Maybe something that the U-2 spy-plane used?Two of the four wheels dropped after take-off.Would allow you to have a quite heavy landing gear capable of emergency landings right after take-off, and you don't need to carry them all the way to orbit.
Quote from: Hempsell on 05/13/2011 08:00 amQuote from: tnphysics on 05/12/2011 11:30 pmMakes sense! One other idea-what about another heat exchanger, from the hot He from the precooler directly to the GH2 from the first heat exchanger it passes through? Might cut the amount of LH2 needed significantly, at the expense of very high temperature hydrogen heat exchangers being needed (but doesn't the preburner already need that)?I am not quite sure I understand this one. The precooler (which is staged so is HX1 and HX2) is followed by HX3 in the preburner to further heat the Helium up so it has the power (100’s megawatts) to drive the turbines and pumps, we do not want to do any cooling of the Helium until it has done its work. It is a classic thermodynamic cycle using the temperature difference between the heating end (HXs 1 to 3) and the cooling end HX 4 and we want to maximise the temperature difference.This would be a separate heat exchanger that would operate in parallel (not series) to HX1 and HX2 and their associated turbomachinery. It would do no work, but it would cool air, allowing lower H2 flows-and thus greater airbreathing Isp.My understanding of it is that there is an abundance of power at these high airspeeds.
Quote from: tnphysics on 05/12/2011 11:30 pmMakes sense! One other idea-what about another heat exchanger, from the hot He from the precooler directly to the GH2 from the first heat exchanger it passes through? Might cut the amount of LH2 needed significantly, at the expense of very high temperature hydrogen heat exchangers being needed (but doesn't the preburner already need that)?I am not quite sure I understand this one. The precooler (which is staged so is HX1 and HX2) is followed by HX3 in the preburner to further heat the Helium up so it has the power (100’s megawatts) to drive the turbines and pumps, we do not want to do any cooling of the Helium until it has done its work. It is a classic thermodynamic cycle using the temperature difference between the heating end (HXs 1 to 3) and the cooling end HX 4 and we want to maximise the temperature difference.
Makes sense! One other idea-what about another heat exchanger, from the hot He from the precooler directly to the GH2 from the first heat exchanger it passes through? Might cut the amount of LH2 needed significantly, at the expense of very high temperature hydrogen heat exchangers being needed (but doesn't the preburner already need that)?
You may also like to look at http://www.bis.gov.uk/ukspaceagencyWhere you can download the UK Space Agency’s report
The pre-burner is required to handle a large range of flow rates and mixture ratio variations in the course of the SKYLON mission. This said; its function differs from that of a classical pre-burner in that, whereas a classical staged combustion approach uses the output of the pre-burner to directly power the turbomachinery for the pumps, the SABRE engine uses it as a heat source to top off the heat input into the helium loop. The helium then goes on to power the turbo-machinery for the turbo-compressor and LOX pumps.
http://forum.nasaspaceflight.com/index.php?topic=24621.msg744330#msg744330
What is the music in the first segment of that video?Dvorzak? Stirring stuff!
Quote from: ciscosdad on 06/02/2011 04:00 amWhat is the music in the first segment of that video?Dvorzak? Stirring stuff!Kind of off topic but this is the same music they play at the beginning of 'Triumph of the Will'. (I only know this because I had to watch it for a class freshman year)Back on topic. I always wished that we would have continued with the X-33 and VentureStar. The issue with the propellant tanks could have been solved by using Li-Al alloy tanks. The metallic heat shield would have solved a lot of the issues with the orbiters with regards to cost/safety. Hopefully the people on the other side of the pond will actually build this and make it work.
Could the Skylon be refuelled at an orbital base station and fly to Earth-Moon Lagrange 1 or low lunar orbit? (Delta-V of 3.77 km/s and 4.04 km/s respectively.)
So, in process of designing SABRE, they've managed to reinvent the staged-combustion rocket. Would there be any advantages to doing this for a conventional staged-combustion rocket?
I noticed that the sabre engine uses high pressure staged turbopump driven rocket engines that are similar to the ssme. Given the maintance costs of those engines, this might be a problem.
