Sadly, the Orbiting Carbon Observatory (OCO) had a launch failure, and is now spread out on Antarctica somewhere. Ironically, I'd written earlier today about the economics of the New Horizons mission.

For New Horizons, well, that launched successfully. OCO did not. This is a fundamental part of rocket science-- it either works or it doesn't. It either blows up or remains intact. When you're only launching one, the stakes are high. And rockets are risky.

The OCO satellite did everything it was supposed to do during launch-- namely, sit tight and not do anything. It was a rocket failure, but that's enough to kill OCO.

There's still talk of possibly using a 'flight spare' to relaunch. I was with one mission that did this. Astro-E had a rocket mishap, so they used flight spares to build another and launch as Astro-E2.

The pluses of using flight spares is that the hardware research is already done, as is most of the manufacturing. So the cost is much lower.

The downside is, a flight spare isn't a ready-to-fly backup. Instead, it's one or more partial assemblies of the equirment. Typically, it hasn't been tested-- or it's the parts that were tested and failed, so they got shuffled out of the final payload. So flight spares can be a source of parts, but slightly lesser parts.

Often, you'll make several of a key component-- a CCD, a collimator, an amplifier. Then you'll test them all, and put the highest performing one onto the final payload. So the spares aren't 'bad', per se, but they are not as optimal as the ones you use (obviously enough).

And, bear in mind launches aren't cheap-- for New Horizons, it was estimated as $205 million, or a quarter of the entire mission cost.

So what is OCO's future? It is possible that a new OCO could be built, and it's certainly more cost-effective to rebuild a satellite than to start a new design from scratch. That's why GPS and TDRSS and Iridium satellites are sent as multiples-- they use a tested design to simply rinse and repeat the same goal. But there are still costs involved, that have to be weighed.

Rocket science, in the end, is about risks more then easy answers. RIP, OCO satellite, and good luck, OCO project.

Alex, the daytime astronomer