No Candle Lit in Copenhagen Today--But a Silver Lining

Message to my Pacific Spaceflight group today, describing the events at Copenhagen Suborbitals as I understand them (photo of an intact and burst 'burst disk'):

Well I was up all night watching the live stream on YouTube, but no engine ignition for the static test today. Here is why, which is very instructive.

The rocket uses alcohol as fuel and liquid oxygen (LOX) as the oxidizer. Inject them together, from separate tanks, into the rocket combustion chamber and you get an explosion that is directed out the nozzle, creating thrust in the opposite direction. Cool physics courtesy of a certain Isaac Newton!

The rocket consists largely of two cylindrical tanks, 600kg each of LOX and alcohol. LOX tank above the alcohol tank. Valves open to allow flow of LOX and alcohol to combustion chamber. Rather than pumps or turbines, these fluids were to be injected into the chamber by pressurizing the unfilled volumes of each chamber with inert nitrogen and helium (can't remember which tank was pressurized with which gas).

OK so procedure before firing is to fill tanks partially with alcohol and LOX; that went fine, leaving an unfilled volume in the tanks. Into this volume the gasses were pumped to raise tank pressures to about 18-20 bar (1bar = 1 atmosphere = 14.7psi; so their tanks were to be pressurized to 261 PSI and 290 PSI (can't remember which pressure for which tank). Compare to our scuba tanks at 3k psi.

So, tank filling was fine, about 30 min before proposed ignition.

Now followed tank pressurization. Everyone (mostly) well clear of the pad because if the tanks rupture you have a bomb and only the most dedicated 'pad rats' were still on-site to monitor these last phases. Alcohol tank pressurization was fine up to its specified about 20bar. LOX tank pressurization, monitored by a remote digital gauge, went fine, up to 8bar, but then a moment later the gauge read 0.8bar. HMMM???. A glance at the rocket showed no LOX leak or anything else awry. As the crew tried to determine the problem, a jet of LOX was seen to shoot out of the side of the rocket. This was instantly identified by Peter M. on the radio as a 'burst disk', and while I muttered damn he instantly said "LOX burst disk, engine firing is scrubbed for today".

This is because while the team were thinking over the issue, LOX tank pressure continued to increase even without pumping in new inert pressurization gas! That is because LOX has to be stored at -369F; if the temperature rises, it begins to boil, increasing pressure in the LOX tank. There is no provision to keep the LOX cool once it's in the rocket, that is heavy machinery, so once fuelled you have to pressurize and then get outa dodge! In just a few minutes, though, that pressure in the LOX tank increased to the point (I don't know the PSI) at which the LOX tank pressure relief valve (AKA 'burst disk') cracked, as it was supposed to do, to dump pressure from the tank. This prevents the tank from pressure rupture. So, why not just reset the pressure relief valve (burst disk) and start over? Because a burst disk is not resettable or reversible; it is literally a patch of metal on the pressure vessel (LOX tank) weaker by a known degree than the rest of the tank. So a 'burst disk' rupture means there is now a hole in the tank, and that's that for the day.

So, a faulty pressure gauge, that gave a bad pressure reading (from 8bar to 0.8 bar over the course of a second) caused the team to spend some time thinking over the issue (backup gauge had been unplugged from the rocket a bit earlier), and in that time the 'passive pressurization' of the LOX tank, by warming LOX, blew the burst disk.

Such is an experimental rocket program. I am sure they're having a glum night at CS tonight. I am sure they are also tracking down the LOX tank pressure gauge fault, and looking at records to see when it was last tested. It worked fine, remember, until 8bar, but then in a moment the gauge died. A backup digital gauge might have helped, but of course you can go down the road of 'backups to backups' and never come out.

The silver lining to me is that the burst disk worked. It did its job of preventing a larger rupture of the LOX tank, wich might easily have burst the alcohol tank, thus making a bomb of the whole rocket. So, the rocket was saved by the correct functioning of the burst disk!

Food for thought RE our own sensors, procedures, checklists, pre-flight tests, and attention to detail.

Regards CMS

Cultural Evolution in Interstellar Migration

Link to my new article, Human Universals and Cultural Evolution on Interstellar Voyages. Synopsis:

"Cameron Smith last joined us just over a year ago with an essay on human interstellar migration in the context of biological evolution. Here he turns to issues of culture and change over time. An anthropologist and prehistorian at Portland State University in Oregon, Dr. Smith brings insights he has gained in the study of the early human experience on Earth to the manifold problems confronting us as we head for the stars. His current work on interstellar issues is part of his engagement with Project Hyperion, an attempt by Icarus Interstellar to develop parameters and reference studies for a multi-generational worldship. Be aware of Dr. Smith’s excellent recent volume Emigrating Beyond Earth: Human Adaptation and Space Colonization (Springer-Praxis, 2013), and ponder the synergies that occur between the study of past human migrations and the ongoing cultural and biological evolution of a species aspiring to leave the world that gave it birth."

New 2d Manikin for Space Suit Configuration Design

From the very useful book "Space Requirements of the Seated Operator" I've copied a mankin in Illustrator for my own purposes. Low-res screen grab.

Back from California

A mind-melting meeting at SpaceX, and a lot learned on both strategic (goals) and tactical (implementation) levels that will improve my work. Unbelievable sights and experiences; more than a dozen gleaming Merlin engines in production ["These will be in space in 4 months," an engineer told me]; grilled by a panel of engineers RE our suit performance; saw their prototype space suit; tried out their launch seat (similar to the seat configuration we're using to design our suit); made good connections; maybe set up a consulting relationship. The visit gave me three concrete ideas to implement ASAP for innovative solutions to some old problems of ensuring astronaut safety in launch-to-orbit and re-entry. Not my photos (not allowed), showing a Dragon capsule mounted on a Falcon 9 rocket, a Merlin engine and interior of the double-decker Dragon capsule, my focus as space suits are closely tailored to particular spacecraft interiors. Feel as though I've had 3,000 cups of coffee. A lot more to report in near future. Ad astra per aspera!

Note: SpaceX is a commercial venture that could collapse at any moment, but Elon Musk's Tesla Motors exists largely to ensure the success of SpaceX, whose ultimate goal is to establish a new branch of human civilization on Mars. Will Elon Musk give up SpaceX and concrete steps towards settling Mars? To that he said "I never give up. I would need be dead or completely incapacitated."

Back to Los Angeles!

Third time to Los Angeles this year -- and this one for a meeting with a panel of engineers at SpaceX, Elon Musk's private spaceflight company. They called a few weeks ago. No details for now, but I'll spend the day there Friday, seeing the facilities and presenting some information on my space suit. Then I get to take a nice long break to see John and Annie and Julian and Vera, both couples living in the beautiful Topanga Canyon (above). What a relief it will be to take a break and relax, but only after what promises to be a mind-meltingly exciting day on Friday! Above photo; man in center shows scale of these Falcon 9 rockets. Engines are Merlins. The Dragon capsule will be my main focus however, as space suits are carefully tailored to the specifics of spacecraft hardware.

Brilliant New Snorkeling Design

This looks great!

Sir Loncke

My buddy, Belgian explorer Louis-Philippe Loncke!

"Today at the European parliament Jane knighted me Jane Goodall Institute Knight for the Youth, the Animals and the Plants in the Order of the Iguana."

Congratulations, Sir Loncke!

Hokulea and Hikianalia Setting Sail!

Wondrous fantasy ships, setting sail today for a round-the-world voyage of education and inspiration. I'll be thinking of those bold explorers of the Pacific, over 3,000 years ago, in tomorrow's pressure suit test. I know how they feel today, casting loose from a dock and leaving land behind!

Early Settlement of Northern Eurasia

Preparing to visit SpaceX in LA next week, but in the mean time also knocking out further figures for the Atlas of Human Prehistory, which is coming along well. Today, in the photo above, drafting out 'Early Settlement of Northern Eurasia'.

From Elon Musk

Advice from Elon Musk, of SpaceX, where I will do a presentation next week.

"Don't tell me what positions you've held, tell me what problems you've solved."

Sounds right to me!

Copenhagen Suborbitals Progress

Update from Copenhagen, where a rocket test tower is being assembled. Headed over in a few months to spend August integrating the space suit with their capsule and its systems, and for a test balloon flight.

"These days the CS crew is working days and nights to prepare the HEAT 2X rocket for its static test. Its been under construction for years, and its liquid propellant engine technology has been tested many times at small scale, and three times at full scale. Now, it finally a complete rocket stage that hits the test stand.
When that happens the whole test structure from the base to the service crane 21 meters up on the gantry will weigh 160 tonnes.
With is 90 sec burn, we can´t even dream of flying passively stable, so this thing only goes up if we can put a computer at the helm and actively control its trajectory.
So what is this in technical terms ? What have wee build, and what can it do if it works ?
Well, to put it shortly, its a very advanced, complex hypersonic flying machine. It lacks only the turbine pump to have all the key components of the big professional space launchers like the Atlas, Delta, Titan, R7, Proton and so on. And that final component is at the testing stage in the experimental department of CS.
--- Peter Madsen"

Two Work Prongs Part 2

Two more! Today's diagram, researched the past week and drawn up today after giving a midterm, colonization of the Caribbean region...and in the PM, installation of both constant-volume elbow joints, the products of many hours of design and construction! Whole weekend, tests scheduled, and some late PM grading. Thanks to Amy W. and Alex K. for their work tonight!