Langkard

I tried to register but have yet to receive the confirmation email. Perhaps that system is merely down. It has been two days now, however.

I didn't say rare earth elements are rare. That is just their name. You do understand that, right? They are, however, expensive because of the processes needed to extract them. Finding deposits that can be readily extracted is difficult and, in the case of the heavier rare earths like dysprosium, are produced entirely in China. Other sources around the world produce the lighter rare earths like praesodymium. China still produces 90% of all rare earths and 100% of the heavier ones. China also periodically attempts to limit their export, which then causes prices to rise. As demand increases, other sources need to be found. A current prospect is ocean sediments, particularly near ocean vents. Mine tailings from the old mining of heavier elements like uranium also are a source of rare earths, as well as possible recycling of things like old electronics. But, for now, those sources are all for the lighter rare earths - relatively abundant. The heavier rare earths remain a Chinese monopoly unless someone finds another source. That means that asteroid mining may indeed end up being cheaper than any earthly prospects. And still safer, when the environmental costs of rare earth extraction and recycling are factored into the price.

Back on the topic of dark energy, an emerging theory called dark fluid attempts to combine dark energy and dark matter into a single framework (from about 2008 onwards). Interestingly dark fluid theory also incorporates cosmic inflation, recently given a boost through the experimental data achieved with the BICEP2 telescope. Dark energy theory alone deals mostly with current cosmic expansion and doesn't easily mesh with cosmic inflation which is several dozen orders of magnitude greater in energy scale.

A minor sub-theme in David Brin's latest sci-fi novel "Existence" deals with that very concept. Rich 20-something children of "trillies" (trillionaires) making sub-orbital joy rides in privately built rockets.

Rare earths. We find more uses for them every day and they are much harder to find and mine than just about anything else. And mining the rare earths can be dangerous as well. The Chinese have perhaps the largest deposits so far discovered and they use leeching to extract the rare earths. Leeching is dangerous, highly polluting and expensive. Basically they poison an entire mountain side with sulfuric acid and other acids and then use further hazardous chemicals to extract the rare earths from the pools formed at the bottom of the hill. If we can find rare earths in asteroids, the costs (both monetary and ecological) will go down drastically, even including the cost of getting to the asteroids. Cheaper and more abundant rare earths means more uses discovered for them. It is amazing what rare earth metals can already accomplish and we're just scratching the surface. We could have been mining the asteroids decades ago. I remember reading an article by Jerry Pournelle suggesting so back in the late 70's or early 80's in a sci-fi periodical. I don't remember which one. Perhaps it was Asimov or maybe earlier in the lost and lamented Galaxy magazine. That article was the first time I ever encountered the term Delta-V. Pournelle suggested in the article that we could reasonably setup an asteroid mining program for about the cost that we spend in the USA on pizza delivery each year. That was 30 years or more ago.

I have several hopes for the ARM. It will encourage development of better ion propulsion systems for further exploration. The solar electric propulsion system is the IPS proposed for the Asteroid Redirect Mission is big. Just designing and building it will improve future ion propulsion systems. The current proposed design is for a SEP with 40-50 kW solar array, an specific impulse of ~3000 s and up to 10,000 kg of xenon. That's a pretty good first step toward a 100 kW system capable of cargo missions to the moon or Mars. We really need to know more about the composition of Near Earth Objects. This mission will give us the ability to do that and also make the point that we need manned exploration. Robots are fine for capturing an asteroid, but we need the SLS and astronauts on site to actually study such an asteroid fully. Vger is correct about the publicity value in such a mission. Let's face it. We really need something to spark the public interest again. Maybe it will even start people thinking seriously about things like detection and help get more funding for the B612 Foundation. If corporations can get the idea that it isn't impossible to do things like the ARM, then maybe more of them will get on board with exploration and actual expansion into space, not just the bleeding edge few that are currently interested in things like asteroid mining. When the bigger conservative (not in the political sense, but in the sense of holding back and letting others do the path finding) corporations get interested, it will improve the outlook for funding priorities for ancillary projects, like renewed Lunar and Mars exploration. Getting the really big corporations interested is necessary because otherwise such things are too far in the future for their consideration. We do have something positive our side. The chairman and the ranking member of that subcommittee are both very pro-NASA and pro-science, even though they are from different political parties. The same can't be said for all of the members of the full committee on Science and Technology (there are several members of the larger committee who have openly expressed belief in a 6000-year-old Earth )

I decided to place this here instead of the Science forum because it has a political element to it. Did anyone else watch the US House of Reps subcommittee hearing on the proposed 2015 NASA budget yesterday? While both parties are generally supportive of NASA, particularly most members of this subcommittee, it quickly became apparent yesterday just from the opening statements of the Space subcommittee chairman, Republican Steven Palazzo, and a rather unusual appearance (he isn't on the subcommittee and it is unusual for the full committee chair to appear at a subcommittee hearing) by the full Science and Technology committee chairman, Republican Lamar Smith, that Republicans are going after the Asteroid Redirect Mission. Both of them made clear statements questioning the need for the ARM and its applicability to space exploration. Apparently the ARM has been chosen by certain members of Congress as a target for budget cutting, so that they can redirect (pun intended) money to areas where they can benefit more, such as NASA-corporate partnerships. I am concerned that this mission might lose its funding, since the Republicans control the House of Reps and the House of Reps controls the budget. I recommend that everyone here who is a citizen of the USA take a moment to write an email to their US Representative, no matter the party, expressing support for NASA and especially for the Asteroid Redirect Mission.

According to the Kerbin Organization for Standardization: KSO 1151 Aerospace Engineering - a 12000 page standards document for Kerbal engineers, often simplified to a single page with the words "More is better!" printed over and over with a short appendix entitled, "No, really", efficiency is defined as... "More is better!"

Attach SEP engines to the mostly water ice asteroids in the Oort Cloud and shift them onto a collision trajectory with Mars. Add water and atmosphere to Mars. The distance of the Oort objects makes them ideal for long, slow trajectory changes like that, as opposed to icy bodies in orbit around Saturn or Jupiter, which would need more delta-V to shift out of those gravity wells. Or, even more efficient than than SEP, use solar power to heat the water ice to steam and use the steam to produce thrust.

You should probably move the Asteroid Redirect Mission launch from 2019 to 2024. I caught a news conference on NASAtv yesterday discussing the small asteroid mission and the latest info seems to indicate a 2024 launch is more likely. I wish I could find the relevant video online, but it doesn't seem to be posted yet. The coolest part of the whole discussion was the information on the capture probe itself. It will be using the Solar Electric Propulsion system with an amazing 30 tons of xenon. 30 tons! They also mentioned 150 m/s several times in the presentation at roughly an 18 month burn. In addition, they named the likely candidate asteroids, for both the small asteroid mission and the proposed later large asteroid mission (relative to the small one) . I should have taken notes! A shame it isn't available on NASAtv at the moment. Good stuff.

I was 10 years old. It was the first time my parents let me stay up all night. I watched from several hours prior to the landing until Armstrong and Aldrin returned to the LEM from their excursion outside. I fell asleep not long before the Armstrong and Aldrin got their own sleep.