Become a fan of Slashdot on Facebook

 



Forgot your password?
typodupeerror

Comment Re: How is it surprising? (Score 1) 26

If they cut Medicaid then here in California where we currently aid the undocumented with our program called Medi-cal (which is really just Medicaid plus some other programs), we will probably not be able to afford to do that. We will need to spend what money we have for the purpose of aiding citizens who have been cut off because this administration wants them dead.

Comment Re:Erm... (Score 2) 122

It will never cost that little. A Falcon 9 has about 400 tons of propellant. If it were all commercial diesel, it would cost $400,000, or $17 per kg of weight launched to LEO. But of course it's not commercial diesel. Liquid oxygen and RP1 are both much more expensive.

Starship burns methane, not RP1.

Between SuperHeavy and Starship, a fully-loaded stack needs 3500 tons of LOX and 1000 tons of CH4. So what do those cost?

Well, oxygen is easy to get from the atmosphere, so the cost of LOX is really just some equipment (which isn't terribly expensive to buy and maintain) plus electricity, and the cost ends up being dominated by the cost of electricity. It takes between 150 kWh and 800 kWh to separate and liquify a ton of oxygen, so if you're paying $0.10 per kWh, LOX costs $15-80 per ton. There are some other costs to handle and store it, so let's say $100/ton.

CH4 can be created many ways. The cheapest is probably to purify natural gas, which costs about $190 per ton (that site shows ~$5 per 1000 ft^3, and a ton is 38k ft^3). Add some costs for purification and cooling, so call it $250/ton.

3500 tons LOX * $100/ton + 1000 tons CH4 * 250/ton = $600k. Musk usually calls it $1M, which seems pretty reasonable, since they're probably not separating/purifiying it themselves and there transportation costs. 150 tons of payload to LEO with $1M worth of fuel means the fuel-only cost is $6.67/kg.

Comment Re:Erm... (Score 1) 122

we have enough accumulated knowledge that just getting to orbit shouldn't be accompanied by a string of failures like Starship has been having

Nonsense. Our only experience with reusable orbital rockets is the space shuttle, which was an unsustainably-expensive and complex beast that was more refurbishable than reusable and had a payload one fifth of what Starship is designed for. It's all of the differences that aim to make Starship both reusable and cheap that make it hard. It's possible that it's just too ambitious, that we don't yet have the technology to make a cheap, fully-reusable (not refurbishable, reusable) orbital rocket with massive capacity. No one else has done it... no one else is even trying, that's how hard it is.

Failure is expected. If they managed to launch and land both Starship and SuperHeavy in less than a dozen test flights, that would be the surprise.

Comment Re:How does this even work? (Score 2) 40

"From 2021 until 2024, the co-conspirators allegedly impersonated more than 80 U.S. individuals"

It's called identity theft. Are you new?

I've had my identity stolen, the problem is that courts don't punish corruption. In fact, they enable it.

Someone bought a car using my identity. Their proof of identity was my social written on a check cashing card. They had my same name, all three names. But the DOB didn't match so the person who sold them the car was in on the scam. Then a court (in Nevada City, CA) awarded a judgement against me based on my social being written in pen on a check cashing card. This does not meet any reasonable standard for SSN verification, but they got the judgement anyway.

That courthouse should be sold and the funds distributed between the court's victims.

Comment boeing stock much? (Score 1) 122

The identities of people who mod posts should be public. That's the single most broken by design thing about the Slashdot moderation system.

That wouldn't make sense if everyone had modpoints and comment scores could be higher, but they don't and they can't.

This isn't a community, and this is a big part of why.

Comment Re:Solution looking for the wrong problem (Score 2) 17

ED: Looks like it's 24(!) hives per beehome, and they charge $2k delivery ($83/hive) plus $400/mo ($400/hive/yr) for maintenance.

Clearly not something of use to amateurs, and I'm not sure whether you can make that economics work out for professionals, either. I guess it depends on how truly independent it is, vs. your local labour costs.

Comment Re:Solution looking for the wrong problem (Score 3, Interesting) 17

There is little correlation between "presence or absence of pollution" (what a general term to begin with...) and CCD. There is a strong correlation with the presence / absence of varroa. And this system treats varroa.

I've been thinking about getting into beekeeping (I first need to increase the accessibility of my ravine where they'd be), and had been thinking about a sort of high tech solution, with electric blankets, heat-exchanging baffles, a flow hive, and maybe some mass and/or noise sensors for monitoring colony health. But this is WAY more high-tech than I envisioned, and honestly I'm scared to even look up the price ;)

Slashdot Top Deals

The hardest part of climbing the ladder of success is getting through the crowd at the bottom.

Working...