FishmanPut your goddamned hand in the goddamned Box of Pain.Registered Userregular
Sorry, there should be a proviso there: I'm talking about launch platforms, not payloads.
Australia did, once upon a time (almost a half century ago) orbit some satellites from Australian soil, but used US and UK rockets to get there.
Still an important milestone! Not really one that counts as having built an rocket of their own capable of orbital insertion, though.
Just remember, when you get there: we were there before you. :P
Those don't make atmosphere, merely change its makeup. To give Mars an atmosphere you have to bring that matter from elsewhere.
We know pretty well how to make atmosphere. It's why Global Warming and climate change are things. If human settlements are set up on Mars, atmosphere is going to follow from our mere presence. But it'd be a whole lot better for Mars than Earth.
The Electron Rocket, 'Still Testing', was the second successful launch from New Zealand and the first to achieve orbital insertion. It was a milestone success and an amazing achievement for a small country that is neither a world power nor a militarised state (as all previous countries to launch to orbit have been).
There's something very... visceral about hearing someone giving a countdown in your own accent. Mission Control Auckland, indeed.
I watched this with my 5-year-old sitting in my lap today, and when it was over, he told me how he wants build and launch rockets as his job, in New Zealand. And we told him if that's what he wants to do, he can.
This is really cool and I'm super happy for them!
Of note: the Electron's engines are electrically-pumped, the first (I believe) for any scale launch. Each engine gets two 50 hp pumps (one for fuel and one for oxidizer) and a honkin' serious LiPo battery. The engine tech alone, including all the 3D printing and EBM printing is worth a documentary all by itself.
They're really doing some fantastic sophisticated work and I tip my hat to them!
When you say electrically pumped what does that mean exactly?
Pumps driven by electric motors?
Yup. Most srs-bzns rockets use gas-turbine pumps, at least for their first stages. As in they burn a little of the fuel/oxidiser in a regular old turbine engine to drive the pump, mostly because of the ridiculous flow rates required. Some engines can use gas pressure in the tank to force through sufficient fuel but they tend to be rarer despite their relative simplicity.
Electric pumps have been ued before but I think this is a first for a first-stage, largely due to battery tech.
The electrically driven pumps are pretty neat, I wonder what sort of specific impulse trade-off or benefit they get from that. Or maybe the primary motivation is reduced complexity?
In most gas-generator rocket engines you need to run the turbines that power the pumps either fuel or oxygen rich for cooling purposes, the end result of the rich mixture is you end up dumping un-utilized oxidizer or fuel out the back (Spacex's Merlin engines do this), so you lose efficiency. The Russian RD-180 rocket engine used in the Atlas V uses a staged combustion cycle that dumps the oxygen rich exhaust into the main combustion chamber at high pressures, boosting efficiency. But a staged combustion design greatly increases engineering challenges and complexity.
When you say electrically pumped what does that mean exactly?
Pumps driven by electric motors?
Yup. Most srs-bzns rockets use gas-turbine pumps, at least for their first stages. As in they burn a little of the fuel/oxidiser in a regular old turbine engine to drive the pump, mostly because of the ridiculous flow rates required. Some engines can use gas pressure in the tank to force through sufficient fuel but they tend to be rarer despite their relative simplicity.
Electric pumps have been ued before but I think this is a first for a first-stage, largely due to battery tech.
Yeah, for reference a "big" engine like the RS-25 (one of the space shuttle's main engines) has fuel and oxidizer turbopumps that develop 69 000 horsepower and 25 000 horsepower, respectively. 69 khp ~= 50 MEGAWATTS. That's just to pump the fuel! :exclamation:
The pumping requirements of rocket engines are just staggeringly large. They're an engineering feat all to themselves, nevermind the fact that you're pumping things like extremely reactive oxygen inside a wildly vibrating structure while accelerating at 2 to 4 g.
Electrically-pumped rocket engines can't get very big. The power's just not there. (And it's also not as efficient because you're lifting dead weight.) But it's cool that the Electron can get away with it. Small total mass, nine small engines (so no one motor or drive has to be unmanageably big), battery tech, smart deliberate trade-offs for simplicity and schedule and reliability. Better to give up a little throw weight in order to make a manageable system!
The most recent guidance from NASA, released in 2017, indicates that all nonessential employees should stay home during a shutdown, while a small contingent of staff continue to work on “excepted” projects. The heads of each NASA center decide which employees need to stay, but they’re typically the people who operate important or hazardous programs, including employees working on upcoming launches or those who operate satellites and the International Space Station.
what does happen during these GOP temper tantrumsshutdowns vis a vis people in space
is there dispensation to keep making sure they have, like, food?
They have several months of supplies on-station at any given point, in case the next supply flight fails. They start to get in trouble if two in a row are missed, but I think the next one is being launched by the Russians anyway.
Also, if they have to ditch the station for whatever reason, the Soyuz escape capsule is managed by Russian flight control after it detaches.
MayabirdPecking at the keyboardRegistered Userregular
Ah yes, that johnny-come-lately Curiosity, landed in 2012. Meanwhile Opportunity, who landed in 2004, is still rolling too, and without the fancy radioisotopes.
(But no seriously I love how the rovers and space probes tend to last crazy long times if they don't fail spectacularly.)
What's the theoretical life on those RTGs? I know they supposedly wear out before the half-life of the material, but could these last for decades longer?
What's the theoretical life on those RTGs? I know they supposedly wear out before the half-life of the material, but could these last for decades longer?
Voyager's is still going after 40 years, albeit at reduced capacity.
Just remember that half the people you meet are below average intelligence.
What's the theoretical life on those RTGs? I know they supposedly wear out before the half-life of the material, but could these last for decades longer?
I believe Curiosity's specs said it would have full power for at least 1 Martian year (687 Earth days). That said, google tells me the expected power output is supposed to be stable for about 14 years and then it will start lowering, most likely at a steady rate, until it doesn't produce enough power to do anything productive.
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BrodyThe WatchThe First ShoreRegistered Userregular
What's the theoretical life on those RTGs? I know they supposedly wear out before the half-life of the material, but could these last for decades longer?
I believe Curiosity's specs said it would have full power for at least 1 Martian year (687 Earth days). That said, google tells me the expected power output is supposed to be stable for about 14 years and then it will start lowering, most likely at a steady rate, until it doesn't produce enough power to do anything productive.
Which is when the aliens will finally swoop in and steal all our stuff.
"I will write your name in the ruin of them. I will paint you across history in the color of their blood."
What's the theoretical life on those RTGs? I know they supposedly wear out before the half-life of the material, but could these last for decades longer?
Voyager's is still going after 40 years, albeit at reduced capacity.
Voyager probably has (had) lower power usage than the Mars rovers though, yeah?
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Mr_Rose83 Blue Ridge Protects the HolyRegistered Userregular
What's the theoretical life on those RTGs? I know they supposedly wear out before the half-life of the material, but could these last for decades longer?
Voyager's is still going after 40 years, albeit at reduced capacity.
Voyager probably has (had) lower power usage than the Mars rovers though, yeah?
1. I wouldn’t bet on it; Voyager was built with 60’s technology and will not be anywhere near as efficient as the electronics in the rovers, plus it’s operating that enormous radio. Though the drive systems may tip the balance back. So yeah, I wouldn’t assume that without the specs to hand.
2. RTGs don’t give a shit about power draw. They produce as much heat as they produce regardless of whether that is getting used or not. Half lives are notoriously difficult to change on the fly.
FishmanPut your goddamned hand in the goddamned Box of Pain.Registered Userregular
The RTG's on Curiosity Rover and Voyager are roughly equivalent in terms of weight and power production, but Voyager 1 & 2 are equipped with 3 of them for 3 times the power output (at time of launch).
Curiosity actually feeds excess power generated by the RTG into a Lithion-ion battery system to enable high-power mode (which is driving, I guess?). So the base power output of the RTG isn't enough, it kicks in excess stored power from the batteries to power whatever it is it is doing. When it's idle and using less power, it charges the batteries back up.
What's the theoretical life on those RTGs? I know they supposedly wear out before the half-life of the material, but could these last for decades longer?
Voyager's is still going after 40 years, albeit at reduced capacity.
Voyager probably has (had) lower power usage than the Mars rovers though, yeah?
Well yeah, but only because the holodeck runs on a completely separate and mysteriously incompatible power system.
Voyager 1 and 2 are down to, last I saw, 249 W of available power. At launch, they had 470 W.
As the spacecraft age, NASA has slowly been turning off instruments and, notably in 2012, the core heater (!) in order to stay under the power budget. Estimates are that there won't be enough power to run even a single instrument by mid-2020s.
Fun facts: their big-dish transmitters are 22.4 W output and the dish gives them a huge 48 dBi of gain. EIRP is therefore probably around 85 dBm. Even with that it takes a huge receiver antenna and a good bit of processing gain to deal with the ~300 dB (!!) of path loss because the things are so damned far out there.
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I mean I guess we've still been occupied by those hostile emus all these years.
Australia did, once upon a time (almost a half century ago) orbit some satellites from Australian soil, but used US and UK rockets to get there.
Still an important milestone! Not really one that counts as having built an rocket of their own capable of orbital insertion, though.
Just remember, when you get there: we were there before you. :P
We know pretty well how to make atmosphere. It's why Global Warming and climate change are things. If human settlements are set up on Mars, atmosphere is going to follow from our mere presence. But it'd be a whole lot better for Mars than Earth.
This is really cool and I'm super happy for them!
Of note: the Electron's engines are electrically-pumped, the first (I believe) for any scale launch. Each engine gets two 50 hp pumps (one for fuel and one for oxidizer) and a honkin' serious LiPo battery. The engine tech alone, including all the 3D printing and EBM printing is worth a documentary all by itself.
They're really doing some fantastic sophisticated work and I tip my hat to them!
Pumps driven by electric motors?
Yup. Most srs-bzns rockets use gas-turbine pumps, at least for their first stages. As in they burn a little of the fuel/oxidiser in a regular old turbine engine to drive the pump, mostly because of the ridiculous flow rates required. Some engines can use gas pressure in the tank to force through sufficient fuel but they tend to be rarer despite their relative simplicity.
Electric pumps have been ued before but I think this is a first for a first-stage, largely due to battery tech.
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In most gas-generator rocket engines you need to run the turbines that power the pumps either fuel or oxygen rich for cooling purposes, the end result of the rich mixture is you end up dumping un-utilized oxidizer or fuel out the back (Spacex's Merlin engines do this), so you lose efficiency. The Russian RD-180 rocket engine used in the Atlas V uses a staged combustion cycle that dumps the oxygen rich exhaust into the main combustion chamber at high pressures, boosting efficiency. But a staged combustion design greatly increases engineering challenges and complexity.
The pumping requirements of rocket engines are just staggeringly large. They're an engineering feat all to themselves, nevermind the fact that you're pumping things like extremely reactive oxygen inside a wildly vibrating structure while accelerating at 2 to 4 g.
Electrically-pumped rocket engines can't get very big. The power's just not there. (And it's also not as efficient because you're lifting dead weight.) But it's cool that the Electron can get away with it. Small total mass, nine small engines (so no one motor or drive has to be unmanageably big), battery tech, smart deliberate trade-offs for simplicity and schedule and reliability. Better to give up a little throw weight in order to make a manageable system!
Apparently the engine is 3D-printed too
I don't even want to think about ass.
yeah
what does happen during these GOP temper tantrumsshutdowns vis a vis people in space
is there dispensation to keep making sure they have, like, food?
Also there are a few other space agencies involved, It hink, like EASA?
Hmmm
They have several months of supplies on-station at any given point, in case the next supply flight fails. They start to get in trouble if two in a row are missed, but I think the next one is being launched by the Russians anyway.
Also, if they have to ditch the station for whatever reason, the Soyuz escape capsule is managed by Russian flight control after it detaches.
Take a picture of them fuckers not yourself
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(But no seriously I love how the rovers and space probes tend to last crazy long times if they don't fail spectacularly.)
smashing
Pushed glasses up,
Curiosity does not have solar panels. It uses decaying plutonium dioxide.
The fact that it's a nuclear powered science tank is one of the coolest things about it.
Um... no. RTGs are the exact opposite of cool.
Edit: In multiple ways, actually.
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Voyager's is still going after 40 years, albeit at reduced capacity.
I believe Curiosity's specs said it would have full power for at least 1 Martian year (687 Earth days). That said, google tells me the expected power output is supposed to be stable for about 14 years and then it will start lowering, most likely at a steady rate, until it doesn't produce enough power to do anything productive.
Which is when the aliens will finally swoop in and steal all our stuff.
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Voyager probably has (had) lower power usage than the Mars rovers though, yeah?
1. I wouldn’t bet on it; Voyager was built with 60’s technology and will not be anywhere near as efficient as the electronics in the rovers, plus it’s operating that enormous radio. Though the drive systems may tip the balance back. So yeah, I wouldn’t assume that without the specs to hand.
2. RTGs don’t give a shit about power draw. They produce as much heat as they produce regardless of whether that is getting used or not. Half lives are notoriously difficult to change on the fly.
Nintendo Network ID: AzraelRose
DropBox invite link - get 500MB extra free.
Curiosity actually feeds excess power generated by the RTG into a Lithion-ion battery system to enable high-power mode (which is driving, I guess?). So the base power output of the RTG isn't enough, it kicks in excess stored power from the batteries to power whatever it is it is doing. When it's idle and using less power, it charges the batteries back up.
Well yeah, but only because the holodeck runs on a completely separate and mysteriously incompatible power system.
Rocket Lab launched a secret payload into space last weekend
Really hope this doesn't explode on the test flight
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But if it does at least it will make a spectacular fireball.
As the spacecraft age, NASA has slowly been turning off instruments and, notably in 2012, the core heater (!) in order to stay under the power budget. Estimates are that there won't be enough power to run even a single instrument by mid-2020s.
Fun facts: their big-dish transmitters are 22.4 W output and the dish gives them a huge 48 dBi of gain. EIRP is therefore probably around 85 dBm. Even with that it takes a huge receiver antenna and a good bit of processing gain to deal with the ~300 dB (!!) of path loss because the things are so damned far out there.