Spacecraft Power (2016)
jpl.nasa.gov
jpl.nasa.gov
This kind of research could help us on Earth, too. For example,
some of the heat that gets wasted when you drive your car could
be reused and put back into the car to charge the battery
or power electronics.
So maybe, this is the breakthrough that was needed. If this technology could recover a few KW from the waste heat, this might greatly improve the fuel efficiency of cars. Or it is just some marketing talk, like, "Look, what we are researching here might be useful to YOU too"...
Can somebody comment on that?
A common question raised by many people is why spend money on space exploration when there are problems to be solved here, on Earth[0]? So NASA and many others try to address it by pointing out just how much of their work end up being used to improve life of everyone down here, on Earth. NASA in particular seems to have boosted their marketing budget recently; something I wish ESA would do too, to get more recognition and public support.
Also, this is a perfect moment to link to the classic: http://wtfnasa.com/ :).
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[0] - Besides space exploration being fucking awesome, which for some reason isn't widely recognized the axiom it is.
I don't see how space exploration is feeding the starving. It would be fucking awesome if we solved that. It maybe a strawman - couldn't these millions be spent on Earth? Instead we have commercial TV asking us to donate to solve problems on Earth.
Regarding your very good question - it has been asked before. I'll direct you to the classic:
In 1970, a Zambia-based nun named Sister Mary Jucunda wrote to Dr. Ernst Stuhlinger, then-associate director of science at NASA's Marshall Space Flight Center, in response to his ongoing research into a piloted mission to Mars. Specifically, she asked how he could suggest spending billions of dollars on such a project at a time when so many children were starving on Earth.
Stuhlinger soon sent the following letter of explanation to Sister Jucunda, along with a copy of "Earthrise," the iconic photograph of Earth taken in 1968 by astronaut William Anders, from the Moon (also embedded in the transcript). His thoughtful reply was later published by NASA, and titled, "Why Explore Space?"
The response is to be read here: http://www.lettersofnote.com/2012/08/why-explore-space.html.
When will this promise be delivered? It's been 40 years and I can imagine Billions spent. Are people still starving?.
No, there's plenty of research to make agriculture (industrial and subsistence farming) more efficient. But it's not trivial getting it into the hands and heads of people since you can only do that locally.
> It seems to have a premise that we can only feed all the people on Earth from space.
No. Nasa and noaa are contributing some parts to a larger machinery. It is not the sole purpose of space missions, but it is a synergetic effect. You need weather forecasts to optimize farming, satellites help with that. GPS helps with international trade which in small part also covers shipping of fertilizer or pesticides to countries.
But what can you possibly mean by "when will this promise be delivered?"
Yes, some humans are still starving, cold, thirsty, or hurt. Some are fighting - some for good reasons, like protecting/providing basic rights and needs for themselves and others, but many are fighting for stupid reasons. Humans still become sick and injured, and we still die.
We cannot "solve" these problems today by throwing money at them. We will probably never be able to completely solve them. By analogy, you cannot complete the task of having clean dishes and laundry by buying new place settings and clothes. But consider that these endless chores have become easier and less impactful with the advent of indoor plumbing, washing machines, cotton gins, sewing machines, and synthetic fabrics - not to mention advances in transportation, communication, and other seemingly unrelated fields.
In the same way, the work of keeping people healthy and fed has been improved by the development of agricultural, medical, and other technology. Certainly, feeding the hungry is important, and we should spend a great deal right now to help those in need. But there are other needs, and it would be foolish to not use some of our effort on making future needs less.
2. long-term vs. short-term planning. we do basic research to improve something in the long term. you don't want all your resources allocated to fixing short-term problems because then you'll have a problem in the future since nobody laid the groundwork to solve the future's problems. space exploration is basic research that pays off in moderate ways today (new materials science, satellites) and hopefully in larger ways in the future, e.g. asteroid mining, planetary defense against asteroids or establishing permanent self-sufficient settlements somewhere else in the solar system.
3. you can't just blame the government for allocating resources in a way that does not seem "moral", you also have to look at the people who prefer to allocate money to such things like commercial TV as you mention yourself instead of solving more basic problems. People's utility functions and their optimization choices are complicated. There's a locality bias (self > monkeysphere > in-group > out-group) and the question how they weight and aggregate over multiple variables (geometric or arithmetic mean, medians, minimum, weights...) so as cynical as it may sound, a new smartphone or a flag on the moon is more important by some factor than feeding a million africans. People may say otherwise when asked directly, but their actual decisions when not having to make that tradeoff directly means they'll choose to use their money that way.
The reasons for people starving in 2017 aren't due to food production issues (we grow enough food) but rather distribution issues, which are much thornier to solve.
In contrast, we spend approximately 1% of our budget on all of NASA - including NASA's deep space exploration programs, it's earth sensing programs, and its manned spaceflight programs, in addition to the unsung work it does in aeronautics, which includes helping develop more efficient passenger planes and safer, more efficient air traffic control. Which means that we spend considerably less than 1% of the federal budget on deep space mission technologies like this one.
So I have a question for you in response to your question: if we can't solve world hunger by spending 50% of our national budget, why should I believe that we can solve it by spending 51%?
Can't we take just a little bit of our budget and spend it on something where we can make real technological progress, right now, and see where that leads us?
These kind of arguments have always struck me as similar to thinking that you can pay off your mortgage by cancelling your newspaper subscription. The math just doesn't work, and in the meantime you actively make yourself less educated.
You're shoving the responsibility for the starving masses on NASA and their relatively small budget - why not the military? How is their mission trying to solve the distribution issues? (It's not.) The Gerald R. Ford class aircraft carrier program cost $36 billion (cf. wikipedia), that's more than NASA's budget. Why spend that money there? There are more than enough ships right now.
If you cut their budget entirely, you would have hundreds of billions to spend. Or education, a group who are also not tasked with food distribution. Or Homeland Security, again not tasked with food distribution.
Why is NASA alone the target of your scorn?
What makes you think that, if NASA were folded right up, all the money would be transferred and the starving masses would be fed? They weren't being fed before NASA was created.
A good portion of the US don't feel that it's their problem to feed the masses, something that could be readily achieved if there was sufficient political will.
Couldn't these millions be taken from military expenditures instead of scientific progress?
I really love the story about Norman Borlaug [0], because it shows how these great advances can be from enormous work from unexpected places. His research and testing - over decades - saved so many lives (he earned the title "The Man Who Saved a Billion Lives", and it may not be an exaggeration).
I vaguely recall the econ nobel a few years ago studied how people starved with food rotting in enormous piles just a few dozen miles away. It's utterly heartbreaking, and the worst is that it was largely bad policy that did it. We already overproduce food enough, but we can't get it where it needs to be.
Now, though, imagine that we find a way to mine asteroids for rare earth minerals. Imagine we can have clean power without the horrific pollution as industrial infrastructure ramps up. How could that change the world, leading to logistics networks that could fix distribution issues?
[0] https://en.wikipedia.org/wiki/Norman_Borlaug
EDIT: terminology, and I'd like to disclaim about the strife problem: space can't really fix. But food and money can't either.
The majority of NASA's budget today is being wasted today on the SLS, a launch system that will be at cost at least 10x more per pound than commercial systems. Most of NASA's budget since Apollo was blown the Shuttle, the most expensive launch system in history, cost over $1.5B a launch for a cargo capacity similar to a Falcon 9 and couldn't get out of LEO. The rest was blown on the ISS so we could run questionable science experiments at a cost of only $200B+.
I want to see a NASA devoted to robotic probes and it's manned missions restricted entirely to commercial launch systems. If they want 200,000 lb lift capacity, bid it out and let commercial providers step up with affordable solutions that aren't required to be built in every state and congressional district.
It's the most powerful rocket ever... There are no comparable commercial systems. It has a 2.4x heavier payload than the Falcon Heavy, which also doesn't exist yet. You can't just compare the cost per pound, and even then your numbers are wrong- at 500 M$/130 MT the SLS is only 30% more expensive than the Falcon Heavy. Even if the SLS wasn't 2.4x bigger, 30% is worth it for the institutional ability to make those rockets. It's NASA, they should have the technical ability to get to space.
>Most of NASA's budget since Apollo was blown the Shuttle, the most expensive launch system in history, cost over $1.5B a launch for a cargo capacity similar to a Falcon 9 and couldn't get out of LEO.
Yes, the shuttle sucks, because it was a military project. It has wings because the military wanted it to. Almost every poor design choice was demanded by the military. The dream of the shuttle was relegated to work-making due to national "security" concerns. The military wanted it to land anywhere in the world, so it got wings, etc.
>The rest was blown on the ISS so we could run questionable science experiments at a cost of only $200B+.
???? We have people in space and international cooperation on an unprecedented scale. Are antarctic bases "questionable"?
>I want to see a NASA devoted to robotic probes and it's manned missions restricted entirely to commercial launch systems. If they want 200,000 lb lift capacity, bid it out and let commercial providers step up with affordable solutions that aren't required to be built in every state and congressional district.
There is a single company that can do it cheaper than NASA, and that's spaceX. Government contracting leads to uncontrollable cost inflation 99% of the time. If you disconnect the managers from the product, bad things happen. It's only when you have companies that are actually dedicated to affordable spaceflight that better things happen. SpaceX is a glowing gem, not the norm. The norm is extreme waste and incompetence. NASA is more competent than any of its contractors with the sole, debatable exception of SpaceX.
You are arguing for something on principles against and enormous mountain of evidence.
And you are quoting launch capacities for the SLS that won't exist until later versions many years later, if they ever exist at sll.
Why should any company build a SLS sized booster if NASA is going to build its own? SpaceX already is working on a bigger design than SLS, I imagine they'd invest more and have even more progress if they had a shot at NASA heavy launches. And the SLS doesn't even have a planned mission.
I'm all in favor of antarctic research because it didn't cost nearly $300B. Nearly all the science we got out of ISS could have been done far cheaper with robotic probes. It's the most expensive PR event ever, an orbiting destination for school kids projects. Just like when NASA refused to make the Shuttle fully automated, they've refused to allow any ISS experiments to be fully automated, so they can claim in both cases, "see, we need a super expensive manned program".
NASA is the hindrance to manned space flight, not its contractors, Every project it does has one key customer, congress. It requires its projects to be built across many congressional districts, and maintains hugely expensive unneeded infrastructure, all to please key congress critters.
It tried to kill the air force space program and gutted commercial launch capacity in the early 80s by moving them to the shuttle. And the shuttle was so expensive it was a step backwards, and now the SLS is a repeat of that very same game plan. Soon they'll demand every government launch to ride the SLS, starving companies like SpaceX.
That number (18 billion) includes the Orion flight vehicle and launchpad upgrades. The actual cost to develop is 10 billion. Again SpaceX is the only company that beats that, nobody else comes close. Nobody else could even do this at all, most likely. The SLS missions run from 2018-2030 currently, so development costs are at most 200 million per launch.
>the $500M/launch number doesn't likely include annual operating costs for the massive infrastructure it requires.
...The $500M comes from Bill Hill's 2 billion annual production and operation budget, with four launches a year[1]. He wants to get to 1.5 billion.
>And you assume that NASA, which has never hit it's cost forecast for manned flights,and under-estimates costs as a political necessity, is going to hit those cost levels.
NASA is great about staying on budget. The shuttle is completely different and was a result of military interference. All the mars rovers were on-budget except curiosity, which was 20% over budget not counting delays. If the cost of production and supply rose 20% from 1.5 billion annually, SLS would still be cheaper than the Falcon Heavy.
>And you are quoting launch capacities for the SLS that won't exist until later versions many years later, if they ever exist at sll.
There isn't even another organization on earth, government or otherwise, that has announced any rocket of this size. Not counting the MCT, because it's reliant on tech that also doesn't yet exist. If you are going to count the development costs, you have to count what is actually being developed, not just block 1.
[1]: https://arstechnica.com/science/2016/08/how-much-will-sls-an...
And your confidence in their big project budgeting i misplaced. The air force didn't force them to miss their 50 flight a year commitment, they greatly underestimated refurb times/costs for the engines, orbiter and SSRbs. They rstinated $15M a flight and actually cost $1.5B a flight.
NASAs own estimates are over $750M a flight over first decade with development (pad costs are dev costs). But they don't even have missions for all those flights, it's extremely unlikely they'll do 4 a year or control their costs when congress is involved.
"During the joint Senate-NASA presentation in September 2011, it was stated that the SLS program had a projected development cost of $18 billion through 2017, with $10 billion for the SLS rocket, $6 billion for the Orion Multi-Purpose Crew Vehicle and $2 billion for upgrades to the launch pad and other facilities at Kennedy Space Center.[12] These costs and schedule were considered optimistic in an independent 2011 cost assessment report by Booz Allen Hamilton for NASA.[79] An unofficial 2011 NASA document estimated the cost of the program through 2025 to total at least $41bn for four 70 t launches (1 unmanned, 3 manned),[2][3] with the 130 t version ready no earlier than 2030.[80]
The Human Exploration Framework Team (HEFT) estimated unit costs for Block 0 at $1.6bn and Block 1 at $1.86bn in 2010.[81] However, since these estimates were made the Block 0 SLS vehicle was dropped in late 2011, and the design was not completed.[82] The Space Review estimated the cost per launch at $5 billion, depending on the rate of launches."
And nothing about the SLS is reusable or hard to duplicate except the blank check they s paying for it. Its reliance on SRBs is low tech, and risky on a manned rated vehicle. It's a far less impressive launch vehicle than the SaturnV.
Raptor is already in testing. The BE-4 is on the way. The Russians built Energia. If NASA bid out its heavy launch capability they'd cut their heavy launch costs by at least 70%.
https://www.formula1.com/en/championship/inside-f1/understan...
It is not a thermo-electric exchange, it's just kinetic, the same way the electric brake energy recovery works.
This is a study on the application of heat recovery systems on IC engines: http://journals.sagepub.com/doi/pdf/10.1177/1687814015590314 "The maximum recuperated power for non-ideal cycle was 1515W at the point where reference engine power was 26,550W. That improves the effective engine efficiency by 5.7% from 33.97% to 35.91%."
Since the amount of electricity generated is related to the temperature difference, the fact that space is cold actually helps quite a bit.
https://en.wikipedia.org/wiki/Advanced_Stirling_radioisotope...
Since the SpaceX launch recently I've been thinking about a system that would negate the need for an expendable second stage. If you had an "orbital taxi" sitting in LEO waiting to grab the payload from the first stage and boost it up to GTO, you could make the entire system reusable. The "orbital taxi" would have to be powered by some kind of nuclear reactor like this using VASIMIR propulsion (http://www.adastrarocket.com/aarc/VASIMR), as solar panels wouldn't be sufficient.
I'm sure this isn't a new idea so I'm wondering if anyone knows of such a design?
https://en.wikipedia.org/wiki/NERVA
NASA planned to use nuclear rockets as "nuclear tugs" to move stuff up into higher orbits and injection orbits. The problem wast that NERVA was too successful in testing, and congress worried it would enable expensive Mars manned missions.
A space elevator of that type is within current technology, and while the cost is obviously higher than a "taxi", the benefits are as well. In answer to your question you could just eat the cost problem and use a really big battery + a large number of taxis, and accept that they will have slow recharges.
NB that there will be a complication with launch windows with both a taxi and a space elevator. You have to be limited more closely to orbital times without a second stage. My personal favorite is still an orbital loop- put a huge superconducting filament in orbit around the earth, then hang tethers from magnetic bearings. There is almost no tensile stress on the loop, so no need for fancy carbon nanotubes- it just needs a sufficient superconductor and enough mass to stay in a stable orbit.
The downsides are of course that the power requirements are staggering, the cost of getting that mass to space is staggering (although much cheaper than a space elevator), and if power fails the tethers fall down (safe but inconvenient).
Edit: as for the RTG- the power, even with these improvements, is waaaaaaaaaay too low. This is a 25% improvement, to RTGs which are in the hundreds of watts and weight hundreds or thousands of kg. VASIMR systems use tens of kW. It also is not possible to make many more RTGs, and certainly not very large ones- they are remnants of cold war nuclear power-building. It is immensely expensive to produce these isotopes. Each one is a work of international diplomacy and bureaucratic art.
It would not be possible to make them hundreds or thousands of times larger, which would be required to be comparable to rockets. Not to mention, these are still filled with radioactive material.