Forgot your password?
typodupeerror

Comment Re:"have left Earth orbit" ?! (Score 1) 73

Pardon? Have you not seen the barge landings?

There are many aspects of a flight profile. Some are based on where you put the payload when it is in orbit. Others are the weight of the payload. As an example, 9's Payload for a GTO orbit is 5.5t when recovered on barge, and 8.3t for an expended mission. LEO orbit, 17.5 t if recovered, 22.8t expendable.

Just because some flight profiles can land at a pad or on a barge, does not mean that this happens in all cases.

References from paper :

A Survey of Launch Vehicle Recovery Techniques

Shraddha C.

Pankaj Priyadarshia

and Devendra Prakash Ghate

Institutes:

Vikram Sarabhai Space Centre, Thiruvananthapuram, 695022, Kerala, India

Indian Institute of Space Science and Technology, Thiruvananthapuram, 695547, Kerala, India

A pretty good read if you have the academic credentials to access it. Clear, at a reasonably high level so not too deep in the weeds, with all manner of different flight profiles for many rockets - including StarShip. And a lot more. Otherwise, I think it is a little premature to claim the success of Starship. The Falcon's are good reliable Rockets. Starship might end up a tad problematic.

Comment Re:Reusable rockets-- (Score 2) 73

Your assignment: Find out why reusable rockets are only useable for very specific launch envelopes. If you use them out of that launch envelope, there are just as disposable as the rockets you think are some sort of complete waste.

Interesting. I've never seen this claim made before; do you have a reference?

https://www.teslarati.com/spac... Forgive the link, it is a real rah-rah piece.

CEO Elon Musk says SpaceX has successfully expanded the envelope of orbital-class rocket recovery with its 50th booster landing, meaning that all Falcon boosters will have a better chance of safely returning to Earth from now on.

https://space-offshore.com/boo... "Falcon 9 missions may need to land on a droneship instead of RTLS due to the weight of the payload or the overall mission profile." I think you have academic access. Here is a good technical report on a lot of rockets that land after use. https://www.sciencedirect.com/.... You'll need academic credentials to download it. But it has a lot more info - and as part of the launch envelopes, there is constraint based on payload as well as direction. If you are going to land, there is a significant reduction in payload.

All of this is why I find it a little amusing that many among us find the most important aspect of launching these candles is the recovery.

tl,dr - where the rocket is going, what it is carrying has a big effect on recoverability. You can force things, reducing payload, or only sending the profiles to places where the first stage can make it back to the launch site, otherwise small extensions to allow it to make it back to a barge.

Comment Re:"have left Earth orbit" ?! (Score 1) 73

"Ladies and gentlemen, I am so, so excited to be able to tell you that for the first time since 1972 during Apollo 17, human beings have left Earth orbit," NASA's Dr Lori Glaze

I can expect some random science reporter to make this mistake, but bugger me, a senior NASA executive? It shows politics are far more important than any knowledge of science at NASA today.

Not only is Orion not leaving Earth Orbit (where the fuck do they think the moon is?) , it is not even entering lunar orbit. Orion's apogee has been pushed up for one orbit, but it's perigee is right down here.

Because Orbital mechanics is pretty difficult for most to grok. She does have bona fides, Doctorate in Environmental Science and Masters in Physics.

So I'm pretty certain that she well knows that Orion is still in orbit around the earth.

But just think about it. We have people in here who think that not re-using a rocket is some sort of crime, not thinking how that first stage can only return if it is close enough to the launch site. That if you want to go to the moon or a planet, you just point your Rocket at it and it's balls to the wall time. Among other misguided notions.

All said, She is an administrator, and I believe her excitement when she said that, so I'm not quite so willing to call her a political appointee. I'd call it an audio typo.

If it was me, I might say it was the first time humans have left Low Earth Orbit since 1972. And since it is a matter of providing soundbites, I would save the Perigee and Apogee part for later. Perigee and apogee are the more interesting parts from my perspective.

Comment Re:Is the bottle half full or half empty? (Score 1, Insightful) 73

But, There is absolutely nothing exceptional here: This has been already achieved almost 60 years ago, with much, much less technology available.

This gets brought up fairly often. And yes, we did it before. Why do it all again?

The learning curve is why. I can't imagine there is anyone from the Apollo project left at NASA. So a whole new group of people have to learn how to make things work. All those people sitting at their consoles are learning, re-learning after a fashion, what the Engineers learned in the 1960's.

It's all good!

Comment Re:Socialism (Score 1) 73

Yeah, it was cool watching those four $146,000,000/each RS-25 engines return to the landing pad. Stupid capitalists.

A lot of people have a lot of trouble understanding that returning a first stage to the launch site puts a huge constraint on where in orbit you can place that rocket's payload.

You can add a bit of flexibility if you return a rocket to a barge in the ocean - but not much. And when you use a barge, you are eating hard into whatever savings there are in capture and refurb.

The first stage has to have enough fuel to make it back to the landing pad or barge. If the launch envelope takes it out of that range, it's just another disposable rocket. As an indicator, people will notice I only mentioned the first stage. Because there's no good way to recover the second. The rocket is way too far downrange, the earth is rotating. There aren't many landing sites at that point.

Comment Re:Socialism (Score 0) 73

The government wimped out and pulled funding repeatedly on re-usable launch systems even ones that were showing success.

Your assignment: Find out why reusable rockets are only useable for very specific launch envelopes. If you use them out of that launch envelope, there are just as disposable as the rockets you think are some sort of complete waste. You are a really smart guy seems like you could teach us all about this stuff.

Comment Re:Five years old (Score 1) 183

That's what I call DEI. Lesser qualified people hired or promoted in preference to merit because of identity politics. In irony, two of the best employees I ever worked with were women, hired using this metric. But that was accidental meritocracy. They would also have been hired for their ability in a non-checkbox world, not because of their sex.

The problem with many here is the automatic assumption that anyone not a white male was unqualified most likely because they are white males.

I understand completely. Many who are orgasming about a Woman and a "Black man because it checks off a box do not like White males, and want less of them doing things. Racism is in no way restricted to the dreaded white male. The people who would call themselves inclusive aer every bit as racist and sexist.

After all, when people say we need more women and people of color in a profession, they are exactly saying they want less White men.

P.S. Race is exactly the biggest social construct ever invented. I'll believe that human races exist when speciation happens, when a human from one group cannot mate and produce offspring.

Comment Re:We need to increase the penalties. (Score 2, Funny) 46

From TFS:

"Whatever the generative AI tool gives you ... you have to read those cases.
You have to read the cases to make sure what you are citing is accurate."

Since the issue seems to be attorneys not reviewing/checking their sources, I suggest the punishment be along those lines. Perhaps a week of extensively fact-checking *everything* the President says, for each offense.

Comment Re: Spacecraft can have solar sails (Score 1) 183

a method of producing Methane

As far as that goes, if you find water ice on Mars and have a spare nuclear reactor around, you've got your methane factory:

1. mine water ice 2. split H2O -> H2 + O (electrolysis - this is where the reactor comes in handy) 3. Sabatier Reaction: combine the H2 with atmospheric CO2 (CO2 + 4H2 CH4 + 2H2O), requires industrial heat source (reactor also handy here) and a catalyst bed (nickel) 4. Recycle the H2O byproduct back into the intake

You gotta have energy though for it to scale. Roughly 17kWh = 1kg of rocket propellant. To fill a Starship back up (1200 metric tons) it would only take ~20.4GWh of energy. So there's that.

Now just between you me, and the fencepost, If we're talking about all that, we could skip a lot of the hassle, and use a hybrid approach. Break Martian ice into Hydrogen and Oxygen components, then utilize Alumina to produce solid Rocket Boosters, using the perchlorates that constitute around 1 percent of the surface area of Martian "soil". Some experiments have been performed using the 60/40 mix of Calcium and Magnesium Perchlorate. looks pretty promising. https://engineering.purdue.edu... Even makes these cool red, white, and blue flames.

Solid boosters and H-O main engines.

All of this is of course hypothetical. There needs to be a reason to establish a permanent human presence on Mars, where people are born, reproduce and die there.

I support sending people to Mars to do research, but that's a whole different setup than the almost inconceivable amount of work needed for the Muskovian pipe dream. In this more practical vision, the return trip materials would be transported separately and in place before the astronauts ever landed. Assembled onsite then come home. It is still an incredible effort, but perhaps a thousandth of the Brave New World plans that still require that reason for all the effort and expense.

What is the reason for a permanent human presence on Mars? Almost certainly living in a cave, and the major industry will be making the fuel and infrastructure to leave Mars. After that, creating the pressurized environment, the air to breathe the water to drink, and the food to sustain life. Oh, the irony.

Comment Re:Five years old (Score 1) 183

Commander Reid Wiseman and the other mission specialist Jeremy Hansen are irrelevant. Just camp followers for the more important crew members

The white male members of the crew have the least amount of space experience with Jeremy Hansen not having a full day in space yet. I suppose people could complain about the crew having a token white guy as he has no background in engineering unlike the rest of the crew.

Given the amount of training involved, I'd suspect they are also quite qualified. And Koch has had enough off-earth time that there's no question.

I think what some people are missing is that even if someone at a meeting at some point said "Let's shake up the crew for this one. We've sent up multi-racial, multi-gendered, multi national crew many times in the past, and it would be pretty symbolic to do it on this voyage." That's not DEI. That's not choosing specifically based on diversity, equity, and inclusion. That is not identity politics, which at base is the whole DEI concept.

DEI is more like how in the job I retired from, where I was denied promotion several times in order to promote a woman. They were pretty up front about it. Women were being promoted over a much more qualified male.

I told them that my skillset was in high demand, (technical competence, social skills and pattern weaver) and I'd be okay with such obvious discrimination as long as I received renumeration for my cooperation. Otherwise I'd be out in two weeks. They saw that as a fair compromise because they knew the score. I was the one who would do the dangerous or dirty work, I was the one who travelled, came in early, stayed late, worked over lunch. They wouldn't. But they filled a checkbox.

That's what I call DEI. Lesser qualified people hired or promoted in preference to merit because of identity politics. In irony, two of the best employees I ever worked with were women, hired using this metric. But that was accidental meritocracy. They would also have been hired for their ability in a non-checkbox world, not because of their sex.

Comment Re:Remember back when spousal abuse was funny? (Score 1) 183

It's not funny, but we should stop associating domestic violence with just men abusing women. It's people abusing people. Turns out same sex couples do it too, and women are twice as likely to use a weapon.

I agree it is a human on human phenomenon, but that isn't the narrative today. When someone gets too caught up in the "It's overwhelmingly men!" narrative, I direct them to the Oxygen Channel's show "Snapped" It's about women who kill their boyfriends, husbands, parents, children, and sometimes others. All true stories, and it has been on many years. They haven't run out of violent women yet.

As well as any man admitting that his wife abuses him is going to be ridiculed. I've come to the conclusion that many women actually enjoy males being hurt by women as some sort of justified action.

Personal experience - A few years ago, my wife went in for rotator cuff surgery. One of the nurses was hell bent on trying to get her to admit that I physically abused her. After the third visit, before surgery - which was starting to feel like an interrogation, she was getting pretty upset. The wife called her surgeon, and told him "My husband has never hit me, never grabbed me nor ever or even yelled at me. Why the nurse keeps pressing, I don't know - and it doesn't even look like he did anything. Keep that nurse away from me, or there will be repercussions." She told me about it, and I said "this is bullshit, in an era of "believe all women" The nurse could have easily ruined me, so the wife filed a complaint against the nurse. A bit of a sticky wicket, where when you have a mandate of believe all women, and they say two opposite things.

But the Nurse was following a popular narrative. That only men abuse women, it doesn't happen the other way around, and in fact, the narrative is more important than the truth. I would have just been justified collateral damage. That no one other than men who have been ruined.

Comment Re: Spacecraft can have solar sails (Score 1) 183

Some of us think it's a bit sad that they are throwing away rebuildable engines and that the cost is so stupendous, but also aren't Leon fans. I think starship is a better bet in the not too long term, and wish he wasn't involved with it.

Re-useable engines are not the panacea people might think. The process of refurbing them is kind of a mixed blessing. We must remember that NASA refurbed the space Shuttle's main engines and solid Boosters.

There is also an elephant in the room - If you are going to have the candles land back at the launch site - it imposes severe restrictions on the launch envelope. Less severe if you land them on a barge, but even then, the landing site for the stage one engines controls the launch envelope and where the orbit ends up.

The reason the shuttle's main engines were refurbished is that the engines came back with the shuttle. The solid Boosters could be retrieved without too much damage from the salt water.

And if your going to have balls to the wall rockets like the Saturn V and Artemis, Launch envelope and power takes priority over landing the first stage. And there is a big reason that Spacex does not land the second stage. Because of the reasons I noted.

It would be great if the reusable concept was just like driving the car home, stopping for gas and doing it again. The biggest proponents act like that is teh case with Rockets - it is not, because they are not taking orbital mechanics into any account.

Starship better? It is still constrained by the launch envelope, and suffered from a different problem. The entire launch stack goes along for the ride. All that weight, and the entire stack must survive re-entry.

I always wondered, Spacex must have a complete launching facility on Mars, a method of producing Methane, as well as a complete engine refurb and replacement facility, and the means of powering them. And where are the first ships going to land - who builds the complete facility for the arrival of StarShips and the colonists? Now perhaps my spidey senses are 100 percent wrong. Perhaps Artemis will fail miserably, and Starship will lead humanity to new and better heights, and NASA will be shut down, and Spacex will have us all on Mars, living our best lives. Not holding my breath for what only exists in the mind of the fans, along with a big rocket that doesn't work.

I won't hold my breath.

Submission + - Python blood could hold the secret to healthy weight loss (colorado.edu)

fahrbot-bot writes: CU Boulder researchers are reporting that they have discovered an appetite-suppressing compound in python blood that helps the snakes consume enormous meals and go months without eating yet remain metabolically healthy. The findings were published in the journal Natural Metabolism on March 19, 2026.

Pythons can grow as big as a telephone pole, swallow an antelope whole, and go months or even years without eating—all while maintaining a healthy heart and plenty of muscle mass. In the hours after they eat, research has shown, their heart expands 25% and their metabolism speeds up 4,000-fold to help them digest their meal.

The team measured blood samples from ball pythons and Burmese pythons, fed once every 28 days, immediately after they ate a meal. In all, they found 208 metabolites that increased significantly after the pythons ate. One molecule, called para-tyramine-O-sulfate (pTOS) soared 1,000-fold.

Further studies, done with Baylor University researchers, showed that when they gave high doses of pTOS to obese or lean mice, it acted on the hypothalamus, the appetite center of the brain, prompting weight loss without causing gastrointestinal problems, muscle loss or declines in energy.

The study found that pTOS, which is produced by the snake’s gut bacteria, is not present in mice naturally. It is present in human urine at low levels and does increase somewhat after a meal. But because most research is done in mice or rats, pTOS has been overlooked.

Slashdot Top Deals

To communicate is the beginning of understanding. -- AT&T

Working...