CatastrophicFailure Posted January 15, 2016 Share Posted January 15, 2016 1 hour ago, fredinno said: Actually, Centaur now has IVF. http://forum.nasaspaceflight.com/index.php?topic=37206.0 A piston engine on a rocket. That just weirds me out. It sounds like it should be so heavy. Link to comment Share on other sites More sharing options...
Streetwind Posted January 15, 2016 Share Posted January 15, 2016 (edited) 11 hours ago, Kryten said: SpaceX have stated F9 can do full GEO missions, and the Soviets demonstrated loiter times of over a week for their similar Blok D stage in the 60s. Weird. That's precisely the opposite of what I heard from SpaceX so far. Could you link me to a source, please? I'd like to know more... Edited January 15, 2016 by Streetwind Link to comment Share on other sites More sharing options...
KSK Posted January 15, 2016 Share Posted January 15, 2016 51 minutes ago, Streetwind said: Weird. That's precisely the opposite of what I heard so far. Could you link me to a source, please? I'd like to know more... Apparently, the Blok D was originally intended for mid-course corrections on the way to the Moon, plus the LOI and PDI burns, so it had to be good for at least three days. A week doesn't seem like too much of a stretch from there. Wikipedia links to a bunch of other articles but unfortunately most of them are either in Russian or at the end of broken links. Link to comment Share on other sites More sharing options...
Streetwind Posted January 15, 2016 Share Posted January 15, 2016 10 minutes ago, KSK said: Apparently, the Blok D was originally intended for mid-course corrections on the way to the Moon, plus the LOI and PDI burns, so it had to be good for at least three days. A week doesn't seem like too much of a stretch from there. Wikipedia links to a bunch of other articles but unfortunately most of them are either in Russian or at the end of broken links. Ah, sorry, I should have been more clear. i was asking about SpaceX upper stage capabilities. *goes to edit post* Link to comment Share on other sites More sharing options...
KerBlammo Posted January 15, 2016 Share Posted January 15, 2016 SpaceX was supposed to fire the engines of the recovered first stage yesterday. Does anyone know if that occurred and if so how long they fired the engines for? Link to comment Share on other sites More sharing options...
Rakaydos Posted January 15, 2016 Share Posted January 15, 2016 Concerning Raptor engine as an upperstage- I recall an Elon post that stated something like "TWR optimization (for the raptor) is settling on a suprisingly low thrust, even with the extra structure for mounting extra engines." If the optimised raptor is small enough, it might actually make sence as an upperstage. Link to comment Share on other sites More sharing options...
Mitchz95 Posted January 15, 2016 Share Posted January 15, 2016 (edited) 5 hours ago, KerBlammo said: SpaceX was supposed to fire the engines of the recovered first stage yesterday. Does anyone know if that occurred and if so how long they fired the engines for? Edited January 15, 2016 by Mitchz95 Link to comment Share on other sites More sharing options...
ChrisDayVACCO Posted January 15, 2016 Share Posted January 15, 2016 14 hours ago, fredinno said: Is there enough TWR though? (You would need landing legs too, and I'm not sure is too much useful science could be done like this...) Good point. The Apollo series LEMs had an initial mass of 15,200 kg and a decent thrust of 45 kN so its acceleration is about 3 m/s. A 3kg 3U CubeSat with the four 100 mN thrusters gives only 0.13 m/s. That is too little to oppose the Moon's gravity. With the Moon's surface gravity of 1.6 m/s^2, a thruster with a TWR of 2 would need to have about 5 N of thrust. A Swedish company, ECAPS, has small 5 N thrusters that they are testing but they would be larger than the 100 mN thrusters sized for CubeSats. Link to comment Share on other sites More sharing options...
Kerbal01 Posted January 15, 2016 Share Posted January 15, 2016 ASDS JRTI left port a while ago under the care of its two tugs(cannot remember their names at the moment) Link to comment Share on other sites More sharing options...
Mitchz95 Posted January 15, 2016 Share Posted January 15, 2016 (edited) Edited January 15, 2016 by Mitchz95 Link to comment Share on other sites More sharing options...
insert_name Posted January 16, 2016 Share Posted January 16, 2016 Is the launch still on the 17th, cause the weather looked pretty bad, like 200ft visibility Link to comment Share on other sites More sharing options...
Mitchz95 Posted January 16, 2016 Share Posted January 16, 2016 11 minutes ago, insert_name said: Is the launch still on the 17th, cause the weather looked pretty bad, like 200ft visibility Apparently they still have 100% chance of favorable conditions. Also: Link to comment Share on other sites More sharing options...
KerBlammo Posted January 16, 2016 Share Posted January 16, 2016 If this was a static fire ahead of an operational launch I wonder what impact would those thrust variations would have? Inspection of the engine and a re-do of the test? Link to comment Share on other sites More sharing options...
RuBisCO Posted January 16, 2016 Share Posted January 16, 2016 Since most of the outer engines are not in use during the return, maybe they need to add a chocking mechanism, something to close off the nozzle hole into the reaction chamber to prevent debris/smoke from getting ingested during return. Link to comment Share on other sites More sharing options...
Mad Rocket Scientist Posted January 16, 2016 Share Posted January 16, 2016 Did anyone else watch the pre-flight conference? Link to comment Share on other sites More sharing options...
Wingman703 Posted January 16, 2016 Share Posted January 16, 2016 Engine 9 is the center one, correct? One of the three used for boostback, initial landing burn, and the only one used for final landing burn? Link to comment Share on other sites More sharing options...
Mad Rocket Scientist Posted January 16, 2016 Share Posted January 16, 2016 2 minutes ago, Wingman703 said: Engine 9 is the center one, correct? One of the three used for boostback, initial landing burn, and the only one used for final landing burn? Nope: Link to comment Share on other sites More sharing options...
fredinno Posted January 16, 2016 Share Posted January 16, 2016 6 hours ago, ChrisDayVACCO said: Good point. The Apollo series LEMs had an initial mass of 15,200 kg and a decent thrust of 45 kN so its acceleration is about 3 m/s. A 3kg 3U CubeSat with the four 100 mN thrusters gives only 0.13 m/s. That is too little to oppose the Moon's gravity. With the Moon's surface gravity of 1.6 m/s^2, a thruster with a TWR of 2 would need to have about 5 N of thrust. A Swedish company, ECAPS, has small 5 N thrusters that they are testing but they would be larger than the 100 mN thrusters sized for CubeSats. I think you might have to hold a propulsion module seperately, in another cubesat bay. Only problem is that would increase the complexity enormously. I think soon 12U Cubesats will become built and used, for longer distance applications. Link to comment Share on other sites More sharing options...
Albert VDS Posted January 16, 2016 Share Posted January 16, 2016 Low quality video of the static fire: Link to comment Share on other sites More sharing options...
Rdivine Posted January 16, 2016 Share Posted January 16, 2016 Incredible. Anyone knows why SpaceX didn't release the footage of the static fire test? Or do they need time to edit the video first? Link to comment Share on other sites More sharing options...
Albert VDS Posted January 16, 2016 Share Posted January 16, 2016 (edited) 11 minutes ago, Rdivine said: Incredible. Anyone knows why SpaceX didn't release the footage of the static fire test? Or do they need time to edit the video first? Why would they need to release it? Or even better, who said they filmed it? Edited January 16, 2016 by Albert VDS Link to comment Share on other sites More sharing options...
Rdivine Posted January 16, 2016 Share Posted January 16, 2016 2 hours ago, Albert VDS said: Why would they need to release it? Or even better, who said they filmed it? I assume that they would always have sets of cameras trained on the rocket just in case something goes wrong and they needed to analyse the footage. Well, i guess it would be good publicity for spaceX to release the footage (probably just show it off in jeff bezos's face). Link to comment Share on other sites More sharing options...
Albert VDS Posted January 16, 2016 Share Posted January 16, 2016 SpaceX isn't in the business to show off recorded footage of a static fire, let alone in Bezos' face. Let's assume they have recorded the static fire, what would it accomplish if they released it? Or what would happen if they didn't? Link to comment Share on other sites More sharing options...
Kobymaru Posted January 16, 2016 Share Posted January 16, 2016 Just now, Albert VDS said: SpaceX isn't in the business to show off recorded footage of a static fire, let alone in Bezos' face. Let's assume they have recorded the static fire, what would it accomplish if they released it? Or what would happen if they didn't? The whole point of showing the launch and the landing of the stage is to demonstrate the ability to *reuse* rockets. Landing it is a great feat, but it's only half of the deal. They also have to demonstrate that the thing that comes down can be used again. Let's just hope nothing went wrong at the test firing... Link to comment Share on other sites More sharing options...
Albert VDS Posted January 16, 2016 Share Posted January 16, 2016 (edited) 2 hours ago, Kobymaru said: Let's just hope nothing went wrong at the test firing... https://twitter.com/elonmusk/status/688173528017850368 Edit: Is there some BB-code for twitter links, because it's not showing up as the previous twitter messages in this thread. Edited January 16, 2016 by Albert VDS Link to comment Share on other sites More sharing options...
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