2019-10-14

@TTownJoe @Erdayastronaut @torybruno @MartianDays @AerojetRdyne Conservation of energy tells you the answer

@Ingvar_Oolsen @neiltyson @Space_Station Looking forward to Kerbal 2!

@MartianDays @Erdayastronaut @torybruno @AerojetRdyne We def could be wrong about this, but it’s actually good to fix high efficiency vacuum engines with giant nozzles in place & only thrust vector engines with smaller nozzles. Don’t need a lot of room & moment of inertia is much lower.

@nextspaceflight @Erdayastronaut @torybruno @MartianDays @AerojetRdyne Also, we’re keeping area ratio low enough to fire Raptor Vac at sea level without flow separation, so that’s leaving a lot on the table

@nextspaceflight @Erdayastronaut @torybruno @MartianDays @AerojetRdyne Couple months, but V1.0 of Raptor Vac is suboptimal, as optimized for speed of development. Isp maybe 365 to 370 sec.

@Erdayastronaut @torybruno @MartianDays @AerojetRdyne Max thrust version of Raptor should achieve true T/W > 170. Target is 1.5 ton engine with >260 t-F. Max Isp version should achieve ~380 sec, but T/W probably <120 due to big nozzle. These are just guesses for now.

@Erdayastronaut @torybruno @MartianDays @AerojetRdyne Oberth effect is not well appreciated. Value of high thrust low in gravity well is not captured in simple delta-v equation. One of the reasons we favor CH4 over H2. https://t.co/LijrUMuJDq

@torybruno @Erdayastronaut @MartianDays @AerojetRdyne This is true. All that matters is number used in ∆v equation. Propellant residuals are incredibly important, often overwhelming engine mass. https://t.co/s2LcEapGAU

@HarryStoltz1 @neiltyson @Space_Station Big challenge for Starship refueling on the moon is finding sources of carbon. Probably some pretty big deposits in craters from meteorites. Same goes for hydrogen & oxygen, also in (shadowed) craters.

@teslaownersSV @Sofiaan @annerajb @tesla_addicted We’re working on a simple initial version of Autopark. Will be safe, but sometimes park in silly places that aren’t actual parking spaces.

@Sofiaan @annerajb @tesla_addicted Yeah, great team!

@J_ump_er @neiltyson @Space_Station To be precise, r is distance from center of masses of two objects. Center of mass of Earth is ~6400km, so gravity change is small at Space Station altitude, which is ~6800km from center of Earth. https://t.co/21hICWczMq

@HarryStoltz1 @neiltyson @Space_Station Exactly. And you can on the moon, since it has no atmosphere.

@neiltyson @Space_Station Most people aren’t aware that orbit (and “zero” gravity) is all about horizontal speed, not altitude. A spacecraft needs to travel about 25 times the speed of sound to stay in space.

@NASASpaceflight @IanPineapple Yeah, will be Raptor vertical test stand. Hopefully allows simplification of Raptor design, as pump shaft wear & drainage is better in vertical config. Also, more representive of flight. Test as you fly …

@annerajb @tesla_addicted Software

@SteveMartineau6 @annerajb @YogiSC1127 @Tesla Yes

@tesla_addicted Will start rendering traffic cones in the display soon

@flcnhvy @aquastorm Venus would be very difficult

@tesla_truth @annerajb @YogiSC1127 @Tesla True

@aquastorm Yes, we will

@annerajb @YogiSC1127 @Tesla It is actually called deep rain, as sort of a joke at Tesla. Takes a surprising amount of deep learning to know when & how fast to move the wipers.

@YogiSC1127 @Tesla Deep Rain™️ neural net coming soon. We’re not trademarking any other Autopilot neural nets, just this one, because rain is deep.

@nate_mccomb @28delayslater @Charalanahzard Yep, good catch

@teslaownersSV @28delayslater @Charalanahzard ♥️ hot pot

@28delayslater @Charalanahzard Cybertruck doesn’t look like anything I’ve seen bouncing around the Internet. It’s closer to an armored personnel carrier from the future.

@Charalanahzard Those rumors are false