The main heat shield has been changed to a monolithic form as opposed to many individual parts. The thermal tiles on the side (look like Space Shuttle tiles) will be getting a highly reflective coating instead of the bare tiles seen on EFT-1.
Its basically a new design. EFT-1 didn't have a service module at all, so EVERYTHING there is new. On the CM, they changed the heat shield to be more easily manufactured (its now made in tiles like the bottom of Dragon, instead of a single piece), the backshell TPS has a new coating on it for additional protection and on-orbit thermal control, the pressure vessel has been redesigned to need fewer welds (lower mass and easier manufacturing), changes to the parachutes and inflatable floatation devices have been made based on issues encountered on EFT-1, the computers are new, and it will carry some life support test equipment.
Fascinating. With the heat shield made of titles, how do they solve the issue of a title or titles disconnecting from the C.M?
Quote from: Raj2014 on 05/28/2017 07:39 pmFascinating. With the heat shield made of titles, how do they solve the issue of a title or titles disconnecting from the C.M? No different than the shuttle
Quote from: Jim on 05/29/2017 12:46 pmQuote from: Raj2014 on 05/28/2017 07:39 pmFascinating. With the heat shield made of titles, how do they solve the issue of a title or titles disconnecting from the C.M? No different than the shuttleIs that not a problem that needs to be solved? Do not want the heat to burn the inside of the C.M and destroy it. Already there has been a past incident of missing titles. I do not want to see it happen again.
Quote from: Raj2014 on 05/29/2017 11:42 pmQuote from: Jim on 05/29/2017 12:46 pmQuote from: Raj2014 on 05/28/2017 07:39 pmFascinating. With the heat shield made of titles, how do they solve the issue of a title or titles disconnecting from the C.M? No different than the shuttleIs that not a problem that needs to be solved? Do not want the heat to burn the inside of the C.M and destroy it. Already there has been a past incident of missing titles. I do not want to see it happen again. Dragon has been flying with a tiled heat shield for a while now. No tiles have been lost, as far as I know. That aspect of Orion does not worry me at all.Once a heat shield reaches a certain size, a monolithic piece becomes impractical.
And the even bigger irony is (IMO) that NASA rejected PICA because it would have to be applied using tiles. And now they are back to Avcoat with tiles.
Since the Dragon capsules has used PICA-X titled heat shields for several launches. Why has Lockheed Martin or NASA not decided to use it for the Orion's heat shield?
Quote from: Raj2014 on 05/31/2017 01:18 pmSince the Dragon capsules has used PICA-X titled heat shields for several launches. Why has Lockheed Martin or NASA not decided to use it for the Orion's heat shield? PICA-X is Spacex propriety material and is not available
Quote from: Jim on 05/31/2017 01:22 pmQuote from: Raj2014 on 05/31/2017 01:18 pmSince the Dragon capsules has used PICA-X titled heat shields for several launches. Why has Lockheed Martin or NASA not decided to use it for the Orion's heat shield? PICA-X is Spacex propriety material and is not availableDid NASA tried to request SpaceX to be the heatshield subcontractor for Orion and they flat denied or they have simply not made the RFQ and is not a pure NASA product?
Quote from: baldusi on 05/31/2017 02:25 pmQuote from: Jim on 05/31/2017 01:22 pmPICA-X is Spacex propriety material and is not availableDid NASA tried to request SpaceX to be the heatshield subcontractor for Orion and they flat denied or they have simply not made the RFQ and is not a pure NASA product?The NASA Authorization Act of 2010 specified the use of existing contractors for SLS and Orion.
Quote from: Jim on 05/31/2017 01:22 pmPICA-X is Spacex propriety material and is not availableDid NASA tried to request SpaceX to be the heatshield subcontractor for Orion and they flat denied or they have simply not made the RFQ and is not a pure NASA product?
PICA-X is Spacex propriety material and is not available
Quote from: whitelancer64 on 05/31/2017 02:56 pmQuote from: baldusi on 05/31/2017 02:25 pmQuote from: Jim on 05/31/2017 01:22 pmPICA-X is Spacex propriety material and is not availableDid NASA tried to request SpaceX to be the heatshield subcontractor for Orion and they flat denied or they have simply not made the RFQ and is not a pure NASA product?The NASA Authorization Act of 2010 specified the use of existing contractors for SLS and Orion.But not every subcontractor. Was any attempt made by LM to sub-contract or license PICA-X from SpaceX? I sincerely doubt it.
Is there anything wrong with Avcoat when used in tiles? Why wound NASA want to change to PICA anyway?
Quote from: Dante80 on 05/31/2017 06:49 pmIs there anything wrong with Avcoat when used in tiles? Why wound NASA want to change to PICA anyway?Cost. Primarily because it is very labor intensive to hand-inject every cell in the honeycomb.
Quote from: Lars-J on 05/31/2017 07:15 pmQuote from: Dante80 on 05/31/2017 06:49 pmIs there anything wrong with Avcoat when used in tiles? Why wound NASA want to change to PICA anyway?Cost. Primarily because it is very labor intensive to hand-inject every cell in the honeycomb.Wouldn't changing to PICA after EFT-1 showed cracks introduce a lot more development cost (and schedule overrun)? Recurring cost differences are almost completely irrelevant for a flagship spacecraft like Orion (and the number of missions that is projected to have). Also, what would changing the material do to the weight of the system (shield + structure)? (any guesses, I have no idea)
What is the height of the crew module of the Orion Spacecraft? I have looked at some websites but can not get an accurate measurement. Sources say it is 3.3 metres tall. Is the Orion C.M taller than the Apollo C.M?
How tall is the Apollo C.M? On the research I have done, some of the websites shows 3.23 metres tall. Is this correct?
Thank you whitelancer64 for the information. I have a idea here. Can they combine the H.I.A.D (Hypersonic Inflatable Aerodynamic Decelerator) to the Orion Spacecraft so you can also have the service module returned and re-used, would this not bring down costs and save time? Has N.A.S.A looked into this?
Quote from: Raj2014 on 09/27/2017 08:43 pmThank you whitelancer64 for the information. I have a idea here. Can they combine the H.I.A.D (Hypersonic Inflatable Aerodynamic Decelerator) to the Orion Spacecraft so you can also have the service module returned and re-used, would this not bring down costs and save time? Has N.A.S.A looked into this?It probably could be done, but it would require a major redesign - and that may cost much more time than it is worth. Also it is the ESA that is building the service module.
Quote from: whitelancer64 on 09/27/2017 08:50 pmQuote from: Raj2014 on 09/27/2017 08:43 pmThank you whitelancer64 for the information. I have a idea here. Can they combine the H.I.A.D (Hypersonic Inflatable Aerodynamic Decelerator) to the Orion Spacecraft so you can also have the service module returned and re-used, would this not bring down costs and save time? Has N.A.S.A looked into this?It probably could be done, but it would require a major redesign - and that may cost much more time than it is worth. Also it is the ESA that is building the service module.True E.S.A is building the S.M but really a major redesign? What I find surprised is that the inflatable heat shield technology has been researched for some time and that they have not thought about it or at list made design plans for a future upgrade for the Orion spacecraft. Is the Orion going to, or not, get upgraded over the years with newer technologies and efficiency?
HIAD is a decelerator, not a heat shield.
Can anyone speak to the history of Orion's delta-v number? Why did they decide to initially rely on Altair for LOI? And why have low delta-v numbers persisted after Altair's cancellation and, later, a complete change in who's doing the SM? What's driving this lack of capability? (and is "lack of capability" an accurate perception of Orion's delta-v budget?)
Can anyone speak to the history of Orion's delta-v number? Why did they decide to initially rely on Altair for LOI?
Quote from: theinternetftw on 12/26/2017 10:06 pmCan anyone speak to the history of Orion's delta-v number? Why did they decide to initially rely on Altair for LOI?My guess is that the low delta-V was needed to allow launch on Ares I, which in turn was needed for political reasons. Just my guess.
If going to the lunar surface is now once again an objective, Orion is underfueled and that capability will have to be made up by a larger lander or on-orbit fueling.
SLS seems little better than Ares 1 for SM sizing though. Orion is near the limit of Block 1 performance to TLI, and Block 1B allows only ~10 tons margin to that trajectory for comanifested payload, which a larger SM will directly reduce. The new Orion Main Engine from EM-3 onwards could improve this without much increase in mass (depending on what engine is selected), but probably not substantially.
Quote from: envy887 on 12/28/2017 05:48 pmIf going to the lunar surface is now once again an objective, Orion is underfueled and that capability will have to be made up by a larger lander or on-orbit fueling.Not true. It has plenty of propellant to get into lunar orbit and back. If a lander is involved, then the lander should provide its own delta V. Apollo conop is not the only nor correct one.
https://www.raumfahrer.net/news/images/Deep_Space_Gateway_gross.jpg And https://lh3.googleusercontent.com/-erKia2v415Y/VkIak_kfLMI/AAAAAAAEPfs/KoE85FXMXMw/w1582-h2048/Orion%2BESM%2BInfographic%2B-%2BNASA.jpg are usually accepted as the closest renderings from NASATheres no dish
Do we have any reliable statement or estimate for the per-unit cost / cost per build of the Orion spacecraft?
Quote from: whitelancer64 on 04/23/2018 09:19 pmDo we have any reliable statement or estimate for the per-unit cost / cost per build of the Orion spacecraft? According to this presentation from Edgar Zapata (page 10, pdf warning) it's $980M per-unit production costs if you build one a year, $654M if you build two a year, and $1,672M if you build less than one a year.
We had a discussion about this a while ago. I believe a number around 500 km was mentioned.
Quote from: Proponent on 07/10/2019 10:29 pmWe had a discussion about this a while ago. I believe a number around 500 km was mentioned.Wow, that's a bit lower than I thought was possible.
Quote from: whitelancer64 on 07/10/2019 11:12 pmQuote from: Proponent on 07/10/2019 10:29 pmWe had a discussion about this a while ago. I believe a number around 500 km was mentioned.Wow, that's a bit lower than I thought was possible.Can't seem to achieve a circular 500 km orbit with only 650 m/s of dV. I think it is more like 2000 km or about 1 lunar radius in altitude. Going from 500 km to 100 km lunar orbit is only about 80 m/s. Orion's deficit is more than that (more like 250 m/s).