March 29, 2024 Quick space links
Courtesy of BtB’s stringer Jay. This post is also an open thread. I welcome my readers to post any comments or additional links relating to any space issues, even if unrelated to the links below.
- JPL releases video that allows viewers to explore a 360 panorama of Curiosity’s location in Gediz Vallis
Makes a nice complement to the many Curiosity images and overview maps I post.
- 20th anniversary of Aviation Week cover that asked, “Can tiny SpaceX rock Boeing?”
Wudda think? Did it?
- Launch tower at the pseudo-commercial launchpad at China’s Wenchang coastal spaceport nearing completion
China is reserving this pad for its pseudo-commercial companies, thus allowing it to maintain full control over what they do.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Courtesy of BtB’s stringer Jay. This post is also an open thread. I welcome my readers to post any comments or additional links relating to any space issues, even if unrelated to the links below.
- JPL releases video that allows viewers to explore a 360 panorama of Curiosity’s location in Gediz Vallis
Makes a nice complement to the many Curiosity images and overview maps I post.
- 20th anniversary of Aviation Week cover that asked, “Can tiny SpaceX rock Boeing?”
Wudda think? Did it?
- Launch tower at the pseudo-commercial launchpad at China’s Wenchang coastal spaceport nearing completion
China is reserving this pad for its pseudo-commercial companies, thus allowing it to maintain full control over what they do.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
I have a question on our Milky Way galaxy … Is there only 1 black hole in our galaxy, the one in its center? I was watching an Anton YouTube video yesterday in which he said our galaxy has merged with other galaxies in its history. If other/all galaxies have a black hole in their center would that mean that the black holes of those galaxies we have merged with would end up in the orbit of the milky way?
Steve Richter: To answer your multiple questions. As far as we presently know:
1. There is only one supermassive black hole in our galaxy, at its center.
2. There are other known black holes in the Milky Way, but they are essentially stellar masses, at most only a few times the mass of our sun. Sagittarius A* is now estimated to be about 4 million solar masses. These smaller black holes are only know because they are in a binary system with another visible star that orbits them. The energy from the interaction reveals the situation.
3. Not all galaxies have central supermassive black holes. The Milky Way is thought to have built up from the merger of other galaxies, most of which were dwarfs too small to have such things. If any larger galaxies with supermassive black holes were part of the process, theory says that its black hole merged with ours to leave one behind.
All of this remains educated speculation, based on what we know, which is remarkably little. And I know even less. Any trained astronomers out there to add detail and correct me if I am wrong?
Regarding Boeing, I am very suspicious that the cause of the problems is the union workforce. But then I cannot explain why Airbus can build reliable planes with union labor while Boeing is failing. It is just that the media has not really attempted to explain the cause of the problems. Which means, to me, that people do know, but do not want to risk putting their name to a report which lays the blame with vested interest groups of the establishment.
Boeing has geographically separated workforces working on different components of the planes. Unions are empowered in the US to put work rules in place and also shield the workers from accountability. Even if both Spirit and Boeing workers are unionized, the two groups are going to see each other as competitors. Meaning when a Spirit work crew from the Midwest comes to Seattle there will be little interaction, cooperation and communication between the Spirit workers who fix a rivet problem and the Boeing people who bolt the door back into place. Union work rules would prohibit Spirit from doing the complete repair task.
On Starship, I am kind of worried that SpaceX will have continued problems controlling the ship as it reenters the atmosphere. Has a vehicle with the shape of Starship ever been able to make it back to Earth intact? The Dragon capsule which returns to each Earth is more cylindrical that Starship. Does the Dragon use thrusters on the side of the ship to keep it from rolling out of control?
I was watching a video where it was said Starship uses thrusters to keep the ship stable on reentry. And there is the famous video where Tim Dodd asks Elon if the booster uses the same thruster control system as Starship. and Elon thinks a bit and says, yeah, good idea. Which means to me that thrusters are used on Starship.
When Starship lost control on this last test, was that because the thrusters did not work? Should these early Starship prototypes be built with more control thrusters than fewer? Maybe have many more available on the ship to keep itself steady? Then, after multiple successful flights reduce the number of thrusters to a minimum to reduce complexity and weight of the ship.
in the Milky Way, is everything orbiting the center at the same rate, in the same direction? A solar system on a bigger scale. Otherwise, the galaxy would not retain its spiral shape?
So our solar system formed during a chaotic period of time when the milky way merged with all or a portion of another galaxy. Must have been nuts back then. But then things settled down and we all became one integrated, seemingly happy galaxy, with the solar masses staying out of each other’s way.
To Steve,
The reason I like stage-and-a-half__to__wet workshop ideas like that of Gene Meyers is because you only fly the hardware once and use as a destination.
Less fatigue.
SH/SS reusability means both craft maneuver violently.
Uri Geller made a name for himself by bending spoons with his “mind.”
What he really did was weaken steel by flexing it a lot of screen.
That’s why he failed when Johnny Carson presented him with NEW spoons that still had strength. New, like SLS.
Steve–
‘Disc’ Stars in our Galaxy, of which our Sun is one, all orbit in the same direction and in essentially the same plane. ‘Halo’ Stars can orbit in any direction.
As to speed– Newton would say, the closer to the center of our galaxy, the faster the orbit.
But….most observed galaxies do not follow that rotational curve, and hence they come up with the magical-invisible-Stuff-matter.
As for Chaos-during-Galactic-Collisions, the average distance between Stars in our galaxy is about 4 light-years.
Milky Way and Andromeda Galaxies Simulated Collision
https://youtu.be/4disyKG7XtU
(1:16)
“… As for Chaos-during-Galactic-Collisions, the average distance between Stars in our galaxy is about 4 light-years. …”
Anton says star formation occurs when galaxies absorb other galaxies. He says a recent discovery has identified the remnant of the dwarf galaxy within the MW whose absorption caused our solar system to form.
https://youtu.be/o03fOU_moHI?si=AdfZtpc8UZLAj7jn&t=442
But then as you say, the stars are so distant from each other that they do not interact. Just odd to me that with all the stellar events in the universe I never hear of an event where two active stars collide with each other.
Steve Richter asked: “On Starship, I am kind of worried that SpaceX will have continued problems controlling the ship as it reenters the atmosphere. Has a vehicle with the shape of Starship ever been able to make it back to Earth intact?”
The Space Shuttle is also large and also had control fins, but it also had several thrusters. Scaling up could be a problem, but we will find out in the next few months. I suspect that computer models and wind tunnel tests suggest that Starship should work as expected.
Starship had an attitude control problem long before reentry, and its fins were not adequate to correcting that problem high in the atmosphere, so when it entered at a bad angle it had no real chance to recover. It should be able to control reentry if it has a small (virtually no) roll as it begins reentry and is oriented properly. Once again, we will find out in the next few months.
“The Dragon capsule which returns to each Earth is more cylindrical that Starship. Does the Dragon use thrusters on the side of the ship to keep it from rolling out of control?”
There are a few thrusters on Dragon that help out. Ballistic reentry vehicles are designed to have an amount of maneuverability due to an interesting effect that they get from having their centers of mass a little bit off their centerlines. This causes the heat shield to be slightly angled relative to the air stream so that the air gives a small sideways force that Scott Manley calls “lift” in the following video:
“Ballistic Reentry vs Aerodynamic Reentry”
https://www.youtube.com/watch?v=HgTNzDCc0gk (8 minutes)
The thrusters are mostly used to rotate the capsule around the centerline to change that “lift” so that the capsule goes deeper, shallower, left, or right depending upon the need. Of course, it all depends upon the capsule being in a good orientation to begin with.
“I was watching a video where it was said Starship uses thrusters to keep the ship stable on reentry. And there is the famous video where Tim Dodd asks Elon if the booster uses the same thruster control system as Starship. and Elon thinks a bit and says, yeah, good idea. Which means to me that thrusters are used on Starship.”
Tim Dodd did a recent video in which he expressed a regret about mentioning that to Musk, thinking that his comment is responsible for the loss of this latest Starship. The idea was to use the boiloff from the propellant tanks for the thrusters, but I do not think that they ran out of boiloff or whatever Dodd thought went wrong.
“When Starship lost control on this last test, was that because the thrusters did not work?”
That does seem to be the case, but we will have to wait to hear from SpaceX to know for sure.
“Should these early Starship prototypes be built with more control thrusters than fewer? Maybe have many more available on the ship to keep itself steady?”
I don’t think increasing the number of thrusters should be necessary. Starship should already have enough to control the attitude and have a few backups, too. Whatever went wrong seems to have been what I will call “catastrophic,” as it seems to have affected all the thrusters, including the backups. This suggests to me that it was some kind of failure to the whole system. Why or how this could occur is a mystery to me.
We think of SpaceX as being open and forthcoming, but several of the fixes that they have done have been described in very general terms that do not really give us enough information to understand details of the problems faced during their test flights. I’m sure they want to keep as much proprietary as possible so that the competition has to be creative with their own solutions.
“Regarding Boeing, I am very suspicious that the cause of the problems is the union workforce.”
Although I am not a fan of unions, I very much doubt that Boeing’s problems are related to the union. I think that Boeing’s management has been making poor decisions. It is generally believed that when Boeing bought McDonell Douglas and incorporated MD’s management into the corporation, the MD management brought with it the poor decision making that caused its own company’s demise. I’ve even heard someone joke that MD bought Boeing with Boeing’s own money.
I remember when “look for the Union label” was not a joke…cheap goods from overseas low quality..
It wasn’t that long ago when I heard corporate GOP stooges calling Union people greedy and taking up for poor workers in India call centers.
That didn’t age well.
I got hung up on lots of times on talk radio. That was cancel culture too.
The populist wing of the GOP looks to be shoving the blue bloods out.
Good.