Author Topic: SpaceX Falcon 9 / Dragon 2 : SpX-DM1 : March 2, 2019 : DISCUSSION (Read 638201 times)

ngilmore · « **Reply #1140 on:** 03/08/2019 04:36 am »

Quote from: Lars-J on 03/08/2019 03:37 am

Quote from: DatUser14 on 03/08/2019 01:44 am
Latest article says there will be a Draco burn to physically separate from the IDA. Was that necessary for similar ports(APAS-95, etc) or is this unique to crew dragon and the SpaceX Docking System?

How else would they separate? Any push from the docking adapter would be very slight.

Usually there is a very slight burn to get some separation, and then a longer burn once outside the immediate vicinity.

From today's article:

Quote

Unlike the current Soyuz and Progress vehicles and the Space Shuttle of the past, Crew Dragon will not undock from the Station using springs to physically separate and push it away from the outpost.

https://www.nasaspaceflight.com/2019/03/eom-spacex-crew-dragons-inaugural-station/

Targeteer · « **Reply #1141 on:** 03/08/2019 06:53 am »

odds that the terms "approach ellipsoid" or "keep out sphere" are used once during the approach of a Russian Soyuz next week? Zero.

Johnnyhinbos · « **Reply #1142 on:** 03/08/2019 06:59 am »

So, being asked for historical context...

When was the last time an American human-rated spacecraft came down under parachutes? Splashed down? Was recovered?

Today’s events represent a milestone that probably hasn’t been achieved in the lifetimes of a large number of readers of this forum.

Pretty amazing...

CJ · « **Reply #1143 on:** 03/08/2019 07:17 am »

Quote from: Johnnyhinbos on 03/08/2019 06:59 am

So, being asked for historical context...

When was the last time an American human-rated spacecraft came down under parachutes? Splashed down? Was recovered?

Today’s events represent a milestone that probably hasn’t been achieved in the lifetimes of a large number of readers of this forum.

Pretty amazing...

Human rated... I can't think of a human-rated US spacecraft that wasn't manned coming down under the silk, so I'm going to have to go with the obvious (and therefor probably wrong) answer; the last manned flight before the Shuttle. Apollo-Soyuz, 1975.

Svetoslav · « **Reply #1144 on:** 03/08/2019 08:17 am »

What about Orion in 2014?

AbuSimbel · « **Reply #1145 on:** 03/08/2019 08:38 am »

Quote from: Svetoslav on 03/08/2019 08:17 am

What about Orion in 2014?

If we're down to this you could as well say why not Dragon in 2010...

WindnWar · « **Reply #1146 on:** 03/08/2019 08:38 am »

Quote from: Svetoslav on 03/08/2019 08:17 am

What about Orion in 2014?

Since that Orion capsule lacked the life support system and several other systems, I don't think it actually qualifies to be human rated as you could not have put human in it. Crew Dragon as far as I am aware has all its systems.

Alexphysics · « **Reply #1147 on:** 03/08/2019 09:01 am »

Quote from: dalek on 03/08/2019 08:59 am

Missed the coverage- has SpaceX closed the nosecone ??

Not yet

b.lorenz · « **Reply #1148 on:** 03/08/2019 10:05 am »

Quote from: Alexphysics on 03/08/2019 09:01 am

Quote from: dalek on 03/08/2019 08:59 am
Missed the coverage- has SpaceX closed the nosecone ??

Not yet

Update thread says it is scheduled to happen after deorbit burn but before reentry. My question is: Does not this carry a slight risk of having problems with closing and securing the cone and not having time to resolve before entering atmosphere? Or are the sensors under it needed for navigation?

kevinof · « **Reply #1149 on:** 03/08/2019 10:12 am »

The star tracker is located under the nosecone. I suspect (don't know) that if it doesn't close , they can still de-orbit and land. Having it closed protects the gear and hatch and would also stop any seawater intrusion.

Quote from: b.lorenz on 03/08/2019 10:05 am

Quote from: Alexphysics on 03/08/2019 09:01 am
Quote from: dalek on 03/08/2019 08:59 am
Missed the coverage- has SpaceX closed the nosecone ??

Not yet
Update thread says it is scheduled to happen after deorbit burn but before reentry. My question is: Does not this carry a slight risk of having problems with closing and securing the cone and not having time to resolve before entering atmosphere? Or are the sensors under it needed for navigation?

photonic · « **Reply #1150 on:** 03/08/2019 11:19 am »

Quote from: b.lorenz on 03/08/2019 10:05 am

Quote from: Alexphysics on 03/08/2019 09:01 am
Quote from: dalek on 03/08/2019 08:59 am
Missed the coverage- has SpaceX closed the nosecone ??

Not yet
Update thread says it is scheduled to happen after deorbit burn but before reentry. My question is: Does not this carry a slight risk of having problems with closing and securing the cone and not having time to resolve before entering atmosphere? Or are the sensors under it needed for navigation?

One issue might be that 4 of the thrusters can no longer be used, since they would covered by the nose cone. (At least that is what I understood from the live stream. This must be the 4 big holes you see around the docking adapter, but still within the area covered by the cone).

b.lorenz · « **Reply #1151 on:** 03/08/2019 11:42 am »

Quote from: kevinof on 03/08/2019 10:12 am

The star tracker is located under the nosecone. I suspect (don't know) that if it doesn't close , they can still de-orbit and land. Having it closed protects the gear and hatch and would also stop any seawater intrusion.

Quote from: b.lorenz on 03/08/2019 10:05 am
Quote from: Alexphysics on 03/08/2019 09:01 am
Quote from: dalek on 03/08/2019 08:59 am
Missed the coverage- has SpaceX closed the nosecone ??

Not yet
Update thread says it is scheduled to happen after deorbit burn but before reentry. My question is: Does not this carry a slight risk of having problems with closing and securing the cone and not having time to resolve before entering atmosphere? Or are the sensors under it needed for navigation?

I do not think Dragon can reenter with nosecone wide open. My concern is not that the backwards side gets damaged, but that the air resistance of the sideways-hanging nosecone causes a strong yaw moment and sends the spacecraft in a spin. But anyway, if it would cover the star-tracker, then they need to keep it open for orbital manouvering, and the closing mechanism is probably quite simple and robust.

WindnWar · « **Reply #1152 on:** 03/08/2019 11:48 am »

They did mention in this mornings coverage that the nose cone could be separated in certain circumstances, so I would guess that it has separation hardware in case it didn't close they could just ditch it instead.

hektor · « **Reply #1153 on:** 03/08/2019 12:09 pm »

Anybody on the ground path to tell us if a plasma trail is visible in the sky ?

hektor · « **Reply #1154 on:** 03/08/2019 12:11 pm »

Nose cone closing live on NASA TV...

hektor · « **Reply #1155 on:** 03/08/2019 12:24 pm »

Are the images in the cabin on NASA TV live ?

Rifleman · « **Reply #1156 on:** 03/08/2019 12:26 pm »

Quote from: hektor on 03/08/2019 12:09 pm

Anybody on the ground path to tell us if a plasma trail is visible in the sky ?

It should be flying pretty close to overhead where I am currently located. I am outside looking, but its snowy here, and I doubt I will be able to see much.

Lar · « **Reply #1157 on:** 03/08/2019 12:37 pm »

Quote from: FutureSpaceTourist on 03/08/2019 12:28 pm

DM-2 is bringing back zero-G indicator ! (SpaceX call it 'Earthy')

Well boo.

dodo · « **Reply #1158 on:** 03/08/2019 12:42 pm »

Maybe an old question, but I was wondering whether, in case of a parachute failure, the SD are ready to attempt a brown-pants splashdown, or if the idea was altogether abandoned.

joncz · « **Reply #1159 on:** 03/08/2019 12:49 pm »

Quote from: dodo on 03/08/2019 12:42 pm

Maybe an old question, but I was wondering whether, in case of a parachute failure, the SD are ready to attempt a brown-pants splashdown, or if the idea was altogether abandoned.

Go here https://forum.nasaspaceflight.com/index.php?topic=47570.0