But anyhow, this is a great discussion. Here is my "affordable" miniature idea. I'd like to land the smallest possible lunar lander at one of the Apollo sites, photograph it a half dozen times, and successfully transmit the images back to Earth on an open channel.I lost the envelope, but it seemed at the time that an F1 would do it.
"Think" I found it, I can't access the site from this computer though:http://www.quantumg.net/mockingbird.pdfRandyEdit: ARrrggghhhh! I "just" noticed it's QuantumG's page.... Ok fess up fella what OTHER information are you holding we should know about!
Nitrous mono-props like Firestar's NOFBX offer greater performance for less complexity.
Quote from: QuantumG on 06/02/2011 10:04 pmNitrous mono-props like Firestar's NOFBX offer greater performance for less complexity. Greater performance than JP5/H2O2?
See Appendix A. They assume 301s (vac) for the 8 low expansion engines and 327s (vac) for the 1 high expansion engine. Firestar are claiming 320s (vac) for pressure-fed NOFBX. So, if you were to pump it, you'd get higher performance.
Quote from: RanulfC on 06/01/2011 07:14 pm"Think" I found it, I can't access the site from this computer though:http://www.quantumg.net/mockingbird.pdfRandyEdit: ARrrggghhhh! I "just" noticed it's QuantumG's page.... Ok fess up fella what OTHER information are you holding we should know about! Great minds.. I was just going to post it. The pdf originally had some horrible long name and was publicly available on the LLNL website.. it might still be, I don't know.
There's been a lot of technology development since '94. Aerogel is now everywhere and sheets can be commercially procured. XCOR has pumpfed engines available off-the-shelf with the performance capabilities that are described. Nitrous mono-props like Firestar's NOFBX offer greater performance for less complexity. The biggest objection to the concept remains the aerodynamics. They were very optimistic in their numbers and probably need to add another 1 km/s of delta-v, and all the knock-on effects that has.
But there's something incredibly sexy about having a 75 kg rocket which you can throw in the back of a pickup truck and go launch a nanosat to orbit from anywhere, with a fuel truck as the only support vehicle required.
Old topic but maybe we can give it a kick.Team Prometheus is attempting to orbit a 20 gram payload launched from 100,000ft.
Quote from: RanulfC on 06/01/2011 07:14 pm"Think" I found it, I can't access the site from this computer though:http://www.quantumg.net/mockingbird.pdfRandyEdit: ARrrggghhhh! I "just" noticed it's QuantumG's page.... Ok fess up fella what OTHER information are you holding we should know about! Great minds.. I was just going to post it. The pdf originally had some horrible long name and was publicly available on the LLNL website.. it might still be, I don't know.There's been a lot of technology development since '94. Aerogel is now everywhere and sheets can be commercially procured. XCOR has pumpfed engines available off-the-shelf with the performance capabilities that are described. Nitrous mono-props like Firestar's NOFBX offer greater performance for less complexity. The biggest objection to the concept remains the aerodynamics. They were very optimistic in their numbers and probably need to add another 1 km/s of delta-v, and all the knock-on effects that has.But there's something incredibly sexy about having a 75 kg rocket which you can throw in the back of a pickup truck and go launch a nanosat to orbit from anywhere, with a fuel truck as the only support vehicle required.
Regarding scaling factors, etc - what if you don't assume launch at sea-level? What if you assume launch at a higher altitude, even using a propellant with lighter molecular weight?
I wonder what the payload would be if the the payload it's self could do part of the orbital insertion burn acting as it's own second stage?Looking at some SSTO concepts you might be able to double or triple the payload that way.
Quote from: Monroe on 05/28/2011 11:33 pmOld topic but maybe we can give it a kick.Team Prometheus is attempting to orbit a 20 gram payload launched from 100,000ft.I'd love to hear more about your plans with Team Prometheus.Newer than the origin of this thread is the N-Prize to launch a 10 to 20 gram satellite to orbit for under 1,000 british pounds. http://www.n-prize.comTheir "press" page has a lot of promising links to a couple Space Shows I look forward to listening to.Also newer than this thread is a 2009 Google TechTalk with Charles Pooley of Microlaunchers, a frequent poster to our forum.
QuoteJim - 11/6/2006 6:20 PMQuotemlorrey - 11/6/2006 3:59 PMQuoteZachstar - 10/6/2006 4:40 PMMight find this interesting http://www.microlaunchers.com/home.htmIt is interesting what micromachinery is being made. Just the other day I was chatting with a fellow at a company that produces MEMS chip liquid cooling devices, made by diffusion bonding hundreds of leaves of 1-3 mil metal, each with their own micro cut patterns.The problem is micromachinery doesn't work very well with fluids. The same reasons that there are no small jst engines, would be the same for turbo pumps. Reynolds numbers don't scale.What makes you think there are no small jet engines? I know a number of modellers who fly jet engines in the 10-100 lb thrust range, and a number of institutions, including MIT, are developing MEMS turbine generators for powering remote devices, many of which are being developed for Army infantry use:http://www.enme.umd.edu/SSSC/pdf/update/Transducers%2097%20-%20Paper.pdfhttp://www.enme.umd.edu/SSSC/pdf/update/HH2000-Turbine.pdfhttp://www.enme.umd.edu/SSSC/pdf/update/MEMS%2099%20-%20Paper.pdfIn fact, turbines reach adiabatic efficiencies of 70% and are able to maintain supersonic turbine speeds while maintaining laminar flow, with Reynolds numbers up around 20,000. The one MIT is working on is an 80 watt turbogenerator, with a turbine disc diameter of about 3-4 mm. The full engine assembly is 1 cm dia.NASA is also working on a "steam" turbine, using Xenon as the working fluid, which is heated by various processes: fuel cells, solar concentrators, radiothermal devices, etc.http://www.nasatech.com/Briefs/Jan03/NPO20933.htmlThe reason for this is because at the microscale, gasses flow with the viscosity of liquids at macro scales.
Jim - 11/6/2006 6:20 PMQuotemlorrey - 11/6/2006 3:59 PMQuoteZachstar - 10/6/2006 4:40 PMMight find this interesting http://www.microlaunchers.com/home.htmIt is interesting what micromachinery is being made. Just the other day I was chatting with a fellow at a company that produces MEMS chip liquid cooling devices, made by diffusion bonding hundreds of leaves of 1-3 mil metal, each with their own micro cut patterns.The problem is micromachinery doesn't work very well with fluids. The same reasons that there are no small jst engines, would be the same for turbo pumps. Reynolds numbers don't scale.
mlorrey - 11/6/2006 3:59 PMQuoteZachstar - 10/6/2006 4:40 PMMight find this interesting http://www.microlaunchers.com/home.htmIt is interesting what micromachinery is being made. Just the other day I was chatting with a fellow at a company that produces MEMS chip liquid cooling devices, made by diffusion bonding hundreds of leaves of 1-3 mil metal, each with their own micro cut patterns.
Zachstar - 10/6/2006 4:40 PMMight find this interesting http://www.microlaunchers.com/home.htm
