The EDL sequence had only been tested once. One better than STS-1, but I’ll be happy when I see the chutes.
I frequently roll my eyes with aerospace companies claim any particular design has heritage, but does any of the cargo Dragon work also make this a better reentry than STS-1?
As far as I know, the PicaX heat shield and SPAM backshell protection are the same, so that is legacy. However, Dragon 1 was passively stable, so could survive an all-systems (except chutes) failure with a ballistic reentry, resulting like Soyuz in an unhappy but alive crew. My understanding is Dragon 2 is assymetrical enough to potentially unstable. I undertsand it has a CoG sled, as well as Draco thrusters for reentry, but if both failed, it could go into a flat spin, leading to a very bad day.
I’ve always wondered why SpaceX went with an all-new design. Dragon cargo, with the addition of life support, would have made IMHO a good crew vehicle.
Of course, it does not have pad abort of launch abort capabilities, but, they theoretically could have used the Super-draco engines on a small pusher stage (like Boeing’s, for Starliner, roughly) placed between the trunk and the Dragon.
Ultimately, the decision was based on the propulsive landing plan that was abandoned pretty late in the program, once it became clear validating the system would be too expensive for the scope of the program. Also the lower bay on Dragon 2 is significantly deeper than the one on Dragon 1 to accommodate the originally mandated 7 crew seats.
An expendable pusher abort module would cost a lot to develop, since it would in effect be a separate spacecraft. Look at the trouble Boeing has had. I don’t know why Boeing did it, since a solid fuel escape tower (like Mercury, Apollo, Orion, Soyuz, and Tienzhou) would be cheaper to create. Soyuz and Shenzhou even show how you can use an escape tower with a spacecraft encapsulated in a shroud (such as a crewed version of Dream Chaser might be). SpaceX had a reason to do what they did, even though it didn’t work out the way they hoped.
NASA is working the heck out of these guys. Are they gaining new enthusiasm for affordable access to space? Or are they afraid this is the last trip for quite a while?
Just trying to get ahead of the curve while they have two experienced EVA guys aboard. Today’s is the 7th EVA for both Cassidy and Behnken, I think. If DM-2 gets down safely and nothing ususual turns up, the USCV-1 Dragon with 4 crew will come up in Sept., most likely. Emergency backup to that is, NASA bought a seat on the Oct. Soyuz (for $90 million plus free cargo, I think).
The EDL sequence had only been tested once. One better than STS-1, but I’ll be happy when I see the chutes.
I frequently roll my eyes with aerospace companies claim any particular design has heritage, but does any of the cargo Dragon work also make this a better reentry than STS-1?
As far as I know, the PicaX heat shield and SPAM backshell protection are the same, so that is legacy. However, Dragon 1 was passively stable, so could survive an all-systems (except chutes) failure with a ballistic reentry, resulting like Soyuz in an unhappy but alive crew. My understanding is Dragon 2 is assymetrical enough to potentially unstable. I undertsand it has a CoG sled, as well as Draco thrusters for reentry, but if both failed, it could go into a flat spin, leading to a very bad day.
I’ve always wondered why SpaceX went with an all-new design. Dragon cargo, with the addition of life support, would have made IMHO a good crew vehicle.
Of course, it does not have pad abort of launch abort capabilities, but, they theoretically could have used the Super-draco engines on a small pusher stage (like Boeing’s, for Starliner, roughly) placed between the trunk and the Dragon.
Ultimately, the decision was based on the propulsive landing plan that was abandoned pretty late in the program, once it became clear validating the system would be too expensive for the scope of the program. Also the lower bay on Dragon 2 is significantly deeper than the one on Dragon 1 to accommodate the originally mandated 7 crew seats.
An expendable pusher abort module would cost a lot to develop, since it would in effect be a separate spacecraft. Look at the trouble Boeing has had. I don’t know why Boeing did it, since a solid fuel escape tower (like Mercury, Apollo, Orion, Soyuz, and Tienzhou) would be cheaper to create. Soyuz and Shenzhou even show how you can use an escape tower with a spacecraft encapsulated in a shroud (such as a crewed version of Dream Chaser might be). SpaceX had a reason to do what they did, even though it didn’t work out the way they hoped.
NASA is working the heck out of these guys. Are they gaining new enthusiasm for affordable access to space? Or are they afraid this is the last trip for quite a while?
Just trying to get ahead of the curve while they have two experienced EVA guys aboard. Today’s is the 7th EVA for both Cassidy and Behnken, I think. If DM-2 gets down safely and nothing ususual turns up, the USCV-1 Dragon with 4 crew will come up in Sept., most likely. Emergency backup to that is, NASA bought a seat on the Oct. Soyuz (for $90 million plus free cargo, I think).