Another Blow for Japan.

Some musings on reliability, and Disposable vs Re-Usable boosters.

After 5 consecutive flawless launches of the Japanese H2A launcher, a failed strap-on booster coupling meant a flight had to be destroyed.

Bugger.

Rand Simberg says:

No matter how vaunted your quality control, and technological prowess, it is simply not possible to reliably or affordably build vehicles for which each flight is a first flight and a last, particularly when you build so few.

Or as we say here, "Sh1t Happens".

I'm not sure that he's wrong, but in all other similar human activities, such as Drag Racing, where the last 5% of performance is crucial, most of the vehicle has to be replaced with new parts after each run.

Meanwhile, the always-readable Rocket Man reveals what he's been working on, the Mars Reconnaissance Orbiter. He also name-drops shamelessly:

As I have said before, I sometimes forget that the projects I work on are not that well known to the general public. I have worked on Cassini, Mars Pathfinder, Mars Global Surveyor, Mars Polar Lander, Mars Climate Orbiter, Stardust, Genesis and other spacecraft, and after a while it sort of becomes routine to work on them. However, I am always surprised when I tell people what I do for a living and they are actually interested in hearing about it.

Sure you are.... :-)

One of my sayings is that most jobs are 90% routine and 10% interesting. My job is no different in that I spend a lot of time working on a CAD system, doing drawings, ordering parts, supervision fabrication, going to meetings, etc. But my 10% is generally much more interesting than most peoples 10%.

Having seen the amount of skull-sweat involved in the mechanical engineering of FedSat, the extreme pains that were taken to keep the CAD model in lockstep with the actual hardware and the myriad minor design changes necessitated during development, I can say that his modesty knows no bounds. While I was frantically scribbling away on the whiteboard brainstorming how to get that ferschlugginer potrzebie of a mass memory unit to work within very tight time constraints, the mech eng guys had to completely re-design the baseplate to gain a vital 3 cm of additional clearance due to a late-changing physical requirement. His saying reminds me of the song's lyrics:

And all the Science
I don't Understand.
It's just a Job, 5 days a week.

Sure it is... And like me, he may not understand all the Science, but he sure understands the Engineering. The Rocket Man also has a gift for understatement that would do a Pom proud.

Building a spacecraft that can make it all the way to Mars and successful complete its mission is not easy.

I can believe that.

I have never worked on an Earth orbiting satellite,

<humour>Not that he looks down his nose at us poor peons who have only worked on one itsy-bitsy satellite in Low Earth Orbit not even 1000 km high... </humour>

...but I do know that the Earth's magnetic field offers some protection from the Suns radiation as they orbit the Earth. Mars does not have the same protective magnetic field as Earth, so from the time they leave Earth orbit, Mars spacecraft are subjected to the unfiltered effects of the Suns radiation. This radiation is very hard on the electronics aboard the spacecraft and great efforts are required to make sure they will work properly during the mission.. Mars does not have the same protective magnetic field as Earth, so from the time they leave Earth orbit, Mars spacecraft are subjected to the unfiltered effects of the Suns radiation. This radiation is very hard on the electronics aboard the spacecraft and great efforts are required to make sure they will work properly during the mission.

Beneath the Van Allen Belts, Orbits are, as he says, protected against much of Dat Ol Debbil Radiation. Alas, the Van Allen Belts themselves protect the Earth by "trapping" a lot of the charged particles within them, they're far worse for Rad Hazard than open space (except during a solar flare). And in the South Atlantic Anomaly, the belts dip to 200 km altitude, which means that Polar Orbital (ie North-to-South) satellites in LEO (Low Earth Orbit) get toasted on at least two passes every 24 hours, plus a lesser toasting over each of the poles every 50 minutes.
But that's just minor detail, his main point is sound: that the Radiation dose that spacecraft get when the journey interplanetary distances means that they must be extremely Rad-hardened. Those going near Jupiter must have even more protection, and 7x redundancy or better to survive the radiation maelstrom there.

Anyway, please go read the whole thing.. He describes the infinite care and patience in testing required to have a chance of successful mission completion. Nothing can guarantee success, but skimping on any one of the myriad steps is guaranteed to cause a disaster, sooner or later.

... the next time you hear about a spacecraft that successfully completes its mission to Mars you will hopefully have a better appreciation of just what it took to accomplish that feat.

Abso-freaking-lutely. Bon Voyage, MRO, you're in good hands.