Category Archives: Space

Thoughts on “Oxygen” and the perils of space

So it’s been nearly a week since the last episode of “Doctor Who”, and before we go headlong into the trilogy that awaits us, I’ve got a few thoughts on “Oxygen”.  I loved it!  It reminded me of the classic serial “Sunmakers” but also had a bit of  “2001” vibe, with the machines deciding to dispose of the humans, and starting right out with two spinning dead astronauts, reminiscent of Frank Poole.  But the underlying theme, as laid out so clearly in the Doctor’s opening lecture, was this: space is an unbelievably hostile environment.  It is always trying to kill you.

And he’s right.  An Apollo astronaut was once asked in an interview whether or not they carried suicide pills, in case of a mishap that prevented them coming back to Earth — a cyanide tablet could give them a quicker death rather than lingering on until they starved.  But the astronaut pointed out that there was no need — in space, dying is actually very easy to accomplish.  If they’d wanted to commit suicide, all they’d have to do is open a valve, and they’d be dead in a couple of minutes flat.


Another perspective comes to us from Akin’s Laws of Spacecraft Design.  In every version of his list of laws, the last one is always this: “Space is a completely unforgiving environment. If you screw up the engineering, somebody dies (and there’s no partial credit because most of the analysis was right…)”  It’s something to soberly consider if you ever find yourself working on a human spaceflight program, since after all, there were engineering decisions that played directly into each of the fatal spaceflight accidents to date.  Apollo 1 was pressurized to greater than 1PSI of pure oxygen on the ground while miles of poorly secured wiring was just waiting to short out and start a fire, and a door designed primarily to keep pressure in also prevented escape.  Apollo 13 was caused by wiring that had worn out due to heavy stress testing, wiring that could not easily be reinspected.  Challenger was caused by a deficiency in the design of the SRB joints, complicated by an overly optimistic engineering analysis which said it should be okay to launch on a day that was below the freezing point.  Columbia was caused by the design of the foam combined with the unexpectedly fragile nature of the RCC carrier panels, which had never been tested for their ability to withstand a strike, since they were believed to be stronger than the tiles; this turned out to be badly mistaken.  Soyuz 1 was struck down by a litany of defects, in a spacecraft whose design really wasn’t complete yet, although the final and fatal insult was a fouled parachute.  And then there’s Soyuz 11.

Soyuz 11 is an accident that definitely bears a relationship to this episode.  It even involves a space station, the only fatal spacecraft accident ever to do so.

It was 1971.  A series of rigorous tests and qualification work following the horrific Soyuz 1 mishap had produced a vehicle that controllers felt very confident about.  So confident, in fact, that they declared they did not have to wear pressure suits for launch and entry.  This would allow the original series Soyuz to carry three crewmen, a feature that was seen as highly desirable for a manned space station program.  For now that Russia had lost the Moon race, Soyuz was being repurposed from a lunar orbiting spacecraft to a space station ferry vehicle, a task at which it ultimately excelled.  In April of 1971, the first DOS (Durable Orbital Station) was launched and dubbed Salyut 1.

Two days later, a crew launched aboard Soyuz 10, but they were unable to dock.  Salyut 1 used the first cone-and-drogue docking system in the Russian space program, a system they continue to use (with refinements) to this day, and there were some growing pains.  Eventually, after completing observations of the station, the crew returned home.  In early June, another crew was launched: Georgy Dobrovolsky, Viktor Patsayev, and Vladislav Volkov.  They were able to dock and carried out a fully successful 23 day stay on the station, setting a bar that the Americans would not clear until Skylab, two years later.  Their work completed, they departed on June 30, 1971.

They never saw Earth again.

During reentry, controllers lost contact with the vehicle.  This was not unusual, but the duration of the blackout was.  Even after the spacecraft was observed descending under parachute — on target, following a nominal reentry profile — there was still complete silence on the radio.  Perhaps some had already anticipated that something was badly wrong, but they wouldn’t know what until they were able to open the hatch and look inside.  Mission controllers waited anxiously, much longer than they expected to wait, before a simple code was transmitted: 1-1-1.  These three numbers indicated the health status of each crew.  5 meant healthy.  1 meant dead.

It is from this mission that we know precisely what happens when a person is exposed to the vacuum of space, for they had died of decompression.  All had been dead for at least several minutes by the time the spacecraft touched down; one of them was still warm to the touch, but it was still too late to resuscitate.  They had blue patches on their faces and blood running from their ears and noses, the result of eardrums and capillaries bursting.  Crew vainly attempted to resuscitate them, but it was far too late.  They had died shortly after retrofire, when the orbital module had separated and a valve remained open that should have been closed.  Autopsies revealed hemorrhaging in the brain, lots of bleeding just under the skin, and evidence that catastrophic bubbles had formed in their blood, causing fatal aeroembolisms — their blood did not literally boil, in the sense that the water did not turn to vapor, but the dissolved gasses (nitrogen, oxygen, and carbon dioxide) had come out of solution.

One thing that’s interesting from their case is that the Doctor isn’t quite right about how one would fare, exposed to space.  He says that you’d pass out in 15 seconds.  This doesn’t turn out to quite accurate — you have about fifteen seconds of useful consciousness, but that’s followed by nearly a minute of confusion before you succumb completely.  The Doctor says you’ll be dead in 90 seconds; perhaps some last longer than others, but we only have three examples to draw from, and they actually lasted twenty seconds longer than that.  Perhaps humans are a little more resilient than the Doctor gives us credit!  He also says you would die due to oxygen bubbles in the brain; actually, nitrogen bubbles are a bigger worry (ask any diver), but that wasn’t what killed the Soyuz 11 crew.  You could get a rapidly fatal aeroembolism, and that might be a mercy.  It’s also total chance where the bubbles end up going first, so don’t count on it.  The Soyuz 11 crew died due to lack of oxygen; they did suffer aeroembolisms, but it seems they weren’t fatal.  What really killed them was the fact that with the oxygen now out of solution, it couldn’t get where it needed to be in order to fuel the brain and other organs.

So how’d the Doctor survive?  Well, obviously it’s some kind of Time Lord biology thing.  It’s also not the first time he’s spacewalked without adequate protection.  (Last time, in “Four to Doomsday”, it didn’t seem to have any lasting ill effects.)  So what happened to his eyes?

There are a few possibilities.  They depict frost forming on Bill’s cheeks as the pressure drops; I am not convinced this would happen, since human body temperature should be plenty high to keep the frost away. Water should be converting to vapor, not solid.  So did his eyes freeze?  Maybe.  What about excessive drying?  People who have survived decompression accidents and felt the water evaporating off of them did not suffer harm to their vision, but it’s theoretically possible, especially if enough moisture evaporated out from the corneas themselves.  This is more likely what the scriptwriter intended, since the Doctor mentions fluids boiling away from the eyes in his opening lecture.  Bear in mind, it’s not a hot boiling — as pressure decreases, so does the boiling point, until you get a situation like dry ice here on Earth — it goes straight from solid to liquid without ever being a liquid in the middle.  But it would be rather harsh.  With this in mind, Stanley Kubrick and Arthur C Clarke had David Bowman scrunch his eyes closed as hard as possible before his very quick helmetless emergency spacewalk in “2001”:

In summary, while there were some minor quibbles with what would happen to you in a real spacing situation, they actually got it pretty good.  Space is extremely hostile, and in the future, oxygen may well become a commodity.  In the meantime, wear your spacesuit for launch and entry and docking, and for gosh sakes, don’t lose your helmet.

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Falcon 9 has lifted its heaviest payload to geosychronous orbit to date: Inmarsat-5 Flight 4, a massive commsat designed to support inflight WiFi and mobile broadband.  The spacecraft was originally slated to fly on SpaceX’s gigantic Falcon Heavy, but the increase in Falcon 9 capacity with the current version (v1.2) meant that if the booster recovery was abandoned, they could actually do the mission with this vehicle.

This is the SpaceX live feed, captured for our enjoyment.  The feed starts 11 minutes into the video, and launch is at 20 minutes.

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PSLV launches GSAT-9

I can’t believe I missed this when it happened!  India launched another Polar Satellite Launch Vehicle, placing the GSAT-9 commsat into orbit.  They’re offering GSAT-9, aka the South Asia Satellite, for the use of all nations in South Asia.  This has had a somewhat mixed reception, with Pakistan seeming particularly unimpressed, but Afghanistan, Bangladesh, Bhutan, Nepal, Sri Lanka, and the Maldives are all signed on to make use of the vehicle.

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The 4th X-37 mission has ended

Without any fanfare, the OTV-4 mission came to an end over the weekend, landing at Kennedy Space Center’s Shuttle Landing Facility following 718 days in orbit.:

As with the previous three Orbital Test Vehicle missions, the majority of its activities remain undisclosed.  However, this time the Air Force did disclose two payloads: an experimental ion thruster built by Aerojet-Rocketdyne and a NASA payload called METIS (Materials Exposure and Technology Innovation in Space) that exposed over a hundred samples of materials, such as polymers, ceramics, and more.

The fifth OTV mission has not yet been announced.

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The wild howls of Saturn, in a strangely empty space

Cassini has just now completed its second close pass; the data isn’t back yet, but in the meantime, mission controllers have released a pleasant surprise from the first pass — although the big High Gain Antenna was used as shield during the pass, the plasma wave instrument (which peeks out from behind the antenna’s big reflector dish) detected almost no particle hits at all, and what it did encounter was no bigger than smoke particles (<1 micron).  This is happy, because it means Cassini will not need to use the dish to shield anymore, except on a couple of passes that will penetrate some ways into the D ring.

But it’s also a puzzle, which is always a fun and exciting thing to encounter in science, because this space was not expected to be so empty.  The corresponding space on the outside of the rings is definitely not so empty, and you can hear the difference in these two audio clips.  The clips were made by converting the information from the plasma wave instrument into audio.

Here’s from a ringplane crossing outside of the rings.   Each crackle and pop is a particle hit, and at the time of the ring crossing itself, there’s a very clear spike:

Now, for contrast, the inside of the rings, where the lack of pops and crackles is made all the more obvious by the fact that the impacts are no longer drowning out the whistles and howls that Saturn’s magnetosphere makes normally, allowing them to crank the gain way up but still without hearing a lot in the way of impacts.  This one sounds a lot wilder, since here you can listen to Saturn itself:

The third periapsis will be in under a week.  Things are moving fast now!

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Spectacular Falcon 9 return footage from NROL-76 launch

SpaceX successfully completed their first flight for the National Reconnaissance Office, carrying an undisclosed classified payload to orbit, designated NROL-76.  As is typical for NRO launches, coverage of the climb to orbit went only as far as first stage burnout.  However, SpaceX still had plenty of first stage footage still to produce, as the stage returned to land back at the Cape.  As a result of that and the favorable lighting conditions to view the rocket climbing away from the historic LC-39A complex, using the exceptional long-range tracking cameras available at KSC, this may be the most spectacular first stage flyback footage yet:

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Tianzhou-1 completes inflight refueling demonstration

Tianzhou-1 has docked with the unoccupied Tiangong-2 station and completed an on-orbit refueling demonstration.  The entire operation took five days.  Tianzhou-1, which is loaded with inert bags to act as mass models of station supplies, will remain at the station for a few months, conducting other tests, before undocking for a free-flight phase of the mission before it is commanded to a destructive reentry.

Tianzhou-1 is the heaviest payload ever launched by China, bigger even than the Tiangong-1 and Tiangong-2 space stations, which speaks to the high aspirations they have for their subsequent stations.  They are planning something substantial, and capable of continuous occupation.  Tianzhou itself is designed to supply the needs of three crewmembers (in food, water, supplies, and breathable air) for a full month.

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