Orbital Information IRL

[Jacke]

Correct me if I'm wrong here, but in the very beginning, they did indeed have difficulties and uncertainties regarding orbital speed. Such as with the launch of Yuri Gagarin, there was the possibility that he would've ended up in an orbit that would've taken more time to decay than he had supplies for.

This isn't so for Vostok. The spec's of the launch vehicle and its trajectory determined the orbit the Vostok spacecraft would be inserted into. From previous spacecraft, Sergei Korolev knew the amount of atmospheric drag it would encounter. With that in mind...

If the retrorocket failed, the spacecraft would naturally decay from orbit within 10 days and the cosmonaut was provisioned with enough food and oxygen to survive until that time.

[AbacusWizard]

I know what an Abacus is, and actually had a toy one when I was a child, but I've never seriously used it. What advantage does it have over using just plain pen and paper?

Part of it is that sliding beads around (once you've had some practice) is WAY faster than writing down numerals. It also encourages use of various shortcuts (e.g. instead of adding 8, you could add 10--a single bead in the next column over--and subtract 2), which at first seem a nuisance, but once you get the hang of it they speed up calculations so much you'll find yourself doing them in your head even when you don't have an abacus in your hands.

I admit I do still use pencil and paper for long division, because I personally find the division method on the abacus to be somewhat cumbersome and easy to lose track of place value--but for addition, subtraction, and multiplication, the abacus is superb.

[pandaman]

Don't all the beads slide to one end in a high G turn?

Edit... @AbacusWizard - just got chance to watch the video - Impressive stuff.

No matter how good technology gets the battery can always go flat. GPS is great, but a map and compass is far more reliable... As long as you know how to use them.

Edit 2... Recent posts on this thread reminded me of a story we read at school (1970's). A group of school children were on a field trip, but they didn't go to school to learn 'stuff' they went to learn how to use their personal portable mini computers to find out whatever they needed when they needed to. Not far off where we seem to be heading nowadays:)

Edited July 17, 2015 by pandaman

[AbacusWizard]

Don't all the beads slide to one end in a high G turn?

Eh, yeah, but on a long trip, maneuvers should be few and far between, so you'd have plenty of time to run calculations during periods of zero acceleration.

[Zephram Kerman]

Dunno if this is true or not, but some guy once told me an inclined orbit can be more easily monitored than an equatorial one; the longitude can be estimated simply by measuring latitude with a sextant and then plotting that against the ground track.