Ultimate Steve Posted October 12, 2018 Share Posted October 12, 2018 Another headache... An Emirati astronaut was supposed to launch on MS-12 and come down on MS-10. That's not happening now. Quote Link to comment Share on other sites More sharing options...
Ho Lam Kerman Posted October 13, 2018 Share Posted October 13, 2018 I say we have two (remotely) viable options: 1. Send remaining crew back on MS-09, leave ISS unmanned Probably the most viable option, though we'd have to leave the ISS unmanned and unserviced, and that'd pose some complications. I think we'd able to pull through, though. (Remember that Skylab lost an entire solar panel!) (If anybody could provide some insight on just how important it is to keep ISS serviced, please enlighten me.) 2. Send a dedicated Soyuz up unmanned, make Soyuz MS-09 reenter on autopilot That would be able to keep Expedition 57 servicing the station for some time. I say we make Soyuz MS-09 reenter on autopilot so we can better investigate the hole. That would pose a cost burden, and I don't think we have a dedicated Soyuz handy. We could possibly send Soyuz MS-11, and use Soyuz MS-12 for the MS-11 crew, Soyuz MS-13 for the MS-12 crew, etc. Two of not exactly the best options, but this is a contingency, after all. Quote Link to comment Share on other sites More sharing options...
Ultimate Steve Posted October 13, 2018 Share Posted October 13, 2018 49 minutes ago, Ho Lam Kerman said: That would be able to keep Expedition 57 servicing the station for some time. I say we make Soyuz MS-09 reenter on autopilot so we can better investigate the hole. That would pose a cost burden, and I don't think we have a dedicated Soyuz handy. We could possibly send Soyuz MS-11, and use Soyuz MS-12 for the MS-11 crew, Soyuz MS-13 for the MS-12 crew, etc. The hole is on the orbital module, not the descent module. The orbital module burns up. Quote Link to comment Share on other sites More sharing options...
Xd the great Posted October 13, 2018 Share Posted October 13, 2018 @Ho Lam Kerman the "leave ISS unmanned" is possible, salyut 7 was left unmanned for some time. It will be tough for the next crew. No crew=no repair=trouble. Quote Link to comment Share on other sites More sharing options...
kerbiloid Posted October 13, 2018 Share Posted October 13, 2018 What's the problem to let the crew stay there a month more? Spoiler Quote Link to comment Share on other sites More sharing options...
Ultimate Steve Posted October 13, 2018 Share Posted October 13, 2018 5 minutes ago, kerbiloid said: What's the problem to let the crew stay there a month more? Shelf life of the Soyuz... IIRC it's rated for 215 days in orbit and usually does 200-ish. Much longer than that and the fuel will dissolve the fuel tanks and other bad things will start to happen. Quote Link to comment Share on other sites More sharing options...
kerbiloid Posted October 13, 2018 Share Posted October 13, 2018 2 minutes ago, Ultimate Steve said: IIRC it's rated for 215 days in orbit and usually does 200-ish. So, it can stay there at least till December and probably at least a month longer (unless they find another hole in a fuel tank). Quote Link to comment Share on other sites More sharing options...
razark Posted October 13, 2018 Share Posted October 13, 2018 38 minutes ago, Xd the great said: the "leave ISS unmanned" is possible, salyut 7 was left unmanned for some time. Not to mention that Skylab was left unmanned between missions. One of the early Shuttle missions was planned to reboost Skylab, as well. Further missions were envisioned, but the program was delayed. If it had happened, it would have been a five-year unoccupied wait before a crew could return. Quote Link to comment Share on other sites More sharing options...
Ultimate Steve Posted October 13, 2018 Share Posted October 13, 2018 1 minute ago, razark said: Not to mention that Skylab was left unmanned between missions. One of the early Shuttle missions was planned to reboost Skylab, as well. Further missions were envisioned, but the program was delayed. If it had happened, it would have been a five-year unoccupied wait before a crew could return. While this is the closest comparison we can make, Skylab and the ISS are two very different beasts. Quote Link to comment Share on other sites More sharing options...
razark Posted October 13, 2018 Share Posted October 13, 2018 Just now, Ultimate Steve said: While this is the closest comparison we can make, Skylab and the ISS are two very different beasts. True. ISS is decades ahead in technology. Quote Link to comment Share on other sites More sharing options...
kerbiloid Posted October 13, 2018 Share Posted October 13, 2018 They need a sticker. Spoiler Wait... They really need it. Quote Link to comment Share on other sites More sharing options...
Xd the great Posted October 13, 2018 Share Posted October 13, 2018 46 minutes ago, kerbiloid said: They need a sticker. Reveal hidden contents Wait... They really need it. Selling ISS to spaceX or blue origin will be a good idea. After building the moon station, of course. Quote Link to comment Share on other sites More sharing options...
YNM Posted October 13, 2018 Share Posted October 13, 2018 9 hours ago, K^2 said: I think Roscosmos and NASA should bite the bullet and send MS-11 unmanned before MS-09 is due to return. It's definitely an option. Though they'll have to be really sure this time. Quote Link to comment Share on other sites More sharing options...
Codraroll Posted October 13, 2018 Share Posted October 13, 2018 2 hours ago, Ultimate Steve said: Shelf life of the Soyuz... IIRC it's rated for 215 days in orbit and usually does 200-ish. Much longer than that and the fuel will dissolve the fuel tanks and other bad things will start to happen. If Scott Manley's last video is correct, the issue isn't that the tanks will corrode (that will also happen, but it'd take years), it's that the Hydrogen peroxide used as fuel will naturally decompose, reacting with itself, so the fuel loses potency over time. Quote Link to comment Share on other sites More sharing options...
Xd the great Posted October 13, 2018 Share Posted October 13, 2018 I know hydrogen peroxide is cheap and potent, but why not use OF2 and CH4, which is space storable. Quote Link to comment Share on other sites More sharing options...
Reactordrone Posted October 13, 2018 Share Posted October 13, 2018 26 minutes ago, Xd the great said: I know hydrogen peroxide is cheap and potent, but why not use OF2 and CH4, which is space storable. Crew safety apparently. the peroxide is used as a monopropellant in the descent module since the decomposition by products are non toxic (even though the propellant itself is very dangerous). Quote Link to comment Share on other sites More sharing options...
kerbiloid Posted October 13, 2018 Share Posted October 13, 2018 They may launch Soyuz MS-11 2018.11.28 https://translate.google.com.tr/translate?sl=ru&tl=en&js=y&prev=_t&hl=ru&ie=UTF-8&u=https://www.interfax.ru/russia/633219&edit-text= Quote Link to comment Share on other sites More sharing options...
satnet Posted October 13, 2018 Share Posted October 13, 2018 6 hours ago, Xd the great said: I know hydrogen peroxide is cheap and potent, but why not use OF2 and CH4, which is space storable. Methane and oxygen are great for main propulsion, but for this application would not be very suitable. Basically in a spacecraft you have two main rocket categories: main propulsion (where most of your delta-v comes from) and RCS/maneuvering thrusters. For RCS you want it to fire quickly and accurately since it is used for fine control of direction. Hydrogen peroxide and hydrazine variant (either as a monoprop or a bi-propellant) have both of these traits and as @Reactordrone said H2O2 is much safer in proximity to people. OF2 and CH4 don't have these properties: they aren't hypergolic so you need to provide some ignition source and they need to be pumped which means you need time to spin up and spin down. They are also cryogenic, which is OK when you have vast quantities for main propulsion and the square cube law means that you aren't paying too much for the insulated tanks (as volume increases you need proportionally less insulated surface area), but prohibitive when you need a small volume and therefore need a relatively large insulated surface area. P.S. I'm not saying methane and OF2, can't be used for RCS just that they aren't well suited to it. I believe the BFR will use CH4/O2 for at least some of its thrusters, but it has a reason to have large tanks of the stuff and is massive enough that even with spin up/spin down time it can be considered fine control. 5 hours ago, Reactordrone said: Crew safety apparently. the peroxide is used as a monopropellant in the descent module since the decomposition by products are non toxic (even though the propellant itself is very dangerous). I agree with this, though relative to other monoprops it isn't very dangerous (though anything which has enough energy by itself to be a viable rocket fuel is arguably dangerous). You can come into contact with small quantities and it is just unpleasant with no real long term effects (which is not true of hydrazine). The main danger is when it is in large quantities where it can get enough energy to explode or you can come into contact with enough of it you can't escape to remove it in a reasonable time frame. Its main issues are spontaneously undergoing exothermic decomposition and it is catalyzed by just about everything (meaning your tanks must be obscenely clean to avoid it decomposing much faster than 200 days). Quote Link to comment Share on other sites More sharing options...
kerbiloid Posted October 13, 2018 Share Posted October 13, 2018 (edited) Soyuz uses peroxide for the capsule orientation when deorbiting.RCS and main engine are UDMH/NTO. And it vents out the remaining peroxide on parachuting. Edited October 13, 2018 by kerbiloid Quote Link to comment Share on other sites More sharing options...
kerbiloid Posted October 13, 2018 Share Posted October 13, 2018 They've found a dashboard camera from the rocket. https://translate.google.com.tr/translate?sl=ru&tl=en&js=y&prev=_t&hl=ru&ie=UTF-8&u=https://www.interfax.ru/russia/633245&edit-text= Quote Link to comment Share on other sites More sharing options...
CatastrophicFailure Posted October 13, 2018 Share Posted October 13, 2018 13 minutes ago, kerbiloid said: They've found a dashboard camera from the rocket. https://translate.google.com.tr/translate?sl=ru&tl=en&js=y&prev=_t&hl=ru&ie=UTF-8&u=https://www.interfax.ru/russia/633245&edit-text= Twitter said there might be camera footage of the booster separation, too, but anyone’s guess if it’s ever made public. Quote Link to comment Share on other sites More sharing options...
kerbiloid Posted October 15, 2018 Share Posted October 15, 2018 A preliminary report is going to be presented 2018.10.17 https://translate.google.com.tr/translate?sl=ru&tl=en&js=y&prev=_t&hl=ru&ie=UTF-8&u=https://www.interfax.ru/russia/633316&edit-text= Quote Link to comment Share on other sites More sharing options...
Teilnehmer Posted October 15, 2018 Share Posted October 15, 2018 (edited) On 10/13/2018 at 2:51 PM, Codraroll said: it's that the Hydrogen peroxide used as fuel will naturally decompose, reacting with itself, so the fuel loses potency over time. Isn’t it possible to refuel the H₂O₂ tanks of the Soyuz in orbit? Is there any spare H₂O₂ on the ISS? If there isn’t, it could be brought up by a cargo mission (Progress, Ocrober 31, or Cygnus, November 17). Edited October 15, 2018 by Teilnehmer Quote Link to comment Share on other sites More sharing options...
Scotius Posted October 15, 2018 Share Posted October 15, 2018 28 minutes ago, Teilnehmer said: Isn’t it possible to refuel the H₂O₂ tanks of the Soyuz in orbit? Is there any spare H₂O₂ on the ISS? If there isn’t, it could be brought up by a cargo mission (Progress, Ocrober 31, or Cygnus, November 17). Doubt it. Besides, it would only be shifting problem from Soyuz to ISS. Hydrogen peroxide stored onboard the station would degrade too, complicating astonauts lives even more without any huge gain. Quote Link to comment Share on other sites More sharing options...
Ho Lam Kerman Posted October 15, 2018 Share Posted October 15, 2018 On 10/13/2018 at 10:08 AM, Ultimate Steve said: The hole is on the orbital module, not the descent module. The orbital module burns up. Ahem. Spacecraft numpty here. Oh and wait. Can't we manufacture any H2O2 on the station? Quote Link to comment Share on other sites More sharing options...
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