The tweet archive.

“@Erdayastronaut @sivanithu @tobyliiiiiiiiii @cabral_psyd @imatsb @thesheetztweetz @SciGuySpace @Some1gee @RocketLab @Peter_J_Beck I have great respect for anyone who gets a rocket to orbit! It’s very hard. I’m spending crazy hours on Starship design/production. It is truly an honor to work with such great engineers. SN4 is almost done 😀”

“@SciGuySpace Yeah. There was also an early engine shutdown on ascent, but it didn’t affect orbit insertion. Shows value of having 9 engines! Thorough investigation needed before next mission.”

“@flcnhvy @SciGuySpace F9 iteration slowed down as payloads became too important to risk. Little change is expected going forward with F9/FH or Dragon. Starship production & thus iterative improvement will be much faster than Falcon. Driving hard for fully reusable orbital flight this year!”

“@SciGuySpace Hardest problem by far is building the production system of something this big. 2nd hardest is achieving full & rapid reuse with payload to orbit of ~2%.”

“@pentaquarky @Erdayastronaut The whole nose tip has to have heat shielding for atmospheric entry at Mach 25+ anyway, so is effectively already insulated well in orbit”

“@Erdayastronaut @flcnhvy @robert_zubrin Shielding is only needed for orbital speeds”

“@yourfavgas Probably 6 months or so. 301 is certainly fine for orbit, but SpaceX 30X will be better.”

“@Teslarati @13ericralph31 Unmodified water tower machines do not work well for orbital rockets, as mass efficiency is critical for the latter, but not the former. Hopper, for example, was made of 12.5mm steel vs 4mm for SN1 orbital design. Optimized skins will be <2mm in places across a 9000mm diameter.”

“@Teslarati This isn’t quite correct. An orbital rocket needs precision that’s 3X to 4X better than a water tower, so super precise parts, fixtures & welding are needed. Suborbital is much more forgiving.”

“@SciGuySpace Tonnage delivered to orbit, normalized to LEO, would be interesting to see”

“@jameslin123321 @Erdayastronaut Loading the Mars fleet into Earth orbit, then 1000 ships depart over ~30 days every 26 months. Battlestar Galactica …”

“@Erdayastronaut Building 100 Starships/year gets to 1000 in 10 years or 100 megatons/year or maybe around 100k people per Earth-Mars orbital sync”

“@Erdayastronaut Starship design goal is 3 flights/day avg rate, so ~1000 flights/year at >100 tons/flight, so every 10 ships yield 1 megaton per year to orbit”

“Megatons per year to orbit are needed for life to become multiplanetary”

“@SPEXcast @SciGuySpace What’s amazing is how non-linear the effect of gravity is. Starship can travel by itself from surface of Mars to surface of Earth, but requires massive booster on Earth with orbital refilling to get to Mars, which is ~38% of Earth gravity.”

“Starship orbital vehicle SN1, liquid oxygen header tank & nosecone https://t.co/IaSEdIyZgP”

“@Alejandro_DebH @macshlibber @SpaceflightNow Advancing humanity’s understanding of the Universe is a fundamental motivator for SpaceX! Starship can put giant 🔭 in orbit & on moon. With an occluder, could image 🌏 in other star systems.”

“@Erdayastronaut @BocaChicaGal @NASASpaceflight Dome to barrel weld made it to 7.1 bar, which is pretty good as ~6 bar is needed for orbital flight. With more precise parts & better welding conditions, we should reach ~8.5 bar, which is the 1.4 factor of safety needed for crewed flight.”

“@NASA @BoeingSpace Orbit is hard. Best wishes for landing & swift recovery to next mission.”

“@SciGuySpace @yokem55 @waynehale Without a fully & rapidly reusable orbital rocket, humanity will never be a multiplanet species”

“@bluemoondance74 @flcnhvy Raptor is evolving rapidly. Probably wouldn’t consider it to be even V1.0 until roughly engine 50, although probably engines 12+ can be retrofitted for orbital flight, especially on Super Heavy, which is less sensitive to engine variation. It just needs crazy up force!”

“@flcnhvy Current global payload to orbit capacity is about 500 tons per year, of which Falcon is about half”

“@flcnhvy If we build as many Starships as Falcons, so ~100 vehicles & each does 100 tons to orbit, that’s a capacity of 10 million tons of payload to orbit per year”

“@flcnhvy Payload to orbit per year of Starship fleet is most mind-blowing metric, as it’s designed to fly 3X per day, which is ~1000X per year”

“@RationalEtienne @LaurenRow5 @EvaFoxU @JohnnaCrider1 @Kristennetten @vincent13031925 @28delayslater @Sofiaan @hamids @InsideEVs Tesla is first American car company to achieve sustained volume production in past ~100 years. Hardest, most painful thing I’ve ever been through, including getting Falcon to orbit.”

“@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.”

“@justpaulinelol @KeithMansfield @Erdayastronaut If 20km works, then orbit”

“Getting ready for flight of orbit-class Starship design”

“@JaneidyEve @flcnhvy @Freiraum77 @SpaceX Aiming for 20km flight in Oct & orbit attempt shortly thereafter. Starship update will be on Sept 28th, anniversary of SpaceX reaching orbit. Starship Mk 1 will be fully assembled by that time.”

“@Erdayastronaut Race to orbit by both teams, although a success by both in close proximity would be amazing & each would count as a win”

“@ShorealoneFilms Vandenberg is great for polar orbits. Will still play an important role long-term, but 80%+ will be eastward.”

“Great progress by Starship Cape team. Started several months behind, but catching up fast. This will be a super fun race to orbit, moon & Mars!”

“@SciGuySpace Yes, detailed review of the first orbital Starship, explaining the pros & cons of each design decision”

“@EvaFoxU @SpaceX That was our last chance to reach orbit. If it had failed, SpaceX would have died.”

“@SciGuySpace Orbital refilling is vital to humanity’s future in space. More likely spacecraft to spacecraft (as aircraft do aerial refueling), than a dedicated depot, at least at first.”

“@WorldAndScience @NASA To be clear: good for in-space transit, but not recommended for Earth to orbit!”

“@annerajb @highlyaaronic Orbital refilling is critical for high payload to moon or Mars. Initially just Starship to Starship, later dedicated tankers.”

“@joe_mckirdy @13ericralph31 @JHC2718 @StephanieeeeeJ 100mT to 125mT for true useful load to useful orbit (eg Starlink mission), including propellant reserves. 150mT for reference payload compared to other rockets. This is in fully reusable config. About double in fully expendable config, which is hopefully never.”

“The @Space_Station is moving at ~25 times the speed of sound & orbits the Earth every 90 minutes”

“@Matthew_Nolan1 @austinbarnard45 Starship will do orbital launches from Boca Chica (near Brownsville) & Cape”

“@Erdayastronaut @flcnhvy For sure moon 1st, as it’s only 3 days away & u don’t need interplanetary orbital synchronization”

“@urnamma After Starship returns from orbit”

“@Cosmic_Penguin Agreed, sent a note to Starlink team last week specifically regarding albedo reduction. We’ll get a better sense of value of this when satellites have raised orbits & arrays are tracking to sun.”

“@13ericralph31 @varunversion1 @Erdayastronaut @SpaceX If we need to tweak sat orientation to minimize solar reflection during critical astronomical experiments, that’s easily done. Most orbital objects are close to Earth btw, as shown by this NASA density map. https://t.co/83MwIZAEP6 https://t.co/NllMXregRg https://en.m.wikipedia.org/wiki/Space_debris”

“@varunversion1 @Erdayastronaut @SpaceX There are already 4900 satellites in orbit, which people notice ~0% of the time. Starlink won’t be seen by anyone unless looking very carefully & will have ~0% impact on advancements in astronomy. We need to move telelscopes to orbit anyway. Atmospheric attenuation is terrible. https://t.co/OuWYfNmw0D”

“@SpaceX Krypton thrusters operative, satellites initiating orbit raise every 90 mins”

“@SpaceX Krypton ion thrusters activate in about 3 hours to raise orbit”

“Space is easy, orbit is hard”

“@Teslarati .@NASA support for reusability with high reliability, the critical breakthrough for orbital rockets, has made a big difference”

“@DannyLaShep With steel membrane wings like a Dragon, we may be able to lower Starship’s orbital reentry temp to ~1000 degrees C, which would allow the whole surface to be uncooled bare metal”