4 ms·

It's really a good sign that these things keep outliving their specified life span, though I also would assume that NASA's life span quotes are probably conserv

by api 5y ago

It's really a good sign that these things keep outliving their specified life span, though I also would assume that NASA's life span quotes are probably conservative to avoid the political fallout of "failure." It's sort of like how companies often make conservative projections because if you make a crazy high projection and almost reach it that's a "failure" to shareholders even if you did exceptionally well.

rbanffy 5y ago
> I also would assume that NASA's life span quotes are probably conservative to avoid the political fallout of "failure." My trusty SPARCstation had a 3 year extended warranty when bought, but it's still going since 1996. Not getting as much usage as it got when young, but she's a very reliable worker.
ilkkao 5y ago
Especially because it uses an off the shelf Qualcomm Snapdragon 801 processor. Can this indicate that the expensive radiation hardened CPUs aren't necessary on Mars?
- api 5y ago
  It can, and that's big news. At the very worst you could get away with simpler CPUs and redundancy instead of massively costly and limited supply rad hardened chips.
- Steltek 5y ago
  Probably still a "It Depends" answer? What do you want that CPU to do? Curiosity and Perseverance could last a long time and would a faster CPU enable significantly better science instruments? A rover might be able to travel farther autonomously, which is cool but it's a science mission, not a race course. Why is this one lasting so long? Presumably we know the radiation conditions on the surface so testing more units in a lab is a better guide than one plucky helicopter.
- MontagFTB 5y ago
  I know they had accounted for the need to reboot the processor in the event of a radiation anomaly. I’m interested to know what real world data they’ve collected in the time the helicopter has been flying.
- robotnikman 5y ago
  It is still probably a good idea to have the main equipment running on radiation hardened hardware, while the more unimportant stuff runs on off the shelf components. That way at least if something goes wrong with the non-rad-hardened equipment, it could be rebooted or debugged using equipment which is rad-hardened I'm no scientist but that's my take on the matter.
- pkaye 5y ago
  They use a RAD hardened FPGA to handle the avionics. The Snapdragon is for the less critical activity.
hoseja 5y ago
This thing is very experimental, I don't think they had a good idea of the potential lifespan/what could go wrong and drastically reduce it.
mywacaday 5y ago
This video https://youtu.be/5MxH1sfJLBQ https://youtu.be/5MxH1sfJLBQ was posted here https://news.ycombinator.com/item?id=30729109 https://news.ycombinator.com/item?id=30729109 about how the actuators work on the James Webb telescope. It's a great watch and shows how well thought out design can produce accurate and long lasting parts.
mynameismon 5y ago
> though I also would assume that NASA's life span quotes are probably conservative to avoid the political fallout of "failure." Isn't that the case with all space agencies? It is usually the best case scenario playing out in most cases, like this one. Even with the JWST, I can safely predict it will last as long as the Hubble, if not longer.
dotancohen 5y ago
> It's really a good sign that these things keep outliving their specified life > span, though I also would assume that NASA's life span quotes are > probably conservative to avoid the political fallout of "failure." Cart before the horse. NASA designates a science goal, which often includes a detailed plan of what to explore. The administration designates a cost budget, a time budget, and a mass budget. These specs then get sent to engineers (at e.g. JPL) who do the best they can to achieve the science goal within the cost, time, and mass constraints. Sometimes they can build a craft that will outlive its initial 90-day science mission by 14 years. Often that is because they got lucky with conditions, i.e. wind cleaning dust off solar panels. In no case have they built a craft with no specific goal, then declared it's operational life expectancy, and then went and found a mission to do with it.
- lmm 5y ago
  > In no case have they built a craft with no specific goal, then declared it's operational life expectancy, and then went and found a mission to do with it. What about the SLS?
  - dotancohen 5y ago
    I concede! SLS, the jobs program, was certainly in need of a scientific mission.
- krisoft 5y ago
  > In no case have they built a craft with no specific goal, then declared it's operational life expectancy, and then went and found a mission to do with it. I don't think the message you responded to said that they built the craft then declared the operational life expectancy. NASA could have designated a science goal which needed 22 flights, and had the same cost, time and mass budget associated with it. Clearly that goal would have been achievable with some probability given that it was achieved. They didn't. The comment in question is speculating about the reasons why NASA might have chosen 5 flight as the target instead of 22 or 222.
  - 5y ago
phire 5y ago
I suspect space probes have a pretty steep bathtub curve. Lots of potential failure points early on, then large stretch of low risk of failure, followed by increasing failure risks as it gets old. So when NASA set a target minimum lifetime goal, it puts them quite far into the bathtub curve, long after all that initial risk goes away. If it makes it to it's target lifetime, chances are it will last a lot longer.

by api 5y ago

rbanffy 5y ago

> I also would assume that NASA's life span quotes are probably conservative to avoid the political fallout of "failure." My trusty SPARCstation had a 3 year extended warranty when bought, but it's still going since 1996. Not getting as much usage as it got when young, but she's a very reliable worker.

ilkkao 5y ago

Especially because it uses an off the shelf Qualcomm Snapdragon 801 processor. Can this indicate that the expensive radiation hardened CPUs aren't necessary on Mars?

api 5y ago
It can, and that's big news. At the very worst you could get away with simpler CPUs and redundancy instead of massively costly and limited supply rad hardened chips.
Steltek 5y ago
Probably still a "It Depends" answer? What do you want that CPU to do? Curiosity and Perseverance could last a long time and would a faster CPU enable significantly better science instruments? A rover might be able to travel farther autonomously, which is cool but it's a science mission, not a race course. Why is this one lasting so long? Presumably we know the radiation conditions on the surface so testing more units in a lab is a better guide than one plucky helicopter.
MontagFTB 5y ago
I know they had accounted for the need to reboot the processor in the event of a radiation anomaly. I’m interested to know what real world data they’ve collected in the time the helicopter has been flying.
robotnikman 5y ago
It is still probably a good idea to have the main equipment running on radiation hardened hardware, while the more unimportant stuff runs on off the shelf components. That way at least if something goes wrong with the non-rad-hardened equipment, it could be rebooted or debugged using equipment which is rad-hardened I'm no scientist but that's my take on the matter.
pkaye 5y ago
They use a RAD hardened FPGA to handle the avionics. The Snapdragon is for the less critical activity.

hoseja 5y ago

This thing is very experimental, I don't think they had a good idea of the potential lifespan/what could go wrong and drastically reduce it.

mywacaday 5y ago

This video https://youtu.be/5MxH1sfJLBQ https://youtu.be/5MxH1sfJLBQ was posted here https://news.ycombinator.com/item?id=30729109 https://news.ycombinator.com/item?id=30729109 about how the actuators work on the James Webb telescope. It's a great watch and shows how well thought out design can produce accurate and long lasting parts.

mynameismon 5y ago

> though I also would assume that NASA's life span quotes are probably conservative to avoid the political fallout of "failure." Isn't that the case with all space agencies? It is usually the best case scenario playing out in most cases, like this one. Even with the JWST, I can safely predict it will last as long as the Hubble, if not longer.

dotancohen 5y ago

> It's really a good sign that these things keep outliving their specified life > span, though I also would assume that NASA's life span quotes are > probably conservative to avoid the political fallout of "failure." Cart before the horse. NASA designates a science goal, which often includes a detailed plan of what to explore. The administration designates a cost budget, a time budget, and a mass budget. These specs then get sent to engineers (at e.g. JPL) who do the best they can to achieve the science goal within the cost, time, and mass constraints. Sometimes they can build a craft that will outlive its initial 90-day science mission by 14 years. Often that is because they got lucky with conditions, i.e. wind cleaning dust off solar panels. In no case have they built a craft with no specific goal, then declared it's operational life expectancy, and then went and found a mission to do with it.

lmm 5y ago
> In no case have they built a craft with no specific goal, then declared it's operational life expectancy, and then went and found a mission to do with it. What about the SLS?
- dotancohen 5y ago
  I concede! SLS, the jobs program, was certainly in need of a scientific mission.
krisoft 5y ago
> In no case have they built a craft with no specific goal, then declared it's operational life expectancy, and then went and found a mission to do with it. I don't think the message you responded to said that they built the craft then declared the operational life expectancy. NASA could have designated a science goal which needed 22 flights, and had the same cost, time and mass budget associated with it. Clearly that goal would have been achievable with some probability given that it was achieved. They didn't. The comment in question is speculating about the reasons why NASA might have chosen 5 flight as the target instead of 22 or 222.
- 5y ago

phire 5y ago

I suspect space probes have a pretty steep bathtub curve. Lots of potential failure points early on, then large stretch of low risk of failure, followed by increasing failure risks as it gets old. So when NASA set a target minimum lifetime goal, it puts them quite far into the bathtub curve, long after all that initial risk goes away. If it makes it to it's target lifetime, chances are it will last a lot longer.