that I couldn't find a TV at that hour.  The strapped together tanks and rockets gave Columbia a very different look to the Saturn V, described by some as a "space-age Taj Mahal," it's external tank painted white in those days.  The Shuttle also had a more muscular feel to it in contrast to the slower moving Saturn and "leapt off the pad."  Astronauts John Young and Bob Crippen became national heroes for a while.  A wide frontier of unknown possibilities seem to open before us.  The flight captivated us.  Here was something new, an engineering marvel, and it all went off perfectly (almost) on the very first flight.  Wow.

June 18, 1983
STS-7 (Challenger)
With the shuttle emerging from its test flights into "operational" status, things seem to settle into a routine of sorts, and this opened the doors to some long neglected opportunities.  The first major Shuttle highlight and media show after STS-1 was the flight of the first american female astronaut, the late Sally Ride.

August 30, 1983
STS-8 (Challenger)
First African-american astronaut, Guion Bluford, was in fact the first "minority" astronaut of any kind.  It was also the first Shuttle night launch and night landing, always a spectacle.  The flight also featured the first close call of the program, and a warning sign, as one of the booster nozzles very nearly burned through during launch.  This could have caused the entire ascending vehicle to tumble out of control.

February 3, 1984
STS-41-B (Challenger)
This mission produced one of the most famous and iconic images from the Shuttle era, that of Bruce McCandless floating free in space, the first untethered space walk in history.  It also marked the clumsy change in flight designation numerology, and the first landing at Kennedy Space Center, Florida, marking the first return to launch site and closing one of the last remaining links to the Shuttle's promised reusability.

April 6, 1984
The Solar Max Repair mission was the first to capture and repair a satellite in orbit, fulfilling another of the promised objectives of the program.  It did not go smoothly at first, as the attempt to capture the satellite by astronaut Nelson failed and the satellite began to tumble.

June 26, 1984
STS-41-D (Discovery)
First launch abort after engine ignition of the Shuttle (and first such since Gemini 6 in 1965).  There was also a brief hydrogen fire on the pad shortly afterwards, but it was contained before any damage could occur.

January 24, 1986
STS-51-C (Discovery)
First classified DoD shuttle mission.  'nuf said.  The military was still building the Vandenberg shuttle launch complex in California at this time.

January 28, 1986
STS-51-L (STS-25, Challenger)  
Five years into flight, we had come to think of shuttle launches as somewhat routine, and watched with scorn, frustration, and open mockery as NASA struggled in seemingly futile attempts to launch the thing on schedule.  Something wasn't working right but we mostly assumed it would work itself out eventually.  One thing was clear, the shuttle wasn't exactly living up to its touted capability of 100 routine launches a year.  The machine was already proving much more complex and costly than had been (irrationally) projected.  

Still, this seeming irregularity was taking on many of the familiar hallmarks of air travel, with its weather and other delays.  This time there was "citizen" astronaut on board, school teacher Christa McAuliffe.  After numerous delays, and a hard freeze the night before, launch proceeded over strenuous engineering objections.  School children across the country were watching live on CNN.  Despite this novelty, many only saw the launch when their programming was interrupted by the news bulletin.   

High in the sky for all to see, the familiar rocket plume abruptly blossomed into a large orange cloud as the two solid rockets shot out free and began wandering the sky.  The image of the giant "Y" or perhaps a "Why?" in the sky over Florida, formed by the two solid rocket booster exhaust plumes trailing forward, became seared into the memory of anyone old enough to understand its meaning.  Those familiar with shuttle launches knew it was wrong but some wondered.  The fact that it occurred 1 day after the anniversary of the Apollo-1 fire in 1967 was jarring.

I myself woke late (I was in graduate school studying planetary science at Washington University in Saint Louis) to try and catch any new images from the Voyager 2 Uranus encounter 4 days earlier.  Instead I was caught up in the coverage 15 minutes after the explosion.  The rest of the day was spent in a mental and emotional haze.  Working effectively just wasn't going to happen.  The TV coverage (there was no internet) continued throughout most of the day, followed by Reagan's memorable address to the nation that afternoon.

The national shock was enormous, the "JFK" moment of our generation.  The New York Times noted the importance of the event with its headline "The Shuttle Explodes," not "a" but "The" shuttle.  Quoting Don Davis, "The Challenger Disaster was a mortal blow to the optimistic dreams of widespread access to space such as we still had then."  Many felt the shuttle program had only just begun to fulfill its potential and the march into space had been cruelly interrupted.  A great determination to pick ourselves up off the ground, dust ourselves off, and get back on our winged horse and resume the great adventure took hold.

Each step in the redesign and testing of the systems components was reported in detail over the next 2 years, as were the finding of crew remains and the hearings that exposed the management weaknesses of NASA and its improper handling of the shuttle system outside its design limits and this launch in particular.  It was also by now clear that the Shuttle was much more complex and tempermental than hoped for.  Also, the decision to use one vehicle for all our launch services and especially using humans to launch telecom satellites was now obviously seriously flawed and the Shuttle manifest was quietly reshuffled.  NASA scrambled to readjust launch manifests but some vehicles could not be moved and exploration vehicles like Galileo, Ulysses, HST and Magellan remained tethered to the shuttle launch system, delayed by years as a result.  The effects on Galileo included a 6-year delay and a serious antenna failure, both of which would impact on my own work on the Jovian satellites.  Yet it is the kick in the gut that day that lingers.

April 15, 1986
Titan 34D rocket explodes 8.5 seconds into flight
May 3, 1986
Delta rocket explodes 90 seconds into flight
Coming within months of the Challenger accident, these two successive launch failures came as a new shock as our space program seemed to falter.  Both vehicles would be launching again within a year but the US seemed suddenly impotent in space, with little if any reliable access to orbit.

September 28, 1988
Return to Flight
STS-26 (Discovery)
The tension and anticipation across the nation and at the JPL auditorium where I watched the countdown was palpable.  If the nation could have stood on the pad and pushed the thing skyward I think they might have.  At the time, the Reagan era was grinding to its drawn-out conclusion but distractions were few and the entire nation focused on the launch.  The drama of launch was hightened further by a false alarm threatening to hold the count at T-0:31.  Even the voice of NASA, Jack King, was having a little trouble maintaining coherency, but watching the launch replays (you can see them on YouTube) and hearing that whooping cheer at liftoff can still give one a sense of the relief and exhilaration felt as "american's return to space," in Jack's words, as the long 2 and half year grounding came to an end.  Reactions differed but few watching remained emotionally indifferent.  I still choke up a little every time I watch the replay.

STS-26 "Return to Flight" CNN coverage

November 15, 1988
STS-27 (Atlantis)
This classified DoD mission remains shrouded in mystery but the second post-Challenger flight is also highlighted by unusually severe thermal tile damage, foreshadowing the destruction of Columbia 14 years later.

November 15, 1988
NASA was still wounded by Challenger when the Soviet Union launched their version of the Shuttle, Buran.  Many questioned our national choices in space, pointing to the apparent soviet successes on space station Mir, their new launch vehicle Energia and now this new Space shuttle, seemingly a better version of our own.  Although motivated by fears of a military gap, their shuttle suffered from similar doubts about purpose and value. Within 3 years the nation that brought forth Buran would itself break apart, and the historic space agency it founded would be brought to the brink of collapse.  The Mir space station would later suffer a series of near catastrophic accidents and breakdowns.  This would be the soviet shuttle's only flight.  Buran itself was destroyed when its hanger collapsed in 2002.

April 24, 1990
Hubble Space Telescope deployment
STS-31 (Discovery)
The HST was to be a great leap forward in astronomy, lifting our sights above the turbulent atmosphere that protects us to see deeper and more clearly than possible from the ground.  Great discoveries were expected and the flight was well covered.  Designed to be serviced by astronauts, the HST also seemed to embody the stalled hopes of the Shuttle system in which astronauts, in a real-life version of the McCall painting on the walls of the Air and Space Museum, would wander the skies like auto mechanics, servicing a vast space infrastructure.  Challenger killed that dream, but part of it lived on in the telescope, and fortunately so when it soon became apparent that the mirror had been ground improperly.  NASA and its telescope instantly became cannon fodder to late-night comedians and critics alike.  

December 2, 1993
Hubble Servicing Mission
STS-61 (Endeavour)
The first scheduled servicing flight to HST became much more than that when it also became a mission to fix the optics and salvage NASA's reputation.  The early 1990's were a difficult time as a number of old decisions were coming back to haunt the agency and it's capability to perform was seriously in doubt.  The most embarrassing of these was the condition of its flagship space telescope.  The telescope was well over budget and beset with technical problems, most of which were not completely solved by launch time.  In the 3 years since launch so many of the machines systems had either broken or proven flawed that 5 full days of spacewalks had to be scheduled to repair them all.  Gyros, solar panels, magnetometers, etc., all had to be replaced or repaired, the most pressing of these being the perfectly flawed primary optical mirror.  The Hubble was in danger of becoming an albatross.  NASA's very future was riding on the success of this mission, or so it seemed to many.

The key element in the repair effort was the exceptionally clever set of small precision lenses to be placed in the light path to adjust for the distorted main mirror.  The night launch added to what was already for NASA one its most dramatic launches since Apollo.  The spacewalks went off with few hitches and NASA's detailed preparations payed off handsomely when the first sharp clear images were released later that month.  Their efforts helped make Story Musgrave and his companion spacewalkers folk heroes for a while, the first of their kind since Sally Ride and the crew of STS-1.  That week may well have been the high-water mark of the Shuttle program.  The fact that the fix came just in time for Hubble to return spectacular images of a comet striking Jupiter in 1994 was a wonderful coincidence and seemed a very good omen indeed.  All seemed right with NASA again.

Shuttle Endeavour approaching HST,  
the distorted solar panels plainly visible to the crew

June 27, 1995
Shuttle-Mir docking
STS-71 (Atlantis)
The sight of the soviet space station from the shuttle was fascinating from the gee-whiz POV and a foretaste of the International Space Station that replaced it. The 7 flights to Mir marked the beginning of the first true sustained international collaboration in manned space.

October 29, 1998
John Glenn returns to space
STS-95 (Discovery)
Although widely panned as a publicity stunt, the return to space of the first american to orbit the Earth (the first human was Yuri Gagarin, a Soviet citizen), was widely watched.  Those old enough to remember his original flight in 1962 were either happy to see him return or oddly disinterested.

December 4, 1998
First ISS Assembly Launch
STS-88 (Endeavor)
At this time, the shuttle began to concentrate almost all of its efforts in support of the Int'l Space Station, beginning with the launch of the Unity component to mate with the previously launched Zarya russian component.  The concept of using manned vehicles and their inherent complexity, cost and risk to lift hardware had long been discarded but the Shuttle no longer had (or was given) any other role to play.  It was available, and all the hardware had been designed to fit in the shuttle anyway, and it kept the nation "in space".  Oddly, the shuttle's next loss would not involve the ISS at all but occur on its last dedicated science mission.

February 1, 2003
STS-103 (Columbia reentry)
When the Columbia broke apart in the skies over north Texas, less than a week after the annual Challenger anniversary, the nation wept again.  The TV kept replaying the amateur video of the splitting contrails streaking across the skies of north Texas, as the Shuttle broke apart at 200,000 feet and debris rained down.  They were 15 minutes from landing and only a few minutes from the end of atmospheric reentry.  This time it was different.  With Challenger, we had only begun this new phase of man's journey into space.  Loss of Challenger left us with a resolve get back into space but this time the feeling was more of resignation and defeat, like having the wind knocked out of you.  We all seemed to say to ourselves "oh no, not again."  I was at a retreat in rural central Texas and woke to what sounded like a clap of distant thunder in a clear sky, learning only an hour later that it was the sonic boom of the shuttle 200 miles to the north over Dallas as it began to break apart.

This was also only 18 months after September 11, and in the middle of the run-up to the Iraq war.  Israel's first astronaut was also aboard, and they too mourned.  We resolved to restore the Shuttle fleet to operations but the shuttle's fragile nature could no longer be ignored (a piece of foam had knocked a hole in the wing, leading to a burn-through on reentry), nor could the return of complacency and the sometimes casual insistence that the shuttle could operate like a city bus.  In essence, the rather routine damage that had been occurring at launch due to shedding foam was becoming ingrained as acceptable, leading to the false conclusion that the orbiter could not be seriously damaged.  Regardless, the compromises that went into the original shuttle design were now being openly discussed and NASA and the nation finally began to openly debate how to replace the aging fleet, leading directly to the 2004 Bush decision that the shuttle be retired and replaced.  That first fact is now upon us.  The future course is before us . . .

memorial tributes, February 3, JSC entrance  . . .

July 26, 2005
STS-114 (Discovery)
Return to Flight
Different than 1988, this mission signaled the beginning of the end-phase of Shuttle history and we all knew it.  There was relief to be flying again but the sense of future was lacking.  The irreversible decision to retire the fleet by 2010 had already been taken by Mr. Bush.  Each subsequent mission was operated with great labor and care so as to minimize risk, but the remaining focus was almost solely on completion of the Space Station. The fact that foam damage occurred again during launch led to a year-long interruption as the problem was reexamined yet again and largely if not finally solved.

August 8, 2007
STS-118 (Endeavor)
The mission featured the flight of teacher Barbara Morgan, after a 21 year battle to get her mission as the back-up for Christa McAuliffe.  Although NASA refused to call her a Teacher in Space, not wishing to stir memories of Challenger or disturb Christa's long sleep, it was still nice to see this dream come true.

October 23, 2007
STS-120 (Atlantis)
Much of the Shuttle and Space station work went unheralded and unnoticed, even when testing human skill and ingenuity, as they often did.  Case in point: the space walk by Parazynski to repair tears in a ISS solar panel at the utmost reach of robotic and human arms. 

May 11, 2009
STS-125 (Atlantis)
Final Hubble Space Telescope servicing mission.   The joint Shuttle-HST story may be one of the most enduring of the shuttle era.

April 22, 2010
Boeing X-37 Spaceplane
This highly classified mission, a sort-of miniature Space Shuttle, heralds one possible future for space.  The need to separate the crew and cargo capabilities of the Shuttle was clear but could the X-37 fill the first of those goals?  The air force is mum.

May 14, 2010
STS-132 (Atlantis)

February 24, 2011
STS-133 (Discovery)

May 16, 2011
STS-134 (Endeavour)
Beginning with the retirement flight of Atlantis, the nation starts a year-long celebration, commemoration, goodbye for its' Shuttle.  Each in turn, the 3 remaining spacecraft are taken on their final flights, completing the job of Space Station construction to which they had been assigned for most of the past decade.  STS-134 (Endeavour) mission commander Mark Kelly, husband to Congresswoman Giffords,  was to be the final Shuttle commander until Atlantis was rescheduled for an additional, final, flight (STS-135).

July 8, 2011
STS-135 (Atlantis)
Final Flight
Joy, pride, melancholy, and a few tears, the final flight of Atlantis and of the Shuttle fleet is watched nationwide.   Those of us who were old enough to remember the first Shuttle flight 30 years ago that spring (and indeed the difficult 'birthing' process of the development years), could not help but recall with similar emotions those times and the vivid memories of the Shuttle's triumphs and defeats.
So much had changed across our planet and society in the 30 years since 1981, technologically, socially, politically . . . it would take days to review them all.  The Shuttle itself also matured technically, with glass cockpits and other improvements, but it remained the same basic space truck, a line of continuity through a quarter of a century of history.


Although dictated by the remorseless logic of aerodynamics and weight restrictions, the Space Shuttle possessed a certain beauty.  From the triple stack of the tank and two external boosters, down to the black on white lines along the edge and wing, the Shuttle's design lines gave it an architectural monumentalism, especially when it was painted all white during its first launches, and seen in some of the images posted above.  The orbiter itself is a work of engineering art.  The sight of the elegant winged vehicle drifting gracefully across the black void, Earth in the background, is one of those scenes that is on my list of must do's but never could and now never will see.  The images of the Shuttle in space are some of the prettiest of the space age.

Much has changed since the first launch in 1981. Over the next three decades we witnessed the Internet, DVD, the cell phone explosion, music CDs followed by MP3 players, iPods and iPhones, two Gulf Wars, September 11, and all that followed.  Part of our present difficulty stems from the virtual national bankruptcy inflicted on us as a result of the gross mismanagement of the second of those wars.  It is important to remember here also that the decision to retire the Shuttle is entirely a G.W. Bush legacy.  The decision for retirement was a direct result of the loss of Columbia over the skies of Texas, and the final realization of the Shuttle's inherent limitations in safety and capability, with a shift of funding and resources toward the building of a new and more versatile space vehicle.  Whether that will now happen depends ongoing debates.  Oddly enough, the Shuttle program began with a 6 year hiatus in manned flight, and we look to repeat that again.

27 August 2012

The Planets at 50 - Venus & Mars

Note:  Here is part 2 of the continuing story of "The Planets at 50".   This and blogs to follow are related to a set of lectures I gave in June (and am available to do so on again for your group).  I spent the month of June in Europe, highlighted by two presentations on the Isle of Man sponsored by the Astronomical Society on the topic of "50 Years of Planetary Exploration: What Have we Learned?" a presentation that can be given again.  The Isle was beautiful and our hosts wonderful and I had a great time telling this story to students and citizens.   This post is also associated with the similar story set to appear in the next issue of The Planetary Report.  The past 50 years have seen great discoveries but also fundamental revolutions in our understanding of how planets and solar systems work.   The posts today and over the next few months will tell that story.  

PART 2: 

The engineers were understandably nervous; they had tried this only 4 weeks earlier.  Missiles had an annoying predilection for disintegrating prematurely.  The twin of the metallic insect on the Florida launch pad had fallen into the Atlantic when tracking and guidance transcription errors (including a missing hyphen or overline) doomed the flight.  Mariner 2 (twin to that ill-fated Mariner 1; in the early days of the Space Age it was prudent to build two in case one was lost) began life as part of NASA's exploration charter but was quickly accelerated in response to the Soviet Union's failed attempt to reach Venus in 1961.

Mariner 2: Launch and Mission
Note how many bits of data were returned . . . 

Nearby Venus was high on the list of targets, so similar in size and composition to Earth, yet a profound mystery.  We knew it was warmer than Earth but how much so remained uncertain.  Despite the high scientific interest and prestige value, Mariner's flight did not, as was also noted at the time, "capture the public's imagination."  The low interest may have been due to Venus' mystery shroud of white but more likely because of the lack of a camera on board.  The impenetrable clouds meant there were no observable surface features on which to hang a credible anthropomorphic concept like the "canals" that made Mars such a powerful stimulant to the imagination.  The clouds thus gave free rein to fantasy, leading to some lurid ideas, captured in paintings, of steaming jungles and large reptiles, bubbling oily wastes, or windblown craggy sand heaps.  In 1962 Venus just wasn't Mars.  Nonetheless, the flight of Mariner 2 counts as one of the seminal accomplishments of the Space Age, challenging engineers, smashing distance records, and ushering in a new age.

The Venus that never was . . .
Just one vision of a steamy hot Cretaceous style Venus from the late 1950s.

Mariner 2 resembled nothing so much as a 16-foot-wide metallic dragonfly, basically a hexagon box with two solar panel wings, antenna, and instruments.  The Atlas bearing Mariner 1 veered off course and was destroyed, but the second Atlas soared nominally (drifting dangerously off-course only briefly) to start Mariner 2 on its 4-month 180 million mile cruise to the cloud-shrouded world on August 27.  The cruise had its share of tense moments, from eventual failure of one of the solar panels to a blown fuse, but engineers and scientists began to hope for success as the limping dragonfly swooped in toward the planet on December 14.

A flight spare of the Mariner 1/2 spacecraft currently hanging in the Smithsonian Air and Space Museum.  You might not notice this small part of history if you don't look up.

That brightest of sky objects, the Evening and Morning Star familiar to sky watchers, had its first visitor.  There was joy in Mudville (also known as the Jet Propulsion Lab in Pasadena) as coherent telemetry was received that day.  About 60 Mb of data were returned from the mission.  Thats right,60 Mb, but the readings proved Venus to be a hot dry place most unlike Earth, under a dense atmosphere 90 times as heavy as our own and surface temperatures of at least 800°F.  It would be 8 years before we had our first picture from the surface and another 22 years before we had a global map and could unravel the history of our nearby twin, all of which would show a fractured volcanic world not unfitting its hadean surface conditions.  No place to raise your kids, certainly, let alone establish a human colony.

Venera 4 (1967), first to successfully probe the atmosphere of another world, though its instruments did not survived the descent to the hot crushing atmosphere at the surface of Venus.  Venera 7 would do that in 1970.

Beyond the scientific breakthrough in our understanding of another celestial body, Mariner 2 showed simply that a long duration robotic flight into deep space could be done.  Long range communications and command and control protocols were proven for the first time.  Everything we have since accomplished in our explorations, from Venera 4 to Voyager, from  Mariner 4 to Curiosity, begins on December 14, 1962, 50 years ago this autumn.

Part 2b:  Maybe Mars . . . 

It was now undeniable that Venus was a most inhospitable place, but Mars still beaconed.  It had to wait 2 and 1/2 years for the next close approach to Earth and a viable spacecraft.  Like Mariner 2, the first Mars Mariner followed several failed Soviet attempts to reach Mars, beginning a long and continuing history of russian frustration at the Red planet.  Like Mariner 2, it also succeeded its own twin to Mars (for Mariner 3's protective launch shell failed to open one month before).  Mariner 4 began its pass over Mars on July 14, 1965, and this time there was a camera.

The fierce orange glow of Mars in the night sky was difficult to ignore.  Its skies after all were clear and the white "icy" polar caps, rust-colored surface and the ethereal ever changing dusky "linear" markings fueled rich if poorly informed speculations.  Even so, the largest telescopes of the time, including the 200-inch Palomar, could not make out geologic features.  This was well before adaptive optics and space telescopes.  Nonetheless, it was possible that Mars was near enough to the Sun and Earth-like enough (including its curiously Earth-like 24.6-hour long day) to be or have once been warm and perhaps wet enough to support life.  This question was a source of intense speculation in the early 20th century and science fiction flourished on it, leading to Orson Well's "War of the Worlds" broadcast of 1938.  Although Mars was looking a little less friendly in 1964 as we began to tease out more data, we were not prepared for what we did find.  Yet the question of life there, both ancient and recent, remains unresolved to this day.  

The best of Mariner 4 (first Mars image, left; best resolved image, right).
Effective resolution is 3 to 5 km.

A grand total of 635 kB worth of data were returned by Mariner 4, required more than week to transmit to Earth, such was the maturity of the instrumentation and deep space telecommunications in 1965.  Other instruments confirmed that the atmosphere was extremely thin, that Mars lacked a magnetic field, and cosmic rays bombarded the surface.  For many the Mariner 4 imaging results were key.  These were the first images of another world from deep space.  And they were discouraging.  The 22 grainy 6-bit images seemed to show only craters, when they showed anything at all.  Gone were canals and green "vegetation" and all the other fantasies of the first half of the 20th century.  Mars now seemed dry, hostile and barren.  Interesting conclusions to draw from modest images of less than 2% of a planet.

Mariner 6 and 7 arrived in July-August 1969 just a week or so after the Apollo 11 lunar landing.  Together they increased mapping coverage to ~20% of the surface, but in a classic case of restricted perception imaging was planned without any understanding of the planets markings and missed all the interesting features that would make Mars interesting!  Most of what it showed only seemed to reinforce the dried-out Moon-like perception from Mariner 4, but also showed some odd surface "chaos" textures, the importance of which would not be understood until 1972.  Again, no canals . . . 

Ode to a Lost Bird:  Launch of Mariner 8, May 9, 1971.  

The first man-made object to orbit another planet (narrowly beating Mars 2), Mariner 9 arrived in November 1971 at Mars to map the entire planet in preparation for the Viking landers planned for later that decade.  This mission marks my first real interests in planetary missions, and I still have the newspaper clippings beginning with the failure of Mariner 8.  The Mariner 9 mission was hastily redesigned to complete both the global mapping and high-reolution - surface-changes tasks of the two birds.

As the global dust storm that greeted the Soviet and American spacecraft abated, a remarkably complex planet of giant volcanoes and chasms, and, most provocatively, dry river valleys emerged.  Mariner 9 revealed a complex planet that had been geologically active and very wet indeed.  Mars was surprisingly Earth-like after all, or at least had been.  Hopes were rekindled.

It takes an Orbiter.  To really get at a planet and unravel it, it helps to stay awhile and map it in its full glory, as this Mariner 9 mosaic of channeled areas on Mars demonstrates.  Cassini is paying so many dividends at Saturn for that very reason.

Hopes were rekindled for the Viking landers, whose dramatic landings in 1976 produced only ambiguous results for biology but dramatically showed us a planet that had been very wet in its distant geological past.  There would be an 17 year gap between Viking's end and the next successful arrival, Mars Global Surveyor and Pathfinder/Sojourner in 1997.  These were followed by a more spacecraft, producing global maps and amazing vistas more astounding than any artist could imagine.

Pollack?  or Mars?  If you guessed Mars you are correct.  Sometimes the Universe is just plain beautiful, but if you must know, these are layers a few meters thick near the polar region of Mars.

Terrabytes of data returned from a slew of instruments bring us to today where we have meter-scale mapping from orbit, rovers traversing kilometers, layers of gypsum and other water bearing minerals.  Mars is now the most comprehensively mapped celestial body outside our own.  Despite this, the basic question of life on other worlds remains unanswered but the discoveries at Mars and in the Outer Solar System would radically alter our understanding of its probability.  

With the successful landing of the MERs and Curiosity on Mars, we see the beginning of real surface exploration of other worlds.  We also saw something perhaps unexpected.  Ordinary citizens came along for the ride.  Millions watched on the WWW, but thousands came out into the street to watch live in Times Square, New York and dozens of places world wide as the vehicle landed.  True, much of that night and the fascination of the wheeled vehicle zipping around the alien landscape was the technological thrill ride of it all.  But it also speaks well of our nation and says that intelligence is not quite dead yet, and that we in this nation do support space exploration  We do want to know what is out there.  With the vast volumes of data yet unexamined (we have much work to do) we may yet begin to understand what happened there while life began here.

Next Posts:
Voyager - A Solar System Wide Open
Modern Mars
50 Years - What We've Learned (Parts 1-3)
The Future

01 June 2012

The Planets at 50

The metallic dragonfly known as Mariner 2, a derivative of the then-struggling lunar Ranger series and modified for interplanetary cruise and launched in August 1962 toward the planet Venus.  With a wingspan at just over 5 feet (almost 2 meters), this dragonfly would have outsized even its Jurrasic cousins.

2012 is an important year for celebration, at least in the semi-arbitrary sense of human numerology.  The fact that we have ten digits, count our personal anniversaries on the basis of seasonal revolutions of the Earth about the Sun and measure our life spans in decades dictates that decadal anniversaries are regarded of some importance, and century anniversaries in particular.  August 2012 marks the 50th anniversary of the launch of the first successful interplanetary explorer, Mariner 2, which lifted off from Cape Canavaral in August 1962 and encountered Venus in December that year.  This marked the first successful interplanetary* exploration in human history.  This event also marked what can be considered the true beginning of the current revolution in our understanding of our Solar neighborhood, including fundamental revelations about how our own planet came into being and evolved.  With this in mind and the imminent Venus transit on June 5th, it's a good time to look back on that half century and see what we have accomplished and what we have learned, scientifically and as a species.

To celebrate that achievement, I will be posting an extended discussion of those 50 years, the first pioneering voyages, the major milestones, where we have been and what we have learned from it all.  The plan is to publish these articles in a series of 5 or 6 posts over the next few weeks.  It all begins today with an assessment of where we stood 50 long years ago on the eve of launch . . .

*Planetary in this case referring to beyond the twin Earth-Moon system, and is focused on the "debris" currently orbiting the Sun (as such Sun-focused exploration will not be addressed).

1958-1962:  In The Beginning . . .

Today we have an international armada of spacecraft (below) orbiting or on their way to (at last count) one comet, three dwarf planets (in both the Kuiper and Asteroid Belts), and to every planet except Uranus and Neptune (hey NASA, ice giants are key members of the Solar System too!).  We have in the past decade or two also visited 4 other comets, at least a dozen asteroids, and had a virtual armada in orbit or on the surface of Mars since 1997.  That is indeed an impressive state of affairs, considering that as recently as 1988 we had but two interplanetary spacecraft at all beyond the Earth-Moon system (that being Voyager 1 & 2).  But in 1962 we considered ourselves fortunate whenever vehicles made it into Earth orbit, and even then surviving as a functioning robot until planetfall was an eventful ride.  It is still not a risk-free endeavor as the Phobos-Grunt, Mars Polar Lander and Akatsuki experiences remind us.  

Olaf Frohn's chart showing the fleet of interplanetary spacecraft currently in operation (as of April 2012).  Courtesy of Emily Lawdawalla's blog.  The chart would be empty in Summer 1962.

IGY and the Space Race
It is useful to remember the context in which all of this started.  Post World War II, the United States and Soviet Union were engaged in the Cold War, with its subsidiary competitions the Arms Race, Missile Race (or Gap), and of course the Space Race.  Beginning in 1957 it had suddenly become very important for national prestige to be the first to do something or go somewhere in space.  The Space genie had been let out of the bottle so to speak in the late 1950's, when plans were put in motion to finally launch the orbiting satellites long dreamt of by novelists, artists, and scientists alike.  The impetus to do so in earnest was the Int'l Geophysical Year (IGY), a cooperative scientific agenda or program focused on investigating Earth geophysics, including its interior and its interactions with the space environment.  This program and the prestige associated with it (which was quote pronounced for its time) motivated the superpowers to push their advancing rocket technology to place a satellite into orbit, preferably with science instruments aboard.  Even the official emblem for IGY (below) featured a then-nonexistent Earth-orbiting satellite, symbolizing the scientific hopes attached to space.  While the Soviets reached orbit first, it was the americans who did so first with instruments dedicated to IGY, leading to fundamental and radical discoveries about the radiation belts and the solar wind, among other things.  These were among the first real indications of the vast unknowns awaiting us in our own solar neighborhood.

The lunar landing initiative launched by Kennedy in 1961 focused our early efforts to understanding the Moon in preparation for Apollo, at least for the 1960's.  The Moon's close proximity and relative ease of access (despite the low rate of early success) also made it the obvious first target.  Despite this, NASA's charter (http://history.nasa.gov/spaceact.html) was specifically written in 1958 to say, among other things, "(c) The aeronautical and space activities of the United States shall be conducted so as to contribute materially to one or more of the following objectives:  (1) The expansion of human knowledge of phenomena in the atmosphere and space;".  The fact that this objective is listed first may be regarded as more than a coincidence, but it is a broadly defined objective, and our planetary neighborhood has been a major component of NASA's exploration program since inception.  

Despite the lunar focus, Venus and Mars remained on the menu, and the first realistic opportunity arose during the 1961 conjunction with Venus.  There have always been strong academic communities genuinely interested in science and outer space and at least in the US of A, where control over space programs was handed over to the civilian sector, they have been allowed to at least partially drive the planning and design of much of our planetary program.  The planets were obvious and convenient targets as the outer space frontier opened up, the race to reach them first was on.  The Soviets launched the first missions to both Venus and Mars that year but each attempt failed either during launch or from in-flight failures long before reaching their targets.  Both sides would have to wait for 1962 to try again.


Before we look at the first flight to Venus and how far we've come generally, let's review where we stood in the summer of 1962.  

Since the heady first discoveries of Galileo and Cassini and others (the men, not the machines), the Solar System had become something of a backwater, relegated in the early 20th century to off peak hours at the telescope in favor of the more glamorous nebular and galactic branches of astronomy.  Planets and especially asteroids were "vermin of the sky", interfering with more "profitable" observing.   In the decades leading up to the Space Age, planetary observations were limited to photometric studies or similar endeavors, as true spectroscopy was still in its infancy and adaptive optics were a mere concept if that.  Our nearest neighbors in space, Venus and Mars, were fuzzy tennis balls or enigmatic spheres with tantalizing but hopelessly cryptic dusky markings.  There just wasn't much to say about our planetary neighbors.

Literature on the planets in the late 1950's had a quality that reminds one of the shrouded mysteries of the North American continent evoked by the sketchy and grossly incomplete (and often inaccurate) maps of the 16th and 17th century.  Together with the tall tales coming back from early explorers, the lure of that (not quite) virgin  land mass was irresistible for some.  Similarly for the unexplored and largely unknown Solar System visible in our own back yard as bright lights in the sky.  Articles in Collier's and books by Willy Ley and Arthur Clarke, among others, often accompanied by illustrations by Chesley Bonestell and Ludek Pesek, among others, evoked alien landscapes constrained only by the imagination and by a few meager (and sometimes erroneous) facts.

Books on the Solar System in 1962 could be 100 pages long and still be complete, reflecting how little was known about the Solar System and its members.  Even plate tectonics did not fully exist as yet as a coherent theory of how our own planet works (the IGY contributed fundamentally to this but it would be nearly a decade before all the pieces could be put together to understand the big picture).  Indeed, large section of these texts, especially popular books, were given over to speculations.  Much of that speculation focused to Mars, the nearest body for which we could resolve any markings, and hence the one believed tobe most Earth-like and most rife with possibilities.  We were still uncertain of what the atmosphere of Mars was made of or how dense it was, however, but those cryptic and changing dark markings gave seed to many an interesting idea (more on that later).

Cover of the book "All about the Planets," published in 1960 and resident of many a youngster's book shelf in the early 1960's, including my own.  The serene cover artwork portrays a Solar System of static order and tranquility, yet one shrouded in mystery and wonder, not unlike the North American continent in the 16th and 17th centuries.

In 1962, the Solar System was a static, well-ordered place where, aside from a stray comet, not much happened, a view in stark contrast to our present understanding (which I will describe in some detail next month).  It was thought "there may or may not be planets beyond Pluto."  "Certainly we shall have stronger evidence in a few years and then be able to say whether the changing seasonal colors on Mars are due to vegetational responses, or are just the result of sand storms."  A paragraph was sufficient to describe all we knew then about the amazing planet-like Galilean satellites of Jupiter.  It was believed even back then that the inner two, Io and Europa, were Moon-like but that the outer two Ganymede and Callisto had significant quantities of ices, but other than the unusual brightness of their surfaces, little else was known.  The size of Neptune's largest moon, Triton, could not be reliably ascertained until 1989, when Voyager 2 observed the disk of this frigid orb directly.  

Even some of the most basic properties of neighboring planets, such as the rotation periods of Venus and Mercury, were incorrectly estimated.  The innermost planet was described in one book as "a bare ball of rock and metal, with 'light areas" and "dark areas," none of which could be reliably correlated from one observer to another or one apparition to another.  Such were the mysteries that abounded in the cryptic void of hard information.  Such were the uncharted terrains described in books a young lad would read in the dawning years of the space age.

Prelude to Venus
So then, on the eve of the launches of Mariner 1 and 2, what did we think was going on at Venus?   Only slowly did the veil lift from the Mother of Loves, brightest star of the evening and morning skies.  Little more than a dusky bright white disc for centuries, its atmosphere was not confirmed until the transit of Venus across the Sun in 1761.  Indeed, it was these transits that first indicated the similarity in size between the Earth and Venus, giving rise to speculations about twin planets and all that that loaded comparison might suggest for life on our nearest neighbor.  But it would require another two ceturies for more secrets to be revealed.  CO2, the first atmospheric component to be reveled, was not confirmed until 1932.  Microwave observations in the 1950's hinted at a warm surface, possibly several hundred °K.  The cloud composition was still uncertain, as was the rotation period (finally pinned down by Earth-based radar observations beginning in 1962).  

One nightmarish vision of a windswept Saharan Venus.

Even though the composition of the clouds was not known till much later, the dense cloud cover gave rise to visions of dank steamy swamps and coal beds across Venus, not unlike conditions in the Jurassic on its twin, Earth.  By the time Patrick Moore wrote his book on "Venus" in 1958, that view was considered unlikely, and a hot dry Sahara-like Venus was gaining some popularity.  The thick carbon-dioxide rich atmosphere gave rise to informed speculations about trapped heat and "greenhouse effects" on Venus (and subsequently on Earth) championed by Carl Sagan in some of his first scientific work.  But even Sir Patrick, in his otherwise fine book, gave some final speculative thoughts to life on Venus, concluding that a near Cambrian Venus, with primitive life forms slowly developing in a warm oxygen-poor atmosphere, was possible, wistfully awaiting new knowledge.  Confirmation of life-threatening hot surface temperatures would have to wait for close examination by spacecraft, as would the presence or absence of radiation belts and a shielding magnetic field.  The stage was set for the Mariners . . .

. . .  Next week:  First to Venus, First to Mars

Comments and additional recollections are welcome!