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MIPS in Space: Inside NASA’s New Horizons Mission to Pluto
- randsp 11y agoThe hardening argument seems disturbing to me giving the achievements that SpaceX have done in a short time. Apparently SpaceX is using some sort of redundancy system (https://lwn.net/Articles/540368/ https://lwn.net/Articles/540368/) to avoid all the hardening stuff enabling them to use more powerful and COTS hardware that NASA or ESA.
- rjsw 11y ago... or the COTS hardware is reliable enough in Low Earth Orbit.
- randsp 11y agoMaybe... Anyway, it's an interesting question to be answered. If hardening technics could be improved significantly, it'd mean we could use incredible faster and cheaper hardware.
- david-given 11y agoLow Earth Orbit is under the Van Allen belts, and so is shielded from a lot of the radiation of the inner solar system. The outer solar system is dead quiet and quite safe... but of course you have to get there first.
- baq 11y agodoing a gravity assist at jupiter means you either have radiation hardening or you're cooked.
- deleted 11y ago[deleted]
- mturmon 11y agoSpaceX seems to be using TMR. You'd have to look at the power requirements for TMR. According to TFA, power was a mission driver for New Horizons. Additionally, as others have pointed out, LEO is a very different radiation environment than deep space.
- akiselev 11y agoThe hardening argument is hardly the most important one since it's a matter of having money to pay a silicon fab for the massive set up cost. According to [1] and [2], NASA has about as many still active deep space probes as there have been Falcon launches and many of them are as old or older than SpaceX the company, so we're talking about very different goals, histories, and organizations. In order to achieve that kind of success while also dealing with the risk-averse public and obstructionist political system you need decades of reliability data for every mechanism, silicon fabrication process, and part in the space probe. Every cable tie, connector, all thermal and electrical insulation, every screw and panel, literally everything has to be extensively tested and their performance under a wide variety of conditions has to be completely mapped out. For example, the last satellite I was involved in (NuStar, orbital xray telescope) which was designed mid to late 2000s, the PIs didn't even bother reviewing SSDs (Still at least a decade before they're used in critical missions) and hard drives were passed because no one wanted to risk our first xray telescope in decades, which happened to be several orders of magnitude more powerful than anything we've ever had in that spectrum. I left before the final decision was made but I have little doubt that the satellite uses tape drives fo rstorage because anything else is just not worth the risk. [1] https://en.m.wikipedia.org/wiki/List_of_Falcon_9_and_Falcon_Heavy_launches https://en.m.wikipedia.org/wiki/List_of_Falcon_9_and_Falcon_... [2] https://en.m.wikipedia.org/wiki/List_of_active_Solar_System_probes https://en.m.wikipedia.org/wiki/List_of_active_Solar_System_...
- randsp 11y agoYes reliability and safety are the most important points but at same time, most of the certification processes to go to space are usually overbloated. Anyway, i'm just asking from the technical point of view if the radiation issue could be solved or not using some modern technics as SpaceX is using.
- CountSessine 11y agoOverbloated - what set of requirements do you think are being unnecessarily exceeded? NASA is a government agency overseen by elected representatives. Failure isn't merely a technical or even an economic setback - it can be a political risk as well. Every failed launch is ammunition for NASA's political adversaries. Besides - this isn't a Falcon test capsule; it's a one-of-a-kind X-ray telescope. It's loss to the astronomy and astrophysics community couldn't be dismissed with a shrug of the shoulders and a quip on twitter.
- Klathmon 11y agoI love the table in the hardware section.
- alexvoica 11y agoThanks!
- alexvoica 11y agoWhen I wrote my first article, a lot of people said "Why are they using old technology in a space probe?" By creating that chart, I wanted to show that a space probe is not a phone or PC. You can't just throw octa-core SoCs inside, pack it up and send it flying into the night sky.
- ajross 11y agoA digression, but it's amusing how far afield they had to go to find a modern SoC with a IMG GPU (vs. the rest of the world that is to first approximation all Qualcomm, with a few Mali's running around from Samsung). Obviously the real IMG flagship is the Apple A9, but that's not co-branded appropriately.
- alexvoica 11y agoI wouldn't call Meizu, Xiaomi or other similar brands "far afield". They ship tens of millions of devices (and soon maybe even hundreds) every year.
- ajross 11y agoBut not on this particular SoC. Qualcomm (with Apple and Samsung not terribly close behind) remains the volume king even in China, last I checked. This other small-vendor SoC's are gaining momentum, but they're not there yet.
- alexvoica 11y agoThe reality today is that MediaTek is number two in mobile after Qualcomm. Meizu MX5 uses a MediaTek SoC as does the new Xiaomi Redmi Note 2 and many others. Trust me, it's my job to know.
- userbinator 11y agoMIPS is a good choice here because the relatively small transistor count means it can be produced in a larger process, which gives better resistance to radiation.