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The 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

by randsp 11y ago

The 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 ago
  Maybe... 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 ago
  Low 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 ago
doing a gravity assist at jupiter means you either have radiation hardening or you're cooked.
deleted 11y ago
[deleted]
mturmon 11y ago
SpaceX 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 ago
The 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 ago
  Yes 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 ago
    Overbloated - 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.

by randsp 11y ago

rjsw 11y ago

... or the COTS hardware is reliable enough in Low Earth Orbit.

randsp 11y ago
Maybe... 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 ago
Low 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 ago

doing a gravity assist at jupiter means you either have radiation hardening or you're cooked.

deleted 11y ago

[deleted]

mturmon 11y ago

SpaceX 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 ago

The 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 ago
Yes 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 ago
  Overbloated - 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.