Difference between RP-1 and RG-1

[fredinno]

Russian rockets like the Soyuz are listed as using RG-1, while American one's, even if they use Russian engines, like Antares: https://en.m.wikipedia.org/wiki/Soyuz-2_(rocket)

https://en.m.wikipedia.org/wiki/Antares_(rocket)

 

I also read that the oil reservoir used to make RG-1 was depleting, and that this was a concern for their rockets. What is the difference between RG-1 and RP-1, and could an engine be modified to use RG-1 just as easily as RP-1 (which seems to be more common)?

[Steel]

From Wikipedia:

"Soviet and Russian rocket-grade kerosenes are very similar to RP-1 and are designated T-1 and RG-1. Densities are higher, 0.82 to 0.85 g/ml, compared to RP-1 at 0.81 g/ml "

Edited January 6, 2016 by Steel

[fredinno]

27 minutes ago, Steel said:

From Wikipedia:

"Soviet and Russian rocket-grade kerosenes are very similar to RP-1 and are designated T-1 and RG-1. Densities are higher, 0.82 to 0.85 g/ml, compared to RP-1 at 0.81 g/ml "

So, basically RG-1 is basically a denser RP-1? Meaning RG-1 engines can run RP-1 just fine?

[Kryten]

RD-180, NK-33, and RD-181 have all burned both RP-1 and RG-1 without modification, we can safely assume they're practically identical.

[Steel]

From what I gather, they are just two different (albeit very similar) specifications of highly refined kerosene. One may have slightly different tolerances for impurities, hydrocarbons and what have you, but they are designed for the same application at the end of the day and so are necessarily very similar.

[fredinno]

11 minutes ago, Kryten said:

RD-180, NK-33, and RD-181 have all burned both RP-1 and RG-1 without modification, we can safely assume they're practically identical.

Well, that removes tone of the main selling points for Soyuz-V. Why build a new rocket when you can just use a different, more common fuel, with Few modifications (but reduced payload)?

[Kryten]

They're not switching to kerolox for soyuz-5 because RG-1 is running out, they're switching because that lets them switch to autogenous pressurisation (for lower complexity of operations, so lower cost), full-flow staged combustion engines (so higher performance), and delivers the maximum possible payload weight relative to GLOW (so can loft large payloads within weight limits of existing soyuz pads).

[fredinno]

25 minutes ago, Kryten said:

They're not switching to kerolox for soyuz-5 because RG-1 is running out, they're switching because that lets them switch to autogenous pressurisation (for lower complexity of operations, so lower cost), full-flow staged combustion engines (so higher performance), and delivers the maximum possible payload weight relative to GLOW (so can loft large payloads within weight limits of existing soyuz pads).

https://en.m.wikipedia.org/wiki/Soyuz-5_(rocket)

Apparently, the lack of RG-1 was one of their listed reasons. I don't like the Soyuz-V though, since it gets rid of the R-7 rocket structure. How could you Russia?!?!  Reuse might redeem it for me (possible since it also has excess payload capacity).