Also how do you calculate mass flow rate for Raptor?
Your asking me to prove it is more EFFICIENT, that is completely different from saying it is SIMPLER. I have NEVER claimed it is more efficient, but you keep confusing the thouse concepts.
A heat shield has many benefits, and will be employed to maximize those obvious benefits (without adding complexity and risk to the design such as an inflatable HAID) and retro-propulsion will do the rest*.
Quote from: AncientU on 08/07/2016 10:56 amA heat shield has many benefits, and will be employed to maximize those obvious benefits (without adding complexity and risk to the design such as an inflatable HAID) and retro-propulsion will do the rest*. A HIAD is just a more efficient heatshield. It is a simple concept and it has been shown to work. This NASA video shows the application of a HIAD for the safe return of a cargo spaceship from the ISS. It is not a great leap to imagine the same technology being used for the return of an F9S2.https://www.nasa.gov/directorates/spacetech/game_changing_development/HIAD/HEART-Desig-Concept.html
Adding a HAID to the flamey end of a F9 is not simple. It has to deploy from the engine compartment/octaweb over hot engines between burns and then get out of the way for the landing burn. Efficient, maybe. Simple, NOT.
Quote from: AncientU on 08/07/2016 12:24 pmAdding a HAID to the flamey end of a F9 is not simple. It has to deploy from the engine compartment/octaweb over hot engines between burns and then get out of the way for the landing burn. Efficient, maybe. Simple, NOT.Who said to add it to the flamey end?https://forum.nasaspaceflight.com/index.php?topic=37808.msg1565000#msg1565000Just pack it in the interstage with some nitrogen bottles.
A HIAD is just a more efficient heatshield. It is a simple concept and it has been shown to work. This NASA video shows the application of a HIAD for the safe return of a cargo spaceship from the ISS. It is not a great leap to imagine the same technology being used for the return of an F9S2.https://www.nasa.gov/directorates/spacetech/game_changing_development/HIAD/HEART-Desig-Concept.html
How many of the cargo return proposals/designs are using HIADs?NASA PowerPoint/video does not an operating system make.
Quote from: AncientU on 08/07/2016 12:53 pmHow many of the cargo return proposals/designs are using HIADs?NASA PowerPoint/video does not an operating system make.HIAD is way beyond PowerPoint presentations. Google is of course your friend, but there have been successful tests of the technology, and it's potential applications also extend to super heavy Mars landers.
Quote from: OneSpeed on 08/07/2016 01:09 pmQuote from: AncientU on 08/07/2016 12:53 pmHow many of the cargo return proposals/designs are using HIADs?NASA PowerPoint/video does not an operating system make.HIAD is way beyond PowerPoint presentations. Google is of course your friend, but there have been successful tests of the technology, and it's potential applications also extend to super heavy Mars landers.How many super heavy Mars landers have used HIADs? Why is that?Google "If a hammer is the only tool"
2020 and exomars aren't going to be significantly larger than MSL.This is a dumb way to argue. Please bring better game.
Quote from: Robotbeat on 08/07/2016 05:24 pm2020 and exomars aren't going to be significantly larger than MSL.This is a dumb way to argue. Please bring better game.Fine. What evidence is there that MCT will use a HIAD?
Quote from: AncientU on 08/07/2016 05:50 pmQuote from: Robotbeat on 08/07/2016 05:24 pm2020 and exomars aren't going to be significantly larger than MSL.This is a dumb way to argue. Please bring better game.Fine. What evidence is there that MCT will use a HIAD?There's some indirect evidence that it may be one of several options they'll consider.
Quote from: Impaler on 08/07/2016 08:51 amYour asking me to prove it is more EFFICIENT, that is completely different from saying it is SIMPLER. I have NEVER claimed it is more efficient, but you keep confusing the thouse concepts.I'm merely asking for evidence that's it's physically possible, not proof that it's optimal. It does appear possible for a stage that only enters from LEO or suborbital trajectories.GTO and BLEO orbits would require a 3rd stage with a lot of Delta V, but I suppose that's not an issue is you assume BFS is a third stage and SEP tugs will fill some of those roles eventually.