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Posted by Jack Crossfire | Jan 22, 2019 @ 01:59 PM | 1,119 Views
https://www.popularmechanics.com/spa...ainless-steel/

Most interesting was the double hull idea & that it was never proposed before, which probably means it was proposed before but didn't work. A lot of money & people were invested in carbon fiber rockets for the last 100 years for stainless steel to be that easy. It's a case where the heavy, expensive carbon fiber could be the tried & true solution while the shiny stainless steel could be the risky solution.


He claimed to be on his own in promoting stainless steel, which revives the ages old debate on whether sole visionary leaders or large teams contribute more to progress. We may never know how much of Apple & SpaceX were really contributed by their sole visionary leaders or their lowly employees.
Posted by Jack Crossfire | Jan 20, 2019 @ 07:58 PM | 1,052 Views
PHX4 Rocket launches to over 200000' attaining the highest amateur two stage flight. (15 min 55 sec)



Took a while to show up in the lion kingdom's gootube recommendations. 46 miles is pretty huge for a private individual working with a few friends & a truck. In 4 miles, he's at the scientific definition of space which is rapidly becoming 50 miles.

Very conspicuous how the rocket was never photographed & the design was never revealed. The internet guessed various commercially available motor sizes. The only design clue is a long ramp for lifting off. He's well within ICBM territory & either didn't want it used by terrorists or was banned by ITAR. The terrorism danger is going to keep amateurs from sharing plans & getting into space for some time.
Posted by Jack Crossfire | Jan 13, 2019 @ 03:23 PM | 1,225 Views
Lions have to remind themselves they've actually seen 2 Apollo capsules & the Apollo program was a bigger childhood fascination than the shuttle. Most humans are lucky if they just saw the Apollo 11 capsule on tour. Lions of course covered a shuttle, too.
Posted by Jack Crossfire | Jan 13, 2019 @ 05:06 AM | 1,095 Views
Intriguing news about a Falcon 1.9 being planned for after the main development of the BFR is done. The Falcon 1.9 would be somewhere between the Falcon 1 & never realized Falcon 5 & provide an alternative to micro launcher startups. They want some amount of it to be reusable, maybe all of it if it uses raptors.


It means they're finding these micro launcher startups really are going to impact their business by filling a niche that the BFR can't: small 1 off satellites going to unique orbits, which can't share a launch with hundreds of other satellites or wait for all the other satellites to be ready. It also means major parts of BFR development could wrap up sooner than we think.

Never Seen Before Concept Designs At SPACEX!!!! (4 min 35 sec)

Posted by Jack Crossfire | Jan 10, 2019 @ 01:51 PM | 1,134 Views
So what happens to Blue Origin now that Jeff & Mac have split?

Technically, if the stock market continued rising, Jeff Bezos could have funded Blue Origin with $1 billion every year for the next 136 years. After the divorce, it's optimistically only 68 years. In reality, Seattle's community property law is imaginary. Most divorces end up with an equitable distribution like everyone else.

Based on non monetary contributions to the "community property" like raising kids, managing Jeff's finances, creating an anti bullying organization, Mac will take most of Blue Origin's funding. That could reduce Jeff's nest egg to just $30 billion.

The reality is either the stock market won't keep going up or $1 billion per year won't be enough to fund Blue Origin. It certainly isn't enough to buy 1000 houses anymore like it was 10 years ago. That $1 billion/year pledge was always a tenuous issue.

He certainly didn't plan on spending everything on Blue Origin. Every time he exercised his options, the stock price went down. Then, he's not free to buy anything he wants. If he doesn't invest most of his options in charities, he's gone & he's so far not keen on quitting his job for the cause of space.

The biggest impact will be Mac now owning a majority stake in Blue Origin. She could decide this space stuff is stupid & shut it down or at least slow it way down as Richard Branson did to Virgin Galactic.
Posted by Jack Crossfire | Dec 26, 2018 @ 01:57 AM | 4,588 Views
It burned 330mAh/mile to carry the required batteries & food.
Posted by Jack Crossfire | Dec 25, 2018 @ 02:51 PM | 4,370 Views
How did we end up with old fashioned stainless steel as the ideal material for making spaceships? Most of us older than millenials have lifted pieces of steel. It's very very heavy. Lions 1st encountered stainless steel on boats in the 1970's. Stainless steel became widely available in the 1930's.


Steel represents the reality of how materials engineering experiences 100 year breakthroughs followed by decades of small steps. For interplanetary colonization, we're still limited to the steam boiler technology our ancestors created. The last 100 years of carbon composites created small improvements but just weren't the generational advancement required. Old timers wondered what advancements happened since the X-33 to enable large carbon fiber tanks now & the answer was not really enough. Steel isn't ideal but it's all we have.
Posted by Jack Crossfire | Dec 19, 2018 @ 01:19 PM | 3,977 Views
Boring side wheels (0 min 10 sec)



The lion kingdom gathered individuals weren't allowed to photograph their demo rides through the boring tunnel. The sled idea gave way to retrofitting existing cars with side wheels in front. It sounded rather bumpy, since the side wheels on a monorail are pneumatic, with their own suspension systems. The only video of a real trip was on CBS & like any supposedly autonomous car, it was actually being driven by a hipster who was always kept just out of frame. It was implied that the demo would be some fully automated vision of the future, but reality was more smoke & mirrors.

The side wheels do have some compliance. On the one paw, they avoided the complexity of distributing sleds to all the tunnels. On the other paw, it wouldn't have taken a massive sled to do what the side wheels are doing.
Posted by Jack Crossfire | Dec 15, 2018 @ 04:38 PM | 4,076 Views
For the 1st time, an ESC blew up from getting wet. All 3 PFETs blew up. They had been flown in rain, flown from wet fields, but never blew up before. Dunking in puddles finally got one wet enough to do the job. Potted it in aquarium sealer. It's not reworkable anymore.
Posted by Jack Crossfire | Dec 14, 2018 @ 11:46 PM | 4,194 Views
To make the miles more interesting, the decision was made. Originally wanted to discard the ears & just use the antlers, but didn't have the stomach to tear it all apart, despite being $1. The intact antlers are easier to break down. The nose was an LED light bulb with a red LED replacing the white LEDs. The red LED needed a diffusing cover in the form of translucent heat shrink which is no longer made.
Posted by Jack Crossfire | Nov 03, 2018 @ 05:02 PM | 5,384 Views
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Posted by Jack Crossfire | Oct 17, 2018 @ 10:03 PM | 5,291 Views
https://www.reddit.com/r/spacex/wiki...to_performance


Nifty table of all the SECO orbits. The speed & altitude can be derived from the webcasts, but the inclinations are not broadcast. Not sure how they calculated the inclination change. Even without inclinations, rough calculations based on high school geometry showed it achieving abnormally low orbits. The table confirmed those calculations were right. To recover the booster after launching a 7000kg satellite, it can only reach an elliptical 11000 miles. That's lower than GPS. It's a long way from the direct GEO insertion advertised but never used by the delta IV heavy.
Posted by Jack Crossfire | Oct 15, 2018 @ 03:59 PM | 4,922 Views
Can a PASSENGER land a PLANE? Presented by CAPTAIN JOE (15 min 51 sec)



After months of thinking about the problem, it became clear the passenger should fly manually instead of trying to reconfigure the autopilot as depicted. We're all familiar with the basic airplane controls, have played flight simulators, & can drive cars. Getting the plane to point in a certain heading & controlling speed isn't very hard.


The autopilot is a horribly complex addition. Most of the radio time is spent explaining how to use the autopilot & looking for the controls. She had to lower flaps, lower gear, & reverse thrust, despite the autolanding being engaged. A 2nd passenger could have managed the flaps & gear.
To the lay lion, manually flying would greatly increase the chances of success, but Caption Joe based the video on no doubt what the FAA recommends.
Posted by Jack Crossfire | Oct 13, 2018 @ 01:21 AM | 5,716 Views
Fascinating closeups of the tested fairing half dropped by helicopter. "LATCH +YA2", "PUSHER S/N 6", carbon fiber weaving, nitrogen bottles, are hanging out for all to see. Most important is the "NOT FOR FLIGHT !@%*@! SCRAP" written on a piece, obviously perfected from reviewing many job applications.


https://www.teslarati.com/spacex-mr-...test-practice/
Posted by Jack Crossfire | Oct 11, 2018 @ 12:35 AM | 4,853 Views
Falcon 9 launches & lands behind San Francisco (5 min 34 sec)



The plume had a similar effect as the eclipse in that it was much bigger in the sky than it looked in a photo. The flight went from Salesquota tower to the golden gate bridge. You think these events are tiny dots in the sky when in reality, they seem to take the entire sky up & they're bright. The plume was so big & bright, it felt as significant as the eclipse. Everyone else within view of it must have been as fixated on it as the eclipse.


Hopefully, someday rocket launches will be an hourly occurrence, with the bright plumes a routine sight.
Posted by Jack Crossfire | Oct 04, 2018 @ 01:22 AM | 5,585 Views
New model, showing the latest 10m thrust structure which is as wide as a Saturn V, the paint scheme you'll probably see on the real thing, a 31 engine arrangement, a window configuration which is slightly easier to model than depicted. Never perfect, but always getting better. The wings are bad, but we can see how they would interfere with a gridfin deployment on the pad. Suspected the wings & landing gear would have to be fatter than depicted to support the landing mass.
Posted by Jack Crossfire | Sep 14, 2018 @ 03:07 AM | 4,965 Views
A little more gamma reveals the blended wing body replaced by much simpler beveled wings & canards. The wings & rudder serve as landing gear. Horizontal surfaces are folding, so they can be flat to provide lift, then be a triangle to serve as landing gear. The folding might also provide aileron functionality. There are a lot more windows & they're tinted. The single piece window of BFR 1 returns. The heat shield is a simpler flat shape.

The engines seem to be the scaled down raptors that were tested 1st, but with vacuum nozzles. He decided to reuse the test engine for the upper stage, while reserving the full size engine for the lower stage. It would speed up development to not delay the ship for the full size engine. A bit disturbing to see ablative nozzles.

A bit puzzling how vacuum nozzles would allow landings on 2 different planets with different air pressures. An overexpanded nozzle is too unstable.

They could also be full sized engines with retracting nozzle extensions.
Posted by Jack Crossfire | Sep 14, 2018 @ 03:06 AM | 4,936 Views
Pay $30 for 4 new servos & the old one will start working again.


Anyways, reflowed the QFN's solder joints, & made a servo exerciser to thrash it all night. Naturally, it would never fail on the bench, but the new servos alone stood a good chance of reviving it. The last order of standard servos was 2001. They were $6 Tower Hobby branded, but shipping was much lower. Those hobbyking servos are now $5, but shipping has followed inflation.

Signs started pointing to a glitching battery connector crashing the microcontroller on the servo. The mane CPU also had glitches, but didn't lock up. The servo may just lock up under certain power glitches. After a cleaning, the $60 servo was revived & didn't crash again. So it's a lot more sensitive to electrical noise than a brushed servo. It must run at a much higher clockspeed.
Posted by Jack Crossfire | Sep 06, 2018 @ 02:42 AM | 21,730 Views
After 400 miles, the $60 brushless servo died & it went into the street. The death was intermittent, as it briefly came on again. Back on the bench, it managed to still have a fault. All the voltages were normal, with no voltage going to the MOSFET gates. Power cycling it a few times in the street didn't bring it back, but it did come back after a power cycle on the bench. Nothing that suffered mechanical wear seemed to be worn out. It was a microcontroller that had become flaky.



It's a Silicon Labs F330, 8051 core. Dave would check all the pins & try to fix it.

After all the servos, there's a real need to build a servo from scratch to last forever. The $60 one has enough useful parts to work again with a custom board, but this would be a significant investment in a rare time when the lion kingdom's time is actually worth more than a servo.



It would be a matter of removing the F330 & soldering a bare ATmega on a separate board to the 6 MOSFETs, PWM, & power. Not sure how the MOSFETs on the underside would be accessed.



Expensive, high performance servos have consistently died much faster than cheap servos. The biggest failure was the Airtronics 94761. https://www.rcgroups.com/forums/show...al#post9953885 A terrible waste from not knowing the importance of PWM frequency in tail rotor actuating.



The longest lasting might be the Tower Hobby brand from 20 years ago. Futabas are in the middle. Servos might have too many moving parts, moving too fast, in too little space.
Posted by Jack Crossfire | Aug 07, 2018 @ 04:17 AM | 5,317 Views
Amazing night views from a Falcon 9 (1 min 7 sec)


The lights of Fl*rida appear after stage separation. Then, we see lightning over the gulf of Mexico as the grid fins deploy, lit by the flickering light of the 2nd stage engine. Then, the sparks fly & the grid fins glow purple as we enter the hottest part of reentry.

https://www.rcgroups.com/forums/show...entid=11134499

It looks quite serene compared to block 3's barbeque, masking the growing spray of water in the octaweb. Can only imagine, after it hits the hottest part of reentry & the camera goes out, the water boilers are going full tilt, the grid fins are glowing, plasma is roasting the interstage & it's a pure hell.