I imagine little exploding steam pockets or increased thermal conductivity in your heatshield wouldn't be the most desirable thing in the world.
Quote from: woods170 on 07/13/2018 01:00 pmQuote from: rpapo on 07/13/2018 09:43 amQuote from: Comga on 07/13/2018 04:40 amWhat are we seeing in that photo of Dragon 2 with the Super Dracos?Beyond the white or light grey ramps, as opposed to black, are those covers over the exhaust ports?I wonder if they are to prevent water intrusion and were added when SpaceX went from land landing to ocean?Notice two things from the HR version of that photo: (1) The exhaust ports are covered by something that is marked as "remove before launch", and (2) The color of the ramps is not grey, but silver. That makes sense in the same sense as they silvered much of the tail portion of SpaceShip Two. Reflecting heat away is more effective than absorbing it, at least for certain cases.The silver material is NOT for heat reflection.It is the same silver-colored material that is used to cover the primary heat shield on Cargo Dragon, as well as the primary heat shield on Crew Dragon. It is for moisture protection. Given that the exhaust ports for Super Draco are covered in the same material as the primary heat shield (PICA-X) you can expect the same application of silvery material for moisture protection.PICA(-X) is known to absorb moisture (water) from the atmosphere. When absorbed into the PICA material the water negatively influences the performance of PICA as a heat shield material. It is therefore necessary to prevent PICA from absorbing moisture. That is why the PICA is covered in the silvery material as seen in the recent pictures.More on this subject: https://uknowledge.uky.edu/cgi/viewcontent.cgi?article=1083&context=me_etds
Quote from: rpapo on 07/13/2018 09:43 amQuote from: Comga on 07/13/2018 04:40 amWhat are we seeing in that photo of Dragon 2 with the Super Dracos?Beyond the white or light grey ramps, as opposed to black, are those covers over the exhaust ports?I wonder if they are to prevent water intrusion and were added when SpaceX went from land landing to ocean?Notice two things from the HR version of that photo: (1) The exhaust ports are covered by something that is marked as "remove before launch", and (2) The color of the ramps is not grey, but silver. That makes sense in the same sense as they silvered much of the tail portion of SpaceShip Two. Reflecting heat away is more effective than absorbing it, at least for certain cases.The silver material is NOT for heat reflection.It is the same silver-colored material that is used to cover the primary heat shield on Cargo Dragon, as well as the primary heat shield on Crew Dragon. It is for moisture protection. Given that the exhaust ports for Super Draco are covered in the same material as the primary heat shield (PICA-X) you can expect the same application of silvery material for moisture protection.PICA(-X) is known to absorb moisture (water) from the atmosphere. When absorbed into the PICA material the water negatively influences the performance of PICA as a heat shield material. It is therefore necessary to prevent PICA from absorbing moisture. That is why the PICA is covered in the silvery material as seen in the recent pictures.More on this subject: https://uknowledge.uky.edu/cgi/viewcontent.cgi?article=1083&context=me_etds
Quote from: Comga on 07/13/2018 04:40 amWhat are we seeing in that photo of Dragon 2 with the Super Dracos?Beyond the white or light grey ramps, as opposed to black, are those covers over the exhaust ports?I wonder if they are to prevent water intrusion and were added when SpaceX went from land landing to ocean?Notice two things from the HR version of that photo: (1) The exhaust ports are covered by something that is marked as "remove before launch", and (2) The color of the ramps is not grey, but silver. That makes sense in the same sense as they silvered much of the tail portion of SpaceShip Two. Reflecting heat away is more effective than absorbing it, at least for certain cases.
What are we seeing in that photo of Dragon 2 with the Super Dracos?Beyond the white or light grey ramps, as opposed to black, are those covers over the exhaust ports?I wonder if they are to prevent water intrusion and were added when SpaceX went from land landing to ocean?
Quote from: Nomadd on 07/13/2018 04:58 pm I imagine little exploding steam pockets or increased thermal conductivity in your heatshield wouldn't be the most desirable thing in the world. Yeah, that's basically it. PICA is a great heat shield material as long as you make sure it is prevented from behaving like a moisture sponge.
Quote from: gongora on 07/13/2018 04:00 pmQuote from: woods170 on 07/13/2018 01:00 pmQuote from: rpapo on 07/13/2018 09:43 amQuote from: Comga on 07/13/2018 04:40 amWhat are we seeing in that photo of Dragon 2 with the Super Dracos?Beyond the white or light grey ramps, as opposed to black, are those covers over the exhaust ports?I wonder if they are to prevent water intrusion and were added when SpaceX went from land landing to ocean?Notice two things from the HR version of that photo: (1) The exhaust ports are covered by something that is marked as "remove before launch", and (2) The color of the ramps is not grey, but silver. That makes sense in the same sense as they silvered much of the tail portion of SpaceShip Two. Reflecting heat away is more effective than absorbing it, at least for certain cases.The silver material is NOT for heat reflection.It is the same silver-colored material that is used to cover the primary heat shield on Cargo Dragon, as well as the primary heat shield on Crew Dragon. It is for moisture protection. Given that the exhaust ports for Super Draco are covered in the same material as the primary heat shield (PICA-X) you can expect the same application of silvery material for moisture protection.PICA(-X) is known to absorb moisture (water) from the atmosphere. When absorbed into the PICA material the water negatively influences the performance of PICA as a heat shield material. It is therefore necessary to prevent PICA from absorbing moisture. That is why the PICA is covered in the silvery material as seen in the recent pictures.More on this subject: https://uknowledge.uky.edu/cgi/viewcontent.cgi?article=1083&context=me_etdsIn the vacuum of space wouldn't the water evaporate or boil off, even sublime? Although prevention always seems the first choice.
Quote from: woods170 on 07/13/2018 09:03 pmQuote from: Nomadd on 07/13/2018 04:58 pm I imagine little exploding steam pockets or increased thermal conductivity in your heatshield wouldn't be the most desirable thing in the world. Yeah, that's basically it. PICA is a great heat shield material as long as you make sure it is prevented from behaving like a moisture sponge.Which is why SpaceX probably isn't thrilled about splashing down. Not sure if any of the flight-proven Dragon 1 missions have used flight-proven heatshields.
Quote from: deadman719 on 07/13/2018 03:09 amQuote from: cppetrie on 07/13/2018 03:01 amQuote from: deadman719 on 07/13/2018 02:45 amQuote from: FutureSpaceTourist on 07/12/2018 09:00 pmQuotespacex Crew Dragon arrived in Florida this week ahead of its first flight after completing thermal vacuum and acoustic testing at @NASA’s Plum Brook Station in Ohiohttps://www.instagram.com/p/BlJVBidF4I2/Edit to add: higher-res photoAnyone have insight as to why the window on the right side has a plate instead of a glass? Respectfully,RobCovers for transport? There appear to be covers over every opening to seal out debris. Seems likely they’d cover the glass to prevent debris from damaging the glass in transit.I thought that at first. If it was for protection during shipment, why would the left window have plastic taped over the window while the right one appears to have a bolted-in-place panel?The window at the right is not actually a window. It is a cover-plate to fill in the void between the outer-shell panels where there could be a window (per design) but where there is not actually a window on this particular vehicle. The pressure shell underneath doesn't have the window frame welded into it at that location.The DM-1 vehicle carries only two windows, one each left and right of the crew hatch. There is no need to carry more given that the vehicle is un-crewed and the two windows present are enough to satisfy window qualification requirements on this mission.
Quote from: cppetrie on 07/13/2018 03:01 amQuote from: deadman719 on 07/13/2018 02:45 amQuote from: FutureSpaceTourist on 07/12/2018 09:00 pmQuotespacex Crew Dragon arrived in Florida this week ahead of its first flight after completing thermal vacuum and acoustic testing at @NASA’s Plum Brook Station in Ohiohttps://www.instagram.com/p/BlJVBidF4I2/Edit to add: higher-res photoAnyone have insight as to why the window on the right side has a plate instead of a glass? Respectfully,RobCovers for transport? There appear to be covers over every opening to seal out debris. Seems likely they’d cover the glass to prevent debris from damaging the glass in transit.I thought that at first. If it was for protection during shipment, why would the left window have plastic taped over the window while the right one appears to have a bolted-in-place panel?
Quote from: deadman719 on 07/13/2018 02:45 amQuote from: FutureSpaceTourist on 07/12/2018 09:00 pmQuotespacex Crew Dragon arrived in Florida this week ahead of its first flight after completing thermal vacuum and acoustic testing at @NASA’s Plum Brook Station in Ohiohttps://www.instagram.com/p/BlJVBidF4I2/Edit to add: higher-res photoAnyone have insight as to why the window on the right side has a plate instead of a glass? Respectfully,RobCovers for transport? There appear to be covers over every opening to seal out debris. Seems likely they’d cover the glass to prevent debris from damaging the glass in transit.
Quote from: FutureSpaceTourist on 07/12/2018 09:00 pmQuotespacex Crew Dragon arrived in Florida this week ahead of its first flight after completing thermal vacuum and acoustic testing at @NASA’s Plum Brook Station in Ohiohttps://www.instagram.com/p/BlJVBidF4I2/Edit to add: higher-res photoAnyone have insight as to why the window on the right side has a plate instead of a glass? Respectfully,Rob
Quotespacex Crew Dragon arrived in Florida this week ahead of its first flight after completing thermal vacuum and acoustic testing at @NASA’s Plum Brook Station in Ohiohttps://www.instagram.com/p/BlJVBidF4I2/Edit to add: higher-res photo
spacex Crew Dragon arrived in Florida this week ahead of its first flight after completing thermal vacuum and acoustic testing at @NASA’s Plum Brook Station in Ohio
Quote from: FutureSpaceTourist on 07/12/2018 09:00 pmQuotespacex Crew Dragon arrived in Florida this week ahead of its first flight after completing thermal vacuum and acoustic testing at @NASA’s Plum Brook Station in Ohiohttps://www.instagram.com/p/BlJVBidF4I2/So, where are we in the flow to DM-1?
Quotespacex Crew Dragon arrived in Florida this week ahead of its first flight after completing thermal vacuum and acoustic testing at @NASA’s Plum Brook Station in Ohiohttps://www.instagram.com/p/BlJVBidF4I2/
Quote from: butters on 07/13/2018 10:37 pmQuote from: woods170 on 07/13/2018 09:03 pmQuote from: Nomadd on 07/13/2018 04:58 pm I imagine little exploding steam pockets or increased thermal conductivity in your heatshield wouldn't be the most desirable thing in the world. Yeah, that's basically it. PICA is a great heat shield material as long as you make sure it is prevented from behaving like a moisture sponge.Which is why SpaceX probably isn't thrilled about splashing down. Not sure if any of the flight-proven Dragon 1 missions have used flight-proven heatshields.They have not.
From twitter there have been 16 D2 parachute tests till June 26 2018.https://twitter.com/spacex/status/1011703684454014976?lang=enHow many test articles can we confirmed for these tests?
Mike Pence will visit Cape Canaveral next month for a big space update Quote Pence, who chairs the National Space Council, will confirm a new launch date for the first private crew missions and announce which crew capsules each of the four selected astronauts will ride in to the International Space Station.
Pence, who chairs the National Space Council, will confirm a new launch date for the first private crew missions and announce which crew capsules each of the four selected astronauts will ride in to the International Space Station.
Quote from: jpo234 on 07/17/2018 04:25 pm Mike Pence will visit Cape Canaveral next month for a big space update Quote Pence, who chairs the National Space Council, will confirm a new launch date for the first private crew missions and announce which crew capsules each of the four selected astronauts will ride in to the International Space Station. We will get an update by VP Pence on commercial crew on August 3rd. See the link above.
Spiro Agnew didn't announce that Armstrong would command Apollo 11.....
With the forth parachute added why couldn't crew dragon make a land landing in the southwest desert as Starliner is doing?