Comments for en-gb 30 Fri 27 Feb 2015 04:19:19 GMT+1 A feed of user comments from the page found at Stephen Ashworth Thank you, AsaScot, for telling me that I am completely missing the point.I am relieved and delighted to hear this!Would you or Jonathan please let me know which Esa technical centre has responsibility for developing and operating a prototype space solar power satellite, with the object of demonstrating whether or not this future power source is practical and what the financial and environmental costs are, relative to other power sources?Thank you.Stephen29 July 2009 Wed 29 Jul 2009 13:09:35 GMT+1 robertlucien With todays primitive space technology commercial space solar power is just another fantasy. Even the biggest launchers in development today can only lift 100 to 200 tons, for commercial production of any scale that needs to be multiplied by a hundred or more. That may sound impossible and it probably is with primitive rockets - certainly unimaginably expensive, however it is merely sticking with this technology that is the real problem. There are many better potential solutions out there, space elevators, one stage to orbit systems, or photonic lifters. A system I have been working on myself for the last year (as an amateur) has the potential needed . The only thing really required for much more efficient access to orbit is a more efficient engine, and the basic route to efficiency is higher exhaust speed. The engine I am working on is much more complicated than a rocket, but from the ground up to 90% of launch weight can make it into orbit. That means that a craft that weighs 100 tons on the ground could lift maybe 10 to 30 tons of cargo mass into orbit, and since it is scaleable 1200 tons on the ground might lift up to 400 tons of cargo into orbit. That is a lot closer to making space solar power practical.BTW better orbital tech is also just as applicable to interplanetary missions. A single stage system that can make orbit, can refuel there -fly to the moon and return, refuel again and use retro braking to land back on earth. Flying to Mars or the outer planets is far more complicated but the main difficulty is having a suitable refuelling facility at the other side. - It is possible which it basically isn't with todays rockets. Sun 26 Jul 2009 15:50:37 GMT+1 Mike Mullen Sorry but Astronist seems to be completely missing the point of Harwell. it's focused on powering spacecraft further out into the solar system. There are plenty of organisations working on improved solar arrays; and and developing techniques for putting them into space would fall under the remits of other research facilites.Frankly I feel Harwell's nuclear research isn't broad enough, surely nuclear energy for propulsion should be under consideration? Whether as a source of electrical power for ion propulsion or more directly through nuclear rocketry.Orbiting solar power is not some magical panacea, given the problems with siting cell phone masts who would want the recievers for these arrays power anywhere near them. Build them in remote spots? Just wait for the protests about 'endangered species' and 'environmental damage'. Sat 25 Jul 2009 21:51:07 GMT+1 Hugh Morley Esrec - European Space Robotics & Energy Centre.Esrecc - European Space Robotics, Energy & Climate Centre Fri 24 Jul 2009 22:13:21 GMT+1 Jonathan Amos Astronist: Thanks for the post again. I guess, it's now down to someone to knock on the door of Harwell with the bright idea. "Bring us your ideas" is supposed to be the philosophy. On the issue of space solar, I don't know what you thought but I was very struck to hear SpaceX's Elon Musk dismiss it when he gave his RAeS lecture last year. This is the man, remember, who has invested millions in solar and knows a thing or two about space.Also, we're back to those acronyms. I asked Jean-Jacques Dordain if he had one for Harwell. He's got one for all the other Esa centres Esoc, Esrin, Estec, etc. I suggested "Esic" "European Space Innovation Centre". This wouldn't do, he said, because it suggested the other centres were "not innovative". Any bright ideas on this particular issue? Fri 24 Jul 2009 20:10:40 GMT+1 Stephen Ashworth This is a perfect illustration of the modus operandi of Esa.The world is crying out for novel power systems -- ones which do not generate carbon dioxide or radioactive waste and which are not only long-term sustainable but capable of supporting further economic growth worldwide.Space technology has one possible answer, in the form of space solar power, beamed down to Earth on microwaves. Such a system was described in some detail in the October 2007 report by America's National Security Space Office, part of the Pentagon.But question marks remain over the economic viability of the system, the feasibility of low-cost access to orbit (in which the UK is a world leader through the work of Reaction Engines and Bristol Spaceplanes) and the use of extraterrestrial materials to construct orbiting power satellites.So naturally Esa goes off to explore Mars and the outer planets, and dismisses space solar power as something for the longer-term future.Given the political urgency of establishing low-pollution industrial-scale energy, Esa's attitude can only be described as irresponsible.Not that I believe for one moment that increasing the trace of CO2 in the atmosphere presents any real threat. It is just the disjunction between Esa's emphasis on "exploration" and the more practical interests of its political masters which amazes me.Best wishes,Stephen24 July 2009 Fri 24 Jul 2009 18:00:33 GMT+1