Talk-Polywell.org

I dunno— Musk seemed pretty excited about this when he first tweeted about the “delightfully counterintuitive” design change they had in store. Musk seems pretty transparent in expressing his feelings; I’m betting this came from SpaceX, not a NASA compromise.

Yes steel. AFAIK, the reason he’s tweeted about isre-entry heating, not radiation— but the radiation seems like a fair point too. Steel holds strength in high temps unlike carbon fiber. Rather than use an ablative heat shield, active cooling using fuel as the heat sink. Also, he claims to have a new...

The demonstrator may end up waiting on a pad, though: https://www.nextbigfuture.com/2019/01/crude-spacex-starhopper-is-70-to-120-days-from-first-test-flight.html?utm_source=spotim&utm_medium=spotim_recirculation&spotim_referrer=recirculation&spot_im_comment_id=sp_APwizggX_153130_c_kjcWPF This thing ...

Spoke a little too soon skipjack... EDIT: Made original comment as the booster was spiraling out of control and was picturing a fireball on impact (was hoping not in a bad place). Pretty phenomenal that it apparently actually kept enough control to make a controlled water landing-- can't wait to see...

Per tweet today from Musk, there are new radical changes to BFR; BFR is being accelerated in place of Falcon 9 stage 2 reusability.

Guesses anybody? (Hint: Musk says the changes are “counter intuitive”)

National Geographic has an episode of their Mars series out where they go behind the scenes for the Falcon Heavy launch. Definitely worth watching: https://www.nationalgeographic.com/tv/watch/12e413e68c538ba79a298f709efc1607/ Haven't watched that series...any discussion of how said hypothetical fut...

National Geographic has an episode of their Mars series out where they go behind the scenes for the Falcon Heavy launch. Definitely worth watching: https://www.nationalgeographic.com/tv/w ... 09efc1607/

They didn’t even try to catch. No reason was given, but rough seas + night attempt may have been factors.

Awesome time lapse:
https://www.reddit.com/r/interestingasf ... _9_launch/

Nevertheless, the 2018 date is good news (assuming NBF info is not 2 years old). It seems this Seattle Business Magazine story from April is the source for this NBF article; looks like they took a bit of info from that article (including the end-of-year target) and mashed it with existing copy on H...

General ranges via wikipedia: Lithium ion: Energy density: 250–693 W·h/L (0.90–2.43 MJ/L) Specific energy: 100–265 W·h/kg (0.36–0.875 MJ/kg) Zinc air: Energy density: 1480-9780 Wh/L (5.328–35.21 MJ/L) Specific energy: 470 (practical),1370 (theoretical) Wh/kg (1.692, 4.932 MJ/kg) However, the fact th...

Also 1500 installations and 6 years of field testing? Could be legit?

I’m a software developer, not a scientist, but I think there’s a strong parallel with the “it works on my machine” phenomenon I’ve experience quite often. Frequently code written on my machine that works great for me ends up not working for a tester (or worse, a customer) because I didn’t account fo...

Heidi Fearn will be taking a working device to Dresden and will stay with them until they get it working. Dresden had problems with a previous device and published bad results.

Hmmm. Does this interfere with the concept of independent validation?

Pathological skepticism is great! I think everyone could use more skepticism. I am comforted that you all are not concerned by this design change, though no one has really addressed how such a large surface area can be reliably/safely actuated at hypersonic speeds. As an aside, why would separate le...

Perk, the question was why further design changes were made, and Musk's response was to describe why fins were added (for aesthetics). He said that added risk, but did not go on to describe how that design might reduce risk in any other way. The only part where reduced risk was mentioned was in rega...