StarStreak2109 Posted November 5, 2016 Share Posted November 5, 2016 http://www.universetoday.com/131796/spacexs-fueling-process-makes-nasa-queasy/ Still working on it... Also this: http://www.spacex.com/news/2016/09/01/anomaly-updates Link to comment Share on other sites More sharing options...
Northstar1989 Posted November 5, 2016 Share Posted November 5, 2016 (edited) 6 hours ago, StarStreak2109 said: http://www.universetoday.com/131796/spacexs-fueling-process-makes-nasa-queasy/ Still working on it... Also this: http://www.spacex.com/news/2016/09/01/anomaly-updates The writer of the first article had a laughable knowledge of ricket science. He literally called KeroLOX a non-conventional rocket fuel, even though it's the MOST conventional rocket fuel in existence (we used it back in the 60's on the Saturn rockets, for crying out loud). He also wrongly stated that KeroLOX has less mass than HydroLOX (that's laughable, as the main reason HydroLOX is preferred is that you can use less mass of IT- although its reduced density means you need a bigger rocket to hold the same fuel mass...), and seemed to think that KeroLOX is less tolerant of loiter times on the launchpad than HydroLOX due to its cryogenic nature (HydroLOX is, of course, *FAR* more cryogenic than KeroLOX). Clearly, the writer was a moron. Possibly he just assumed that whatever ULA's been doing is easier and more conventional, and that SpaceX must sonehow be doing the difficult and new thing with its fuel choice. Which is, of course, the opposite of the truth (SpaceX does plenty of hard things, but opting for KeroLOX over HydroLOX is not one of them)- and thus really showcases that the writer was writing from complete and utter ignorance... It's sad how little the media- including even many science writers- understand about rocketry... Regards, Northstar Edited November 5, 2016 by Northstar1989 Link to comment Share on other sites More sharing options...
Eklykti Posted November 5, 2016 Share Posted November 5, 2016 On 30.10.2016 at 6:02 PM, Elthy said: SpaceX would have to develope a LEO optimised cargo version. The biggest problem with that is fitting a big fairing on top while still keeping the aerodynamics for reentry. Why need a fairing at all? Just make a cargo bay like in Space Shuttle, go to orbit, open the cargo bay and release the payload, then return. Link to comment Share on other sites More sharing options...
StrandedonEarth Posted November 5, 2016 Share Posted November 5, 2016 2 hours ago, Northstar1989 said: The writer of the first article had a laughable knowledge of ricket science. He literally called KeroLOX a non-conventional rocket fuel, even though it's the MOST conventional rocket fuel in existence (we used it back in the 60's on the Saturn rockets, for crying out loud). He also wrongly stated that KeroLOX has less mass than HydroLOX (that's laughable, as the main reason HydroLOX is preferred is that you can use less mass of IT- although its reduced density means you need a bigger rocket to hold the same fuel mass...), and seemed to think that KeroLOX is less tolerant of loiter times on the launchpad than HydroLOX due to its cryogenic nature (HydroLOX is, of course, *FAR* more cryogenic than KeroLOX). Well, the writer got one thing right, that the propellants expand if allowed time to warm up. What he left out is that kerosene is chilled (not how kerosene used to be handled) and the lox is chillled far below the boiling point, which is also unusual. All to increase the density and the mass of propellants that can be packed on board. Link to comment Share on other sites More sharing options...
tater Posted November 5, 2016 Share Posted November 5, 2016 Still, what could be more conventional than kerlox? Link to comment Share on other sites More sharing options...
Northstar1989 Posted November 5, 2016 Share Posted November 5, 2016 (edited) 7 hours ago, StrandedonEarth said: What he left out is that kerosene is chilled (not how kerosene used to be handled) and the lox is chillled far below the boiling point, which is also unusual. All to increase the density and the mass of propellants that can be packed on board. Still not getting how that works. Chilling cryogenics shouldn't increase their density hardly at all. In fact I had a long debate over on the RealFuels thread a year back because, not realizing LOX and most rocket fuels are incompressible, I spent a long time arguing that chilling or pressurizing LOX *should* increase its density, based on a bit of stubborness and a knowledge-gap I'm not proud of... Unless the LOX is superchilled to the point some of it freezes into a slurry. That's a different story... Also, this reminds me- whatever happened to the idea of adding tiny bits of aluminum powder to the fuel supply of rockets to increase the fuel-density? Aluminum powder burns quite violently, and it sounded like a nice way to get a fuel-density closer to hypergolics without any of the nasty toxicity issues those involve, and the higher fuel-density should make up for lost ISP, and then some, at least on launch stages... EDIT: And I guess I was right way back when. Durther research shows LOX can increase in density more than 10% if chilled enough, and by 1-2% if pressurized enough. <REDACTED BY MODERATOR > Edited November 5, 2016 by Frybert Redaction Link to comment Share on other sites More sharing options...
Elthy Posted November 5, 2016 Share Posted November 5, 2016 Tiny solid particels sound like a great way to corrode turbines and injectors, the opposite of reusability. Also i remember "Ignition!" stating that they had a realy hard time having the metall powder staying evenly distributed in the fuel. Link to comment Share on other sites More sharing options...
StrandedonEarth Posted November 6, 2016 Share Posted November 6, 2016 (edited) 22 hours ago, Northstar1989 said: Still not getting how that works. Chilling cryogenics shouldn't increase their density hardly at all. In fact I had a long debate over on the RealFuels thread a year back because, not realizing LOX and most rocket fuels are incompressible, I spent a long time arguing that chilling or pressurizing LOX *should* increase its density, based on a bit of stubborness and a knowledge-gap I'm not proud of... Well, from this site I found this chart, which shows an 8.8% difference in density over the liquid temperature range. Nothing to sneeze at Densities of liquid oxygen Temperature, ° Abs Temperature, ° C Density. 68.0 -205 1.2489 70.0 -203 1.2393 74.0 -199 1.2200 78.0 -195 1.2008 80.0 -193 1.1911 82.0 -191 1.1815 86.0 -187 1.1623 89.0 -184 1.1479 Edit: Increasing density through chilling is quite different than increasing density by compressing. Edited November 6, 2016 by StrandedonEarth Link to comment Share on other sites More sharing options...
cfds Posted November 6, 2016 Share Posted November 6, 2016 How could there ever been any doubt that cooling LOX increases its density? That is true for pretty much any liquid, that water behaves differently below 4°C is what makes it special. Link to comment Share on other sites More sharing options...
shynung Posted November 6, 2016 Share Posted November 6, 2016 @cfds It's not whether it does, but by how much. StrandedonEarth's conclusion above your post looks pretty promising; density above 1.2 is pretty good for a liquid propellant. Link to comment Share on other sites More sharing options...
tater Posted November 10, 2016 Share Posted November 10, 2016 http://arstechnica.com/science/2016/11/as-trump-takes-over-nasa-considers-alternatives-to-its-orion-spacecraft/ Quote Nevertheless, three sources familiar with the RFI, who agreed to speak on the condition of anonymity, told Ars there is more to the request than a simple extension for Orion’s primary contractor, Lockheed Martin. Perhaps most radically, the RFI may even open the way for a competitor, such as Boeing or SpaceX, to substitute its own upgraded capsule for Orion in the mid-2020s. later... Quote The RFI clearly leaves the door open to other alternatives, however. The original structure of NASA’s contract with Lockheed Martin is such that NASA “owns” the design work when it is completed, so another contractor, if it could demonstrate a compelling cost advantage, could take over for Exploration Mission-3 and beyond. Link to comment Share on other sites More sharing options...
kunok Posted November 10, 2016 Share Posted November 10, 2016 I don't think SpaceX (or any other of Musk companies) will be beneficed by any of the Trump Government big decisions. But entering in that would be entering in politics. I don't know how to talk about a politics controlled program without talking about politics Link to comment Share on other sites More sharing options...
tater Posted November 10, 2016 Share Posted November 10, 2016 Commercial space is very much along the lines of where the new administration has said they want to go (there was a recent space news article about possible space policy net year) (I'm making a concerted effort to not even name people, etc, and certainly not discussing the merits either way). The fact I linked above is a fact, however, and they must have their reasons. Link to comment Share on other sites More sharing options...
_Augustus_ Posted November 10, 2016 Share Posted November 10, 2016 On 10/15/2016 at 11:19 AM, tater said: This part of NASA's url is simply awful: "nasa-shakes-up-orion-test-article-for-the-journey-to-mars". This constant conflation of Orion with Mars is absurd. NatGeo kids had a Mars issue my son just got, and there is, I kid you not, a picture of an orion capsule on Mars. Resting on the heat shield, after chute deployment. As if that would work. That's what reporters and an artist hired by National Geographic thought---largely because of hyperbole like the link above. Don't blame NatGeo, they're too stupid to understand. Link to comment Share on other sites More sharing options...
Superluminaut Posted November 12, 2016 Share Posted November 12, 2016 In California traveling east on the I-10. It was stopped on the Alabama st. off ramp strapping down the load, then got back on the I-10 east . Anyone know which launch this is? Where did it come from? Where is it going? Link to comment Share on other sites More sharing options...
tater Posted November 12, 2016 Share Posted November 12, 2016 They have a mid December launch from VAFB coming up. Link to comment Share on other sites More sharing options...
Superluminaut Posted November 12, 2016 Share Posted November 12, 2016 VAFB is west though. Link to comment Share on other sites More sharing options...
Karriz Posted November 12, 2016 Share Posted November 12, 2016 (edited) Could be going to Texas test facility. The return to flight mission is either Echostar from KSC or Iridium from VAFB. I don't think it's been confirmed yet which one will fly first. But in any case the stages go to Texas first. Edited November 12, 2016 by Karriz Link to comment Share on other sites More sharing options...
insert_name Posted November 12, 2016 Share Posted November 12, 2016 What you saw was definitely not iridium, that one was at vafb before the Amos 6 anomaly, probably echostar, maybe CRS 10 Link to comment Share on other sites More sharing options...
Aethon Posted November 16, 2016 Author Share Posted November 16, 2016 Diaphragm layers being placed for the Orion stage adapter. http://www.nasa.gov/exploration/systems/sls/multimedia/diaphragm-layers-for-Orion-stage-adapter Link to comment Share on other sites More sharing options...
stormtrooper09 Posted November 16, 2016 Share Posted November 16, 2016 So they tested their huge prototype tank. There's also a video to the left. Link to comment Share on other sites More sharing options...
kerbiloid Posted November 17, 2016 Share Posted November 17, 2016 Kessler Space Program? https://www.reddit.com/r/spacex/comments/5d9724/spacex_has_filed_for_their_massive_constellation/ Link to comment Share on other sites More sharing options...
StarStreak2109 Posted November 17, 2016 Share Posted November 17, 2016 First they'd need a rocket anyway, which works and doesn't blow up on the pad! Link to comment Share on other sites More sharing options...
Green Baron Posted November 17, 2016 Share Posted November 17, 2016 You're mean :-) Seemingly they are preparing for flight again. Spacing: According to this page some satellites in stationary orbit are "just" 73km apart, debris not counted. Seems like at some time a coordinating position is needed to administer slots and spacing or we really get a lot of new "open clusters" ... population III :-) ? Link to comment Share on other sites More sharing options...
Lukaszenko Posted November 17, 2016 Share Posted November 17, 2016 Indeed there are a limited number of useful slots in the geostationary orbital ring, and this does cause disputes between countries, but this is already addressed by the International Telecommunication Union. Link to comment Share on other sites More sharing options...
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