Author Topic: SpaceX Falcon 9 / Dragon 2 : SpX-DM2 - EOM/Return: August, 2020 : DISCUSSION (Read 87402 times)

sdsds · « **Reply #60 on:** 08/02/2020 12:40 am »

Quote from: yg1968 on 08/02/2020 12:01 am

So what I called the PMA-2 hatch in my post above is actually the same as the APAS hatch. Correct?

Caveat: I am not a space station engineer. However as I recall the PMA interior has been open to space when it has been relocated between station CBM berths. Does that clarify the matter, or just confuse it more?

deadman719 · « **Reply #61 on:** 08/02/2020 12:49 am »

Just watched the ISS and Endeavor pass overhead, just outside Boston. Both were very bright and easy to see. Attempted to take a photo but it didn't turn out well. Will try again in about 90 minutes.

Also saw the pair just prior to docking.

Respectfully,
Rob

Robotbeat · « **Reply #62 on:** 08/02/2020 01:01 am »

Quote from: Bob Shaw on 08/01/2020 11:22 pm

Slight differences in Covid-19 culture!

(Houston not wearing masks, SpaceX is.)

That's actually a little surprising to me. NASA is normally much more risk averse than SpaceX is. Must be a Texas vs California thing (or the "NASA is super safety focused and SpaceX is reckless" narrative is balooney...).

Jorge · « **Reply #63 on:** 08/02/2020 01:15 am »

Quote from: Robotbeat on 08/02/2020 01:01 am

Quote from: Bob Shaw on 08/01/2020 11:22 pm
Slight differences in Covid-19 culture!
(Houston not wearing masks, SpaceX is.)

That's actually a little surprising to me. NASA is normally much more risk averse than SpaceX is. Must be a Texas vs California thing (or the "NASA is super safety focused and SpaceX is reckless" narrative is balooney...).

The rule in Houston is, masks are optional while seated at your console if the nearest person/console is more than six feet away. When walking to or from your console, masks are mandatory.

Robotbeat · « **Reply #64 on:** 08/02/2020 01:23 am »

Quote from: Jorge on 08/02/2020 01:15 am

Quote from: Robotbeat on 08/02/2020 01:01 am
Quote from: Bob Shaw on 08/01/2020 11:22 pm
Slight differences in Covid-19 culture!
(Houston not wearing masks, SpaceX is.)

That's actually a little surprising to me. NASA is normally much more risk averse than SpaceX is. Must be a Texas vs California thing (or the "NASA is super safety focused and SpaceX is reckless" narrative is balooney...).

The rule in Houston is, masks are optional while seated at your console if the nearest person/console is more than six feet away. When walking to or from your console, masks are mandatory.

I am very surprised since it's not so lax at other Centers...

Also, 6 feet isn't anything at all like a hard cut-off on transmissibility (think like somewhere between one and two standard deviations reduction...), particularly indoors and for long periods. Interesting that no one in that shot has voluntarily worn a mask, either (except in the upper observation deck where it may not be optional). SpaceX seems similarly spaced out but they're all wearing masks.

Anyway. Very surprising.

sdsds · « **Reply #65 on:** 08/02/2020 01:30 am »

"Compunerd helpline. How can we help?"

"Yes, that's a known issue with the Safari browser. Please reboot."

LOL

SpaceX CORE has completed a (less humorous) conversation with Bob regarding the Timeline app on his iPad.

sdsds · « **Reply #66 on:** 08/02/2020 01:32 am »

Sigh. Regarding COVID protection procedures, it might be that personnel in different mission control centers have different levels of access to quick-turnaround saliva tests. Beer bets on that?

Torlek · « **Reply #67 on:** 08/02/2020 01:36 am »

Quote from: Robotbeat on 08/02/2020 01:23 am

I am very surprised since it's not so lax at other Centers...

That's the rule we have to follow in DoD facilities. Mask up if you're away from your desk or are within 6' of somebody else.

SpaceX is probably just taking greater precautions because they're a private company in California.

yg1968 · « **Reply #68 on:** 08/02/2020 01:42 am »

Quote from: sdsds on 08/02/2020 12:40 am

Quote from: yg1968 on 08/02/2020 12:01 am
So what I called the PMA-2 hatch in my post above is actually the same as the APAS hatch. Correct?

Caveat: I am not a space station engineer. However as I recall the PMA interior has been open to space when it has been relocated between station CBM berths. Does that clarify the matter, or just confuse it more?

Thanks. My question was actually simplier than that. I was just wondering if the APAS hatch was the exterior PMA-2 hatch and it seems that it is. You had already answered my question in your first post but I just wanted to make sure that I understood your answer correctly. In any event, here are some images that I found that shows the APAS hatch.

https://twitter.com/DeltaDizzy/status/1274423133378949121

https://twitter.com/genejm29/status/1267134666940780547

Michael S · « **Reply #69 on:** 08/02/2020 01:57 am »

Weather is HOT. Some clouds, but they are forming as they move north. Skies in the "splash down" area should be fairly clear. I live/work just west of Pensacola the waves close to shore were fairly small today (Saturday, Aug. 1) and the visible horizon sea state was fairly smooth. Unfortunately, that assessment is only viable for the time in which it was observed. A helpful guide I use for remote areas not usually covered by the Weather Channel is a combination of:
Worldview https://worldview.earthdata.nasa.gov/?v=-96.47967437854165,26.109020061687595,-81.12518219104165,33.351207561687595

Nullschool https://earth.nullschool.net/#current/wind/surface/level/orthographic=-92.38,28.74,852

mlindner · « **Reply #70 on:** 08/02/2020 03:44 am »

I really hate how both the NASA person and the SpaceX person keep saying that Dragon isn't visible from the ground without a telescope. NASA and SpaceX need to educate their employees better.

Michael S · « **Reply #71 on:** 08/02/2020 05:24 am »

Sdsds, intentionally or not, made me think.

here is a link to a marine map to know the area better:
http://fishing-app.gpsnauticalcharts.com/i-boating-fishing-web-app/fishing-marine-charts-navigation.html#7.58/29.699/-87.534
add to it the NOTAM coordinates for the Pensacola site:
https://www.google.com/maps/place/29%C2%B048'00.0%22N+87%C2%B030'00.0%22W/@29.5377584,-87.7094732,8.75z/data=!4m5!3m4!1s0x0:0x0!8m2!3d29.8!4d-87.5

Edit: dealing with a huge learning curve

mlindner · « **Reply #72 on:** 08/02/2020 05:28 am »

Just had a supposedly really good pass but couldn't see Dragon. Is it substantially earlier/later than the ISS? I saw the ISS clearly. The light pollution is quite bad here though with a sky that can only see a dozen or two stars. Limiting magnitude is probably 1st magnitude, maybe 2nd, nothing really dimmer.

Michael S · « **Reply #73 on:** 08/02/2020 05:54 am »

last post for the night.
found "Go Navigator" at Pensacola Naval Air Station

https://map.openseamap.org/

going to view in the tool bar you can select "show coordinates" and "marine traffic"

from NOTAM (Latitude: 29º48'00"N, Longitude: 87º30'00"W)

Edit: Dealing with a huge learning curve

Halidon · « **Reply #74 on:** 08/02/2020 01:52 pm »

Am I reading too much into the fluids discussion a little while ago? Sounded like the crew was indicating they were planning to drink a lot more water than bad been scheduled.

dgates · « **Reply #75 on:** 08/02/2020 02:14 pm »

How much "cross track" will the Dragon have to use to land today? How much cross track can the Dragon do aerodynamically during re-entry? I know the aero shape is asymmetrical and the CG is also probably offset, the Apollo capsule could be steered as a result; same deal for Dragon?

mulp · « **Reply #76 on:** 08/02/2020 02:24 pm »

Are they doing extra testing this trip down, like on the trip up, instead of undocking getting outside the exclusion zone, and then maneuvering for deorbit burn and landing?

Or are the steps to get ready to board Dragon so lengthy they need a sleep cycle before a lengthy deobit, recovery, de-brief inspection, etc.

Herb Schaltegger · « **Reply #77 on:** 08/02/2020 02:42 pm »

Quote from: mulp on 08/02/2020 02:24 pm

Are they doing extra testing this trip down, like on the trip up, instead of undocking getting outside the exclusion zone, and then maneuvering for deorbit burn and landing?

Or are the steps to get ready to board Dragon so lengthy they need a sleep cycle before a lengthy deobit, recovery, de-brief inspection, etc.

This was all discussed on yesterday’s LaunchAmerica livestream prior to undocking: no tests or extraneous maneuvers; all 3 departure and phasing burns were completed before the crew sleep cycle last night. The only burn left is the de-orbit burn early this afternoon (EDT).

Jeff Lerner · « **Reply #78 on:** 08/02/2020 03:10 pm »

I’m not clear on the impact of the failed generator on the ship...yes, I know it’s the “backup “ but what does the primary generator do ..??..does it provide electrical power for the whole ship, ..??..power for the hoist ..??...if the the primary generator also fails, how would Dragon be recovered ..

I’m sure there are lots of procedures to deal this...I’m just trying to understand the potential implications...

eriblo · « **Reply #79 on:** 08/02/2020 03:10 pm »

Quote from: dgates on 08/02/2020 02:14 pm

How much "cross track" will the Dragon have to use to land today? How much cross track can the Dragon do aerodynamically during re-entry? I know the aero shape is asymmetrical and the CG is also probably offset, the Apollo capsule could be steered as a result; same deal for Dragon?

The orbital plane passes over the nominal splashdown coordinates at about 18:44 UTC (~4 minutes before splashdown) so there is likely no cross range needed. I do not think that we have seen any numbers for the cross range capability of Dragon but (as for all capsules) it would be much less than the Space Shuttle. It does indeed perform a lifting reentry in order to limit the g-forces and improve landing accuracy (which seems to be about as good as you can get with parachutes).