Voyager Mission - Doing so much, with so little

darb1972

Senior Member
Hi All

While this isn't strictly related to PICaxe (although there is a "PICaxe In Space"), I thought this might be of interest for those who not only appreciate the complexities of Space Exploration, but also what one can do with electronics. Sometimes we tend to "complain" that the likes of a PICaxe isn't powerful enough, or fast enough to do the task at hand. Much to my amazement, the Voyager Mission was based around fairly basic CMOS (but at the time, cutting edge) electronics with memory of just under 70kB. The NASA team continued to receive data and communicated with the two Voyager units for decades (40th Anniversary, launched in 1977). They even managed to "reprogram" the unit/s (using FORTRAN) as these marvelous creations hurdled through space at astronomical speeds.

Absolutely amazing stuff. I would recommend that you watch the video in part one. The other (currently three) parts are also linked. Most of us would tend to enjoy part four "The Brains of the Voyager Spacecraft: Command, Data, and Attitude Control Computers". It's a nine part series.

https://www.allaboutcircuits.com/news/voyager-mission-anniversary-celebration-introduction/

Based on what I have read (so far) on this program, I will try to never complain again about the power we have available via the likes of micro-controllers such as PICaxe.

I hope you enjoy the articles.

PS: Although this is of immense interest to me, I don't really get much time to read up on the amazing world of Space Exploration. What I know about Space and Space Exploration you could write on the foreskin of a Bee. So, on that basis, I am by no means an authority in this area. I just thought this was worth bringing to the attention of PICaxe clan.
 
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MFB

Senior Member
Many thanks for the enjoyable links. I'm also fascinated by the ingenuity of past instrument designers and would recommend taking a look at the publications of George Ludwig...

http://ir.uiowa.edu/do/search/?q=author_lname:"Ludwig" AND author_fname:"George"&start=0&context=653496&sort=date_desc&facet=

George Ludwig was a University of Iowa student involved with the development of electronics for the first US satellites. Transistors were very new in the late 50's and the papers give an insights into the difficulty of obtaining practical applications information. George often found hobby publications as helpful as academic publications. I found much the same when designing electronics for scientific balloon and oceanographic instrumentation in the 70's. Which surprisingly (to me anyway) led to the remainder of a career in motorsport data acquisition and telemetry.
 

darb1972

Senior Member
Hello MFB

Thanks for the link on George Ludwig. I will take a look at these (always hard to find enough reading time!).

What really amazes me about the Voyager program is that when one of the Voyager Satellites went past Neptune, the video said (from memory) that the Satellite was 12,000 Miles off course and even more impressive, only 1 second off the predicted mission flyby time. When you consider the billions of miles of travel and distance from Earth, that's really impressive, I'm sure even by today's standards. To think that it was all done with electronics from the late '70s. Wow!!!
 

MFB

Senior Member
Another successful space mission that relied on PICAXE like levels of performance was the Sojourner Mars rover launched in 1996. This used a single 80C85 running at at a clock rate of 2MHz. The radio link to the lander, for remote control and telemetry, was only able to operated at a similar data rate to an audio dial-up modem of the day. Those JPL designers really did amazing things with technology that was rather mature even by mid-90's standards.
 

fernando_g

Senior Member
And my understanding is that the Soviets were -at least on microelectronics- one full generation behind the US. (please correct me if I'm wrong).

They compensated this with more powerful boosters (to launch heftier payloads) and very ingenious electro-mechanical systems.
 

premelec

Senior Member
i recall there was a project that a USA physicist wanted to launch on USSR rocket and they couldn't export the electronics as built so they did a re-build of the unit with older parts that were legal to export... ;-0
 

roho

Member
And my understanding is that the Soviets were -at least on microelectronics- one full generation behind the US. (please correct me if I'm wrong).

They compensated this with more powerful boosters (to launch heftier payloads) and very ingenious electro-mechanical systems.
I believe that you are correct. I saw a comparison of US and Soviet chip technology from around the end of the Soviet era and, if I recall correctly, it showed the same conclusion. Another consequence of this lag is that the Soviets had to be efficient code writers.

All of this has got me thinking what the technology was like that first took man to the moon and back.
 

darb1972

Senior Member
All of this has got me thinking what the technology was like that first took man to the moon and back.
I don't know do for certain, but it must have been rather primitive by today's standards. I don't think I'd want today's micros managing my flight to the moon (and hopefully back) let alone something that NASA knocked together some 50 years ago. Bugger that. Either the Astronauts were really brave or really insane adrenaline junkies (or maybe a bit of both). :eek:
 

lbenson

Senior Member
I don't know do for certain, but it must have been rather primitive by today's standards. I don't think I'd want today's micros managing my flight to the moon (and hopefully back) let alone something that NASA knocked together some 50 years ago. Bugger that. Either the Astronauts were really brave or really insane adrenaline junkies (or maybe a bit of both). :eek:
"Light this candle"
 

techElder

Well-known member
If I remember details from the Space Center near Houston (been there many times), the computers in early space voyages were 386-type tech with VERY conservative and redundant programming.
 

oracacle

Senior Member
I don't know do for certain, but it must have been rather primitive by today's standards. I don't think I'd want today's micros managing my flight to the moon (and hopefully back) let alone something that NASA knocked together some 50 years ago. Bugger that. Either the Astronauts were really brave or really insane adrenaline junkies (or maybe a bit of both). :eek:
a lot of the maths was also double checked by the astronauts, to the point when they developed slang for when the computer agreed with the old fashioned way. Don't know about slang for when it didn't match.
 

fernando_g

Senior Member
I don't know do for certain, but it must have been rather primitive by today's standards. I don't think I'd want today's micros managing my flight to the moon (and hopefully back) let alone something that NASA knocked together some 50 years ago. Bugger that. Either the Astronauts were really brave or really insane adrenaline junkies (or maybe a bit of both). :eek:
Have you read the story about the 1202 alarm?
A computer fault that almost caused a landing abort about 1 minute before actual touchdown.

https://www.space.com/26593-apollo-11-moon-landing-scariest-moments.html
https://www.hq.nasa.gov/alsj/a11/a11.1201-fm.html
 
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