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LostCosmonaut last won the day on January 15

LostCosmonaut had the most liked content!

About LostCosmonaut

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    Intensive Porpoises
  • Birthday 12/02/1991

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    Upstate NY

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  1. WoT v WT effort-thread

    Played a bit of Wehr Thunder. The Flakpanzer I with mixed HVAP/API belts is hilarious.
  2. Sports meets politics; https://www.si.com/extra-mustard/2018/01/16/donald-trump-height-weight-tim-tebow-mike-trout Not to get all tinfoil hat, but Trump does look pretty chunky.
  3. The Space Exploration Achievements Thread

    Forbes is such trash; https://www.forbes.com/sites/lorenthompson/2018/01/15/doubts-about-spacex-reliability-persist-as-astronaut-missions-approach/#345d36653305 Concern trolling about the Zuma launch written by somebody whose "think tank" receives funding from Lockheed and Boeing (aka ULA).
  4. WoT v WT effort-thread

    Anybody here still play Worst of Tanks?
  5. Comparison of Rocket Payload Fractions

    For whatever reason Encylopedia Astronautica and wiki give the Ariane 1 a lower value for payload to LEO vs. GTO (1400 vs. 1850), which is highly odd. I can't think of any reason why that would be the case (GTO requires much more delta v than LEO). Going by the payload fraction to GTO, I get 1850/207200 = .0089, vs. 6300/705000 = .0089 for Proton-M, and 14220/738960 = .0192 for Delta IV Heavy. I think this is explainable by Ariane 1 being an older rocket with somewhat less efficient engines (the Viking-2s on Ariane 1 have 248 sec. sea level isp vs. 285 on the RD-253 and 365 on the RS-68). EA gives the LEO performance for Ariane 5 as 16000 kg, but to a 51.5 degree inclination orbit, which is going to cut into the performance a lot. Arianespace's site gives a payload to LEO of 20 tons, which gives a payload/mass fraction of .0257, which is better but still not great. Payload to GTO is 10000/777000, which gives a mass fraction of.0129. Also, Ariane 5 does a bit of the same thing STS does and uses a hydrolox first stage with solid boosters. All the Ariane variants look like they are optimized for launches to GTO/GEO, so their payload fraction to LEO is going to suffer a bit. This explains why Ariane 4 and 5 have lower payload fractions to LEO (as far as I can tell your Ariane 4 numbers are correct). *** To build on my previous calcs; STS gets hurt a bit in the payload/mass calcs since it reuses so much of what it lifts to orbit. A better comparison would be Shuttle C, which likewises uses hydrolox/solids, and has a payload/mass fraction of 77000/1966675 = .0391, which is comparable to Delta IV Heavy. Atlas V 552 (actually any Atlas variant without "0" in the middle digit) has solids in the first stage, which, if my thesis is correct, will lower the payload fraction. Theoretically the best Atlas V config for payload/mass fraction would be the Atlas V 402. Performance data for it can be found in the archived Atlas V Handbook. Adding components from page 25 of that doc, we get a gross mass of 331702 kg for Atlas V 402. Wiki says that 402 has a payload to LEO of 12500 kg, which gives a payload/mass fraction of .0377, which is better, but not by much compared to 552. Interesting.
  6. Comparison of Rocket Payload Fractions

    I have compiled some data on the payload fraction (payload to LEO / Gross mass) of various rocket systems; From this, several thing can be seen; Solid rocket boosters utterly ruin your payload fraction. Despite having a significantly higher specific impulse than other engines (365 seconds for the RS-68 vs. 285 seconds for the RD-275), hydrogen-fueled launch systems only have a slightly better payload fraction than hypergolic systems, or are even significantly worse. Larger rockets generally have a larger payload fraction (Saturn I vs. Saturn V, Falcon 9 vs. Falcon Heavy). Titan II and Titan IV are not entirely comparable. STS is a stupid pile of trash. Kerolox first stage provide significantly better payload fractions in almost all cases, while avoiding the difficulties associated with liquid hydrogen. Hypergolics generally have inferior performance to both, but are significantly easier to handle, and the difference is not extreme. Data via wiki, except where noted (the gross weights for Delta IV Heavy and Atlas V 551 were horribly off, especially for the latter). Encylopedia Astronautica data mostly agreed, but that site is severely lacking in info on the Falcon family. @Sturgeon@Collimatrix@T___A
  7. Scale Models Megathread

    Picked up a model during my Colorado trip. @EnsignExpendable
  8. The Meteorology Thread: Irmagerd

    East coast is gonna have a fun day: https://www.washingtonpost.com/news/capital-weather-gang/wp/2018/01/02/monster-storm-to-blast-east-coast-before-polar-vortex-uncorks-tremendous-cold-late-this-week/?utm_term=.0f2fa2b0284c 946 mb, have fun
  9. Documents Repository: Small Arms

  10. General AFV Thread

    Isn’t a mortar with more propellant pretty much a howitzer (in terms of operational performance?). In any case, that turret looks pretty small for both a 40mm autocann and a 120mm mortar, and it it doesn’t look unmanned. They have also cleverly avoided saying exactly how much their thing weighs.
  11. The Star Wars General Discussion Thread

    Rogue One is still the best new Star Wars movie. relevant;
  12. Education and throwing away your life.

    For a non-snarky answer, it's not something that can be definitively nailed down to a single number. I'm not familiar with specific IQ tests, but based on other tests I've taken (SAT), they measure a lot of how good you are at taking the test. IIRC they (the people who offered the SAT) used to say you couldn't improve your score by studying to game the test, but it appears they finally realized what a load of crap that is.
  13. I’d assume that the US would support Norway in any dispute, due to the NATO connection and desire to contain Russia. Norway’s economy already has a lot of oil money coming in, how are they doing at preventing Dutch Disease? I’ve heard they’re doing better than the middle eastern petrostates, but that’s not exactly a high bar to clear.
  14. Bash the Pak-Fa thread

    Any actual information about 6th Generation fighter designs is deep in the bowels of Groom Lake or its Russian/Chinese equivalent, so sure, why not say it can?
  15. WoT v WT effort-thread

    In case @T___A still gives a shit about wot (I think 705 variants are going to be the 9 and 10)