Author Topic: SpaceX F9 : CRS SpX-18 : July 25, 2019 - DISCUSSION (Read 69831 times)

billh · « **Reply #100 on:** 07/25/2019 10:50 pm »

Quote from: cwr on 07/25/2019 10:45 pm

Quote from: eriblo on 07/25/2019 10:33 pm
Quote from: billh on 07/25/2019 10:16 pm
Was that the first time we've ever seen the solar array deployment from S2? It was very brief and right at the bottom of the screen.
No, we have seen it before. CRS-5 had a slightly better shot but was in shadow seconds before sunrise while CRS-6 had a well lit and centered profile view.

I'm confused.
I watched today's CRS-18 launch and saw the Dragon solar panel deploy - shot from a camera
on the dragon underneath the panel cover and folded solar panel.

This is what I've observed on pretty much all prior Dragon launches.
I don't recollect ever seeing a Dragon panel deploy with a camera on S2.
There's a camera switch between watching Dragon separate from S2 and then
watching panel deploy from Dragon.

Carl

I did not recall seeing it before. But I went back and watch CRS-6 as eriblo suggested and you can see it there, too. It's overexposed, unfortunately, but at least both arrays and both covers are in the frame.

Silmfeanor · « **Reply #101 on:** 07/25/2019 10:51 pm »

Quote from: billh on 07/25/2019 10:50 pm

Quote from: cwr on 07/25/2019 10:45 pm
Quote from: eriblo on 07/25/2019 10:33 pm
Quote from: billh on 07/25/2019 10:16 pm
Was that the first time we've ever seen the solar array deployment from S2? It was very brief and right at the bottom of the screen.
No, we have seen it before. CRS-5 had a slightly better shot but was in shadow seconds before sunrise while CRS-6 had a well lit and centered profile view.

I'm confused.
I watched today's CRS-18 launch and saw the Dragon solar panel deploy - shot from a camera
on the dragon underneath the panel cover and folded solar panel.

This is what I've observed on pretty much all prior Dragon launches.
I don't recollect ever seeing a Dragon panel deploy with a camera on S2.
There's a camera switch between watching Dragon separate from S2 and then
watching panel deploy from Dragon.

Carl
I did not recall seeing it before. But I went back and watch CRS-6 as eriblo suggested and you can see it there, too. It's overexposed, unfortunately, but at least both arrays and both covers are in the frame.

See here:
https://forum.nasaspaceflight.com/index.php?topic=37294.msg1358461#msg1358461

AC in NC · « **Reply #102 on:** 07/25/2019 10:52 pm »

Quote from: cwr on 07/25/2019 10:45 pm

I'm confused.
I watched today's CRS-18 launch and saw the Dragon solar panel deploy - shot from a camera
on the dragon underneath the panel cover and folded solar panel.

This is what I've observed on pretty much all prior Dragon launches.
I don't recollect ever seeing a Dragon panel deploy with a camera on S2.
There's a camera switch between watching Dragon separate from S2 and then
watching panel deploy from Dragon.

Carl

Steven Pietrobon · « **Reply #103 on:** 07/25/2019 10:57 pm »

Congratulations to SpaceX and NASA for the successful launch!

Grabs showing nose cover deploy and landed first stage.

cscott · « **Reply #104 on:** 07/27/2019 01:28 pm »

Quote from: Lewis007 on 07/27/2019 05:12 am

Some shots inside Mission Control during the Dragon SpX-18 launch.

source: JSC twitter

So SpaceX mission control had a Saturn V model on the desk, and NASA mission control had a Falcon 9 model...

KenigOld · « **Reply #105 on:** 07/29/2019 08:56 am »

Fdiday:)
https://vk.com/spaceactivityinfographics

DistantTemple · « **Reply #106 on:** 07/29/2019 09:05 am »

Wow I didn't realise the $/Kg of the Dragon was 3x that of progress!!! And to be fair the Russian price is excellent - on this graphic (above) - as SX have been so proud of their $62M with discounts for re-usability.... If progress really is $56M including the capsule, SX still have a long way to go! and were clearly not the first to drive down prices.

KenigOld · « **Reply #107 on:** 07/29/2019 09:10 am »

Quote from: DistantTemple on 07/29/2019 09:05 am

Wow I didn't realise the $/Kg of the Dragon was 3x that of progress!!! And to be fair the Russian price is excellent - on this graphic (above) - as SX have been so proud of their $62M with discounts for re-usability.... If progress really is $56M including the capsule, SX still have a long way to go! and were clearly not the first to drive down prices.

The original price of progress of course in rubles. On this mission of insurance - 3.9 billion rubles. Insurance premium 250 million rubles.

Jcc · « **Reply #108 on:** 07/29/2019 12:07 pm »

Quote from: DistantTemple on 07/29/2019 09:05 am

Wow I didn't realise the $/Kg of the Dragon was 3x that of progress!!! And to be fair the Russian price is excellent - on this graphic (above) - as SX have been so proud of their $62M with discounts for re-usability.... If progress really is $56M including the capsule, SX still have a long way to go! and were clearly not the first to drive down prices.

The graphic shows a mission cost for Dragon of $170M. Don’t know where that comes from, maybe dividing the total CRS contract by number of missions?

scr00chy · « **Reply #109 on:** 07/29/2019 12:49 pm »

Quote from: Jcc on 07/29/2019 12:07 pm

The graphic shows a mission cost for Dragon of $170M. Don’t know where that comes from, maybe dividing the total CRS contract by number of missions?

Not sure, value of the last extension of the CRS contract for 5 launches is estimated at 700 million which averages out to only 140 million per launch. The previous extension was estimated at 150M per launch. Sources: https://www.elonx.net/list-of-spacex-contracts/

Rondaz · « **Reply #110 on:** 07/29/2019 01:25 pm »

SpaceX retracts Falcon 9 booster’s landing legs a second time after speedy reuse..

By Eric Ralph Posted on July 29, 2019

https://www.teslarati.com/spacex-retracts-falcon-9-landings-legs-second-time/

su27k · « **Reply #111 on:** 07/29/2019 03:14 pm »

Quote from: DistantTemple on 07/29/2019 09:05 am

Wow I didn't realise the $/Kg of the Dragon was 3x that of progress!!! And to be fair the Russian price is excellent - on this graphic (above) - as SX have been so proud of their $62M with discounts for re-usability.... If progress really is $56M including the capsule, SX still have a long way to go! and were clearly not the first to drive down prices.

It's not apple to apple comparison, Russian systems' R&D are paid by USSR decades ago, while SpaceX still needs to amortize their investment in Dragon and Falcon 9. Also Dragon can return tons of payload back to Earth, Progress cannot.

And I think we have some comparison of Falcon 9 and Soyuz's $/kg somewhere on this forum, Falcon 9 is quite competitive.

CorvusCorax · « **Reply #112 on:** 07/29/2019 03:24 pm »

I think progress wins because Nasa utilised only a fraction of Dragons payload capacity in this specific mission, while Progress was maxed out 98%.

I dunno if the quoted mass includes the IDA or only pressurized mass

SMS · « **Reply #113 on:** 07/29/2019 03:38 pm »

Somewhere they wrote what caused such a difference:

https://www.nasa.gov/sites/default/files/atoms/files/spacex_crs-7_mission_overview.pdf
International Docking Adapter #1 - 526 kg

https://www.nasa.gov/sites/default/files/atoms/files/spacex_crs-9_mission_overview.pdf
International Docking Adapter-2 - 467 kg

https://www.nasa.gov/sites/default/files/atoms/files/spacex_crs-18_mision_overview_high_res.pdf
International Docking Adapter-3 - 534 kg?

gongora · « **Reply #114 on:** 07/29/2019 04:08 pm »

The number given for Dragon cost is too high, even if you include a lot of certification work it's more like $150M. The 6t capacity of Dragon is very theoretical, it's not large enough to carry that much real cargo, and it doesn't tend to carry commodities like water and fuel (I believe Progress carries both of those?).

Joffan · « **Reply #115 on:** 07/29/2019 04:56 pm »

It is important in this sort of price comparison (Dragon vs other) to factor in that every Dragon visit to the ISS is two missions - one to take mass up, and one to take mass down. This latter mission is probably twice as important/valuable but often effectively valued by commentators at zero.

I think though that's getting off topic for CRS-18 specific chat, so I want to ask if anyone knows any further source for the statement from Teslarati that the landing legs were retracted:

Quote from: Rondaz on 07/29/2019 01:25 pm

SpaceX retracts Falcon 9 booster’s landing legs a second time after speedy reuse..

By Eric Ralph Posted on July 29, 2019

https://www.teslarati.com/spacex-retracts-falcon-9-landings-legs-second-time/

(not that Eric Ralph doesn't have good information - I was just hoping that we might get more details or pictures)

gongora · « **Reply #116 on:** 07/29/2019 05:07 pm »

Quote from: Joffan on 07/29/2019 04:56 pm

so I want to ask if anyone knows any further source for the statement from Teslarati that the landing legs were retracted:

There was a link in the article to a tweet with the picture:
https://twitter.com/throughtjseye/status/1155286791127281667

Alexphysics · « **Reply #117 on:** 07/29/2019 06:13 pm »

There is also another picture of the leg retraction for this booster that was shared on the facebook group.

https://www.facebook.com/groups/spacexgroup/permalink/10157734493651318/

XenIneX · « **Reply #118 on:** 07/29/2019 07:38 pm »

Quote from: sghill on 07/29/2019 06:39 pm

I disagree. We haven't seen this before on a landed booster. The engine was gimbaling in addition to the grid fins to a huge degree, and the oscillations appeared grow in strength, then to die right when the landing legs deployed- so I don't think it was surface winds.

I think they had an oscillation setup that they had trouble dampening. so what caused it? A sticky grid fin? Sticky engine gimbal?

and

https://twitter.com/elonmusk/status/1155567236716740608

It does that literally every time. You just don't see it sometimes because of camera issues.

Go back through daytime RTLS landings. You'll see it on every one.

cscott · « **Reply #119 on:** 07/29/2019 08:05 pm »

There are control inversion transitions both as the grid fins go trans-sonic and as soon as the first leg touches the ground. These are legit engineering reasons for quick control excursions. (Watch the star hopper engine as soon as the first leg touches.) I bet SpaceX can explain the cause of every sharp control input on the video.