A Burning Need... (Part 2)

As the testing of the F1 evolved, it became clear that harmonic instabilities were causing failures. Of course, these instabilities had always been present in rocket engines. They are caused by acoustic pressures building up unevenly and zinging around inside the engine. In the smaller combustion chambers of engines past, they were not so destructive. But inside the massive F1 combustion chambers, these instabilities could become crippling.

Tired of watching their rocket motors exploding, Rocketdyne engineers decided to take control of the process in a unique way. Rather than allowing the acoustic instabilities to initiate and build on their own, they took a "sour grapes" approach, designing an explosive device that could be inserted into the engine upon firing on the test stand. Then, rather than waiting for the instability to build up unpredicted, they could set off their bomb (which was of a known power and yield) and watch a similar acoustic instability build... but with increasingly predictable results.

Eventually, between tests such as the above and many, many redesigns of the injector plate among other components, most of the problems were resolved and the F1 engine was tested in flight and declared flightworthy and man-safe.

However, this is not quite the end of the tale... for as the Apollo program sped on to it's triumphant arrival on the moon in 1969, the Saturn V and the F1 engine continued to have teething pains... the Pogo effect.

A Burning Need... (Part 1)

The development of the Saturn V rocket entailed incredible challenges, but perhaps none so daunting as the creation of the F1 rocket engine, the first-stage powerplant for the mighty booster. Approved for development in the 1950's by the US Army (because, if for no other reason, the Soviets were developing big rockets), the F1 project migrated to NASA when the agency was created. The contract went to Rocketdyne in Canoga Park, California, a division of North American Aviation. This was a huge leap in rocket engine design, and while some of the notions involved were in effect a scaling-up of existing designs, much of the work was well beyond anyone's experience. At this time, large rocket engines were producing on the order of 100,000 or (later) 200,000 pounds of thrust... the F1 would create 1,500,000 pounds! And while cryogenic engines were the trend of the future (supercool mixtures of liquid hydrogen and liquid oxygen), the F1 would produce this power from a mix of liquid oxygen and plain old kerosene.

But early on, the project exhibited growing pains. One major area of concern was combustion instability. When a combustion chamber is scaled up to these dimensions, and the mixed fuels are ignited inside, acoustic waves begin slamming around the chamber and can cause big problems. And in those days, before CAD programs and when computers, such as they were, used that modern innovation- the punch card- engine designs were tested by building and firing. As often as not, they exploded, and the fragments were gathered for a failure analysis. The F1 exploded a lot. And the reason, in most cases, was the gremlin of combustion instability. But the Rocketdyne engineers had a solution in mind, straight out of their collective WWII experience with that simplest of argument solvers, high explosives...

[TO BE CONTINUED]

Beauty in the Infrared

OK, this week's post is a cheat... but only because it is so incredibly cool. Space.com just posted images form NASA's WISE orbiting telescope, launched in 2009 and shut down in February 2011. The reason for the short lifespan? For one thing, the liquid hydrogen coolant that allowed the 'scope to function at infrared wavelengths ran out, and for another, NASA's funding ran out, so an extended mission was not approved. A pity that, for as JPL has so ably proved over the years, an asset in place (i.e., one that has left Earth's gravity well) is always more valuable than another on the drawing board. But what a haul WISE made! Check out these images, all in the infrared and enhanced for human viewing.

Welcome to Mission Control

I've been presenting leadership lectures at Johnson's Apollo Mission Control for a few months now, and every trip there is like a trip to the Church of Apollo. If you ever have a chance to visit, make sure you sign up for the Space Center Houston tour which includes this stop. number of years ago, someone at JSC realized that the old MCC was something special, and should not be repurposed for shuttle control (as the other one was). So with an ultimate partnership with the National Parks Service, the Apollo control room was, so to speak, "mothballed in place" and looks much the same as it did when the last lunar landing flights departed Earth orbit.

Our program gave us the chance to view the fine movie Apollo 13 from the very seats featured in that film. Nothing like sitting at Gene Kranz's console as you watch him (well, Ed Harris) make life-or-death decisions... fantastic.

Of course, there are changes over time. The consoles no longer light up, due to safety considerations. The carpet is very worn, but at this point cannot be replaced due to asbestos abatement expenses. And so many more issues. But the basic structure is there, with the consoles, the chairs, the pneumatic messaging tubes, and all the rest. Just fantastic.

If in Houston, make sure to put this at the top of your list!

Take Care, Endeavor

The current shuttle in orbit, the penultimate flight of the STS program, has tile damage. Seven areas of concern have been indentified by observation from the space station. At this point, they are not considered to be a danger to the return of the orbiter, but more investigation is needed. See details here.

The damaged areas range in size, but a few are larger than a deck of cards. Of course, the depth of the gouges and shape of them will play a role in the decision to fix or not fix. Also, location on the orbiter matters a lot- the temperature buildup in that particular area plays heavily into the equation.

The worst case scenario? A docking with the space station, crew transfer to safe haven, and return to Earth via Atlantis or a Soyuz. Then there would need to be a decision whether or not to attempt an unmanned, computer driven landing with Endeavor. In theory it could be done, and the Soviet Union long ago flew (and landed) their own Buran shuttle unmanned, but for the US shuttles, it is an option previously tested only with a human crew onboard.

As is most common, the damage was from pieces of foam insulation from the external tank (ET). The tank in question was older, having previously survived a hurricane that ripped through the assembly facility, with foam insulation that was over 10 years old.

Apologies, and Goodbye Shuttle...

Well, it seems the US space program isn't the only entity experiencing a hiatus. My apologies to followers of this blog, as I was forced to take an extended leave to deal with some family medical issues- specifically aging parents. One left us, the other is in assisted care. Those of you who have experienced this seemingly inevitable outgrowth of being a Baby-Boomer will understand. As for the rest, please merely accept my apology.

And now onto the shuttle. I have been honored with an unusually high number of radio interviews of late, and a recurring subject of intense interest (other than the "Is Mars really going to be as big as the full moon in August?" question) is the looming end of the shuttle program. While opinions vary, the average caller seems to be confused and appalled by this. Of course, there is the (by some) perceived indignity of US astronauts hitching rides with our old space race adversaries, the Russians, to the space station. In reality our enemies at that time were the leaders of the Soviet Union, not Russians, so it's really a moot point. But the national mood does not seem positive in this regard.

But let's examine the current state of affairs: when Obama's NASA makeover list came out a few months back, it left the shuttle to discontinue operations this year (now extended, by mission slippage, into 2011). Two flights remain as of today. A few billions were aimed toward private industry (read Space X) for orbital vehicles and boosters. NASA's Constellation program (the replacement for the shuttle, looking much like a return to Apollo) was nixed, but the capsule itself was retained as an orbital lifeboat for the space station.

Now this bill is being kicked between the other political organs of the legislative branch, and what is emerging is somewhat amended. The funding for the private sector will likely be slashed by over half, the remnants of Constellation will include a heavy lift booster (also a part of the Obama proposal but more clearly defined), and there will probably be funding for one more shuttle flight in summer. In the near future we will know the immediate fate of the US manned space program.

And what of the space station? At one point, it was to be de-orbited in 2015-2016. Now it has been extended to 2020 (at least under this administration). Time will tell if the nation's appetite for space exploration will support 5-10 years of shuttling to the station in the Russian Soyuz capsule (and paying handsomely for the privilege), and later private US spacecraft.

The shuttles themselves have been allocated (sold, actually) to various US space museums and facilities. They will be huge, beautiful (to this beholder) relics of better times.

And what of the US space program overall? The general direction seems to be towards continued low earth orbit operations, a possible (but still ill-defined) trip to an asteroid sometime around 2020, and a gauzy idea about a manned Mars mission in the 2030 timeframe. By then the Chinese will likely have a base up and running on the moon, and we will be watching at least one, possibly two or three, other parties take up some kind of residence on that real estate, so briefly conquered by us 40 years ago. Unmanned space exploration will continue on the short fiscal leash that JPL has operated on so brilliantly for decades, and the usual smattering of aeronautical and climate research will continue.

It is a singularly unfulfilling mandate, short of bravado, daring and exploratory goals. And it is possibly a natural outgrowth of the seemingly rudderless wind-down of the shuttle years, in which the space station seemed to be the only major goal left for shuttle flights.

Of course, there are contrary voices. Luminaries such as Neil Armstrong and Gene Cernan (Apollo 11 and 17 respectively) have come out in loud opposition to the Obama plan, Buzz Aldrin has his own views, and John Glenn, as well as other former and current politicos, have broad and aggressive ideas. These voices have gone largely unheeded up to now; it's a subject still in play. But is seems clear that a real space program, one of daring and robustly articulated goals, is not to be. Until a large reserve of cash, or a reasonable substitute (the lost Beatles recordings?) are discovered on the moon or Mars, it appears that we will continue to thrash around. Members of congress will, of course, lobby for the space-oriented operations within their constituencies, but that is likely to avail little in this time of global financial drought.

For now, we are a nation without a direction in space. And I would like to join the voices who rise in apology to the men and women of the Apollo years, who labored so selflessly and intensely to get us where we were- and still should be- so long ago.

Feed test

Feed test

DON'T TREAD ON ME!

AKA, don't bomb my moon, dude. As I was preparing to watch the LCROSS impactor hit the moon, I thought to myself, "Is anyone crazy enough to protest this wonderful scientific event?"

Of course. How could I doubt it?

From the same folks who brought you pyramids on Mars and moon landing conspiracies, comes the fear that LCROSS will cause an interplanetary (ok, inter-body) war.

Wow. It makes my brain hurt. But at least I have one.

Check it out here.

And don't forget... WATCH THE SKIES!

MAROONED!

OK, I won't remind you of the funky 1969 movie of the same name... but NASA was always aware of the possibility that a crew could be stranded in space. With the increased duration flights of Skylab, they commissioned Rockwell (builder of the Command Module) to do something about it.

The hypothetical Skylab Rescue Mission would utilize a CM with the storage lockers behind the seats removed, and two extra couches installed. Two astronauts would launch on a Saturn 1B, dock with Skylab (or the ailing CM), transfer the crew of three, and bring all 5 men home.

During the Skylab 3 mission, they almost had a chance to test the craft. The Skylab 3 service module began leaking maneuvering fuel, reducing the working ACS thrusters to just two sets, the minimum allowable. NASA actually assembled a Saturn 1B with the modified CSM atop it in the VAB, prepped to move to the pad whenever needed. As it turned out, the Command Module attached to Skylab was able to bring home its crew after the 59-day mission, but it was a close call.

BURAN, BURAN

Remember the Soviet space shuttle? Way back in the early 1980's, the Soviet Union apparently got a case of "shuttle envy," and though they had experimented with a few unique designs (smaller scaled test vehicles), decided ultimately to build a darned-near drop-dead copy of the US shuttle. The most pronounced and obvious difference was the planned addition of two air-breathing jet engines to allow the Soviet item, named Buran ("Snowstorm") a come-about/landing abort capability.

Oddly, the craft was flown only once, and an unmanned flight at that. In 1988, after a launch through moderate storms, the craft performed two orbits of Earth and returned to land, under computer control, just a few feet from its projected touchdown point. For reasons not fully clear, the next flight was not planned until 1993, 5 years later. But the program was cancelled before that could occur. Buran was then quietly mothballed and left to sit under a large shed in Kazakhstan. There is sat, quietly moldering, until 2002, when record snowfall built up on the (apparently little-maintained) shed roof, and it collapsed, crushing Buran, which sat below. An ignominious end for an apparently capable, if unoriginal, spacecraft.

THANKS FOR EVERYTHING, NOW BACK TO WORK!

On July 24, 1969, just a few days after the first maned lunar landing, Dr. Gilruth, NASA Director, sent this memo of thanks to the various-and-sundry folks who had worked so hard on Apollo. While it didn't repair the broken marriages, ruined health, sleep deprived psychoses, and other maladies resultant from 10 years or tireless work, it sure didn't hurt either. I hope we can see one of these soon, following another high-profile NASA program (are you listening, congress?)...

Sorry for the lapse in posting... my fair city (Pasadena, CA) has been trying to burn itself to the ground, and we've been a bit distracted!

APOLLO VENUS!

Today's post is a pull from Wikipedia- I couldn't resist because it's just so cool. As NASA was staring down the end of the Apollo missions, the Apollo Applications Office was considering a plan that had been under study for years- Apollo Venus. The idea was to send a "wet workshop"- an SIVB stage which could be used as a space station once empty- out to loop around Venus with a crew in a Command Module. The science intended in this mission would soon be carried out by robotic probes, but how cool would a manned flight past Venus be?

From Wikipedia: The proposed mission would use a Saturn V to send three men to fly past Venus in a flight which would last approximately one year. The S-IVB stage would be a 'wet workshop' similar to Skylab, first using the S-IVB engine to launch the mission on course to Venus, and then vented of any remaining fuel to serve as home for the crew for the duration of the mission. The Apollo SM engine would be used for course corrections on the way to Venus and back to Earth, and for a braking burn before the Command Module re-entered Earth's atmosphere. In order to free up more space in the Spacecraft Lunar Module Adapter for the docking tunnel connecting the CSM to the S-IVB, the SPS engine on the Service Module would be replaced by two LM engines. These would provide similar thrust with shorter nozzles, and would also give the mission the added safety of redundant engines.
Precursors to the Venus flyby would include an initial orbital test flight with an S-IVB 'wet workshop' and basic docking adapter, and a year-long test flight taking the S-IVB to a near-geostationary orbit around the Earth.
One oddity of the Venus flyby mission is that, unlike trips to the Moon, the CSM would separate and dock with the S-IVB stage before the S-IVB burn, so the astronauts would fly 'eyeballs-out', the thrust of the engine pushing them out of their seats rather than into them. This was required because there was only a short window for an abort burn by the CSM to return to Earth after a failure in the S-IVB, so all spacecraft systems needed to be operational and checked out before leaving the parking orbit around Earth to fly to Venus.

SPACE ON A DIME

OK, this post is a bit of a departure. But I REMEMBER this as from the comic books of the day. The model was probably worth about $1, but could be yours for only $.10 IF you joined the science club, which would send you a "richly illustrated" 8000-word guide each month with stickers (the kind you had to lick) that you would transfer from the sticker sheet to the booklet. I still remember the taste of the glue, and the coating it left on my tongue after transferring 10 or 15 of those darned things. Even then I really didn't see the point- why couldn't THEY simply put the things in the booklet? I guess the idea was that if we had to peel the skin off our tongues after wetting the things, we'd remember the pictures....

DOCK-IT-TOOME

OK, sorry for the awful pun. But for years I had never seen the docking mechanism between the Apollo Command Module and Lunar Module. Now, thanks to my friends at the Kansas Cosmosphere, I know what it looks like! To the left is the CM, to the right, the LM. As with most things Apollo it's not simple, but it got the job done, and with only the rare hitch. One exception was during the flight of Apollo 14, when it took six tries to dock with the LM still nestled in the SIVB stage. Stu Roosa, CM pilot, made increasingly aggressive docking attempts, but the latches would not lock. He also had to be cognizant of how delicate the LM was- the machine was lightly constructed, and too much thrust during docking could crush the ascent stage like a discarded Coke can. Fortunately for all. on the sixth try the latches fired, and the two spacecraft were off to the moon.

WE HAVE A WINNER!

I've drawn, at random of course, a winner for my first book giveaway. Chris Smith, steadfast follower of this blog, will receive her book in the mail in a couple of weeks. with a personalized author-graph.

If you're looking at this, and aren't a blog follower, you're missing an opportunity to win a free book! Don't be silly! Click to follow now, there to the right----->

NIXON NIXED!

"Oops. You gotta uninvite the president... he might give the boys germs!" How's that for a PR nightmare? At the last moment, President Nixon had his Apollo 11 astronaut dinner canned because of concerns about germs. There was a bit of pressure- ok, outright condemnation- on NASA for the decision, especially at Dr. Chuck Berry, MD, who had made the call. Here, for the record, is the American Medical Association's response. They backed their man!

Currently writing sample chapters for a new Mars book. It will be exciting if it's commissioned. More as it occurs!

MOVING IN SPACE

Ever wonder what those little rockets that move spacecraft around look like? Here's a pic of the RCS, or Reaction Control System, from Apollo (this one on the Apollo Service Module). The RCS system can propel the craft in a fore-and-aft direction, side-to-side, spin, or turn. In a pinch, it can also be used to deorbit with sufficient fuel. Each thruster had about 100 pounds of thrust, and was fueled by a mixture of nitrogen tetroxide and hydrazine. These two chemicals mixed in a hypergolic reaction, that is, they combusted without an ignition source. In fact, great care had to be taken when dealing with the hydrazine, as workers in the Grumman plant in New York discovered one winter. They were working with the volatile chemical, spilled some onto an early show, and watched it burst into massive, incendiary flame.

The RCS quad seen here is located in the Service Module exhibit at the Kansas Cosmosphere.

THE LITTLE COMPUTER THAT COULD...

It's name was DSKY (Display/Keyboard). It was the interface for the Apollo Guidance Computer, the little wizard that guided the Apollo spacecraft from the Earth to the moon, down to its surface, back to the CM and home. Developed by Raytheon and MIT in the 1960's, it was the digital marvel of its time. It was the first use of integrated circuits, and blazed along at 2 MHz. This Block I model had between 12 and 24k, with later models running 32k.

If your toaster has a digital timer, it probably has more memory... but not a fraction of the genius!

Display courtesy of the Kansas Cosmosphere.

LM, THE ALUMINUM BALLOON

Well, not quite. For years science authors (including myself) have searched for a way to express the fragility of the Lunar Module. And make no mistake, it IS fragile. But some of the characterizations may be a bit over the top... it is not as thin as a soda can (somewhere between that and a Toyota fender, though). It is not quite an "aluminum balloon" (though it did flex when "inflated"). And, although it may have been possible, there is no obvious record of a dropped screwdriver puncturing the hull.

As can be seen in this image, Grumman's LM was a compound hull, with an inner layer, perpendicular strengthening ribs, and (not seen here) an outer layer. If one presses against it, it is quite strong. In fact, perhaps more than a worry of puncture was the concern with docking. In Apollo 14, it took almost two hours of repeated, and increasingly aggressive, docking attempts to mate the Command Module with the LM., and there was great concern that if the CM came in too fast it would crush the eggshell delicate (there's another one of those metaphors again!) hull of the LM.

A lazy Sunday here today, prepping samples for a new book. Fun work, but the 95 degree heat is making me wish I was UP there instead or writing about it...

DIG THIS!

At first blush they might look like camping implements... but you'd be off by a few tens of thousands of dollars. This is the tool suite for rock and soil collection on the moon. Developed to be lightweight, efficient and strong, these geology instruments were critical to the success of the Apollo landings, more so as each mission plan developed. By Apollo 17, the rock hammer in particular had gotten a workout as never before, as Harrison Schmitt, assisted by a percussive Gene Cernan, gathered more samples with better documentation than any prior mission.

From top: soil digging and trenching shovel, alloy rock hammer, and short-handle scoop. All tools courtesy of the Kansas Cosmosphere.