Tag Archives: space history

35 years ago today: Columbia’s first flight; 55 years ago today: humanity’s first flight

On April 12, 1981, the Space Shuttle Columbia blasted off the launchpad at Kennedy Space Center’s LC-39A.  Her crew for this test flight were Commander John Young and Pilot Bob Crippen.  Young was already an experienced astronaut, with three flights including a lunar surface mission under his belt, while Crippen was a rookie out of the cancelled MOL program.  This was the first, and so far only, time an orbital spacecraft has made its first flight with human crew on board.  NASA had wanted a suborbital test flight first, but Young had argued against it, saying that the flight profile (a deliberate Return To Launch Site abort) required “continuous miracles interspersed by Acts of God” in order to be successful.  And in the end, he was right.  The risky RTLS was not necessary, and STS-1 was a success.  After thirty seven orbits and 54.5 hours, the two men returned, landing Columbia in the deserts of southern California, at Edwards Air Force Base’s Dryden Flight Research Center (now the Armstrong Flight Research Center).  On this video, note the white External Tank (they stopped painting it after STS-2, which saved considerable weight) and the distinctive black chines that always marked Columbia.

But that’s not the only amazing thing on this date in history, for this is Yuri’s Night.  Today is also the 55th anniversary of Vostok 1.  Yuri Gagarin climbed into the capsule atop an R-7 missile.  The capsule was modified from spy satellites, which had a pressurized reentry capsule to return film for developing and analysis, and it was a tight fight even for the small man.  (All early cosmonauts were short in stature, selected specifically for ease in fitting into tight confines as well as high G-load resistance.)  He completed two orbits of the Earth and then returned, but since Vostok did not have a landing system, he ejected after reentry and parachuted down separately.  He landed in a farmer’s field in Russia, startling the farmer and his daughter.  “When they saw me in my space suit and the parachute dragging alongside as I walked, they started to back away in fear. I told them, don’t be afraid, I am a Soviet citizen like you, who has descended from space and I must find a telephone to call Moscow!”  Gagarin immediately was lauded as a hero, and grounded from future spaceflights; sadly this would not save his life, as he died in a plane crash only seven years later.  But it is Gagarin that all astronauts follow, and will forevermore.


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Lest we forget: 30 years ago today, the Challenger fell

Here’s some suitable music for reading this.  It’s Dernier Rendez-Vous (Ron’s Piece), from the Jean-Michel Jarre album “Rendez-Vous”.  I’ll explain why it’s suitable as we go, and why it’s subtitled “Ron’s Piece”:

30 years ago, on January 28, 1986, seven men and women climbed aboard the Space Shuttle Challenger for the last time.  The mission had been delayed repeatedly; under the naming convention NASA has just introduced, STS-51L meant that this, the 25th mission of the Space Shuttle Program, would be the twelfth manifested mission from Kennedy Space Center in 1985.  (The “5” denoted the year, the “1” denoted KSC as opposed to Vandenberg, where at the time SLC-6 was undergoing conversion to support the Space Shuttle, and the letter indicated the sequence.)  Crews had been shuffled, and shuffled again.  The final crew were Commander Francis Scobee, Pilot Michael Smith, Mission Specialist 1 Elison Onizuka, Mission Specialist 2 Judy Resnick, Mission Specialist 3 Ron McNair, Payload Specialist 1 Greg Jarvis, and Payload Specialist 2, Christa McAuliffe, for the Teacher In Space Program.  (Her backup, Barbara Morgan, would not get to fly to space until over twenty years later, on a mission to the ISS.  But she would use some of McAuliffe’s lesson plans on that flight, finally completing the TISP mission.)  And even after STS-51L finally got manifested for January of 1986, it would still face several more delays and scrubs on the pad, slipping from January 22, then 23 & 24 due to delays with the previous mission, then delayed on a day-by-day basis after that due to bad weather either at KSC or at the trans-atlantic abort (TAL) sites.

It was a cold morning, unusually so, with temperatures well below the freezing point and citrus farmers fretting about their crops.  On the launchpad, huge amounts of ice now decorated the vehicle and pad structures thanks to the interaction of the moist Florida weather with the super cold propellants that had been piped into the Orbiter on January 27 and then detanked again.  This caused considerable alarm, and the launch was delayed a full hour while the Ice Team inspected and reinspected to determine whether any of the icicles could pose a threat if they shattered off of the pad and struck the vehicle at liftoff.


Ultimately, they gave it the all-clear, despite serious reservations by Rockwell (the Orbiter’s manufacturer) and although people like to simplify the Challenger accident to a failure of upper management to listen, I think it’s quite likely that hyperfocus on this very visible threat blinded them to more subtle threats.  For although the ice looked like a very serious threat, it ultimately was not a factor in the accident.  The air temperature that day was very low for Florida, lower than on any other flight, and at the very limits of what the SRB manufacturer, Morton Thiokol, had documented as allowable.  Indeed, overnight it had dropped well below the allowable limit, but by launch time, it had crawled just above, and the “go” decisions were made.  Several engineers at Morton Thiokol tried to express concerns, because they were worried that the O-rings sealing the joints between the segments of the solid rocket boosters could become inflexible, allowing them to leak as the boosters flexed during ascent, but for whatever reason, their concerns never reached the ears of those who needed to hear them.

After a few more pad delays, the final “go” decision was made, and launch proceeded.

At T-6.6 seconds, the SSMEs ignited, precisely according to specs.  At T=0, with the SSMEs at 100% thrust, the SRBs ignited and the hold down posts were released, freeing the Shuttle to leave the pad.  It looked good, but by looking carefully at the video in slow motion afterwards, bad signs were present almost immediately.  I’ll do the rest of the timeline as a list:

T+0.678 – puffs of black smoke are seen near the starboard SRB’s aft strut, which attaches the rest of the Shuttle stack to it via the External Tank, as the SRB segments flex and expand in the heat and from the aerodynamic forces of ascent.  This is smoke from the O-ring being incinerated by the extremely hot gasses inside the SRB.

T+2.733 – the last puff of black smoke is seen; by this time, the O-ring in the vicinity of the leak has been vaporized, and the extremely hot gasses have begun to melt the SRB casing itself; by happenstance, however, some of the rubbery solid propellant has extruded into the gap and temporarily sealed it.

T+28 – Challenger’s main engines begin throttling back to reduce aerodynamic stresses while passing through max-Q (the region of maximum dynamic pressure, or more simply, the sound barrier).

T+35.379 – SSMEs reach 65% throttle.

T+37 – Challenger begins to experience unexpected wind shear events, exceeding any seen on previous flights.

T+40 – Challenger reaches Mach 1.

T+51.860 – SSMEs begin throttling back up towards the intended 104% throttle.

T+58.788 – A plume is visible at the aft attach strut of the starboard SRB; it is believed that the torsion of the wind shear events has flexed the SRB enough to defeat the temporary seal created by the solid propellant, and now the blow-by will remain through the rest of the short flight.

T+60.238 – Pressure inside the starboard SRB has dropped considerably due to the leak, and the plume is now a flame.

T+64 – The wind shear events end.

T+64.660 – The plume seen by the aft attach strut changes shape.  The blow-by of hot gasses from the SRB have now penetrated the liquid hydrogen tank, which is leaking into the plume.

T+66.764 – Liquid hydrogen tank pressure drops due to the leak.

T+68 – CAPCOM Richard Covey calls out “Go at throttle up,” a normal callout to indicate the Shuttle returning to full thrust; there is nothing for the crew to actually do, as this is carried out by the onboard computers.  Commander Scobee acknowledges the callout with “Roger, go at throttle up.”  This is the last communication heard over the radio from the crew.

T+72.284 – The leak from the starboard SRB has burned through the aft attach strut, and the SRB tears free in back.

T+72.525 – Flight data records a sudden lateral acceleration, likely due to the shifted SRB.  The cockpit voice recorder captured Pilot Michael Smith saying “Uh oh”, the last recording of any of the Challenger crew’s voices.  So at this moment at least those on the flight deck likely understood something was badly wrong.

T+73.124 – The external tank aft dome fails, dumping the entire remaining contents of the liquid hydrogen tank into the plume, creating thrust that propels the hydrogen tank upwards into the liquid oxygen tank.  Simultaneously, the starboard SRB pivots around its forward attach point and strikes the intertank region.  The LOX tank ruptures as well, and all the propellants immediately go up in a huge fireball.

T+73.162 – The vehicle begins to break up.  Altitude is 48,000 feet.  The offcenter thrust of the starboard SRB plus the wildly erratic thrust of the exploding ET  push Challenger offcourse and into the airflow, which imparts 20 Gs to the vehicle.  It’s only rated for 5, so it is ripped apart.  The SRBs are stronger, and tear away from the disintegrating vehicle and continue to climb.  As they are normally steered by the Orbiter’s main computer, they are now climbing entirely out of control.  This produces the famous cloud we all know entirely too well.

T+75.237 – Crew module, the strongest portion of the Orbiter, is observed later on video exiting the cloud of debris, still ascending on a ballistic trajectory.

T+89 – In mission control, the flight dynamics officer (FIDO) reports that radar is detecting multiple objects, the first clear indication to MCC that the Orbiter may not have survived.

T+97 – Crew module reaches apogee at 65,000 feet, and begins to fall towards the Atlantic Ocean.

T+110.250 – The Range Safety Officer triggers the self-destruct packages on the two errant SRBs, judging their erratic flight as a hazard to the ground.  They are very near burnout anyway, so the explosion it small.  A solid rocket is destroyed by small shaped charges that essentially split the casing down its length; the sudden increase in surface area accelerates burnup of propellant, while the loss of pressure out the nozzle terminates the thrust.  How much of a boom you get depends on how much propellant is left, and there was not much; if you watch the video, you will see only a brief flash.

T+149 – Ground control reports negative contact, greatly dimming hopes that any part of the Orbiter survived, although the flight controller tells his team to watch carefully for any sign that it has.  Sadly, it has not.

Over the next few days, recovery teams removed much of the structure of the Shuttle stack from the sea floor, and some of the crew remains.  Identifiable remains were returned to the astronauts’ families; unidentifiable remains are interred with Dick Scobee in his plot at Arlington National Cemetery.  Analysis of the wreckage ultimately rules out the ice theory and reveals the real cause: the cold weather had rendered the O-rings inflexible, and one of them had leaked.  The SRB propellant itself had filled the hole, but high winds aloft broke this temporary seal and doomed the flight.  To this day, bits of Challenger still wash up along the Atlantic coast; the debris is stored largely in an abandoned missile silo at Cape Canaveral Air Station.  The crew, meanwhile, were not killed in the initial explosion or the sudden breakup a moment later; their actual cause of death could not be determined, but it is most likely that they were killed only on impact with the ocean, which would’ve been a 200G impact and definitely not survivable.  At least four of them activated their emergency oxygen packs, and severals switches had been set to positions not normal for launch; the only explanation is that Commander Scobee had been attempting to restore electrical power after the crew module lost power as it was ripped away from the fuel cells in the midfuselage.  However, as the cabin would have been depressurizing and the emergency oxygen was unpressurized (much like the emergency oxygen on a commercial airline flight), it is quite possible they lost consciousness before reaching the ocean.


I said I’d explain why the song at the start of this article is called Ron’s Piece, and here it is.  Jean Michel-Jarre has always had a fascination with space, and in 1985 he arranged for McNair to bring a saxophone along on his mission.  McNair was an accomplished sax player, and was happy to prepare for what would become the first professional music recording from space.  Alas, it was not to be, and the sax solo above was recorded later, on the ground, by a non-astronaut musician.  (In the end, the first professional music from space would not be recorded until Chris Hadfield created his album “Space Sessions: Songs from a Tin Can”, recording vocals and acoustic guitar during the ISS Expedition 35 in 2013.)  Jarre would later dedicate the entire album “Rendez-Vous” (the title of which is a play on both romance and spacecraft operations — when two spacecraft fly in formation, it is called a rendezvous, and in French, the word for a date is “rendez-vous”) to the crew of STS-51L.

Several major changes were made following the Challenger accident.  The biggest was a change to the SRB field joint design.  A third O-ring was added, along with heaters and an interlocking mortise and tang structure to reduce flexing of the joint.  They also banned the flight suits and crash helmets worn for ascent and entry on early Shuttle missions, reverting to pressure suits that would keep the crews alive and conscious in the event of a high altitude accident, to preserve possibilities of escape.  And the flight rules were changed, to increase the minimum temperature, require a minimum temperature for a certain number of hours prior to the flight instead of just during the actual launch, and also placing new restrictions on wind shear.  The Shuttle returned to flight in 1988 with Discovery on STS-26; NASA had jettisoned their short-lived naming convention and returned to sequential numbers.  The system was safer than ever.

And yet, in 2003, there would be another fatal accident, and eerily, the same time of year, although this time the weather had nothing to do with it.  But that’s a story for another day.  In the meantime, we have to keep reaching high, and not let our tragedies turn us permanently from the goal of leaving Earth.  As Konstantin Tsiolkovsky said, long ago, “The Earth is the cradle of humanity, but mankind cannot stay in the cradle forever.”  So I will leave us with So Far Away (Welcome to the Mission), from the Alan Parsons album “On Air”, which alludes to the Challenger at the very end:

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22 years ago today: the US returns to the Moon

After the cancellation of Apollos 18-20, it looked unlikely that NASA would be allowed to return to the Moon.  The attitude in the legislature was one of “been there, done that”.  Human spaceflight had been re-aimed at low Earth orbit space stations and spaceplanes, while robotic missions were going ever further into the deepest recesses of the solar system.  In 1977, the final death-knell for American lunar exploration seemed to have been struck when the funding to monitor the Apollo Lunar Surface Experiment Packages (ALSEPs) ran out, and the perfectly good autonomous stations were deactivated.

Perhaps this is why the first return to the Moon since Apollo was not exclusively a NASA project.  In 1994, on January 25, the Clementine spacecraft blasted off from Vandenberg Air Force Base aboard a Titan II rocket (military surplus; the rocket had previously lived in a missile silo).  All of the refurbished ICBM Titan II launches were for one customer: the United States Air Force.  The USAF realistically had no particular interest in the Moon, but their Ballistic Missile Defense Organization had a number of crucial new technologies that it wanted to develop, and somewhere along the way, someone came up with the bright idea of testing them out in a spacecraft that would also orbit the Moon.  This allowed them to get NASA on board, and also the French agency CNES, significantly reducing the amount each agency would need to spend.  On February 19, the spacecraft arrived in lunar orbit, and on May 3, it became the first spacecraft to do something else remarkable: it departed lunar orbit to leave the Earth-Moon system altogether.  The only spacecraft to have left lunar orbit previously were all sending capsules back to Earth.  After leaving lunar orbit, the spacecraft then left Earth orbit, conducting a burn designed to put it on course to rendezvous with the asteroid 1620 Geographos; unfortnately, a thruster malfunction ruined that plan, and they ended up putting the spacecraft into a heliocentric orbit designed to take it one more time through the Earth’s Van Allen Belts for further study.  Contact was lost in June of 1994.

Clementine was a short-lived probe, and one which, like the girl in the song, is now lost and gone forever.  But it did something important in the meantime: it proved there was still a reason to go to the Moon.


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Space History for Jan 10: Venera 6

In 1969, six months before the Apollo Moon landing, and a year and a half after the last Russian and American attempts to robotically explore the planet Venus, Venera 6 was launched.  It was the last of the Venus atmosphere probes launched by the Soviet Union, except for the balloons launched by the Vega mission.  After Venera 6, the USSR would concentrate their planetary efforts on the herculean task of surviving landing on the hellish surface of Venus.

Venera 6 reach Venus on May 17, 1969, and survived approximately 51 minutes before succumbing most likely to the pressure.  Previous attempts had exhausted their batteries before sinking deep enough to be crushed in Venus’ extraordinarily thick atmosphere, so Veneras 5 & 6 (in those days, the USSR always built probes in pairs, in case of mishap) were equipped with much smaller parachutes.  This allowed them to fall to their full crush depth before running out of battery life, enabling measurements as deep as possible within the Venusian atmosphere.

It was a feet that would not be surpassed until late in 1970, when Venera 7 survived long enough to transmit some data from the surface of Venus.

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51 years ago: Voskhod 1

It’s amazing to be hitting the half-century mark after so many space firsts, and today is one that many may not be aware of it.  It was a pretty big deal at the time, but it isn’t as well remembered as the first man in space, first EVA, first woman, etc.  After the flurry of basic “firsts” by Vostok and Mercury, it was time to move into multi-crew missions, to prepare for a moonshot.  America was working on the Gemini program.  Russia was working on . . . well, too many things at once, probably.  Shifting political winds kept moving funds from one team’s spaceflight efforts to the other, a problem which may have ultimately cost them the moon.  But be that as it may, in April of 1964, the Americans launched an unmanned Gemini capsule aboard a Titan II ICBM, an obvious prelude to their first two-man flight.

Gemini had deleted some of the safeguards that Mercury had carried; in particular, it would not have an escape tower.  And it would fly atop a dangerous hypergolic fueled rocket.  Gemini would also carry another innovation that only NASA would ever make further use of during spaceflight: fuel cells.  But what really mattered was that it would carry multiple crews.  That had the potential of robbing the Soviets of a “first”, which couldn’t be allowed to happen.

By October, Sergei Korolev’s team had taken a Vostok capsule and reconfigured the one-man capsule with three seats.  As there would not be room for three ejection seats, for the first time the crews would actually have to land in the thing, so a backup retropack was added for some extra safety.  The rocket was beefed up to carry the extra weight, but it wasn’t quite enough, so the escape tower was removed, as were the crew’s spacesuits to protect them should the capsule depressurize.  As long as they were at it, the Soviets decided to make two of the crew non-pilots.  In addition to Colonel Vladimir Komarov as the pilot, the ship carried Konstantin Feoktistov (PhD in physics and a spacecraft designer who later went on to be chief designer of Salyut and Mir stations) and Dr Boris Yegorov.  They were, respectively, the first scientist and the first physician in space.

The mission lasted just one day and accomplished very little other than to demonstrate that multiple humans could be in the same spaceship at once.  But it maintained Russia’s apparent lead over the US.  The Voskhod program would only last for one more flight, accomplishing the world’s first EVA, before resources had to be focused more intensely on Soyuz.  Arguably, Voskhod was a distraction from Soyuz, which did not fly crewed until 1967.  The crew of that first Soyuz was the same man who piloted Vostok 1: Vladimir Komarov.  Sadly, it would be his final flight, as on Soyuz 1 he became the first man to die during a spaceflight.

But in 1964, his experience was more joyous, and with his two crewmates returned home to a hero’s welcome.  The line in the sand for human spaceflight had been edged a little bit further over.

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Space History for August 4: MARS!

There were two major events in Mars exploration history on this date.  In 1965, Mariner 7  became the third spacecraft to return pictures of the Red Planet, flying past at an altitude of 3,430 kilometers above the planet’s surface.  It was a close thing, too, since less than a week before, JPL had lost contact with the probe, believed to be due to gasses leaking from its battery interfering with the signal from the high-gain antenna; JPL managed to regain contact using the low-gain antenna and were able to sort things out with the high-gain antenna just in time for the pass.  They were even able to mark targeted observations based on the data returned by its twin Mariner 6, just a few days ahead.

Then, on August 4, 2007, a Delta II 7925 rocket blasted off from Cape Canaveral carrying the Mars Phoenix Lander, constructed largely of flight spare components from the ill-fated Mars Polar Lander mission.  Phoenix would complete its nine-month cruise and land successfully on Mars on May 25 of the following year.  Amongst its many discoveries was the first observation of liquid water on the Martian surface — water droplets that briefly persisted on the lander’s legs shortly after touchdown, and then rapidly boiled away in the tenuous atmosphere.  Its surface mission lasted 157 sols, 67 past the mission objective, before the Martian arctic winter claimed it forever.

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