LIVE: SpaceX Dragon CRS-1 (SpX-1) (EOM) Unberthing, Entry, Splashdown

[Valerij]

As others have suggested, I wonder whether SpaceX could develop their own tailor-made rad-hardened electronics, using their own internal cost-saving approaches, and thus save on having to buy them in from outside? Heck, if they succeeded, they could even create a side-business selling cheap rad-hardened electronics to the rest of the space industry.

I absolutely agree, it would be interesting, if Musk creates one more firm, for manufacture of avionics for space vehicles.

[apace]

As others have suggested, I wonder whether SpaceX could develop their own tailor-made rad-hardened electronics, using their own internal cost-saving approaches, and thus save on having to buy them in from outside? Heck, if they succeeded, they could even create a side-business selling cheap rad-hardened electronics to the rest of the space industry.

I absolutely agree, it would be interesting, if Musk creates one more firm, for manufacture of avionics for space vehicles.

If I can remember, there was a new startup a year ago which pitched for money to do such thing... and by the way, rad hardening of avionics is nothing new and not this big price stamp a few here think about it. It will be a combination of new hardware and better software and you get it. We will see, which approach SpaceX is going.

[Robotbeat]

As others have suggested, I wonder whether SpaceX could develop their own tailor-made rad-hardened electronics, using their own internal cost-saving approaches, and thus save on having to buy them in from outside? Heck, if they succeeded, they could even create a side-business selling cheap rad-hardened electronics to the rest of the space industry.

Chance is doubtful to nil.  That is done at the chip level.  It is not a turnkey capability.

Quite right. But there are off-the-shelf rad-hardened FPGAs that they could use and program with whatever chipset they need (provided it has a low enough gate count). But those are much more expensive, use more power, and take up more mass and space and are produced in less volume (thus you're more likely to get early design mistakes).

But anyway, this is all a complicated trade. Do you have four-string backup or two string with rad-hardening?

If the "cautionary principle" applies, why not "n"-string with rad-hardening and shielding, for any large number "n"?

This is a trade.


Also, note that Mercury had no on-board computer. There's a relentless push to use more powerful computers, even if you could get by with using just an 8-bit microcontroller or some analog system. Dragon uses a more powerful computer than Shuttle simply because technology has progressed to allow it to do so. Modern programming techniques make different assumptions about the performance/memory/complexity/generality trade. I've heard that SpaceX uses a Linux kernel for a LOT of their on-board computing.

Usually, a more powerful computer is cheaper than a programmer's time.

[Valerij]

Chance is doubtful to nil.  That is done at the chip level.  It is not a turnkey capability.

Chip can be ordered or bought. At first it would be useful to know, what exactly is necessary for you.

[dragon44]

Just a datapoint for everyone. I used to work at a company that used the RAD750 (for GLAST, now Fermi Gamma-ray Space Telescope). It is a rad-hard version of the PowerPC 750. Apple called it the PowerPC G3. It was used in the multi-color iMacs. It think it is still the top or near the top of the heap for rad-hard CPUs. It runs at 200MHz. It is used on Curiosity, Juno and many others. Cost per board was ~$200,000.

[Prober]

...
My guess, as one who only observes spacecraft computer and software efforts from the sidelines, is that they will improve their system's ability to reboot and resynch.  Sort of what NASA is doing with their smartphone cubesat.  They put in a watchdog circuit that reboots it if it stops transmitting.  It's millions or billions of dollars cheaper than building a rad-hard Android cell phone.

+1.

Because they have three computers, I don't see what the big deal is about losing one on an early mission. When you have a system in place to deal with failure gracefully, people shouldn't get their underwear in a bundle when a failure does occur.

on the other hand we can't dismiss these problems as "what the big deal is about losing one on an early mission". 

Too many issues with SpaceX get "dismissed" as management has it covered.  This line of thinking will bite you.

[mmeijeri]

It's millions or billions of dollars cheaper than building a rad-hard Android cell phone.

Some cell phone components are rad hard already, because they are made with Silicon On Sapphire technology. They're doing this for other reasons, but radiation hardening is a nice side-effect. So there is commercial production infrastructure dedicated to high volume consumer electronics that could be used for rad hard aerospace components.

[Jim]

Too many issues with SpaceX get "dismissed" as management has it covered.  This line of thinking will bite you.

No, they are all being worked.

[Go4TLI]

...
My guess, as one who only observes spacecraft computer and software efforts from the sidelines, is that they will improve their system's ability to reboot and resynch.  Sort of what NASA is doing with their smartphone cubesat.  They put in a watchdog circuit that reboots it if it stops transmitting.  It's millions or billions of dollars cheaper than building a rad-hard Android cell phone.

+1.

Because they have three computers, I don't see what the big deal is about losing one on an early mission. When you have a system in place to deal with failure gracefully, people shouldn't get their underwear in a bundle when a failure does occur.

on the other hand we can't dismiss these problems as "what the big deal is about losing one on an early mission". 

Too many issues with SpaceX get "dismissed" as management has it covered.  This line of thinking will bite you.

yeah, sometimes different standards are applied to protect the pedastal that some want to place certain others on.

If it was "old-space" that blew up an engine, lost a thruster, had computers shut down and not re-sync because they were not rad-hardened, all coolant pumps drop out and a freezer returned warmer than spec, etc then I believe some would be saying:

1.  The workers are lazy and don't care about quality
2.  They are content with sucking NASA for everything they can
3.  New-space could do it better
4.  Elon is going to bury all these dinosuars
5.  Etc, etc

Now let's be clear.  Issues and problems are going to happen.  It's the nature of things in this business.  How they are evaluated, resolved and discussed is also very important.  Just wanting to sweap them under the rug, and I'm not suggest SpaceX is doing this just responding to comments here, is naive. 

[mmeijeri]

yeah, sometimes different standards are applied to protect the pedastal that some want to place certain others on.

If it was "old-space" that blew up an engine, lost a thruster, had computers shut down and not re-sync because they were not rad-hardened, all coolant pumps drop out and a freezer returned warmer than spec, etc then I believe some would be saying:

1.  The workers are lazy and don't care about quality
2.  They are content with sucking NASA for everything they can
3.  New-space could do it better
4.  Elon is going to bury all these dinosuars
5.  Etc, etc

Now let's be clear.  Issues and problems are going to happen.  It's the nature of things in this business.  How they are evaluated, resolved and discussed is also very important.  Just wanting to sweap them under the rug, and I'm not suggest SpaceX is doing this just responding to comments here, is naive. 

Where the heck did that rant come from? It has precisely zero bearing on what I said.

[Comga]

Let me take this viewpoint: NASA purchased launch services from SpaceX, and in the process of doing so issued a number of requirements for SpaceX to conform to. Was the use of RAD-hardened computer equipment amongst those requirements?

If NO, then NASA apparently was short-sighted OR NASA expected other means of compensating for the increased radiation-induced malfunctions in-orbit to be sufficient. (Such as flying with added redundancy).

My emphasis.
NASA purchased a hardware delivery service.
NASA controls the means of delivery, at a fundamental level, to assure that the delivery service doesn't harm their $100B ISS or endanger the astronauts on board it.
SpaceX has the ultimate redundancy of multiple launches.  If they lose one, they have to launch another rocket and capsule.  That's the "other means of compensating."

We fly single string systems whenever the cost constraints don't allow for redundancy.  The CRS-1 Dragon lost one computer, and so still had a fully redundant system.  This should be fine for a two hour descent.  It's just a matter of probability.  If they lost another they might have had to do a passive departure or something else to reduce the risk of collision, but SpaceX still would have departed and reentered.

[Go4TLI]

yeah, sometimes different standards are applied to protect the pedastal that some want to place certain others on.

If it was "old-space" that blew up an engine, lost a thruster, had computers shut down and not re-sync because they were not rad-hardened, all coolant pumps drop out and a freezer returned warmer than spec, etc then I believe some would be saying:

1.  The workers are lazy and don't care about quality
2.  They are content with sucking NASA for everything they can
3.  New-space could do it better
4.  Elon is going to bury all these dinosuars
5.  Etc, etc

Now let's be clear.  Issues and problems are going to happen.  It's the nature of things in this business.  How they are evaluated, resolved and discussed is also very important.  Just wanting to sweap them under the rug, and I'm not suggest SpaceX is doing this just responding to comments here, is naive. 

Where the heck did that rant come from? It has precisely zero bearing on what I said.

Yeah, because I replied to the wrong post, haha.  I fixed it, so no need to worry further.

[Comga]

It's millions or billions of dollars cheaper than building a rad-hard Android cell phone.

Some cell phone components are rad hard already, because they are made with Silicon On Sapphire technology. They're doing this for other reasons, but radiation hardening is a nice side-effect. So there is commercial production infrastructure dedicated to high volume consumer electronics that could be used for rad hard aerospace components.

What cell phone components are Silicon-on-Saphire?  What is is their scale and feature size?  Does this  process have the ability to make processors and ancillary components?   It seems doubtful.  If it were going to lower the cost of rad hard computers we would be seeing it.

[Robotbeat]

yeah, sometimes different standards are applied to protect the pedastal that some want to place certain others on.

If it was "old-space" that blew up an engine, lost a thruster, had computers shut down and not re-sync because they were not rad-hardened, all coolant pumps drop out and a freezer returned warmer than spec, etc then I believe some would be saying:

1.  The workers are lazy and don't care about quality
2.  They are content with sucking NASA for everything they can
3.  New-space could do it better
4.  Elon is going to bury all these dinosuars
5.  Etc, etc

Now let's be clear.  Issues and problems are going to happen.  It's the nature of things in this business.  How they are evaluated, resolved and discussed is also very important.  Just wanting to sweap them under the rug, and I'm not suggest SpaceX is doing this just responding to comments here, is naive. 

Where the heck did that rant come from? It has precisely zero bearing on what I said.

Yeah, because I replied to the wrong post, haha.  I fixed it, so no need to worry further.

Nor does it have a bearing on my post. I'm an old-space fan, too, and I agree with Jim that it's a shame that none of the proposals using EELVs won.

[Prober]

Now let's be clear.  Issues and problems are going to happen.  It's the nature of things in this business.  How they are evaluated, resolved and discussed is also very important.  Just wanting to sweap them under the rug, and I'm not suggest SpaceX is doing this just responding to comments here, is naive.   
 
« Last Edit: Today at 10:06 AM by Go4TLI » "

thanks Go4TLI for bringing a little balance.


 

[Robotbeat]

Attacking strawmen is not "bringing balance."

Identifying true mistakes and errors /does/ bring balance.

[mlindner]

Back to the previous discussion. You guys are talking like the processor failure was permanent. From what I remember, it was down briefly (or rather started producing different results) and so it de-synced from the other processors. They later rebooted it and it was working fine. They _could_ have re-synced it they said but they didn't need to as they were about to leave anyway.
Apparently this is currently a manual process but this most likely could be automated in the future. There is no need to add additional processors.

[mmeijeri]

What cell phone components are Silicon-on-Saphire?

I'm not an electronics guy, all I know is that they are unspecified RF components.

  What is is their scale and feature size?

I've read talk of 150 nm and future upgrades to 90 nm.

Does this  process have the ability to make processors and ancillary components?   It seems doubtful.

According to these links the answer is yes:

Silicon on sapphire

Peregrine Semiconductor

The History of Silicon-on-Sapphire

Soitec boosts production of silicon-on-sapphire wafers

From what I understand SoS was first used as a niche technology for rad hard components, but over time synergies with consumer electronics manufacturing processes were found and still later applications in consumer electronics were found for SoS, which led to further synergies.

If it were going to lower the cost of rad hard computers we would be seeing it.

You're still going to have small production runs, and that means expensive components,but at least you won't need to build your own fabrication facilities. And since many IP cores are available for licensing, I don't think it would be impossible for SpaceX to get into the design of their own custom variants of existing microprocessors. Whether it would be worth it is another matter, but I don't think it would be prohibitively costly anymore.

[Lars_J]

Correct. Redundancy worked just fine.

This time.

For this flight, only one computer went down, but it would only have needed another one to go down, and Dragon would have been flying with no redundancy, with components susceptible to radiation. If a failure had occurred during departure from the ISS, needless to say the consequences could have been severe.

I'm pretty sure Shuttle had occasional issues with one of its triple redundant flight computers... Was the same "sky is falling" mentality expressed about that?

Of course it needs to be addressed - and I'm sure they are doing trades to figure out what combination of hardware and software changes will be the best way to reduce the number of future events like this.

[Valerij]

Just a datapoint for everyone. I used to work at a company that used the RAD750 (for GLAST, now Fermi Gamma-ray Space Telescope). It is a rad-hard version of the PowerPC 750. Apple called it the PowerPC G3. It was used in the multi-color iMacs. It think it is still the top or near the top of the heap for rad-hard CPUs. It runs at 200MHz. It is used on Curiosity, Juno and many others. Cost per board was ~$200,000.

RAD750, possibly, best processor for space which now is available in the market. We will assume that on maned versions of the Dragon will be established three RAD750. It is expensive, but is quite possible. But there is required still lidar and other devices. To use in each device RAD750 to me it seems impossible. It is necessary to know, in what devices it is possible to use usual processors and where it is necessary to use rad-hardened avionics