How the Soviets navigated Soyuz capsules - mechanical navigation computers

[Otter74]

This is really cool, and kind of bonkers - a mechanical computer using a globe that indicated their position and predicted landing location:

Inside the Globus INK: a mechanical navigation computer for Soviet spaceflight

[RNajarian]

Wow! Ingenious. They used this through 2002. Amazing

[911_Dude]

Fascinating. I noticed that globe nav unit in pictures Ive seen in the past. As a commercial pilot, Ive always thought that was a cool mechanical nav display. But I never knew any of the details. 180 km landing accuracy?- I think the NASA boys (and girls) did better than that. Surely the Cosmo's had ground radar assistance for when to fire the retro for landing. Otherwise they were just kind of flying VFR in space. Cant remember the NASA number for hitting the landing spot, but it was at least an order of magnitude tighter.

Very cool none the less. Thanks!

[oldE]

This reminded me of the old story about NASA working to produce a pen which would function in zero gravity. They did it at substantial cost. Later, when going to space with the Russians, they noted the cosmonauts were using pencils.

Best
Les

[GH85Carrera]

Originally Posted by oldE

This reminded me of the old story about NASA working to produce a pen which would function in zero gravity. They did it at substantial cost. Later, when going to space with the Russians, they noted the cosmonauts were using pencils.

Best
Les

And the reality is pencil tips and debris ended up floating around in the capsule, and got in crew members eyes, and into sensitive electronics. The Russians and NASA both used felt tip markers. The Space pen was developed by Fischer. The Russians have used it since 1969. It is still used on the International Space Station.

https://www.nasa.gov/directorates/spacetech/spinoff/How_NASA_Astronauts_Write_in_Space

The Russians did not have the global communications network we have to talk to astronauts throughout the orbit. They had long periods of no communications to the ground.

[oldE]

Cool!
Thanks Glen.

Best
Les

[herr_oberst]

I've been trying to find it, my google fu is weak today, but didn't the Mercury instrument panel have something similar? Maybe not as elaborate but a globe under glass?

(Hey, flat earthers - how do you dispute this?)

[Seahawk]

Two neat articles. Thank you both.

As I have written here before, I did the first flights with a then state of the art Navstar 5 Channel GPS in a Navy aircraft, in my case the SH-60B.

The system integrated with our multi-function display and synced all our tactical symbology. The precise location of the "numbers" on military runways are surveyed and the information is provided in lat/long. On the first flight I entered a fly to point based on the approach end of a runway at Pax River...I was "Data Gathering Monkey" that day and as the helo symbol captured the fly to point we were hovering right above the numbers, which for old pilots like me who flew with manual plotting boards as back-up, was astounding.

Changed everything.

[Otter74]

Originally Posted by 911_Dude

Fascinating. I noticed that globe nav unit in pictures Ive seen in the past. As a commercial pilot, Ive always thought that was a cool mechanical nav display. But I never knew any of the details. 180 km landing accuracy?- I think the NASA boys (and girls) did better than that. Surely the Cosmo's had ground radar assistance for when to fire the retro for landing. Otherwise they were just kind of flying VFR in space. Cant remember the NASA number for hitting the landing spot, but it was at least an order of magnitude tighter.

Very cool none the less. Thanks!

Indeed - by contrast, here's the digital ranging system that NASA used to help determine Apollo location:

The digital ranging system that measured the distance to the Apollo spacecraft

The guy's website is like a library for reverse-engineering vintage electronics. Hard core reminds me of my dad.

[jamesnmlaw]

A Russian antikytheria device.

[GH85Carrera]

When NASA was trying to figure out how to keep track of where they were, the helped develop the new technology of a IMU or Inertial Measurement Unit. It saved Apollo 13 from a death in space.

https://airandspace.si.edu/stories/editorial/restarting-apollo-13-command-module-imu

Also, for the moon buggy, they knew it would be easy to drive out of view of the lunar lander. If batteries were low, they wanted a direct path back to the lander, and not have to back track. A small IMU was used. It could calculate just where they were, and the fastest route back to the lander.

All cell phones now have a IMU and that is how it knows you just raised it up to your face to read or use it. The IMUs are super tiny now, and the ones NASA developed when from refrigerator size to something to fit on a space craft.

[3rd_gear_Ted]

Originally Posted by jamesnmlaw

A Russian antikytheria device.

Is that a Copper Beryllium frame for the gears?

[javadog]

If you want to see the other end of the spectrum, this short video blew my mind. It shows the computer ROOM underneath the floor in the front half of a modern Airbus A350.

I know that Airbus planes are flyby wire and all that but I was astonished to see how many electronic systems and computers they have onboard one.

https://m.youtube.com/watch?v=LxS2RR-Vx_s

[Seahawk]

I have seen the Airbus video before and it always makes me smile for a host of reasons.

Another fun navigation fact that GPS exposed just in case you guys wonder why I geek out on this stuff:

In the SH-60B, that had a very integrated avionics system (radar/ESM/acoustics/data links/doppler nav/radio navigation, etc.) all presented on a multi function display with different "modes"), the designers built geographic "bins" at a certain size for specific missions with an assumed accuracy requirement, very similar to any map program available today.

If I remember correctly, the smallest "bin" was 100yds by 100 yards, more than enough accuracy for the nav systems at the time...long time ago.

During the GPS testing, we were getting odd data sets against the GPS accuracy spec, which for the "undithered" GPS we were testing, was very tight...within feet tight.

BTW, the GPS system "dithered" the civilian GPS signal in those days, meaning it was not as accurate as the military GPS systems. I have no idea why.

Our issue was the accuracy numbers just were not there: 20 yds, 10 yds, exactly on top, then right back to 50 yds. Really interesting and we based the tests on what the entire nav system was seeing and measured the deltas on the MFD.

We decided to enter the same fly-to-point based on a surveyed runway approach and capture it multiple times from a hover, slowly move away, re-enter he FTP and capture it again. We even landed and taxied to the FTP.

Same error sets.

The SH-60B was developed by IBM in Owego, NY...the helo was Sikorsky but all the avionics were IBM, magnificent stuff in the 80's.

So we called the IBM engineers and they came down to Pax to get familiar with our test methodologies and test results.

Five minutes into the first meeting, an IBM guy says, "I know what's wrong."

He explained: "When we designed the tactical symbology and how we would present it to the pilots, we felt that there was no real need to assign the fly to points to the exact same bin position so they just drop into the bin randomly...we don't know where in the nav bin the symbology is, exactly."

This was perfectly acceptable in the days before GPS...100 yds by 100 yds was ballin'

They went back to Owego and gave us a new s/w baseline in a month that assigned tactical symbology to the same exact spot in the nav bin...accuracy problem vanished.

So much more.

Different day and time.

I have been on a s/w phoncon today where all of the above fits on a card the size of a credit card for our UAS.

[DonDavis]

eesh... that thing made my eye twitch becasue it reminded me of the mechanical nightmare called the Mk8 Rangekeeper from my Battleship days.

Talk about "mechanical"...

[GH85Carrera]

My dad was commissioned into the Air Force on October 14th 1953, and became a pilot in Sept 1957. He talked about the navigation system that was fortunately for him in the process of being phased out. He only had to do limited training on a system when the pilot wears a headset and in one ear a beep tone and the other ear has a different beep tone, out of phase with the other ear.

If you were on course, the two tones matched up and became a solid tone, if you were off course the solid tone was became a beep and you knew to correct course. If not it was a constant beep beep.

Imagine trying to fly an airplane, and if all is going right you hear a solid tone in your head. He said it was almost torture after an hour. He was really happy to get away from that system.

We have a 2004 Cessna 182T that has the Garman G-1000 "glass cockpit" with two oversize iPads for the instruments. The factory autopilot is pretty amazing. After takeoff, and getting away from the airport, just punch in the rate you want to climb, the cruise altitude, and the airport designation, and it just climbs to the appropriate altitude at the rate of climb you gave it, and takes you right there. All updated every 30 days. That would be pure science fiction in 1957 for the USAF.

[masraum]

Great thread, folks, keep it up!

One important consequence of this design is that the orbital inclination is fixed by the angle of the globe mechanism. Different Globus units needed to be built for different orbits. Moreover, this design only handles circular orbits, making it useless during orbit changes such as rendezvous and docking. These were such significant limitations that some cosmonauts wanted the Globus removed from the control panel, but it remained until it was replaced by a computer display in Soyuz-TMA (2002).3

Crazy!

Seems "functional" or maybe "barely functional" but way behind the times. Reminds me of the thread a while back talking about the issues with the Russian military and their low quality gear (or complete lack of gear) in the invasion of Ukraine.

[911_Dude]

Originally Posted by herr_oberst

I've been trying to find it, my google fu is weak today, but didn't the Mercury instrument panel have something similar? Maybe not as elaborate but a globe under glass?

(Hey, flat earthers - how do you dispute this?)

I think what you are thinking of was more like an aircraft ADI (attitude direction indicator). Not sure what it referenced off of.

[herr_oberst]

The Project Mercury 'earth path indicator' instrument

https://www.rrauction.com/auctions/lot-detail/340932005505026#:~:text=The%20Earth%20Path%20Indic ator%20(EPI,driven%20by%20a%20clockwork%20mechanis m.

[MBAtarga]

Originally Posted by Seahawk

BTW, the GPS system "dithered" the civilian GPS signal in those days, meaning it was not as accurate as the military GPS systems. I have no idea why.

Paul, I watched a documentary on GPS a while back and remembered accuracy was enabled then disabled, and then enabled again. I'll reference the wiki below instead of summarizing:

https://en.wikipedia.org/wiki/Global_Positioning_System

The GPS project was started by the U.S. Department of Defense in 1973. The first prototype spacecraft was launched in 1978 and the full constellation of 24 satellites became operational in 1993. Originally limited to use by the United States military, civilian use was allowed from the 1980s following an executive order from President Ronald Reagan after the Korean Air Lines Flight 007 incident.[6] Advances in technology and new demands on the existing system have now led to efforts to modernize the GPS and implement the next generation of GPS Block IIIA satellites and Next Generation Operational Control System (OCX).[7] which was authorized by the U.S. Congress in 2000.

From the early 1990s, GPS positional accuracy was degraded by the United States government by a program called Selective Availability, which could selectively degrade or deny access to the system at any time,[8] as happened to the Indian military in 1999 during the Kargil War. However, this practice was discontinued on May 1, 2000, in accordance with a bill signed into law by President Bill Clinton.[9] As a result, several countries have developed or are in the process of setting up other global or regional satellite navigation systems.