[dorlomin]

About $200k of a Falcon 9 is fuel costs. It is as dumb to claim that energy will restrict space flight as to claim energy will restrict computing. The cost is staff, design and fabrication, you increase the rate of flight you drop the cost, even with a tripling of energy costs.

It will be a while before we colonise the solar system. But this is due to poor leadership not inherent cost barriers.

[SeaGypsy]

Actually it's to do with biology & physics. But heck, who said you can't make lots of dosh out of fantasy?

[ralfy]

About $200k of a Falcon 9 is fuel costs. It is as dumb to claim that energy will restrict space flight as to claim energy will restrict computing. The cost is staff, design and fabrication, you increase the rate of flight you drop the cost, even with a tripling of energy costs.

It will be a while before we colonise the solar system. But this is due to poor leadership not inherent cost barriers.

As it is, there is barely enough energy and material resources to meet just the basic needs of the human population.

[SeaGypsy]

If miraculously 'meeting the basic needs of humanity' became the overarching principle, we would all be in a very different situation. For one, these morons fantasies about living in space would appear as vacuous as they really are.

[dorlomin]

As it is, there is barely enough energy and material resources to meet just the basic needs of the human population.

Ralf Wiggum says it true.

[ralfy]

As it is, there is barely enough energy and material resources to meet just the basic needs of the human population.

Ralf Wiggum says it true.

Since you are not interested in discussing these issues reasonably, then I will have to put your account in my ignore list.

[Sixstrings]

About $200k of a Falcon 9 is fuel costs.

$200k is nothin, heck that will just buy maybe 3 teslas lmao.

Seriously, ya, that fuel cost is nothing you're right -- which is why REUSABLE ROCKETS is such a big deal. It will be a massive leap forward. Imagine the difference between Boeing having to build a new 757 for each and ever flight and then how much those tickets would cost, versus a reusable aircraft. Same idea, with rockets.

[Tanada]

Well ESA has announced Venus Express ran out of fuel mid way through the orbit raising burns in November.

The mission then continued in a reduced science phase, as the closest
approach of the spacecraft to Venus steadily decreased again naturally
under gravity.

Under the assumption that there was some propellant still remaining, a
decision was taken to correct this natural decay with a new series of
raising manoeuvres during 23-30 November, in an attempt to prolong the
mission into 2015.

However, full contact with Venus Express was lost on 28 November. Since
then the telemetry and telecommand links had been partially re-established,
but they were very unstable and only limited information could be retrieved.

"The available information provides evidence of the spacecraft losing
attitude control most likely due to thrust problems during the raising
manoeuvres," says Patrick Martin, ESA's Venus Express mission manager.

"It seems likely, therefore, that Venus Express exhausted its remaining
propellant about half way through the planned manoeuvres last month."

Unlike cars and aircraft, spacecraft are not equipped with fuel gauges,
so the time of propellant exhaustion for any satellite - especially after
such a long time in space - is difficult to predict. The end could not
be predicted but was not completely unexpected either.

Without propellant, however, it is no longer possible to control the attitude
and orient Venus Express towards Earth to maintain communications. It
is also impossible to raise the altitude further, meaning that the spacecraft
will naturally sink deeper into the atmosphere over the coming weeks.

http://www.esa.int/Our_Activities/Space ... _the_night

[Subjectivist]

Well that stinks, the artical says they have lost orientation control of the spacecraft so they only get data at intervals as it slowly tumbles in orbit. Within a few months it will enter the atmosphere and burn up.
So long Venus Express, you did your best and we are proud of what you accomplished!

[Sixstrings]

What went wrong? Why did it "run out of fuel?"

It's a reminder that these are very complex missions where anything that can go wrong will and they have to plan for every possibility, and redundancies, and even something unexpected will still go wrong.

Real space stuff gets me thinking of Kerbal Space Progam, lol. Like with Philae, I'm thinking well ok so the rock outcropping is blocking the solar panel -- they should have had an RTG on the thing! That's what I'd have done in kerbal space and I wouldn't have had that problem, I finally learned about blocked solar panels. Now I put on an RTG just in case, and plenty of batteries to cover data transmission even if all power fails.

The old Voyager probes are still amazing, how they made all their targets with gravity assists and exact timing (engineers on ground using slide rules), and did so much with those things.

[Tanada]

What went wrong? Why did it "run out of fuel?"

Because every time you fire a thruster some of the fuel gets used up and unless you get someone to stop by with a fuel tanker eventually you run out. It is not as if this probe was launched last month, it has been in space for 9 years.

Sadly the fuel did not run out exactly evenly so one thruster fired a short time longer than the others and set the probe tumbling. It doesn't take much for that to happen, probably a second of uneven thrust would be more than the internal gyroscopes could compensate for.

[Keith_McClary]

What went wrong? Why did it "run out of fuel?"

It's a reminder that these are very complex missions where anything that can go wrong will and they have to plan for every possibility, and redundancies, and even something unexpected will still go wrong.

Real space stuff gets me thinking of Kerbal Space Progam, lol. Like with Philae, I'm thinking well ok so the rock outcropping is blocking the solar panel -- they should have had an RTG on the thing! That's what I'd have done in kerbal space and I wouldn't have had that problem, I finally learned about blocked solar panels. Now I put on an RTG just in case, and plenty of batteries to cover data transmission even if all power fails.

The old Voyager probes are still amazing, how they made all their targets with gravity assists and exact timing (engineers on ground using slide rules), and did so much with those things.

You just need somebody there to fix stuff that goes wrong.

I guess those backward Europeans never heard of RTGs.

[Sixstrings]

I guess those backward Europeans never heard of RTGs.

I should probably join the kerbal space program forum and make a thread there (but this is my only forum), I know you guys have no idea what I'm talking about but it's just hilarious, it's a classic KSP mishap -- where you're like "doh! the rocks are the shading my solar panels, shoulda had an RTG!"

I don't know why RTGs aren't used more these days, other than mass savings.

This is a radioisotope thermoelectric generator:

Why were solar panels used on the Philae Lander when we have RTG?


http://www.quora.com/Why-were-solar-panels-used-on-the-Philae-Lander-when-we-have-RTG

There was nothing *broken* on Philae other than the harpoons, the main problem wound up being that it relied on solar panels but landed in the shade!

[Sixstrings]

What went wrong? Why did it "run out of fuel?"

Because every time you fire a thruster some of the fuel gets used up and unless you get someone to stop by with a fuel tanker eventually you run out. It is not as if this probe was launched last month, it has been in space for 9 years.

Sadly the fuel did not run out exactly evenly so one thruster fired a short time longer than the others and set the probe tumbling. It doesn't take much for that to happen, probably a second of uneven thrust would be more than the internal gyroscopes could compensate for.

Yes, I realize that, but my question is how did it happen. There really should be no failure. Back in the 60s they were doing calculations with slide rules -- and always accurate.

There's no excuse to just "run out of fuel."

So something happened here, design flaw or malfunction or micrometeorite damage or something? If they just didn't calculate things correctly, there's no excuse for that.

[Subjectivist]

I should probably join the kerbal space program forum and make a thread there (but this is my only forum), I know you guys have no idea what I'm talking about but it's just hilarious, it's a classic KSP mishap -- where you're like "doh! the rocks are the shading my solar panels, shoulda had an RTG!"

I don't know why RTGs aren't used more these days, other than mass savings.

This is a radioisotope thermoelectric generator:

Why were solar panels used on the Philae Lander when we have RTG

There was nothing *broken* on Philae other than the harpoons, the main problem wound up being that it relied on solar panels but landed in the shade!

The hysterical anti-nuclear crowd protests ever RTG launch and have even gone to court seeking injunctions. Eventually the probe builders got tired of it and just went solar to shut them up even though for most probes an RTG would be much more sensible.

[vox_mundi]

So six, where you stashing your Pu 238 ...

Pu 238 Global supply - less than 10 kg

Mars rover Curiosity utilizes 4.8 kilograms of Pu-238 borrowed from a Soviet-era nuclear weapons plant.

Cost - over $8 Million a kg

Rate of production - 1.5 kg per year

Last produced in the U.S. in 1988

There's still hope

NASA considers possibilities for manned mission to Venus
http://phys.org/news/2014-12-nasa-possi ... venus.html

[Sixstrings]

The hysterical anti-nuclear crowd protests ever RTG launch and have even gone to court seeking injunctions. Eventually the probe builders got tired of it and just went solar to shut them up even though for most probes an RTG would be much more sensible.

Ohhhhh so that's what it's about! Ok. There are no anti-nuke protesters in kerbal space program, lol.

There definitely should be an RTG for any probe that doesn't have wheels on it and is landing on anything that has rock outcroppings. Solar panels do not work in the shade.

[Sixstrings]

http://phys.org/news/2014-12-nasa-possibilities-mission-venus.html

It says your link is unavailable.

What would a manned mission to venus do? You sure as heck can't land anyone in on that inferno. (or get them back to orbit, too much gravity + too thick atmosphere)

Could do some eva's in orbit, venus looks boring though:

[Subjectivist]

A balloon filled with earth air at sea level pressure is Bouyant at the same pressure level in Venusian air. That means a probe using a balloon floats at a level where the temperature and pressure is very earth like. There have even been stories about colonists living on Venus in balloon cities floating above the clouds and using robotic equipment to mine the surface.