Author Topic: SpaceX COTS Demo 1 Updates (Read 651046 times)

ugordan · « **Reply #600 on:** 12/04/2010 07:30 pm »

Now that we're within 3 days of the scheduled launch date and a forecast can be made with a higher confidence level, how's the weather looking? Still favorable?

Edit: answering my own question, a weather forecast was issued by the 45th Weather Squadron: http://www.patrick.af.mil/shared/media/document/AFD-070716-028.pdf

Doesn't look too good for the 7th, high winds are a concern. Conditions improve on 8th and 9th.

mnagy · « **Reply #601 on:** 12/04/2010 07:43 pm »

IIRC, the video streams from past flights always ended when they lost signal due to Earth curvature. Since they plan on making few orbits with dragon, can we assume that they have "enhanced" their communication capabilities so they can communicate with it even when it's out of reach (which I assume they will need to be able to do)? Or did they have these capabilities before, just not for the video?

Jim · « **Reply #602 on:** 12/04/2010 07:46 pm »

Quote from: mnagy on 12/04/2010 07:43 pm

IIRC, the video streams from past flights always ended when they lost signal due to Earth curvature. Since they plan on making few orbits with dragon, can we assume that they have "enhanced" their communication capabilities so they can communicate with it even when it's out of reach (which I assume they will need to be able to do)? Or did they have these capabilities before, just not for the video?

There has to be ground stations to receive the signals. Dragon is using TDRSS but probably not for video.

Robotbeat · « **Reply #603 on:** 12/04/2010 07:47 pm »

Quote from: mnagy on 12/04/2010 07:43 pm

IIRC, the video streams from past flights always ended when they lost signal due to Earth curvature. Since they plan on making few orbits with dragon, can we assume that they have "enhanced" their communication capabilities so they can communicate with it even when it's out of reach (which I assume they will need to be able to do)? Or did they have these capabilities before, just not for the video?

TDRS.
Dragon uses TDRS.
http://www.spacex.com/updates.php (and search for "TDRS" with your browser)

ugordan · « **Reply #604 on:** 12/04/2010 07:51 pm »

Would using TDRSS for video require using a directional high or mid gain antenna?

Jim · « **Reply #605 on:** 12/04/2010 07:51 pm »

Quote from: Robotbeat on 12/04/2010 07:47 pm

Quote from: mnagy on 12/04/2010 07:43 pm
IIRC, the video streams from past flights always ended when they lost signal due to Earth curvature. Since they plan on making few orbits with dragon, can we assume that they have "enhanced" their communication capabilities so they can communicate with it even when it's out of reach (which I assume they will need to be able to do)? Or did they have these capabilities before, just not for the video?
TDRS.
Dragon uses TDRS.
http://www.spacex.com/updates.php (and search for "TDRS" with your browser)

That may be only for TT&C and not video. Need larger antenna with pointing for video thru TDRSS

Robotbeat · « **Reply #606 on:** 12/04/2010 07:55 pm »

Quote from: Jim on 12/04/2010 07:51 pm

Quote from: Robotbeat on 12/04/2010 07:47 pm
Quote from: mnagy on 12/04/2010 07:43 pm
IIRC, the video streams from past flights always ended when they lost signal due to Earth curvature. Since they plan on making few orbits with dragon, can we assume that they have "enhanced" their communication capabilities so they can communicate with it even when it's out of reach (which I assume they will need to be able to do)? Or did they have these capabilities before, just not for the video?
TDRS.
Dragon uses TDRS.
http://www.spacex.com/updates.php (and search for "TDRS" with your browser)

That may be only for TT&C and not video

That's true, however TDRSS has enough bandwidth for video (compressed), and SpaceX has tested TDRSS with the Dragon radio at that bandwidth:

Quote

The SpaceX communications flight hardware, developed with subcontractors Delta Microwave (Low Noise Amplifier), Quasonix (transmitter and receiver), and Haigh-Farr (antennas), emulated a complete Dragon spacecraft comm link, and successfully sent and received data through the TDRSS network. Commands were dispatched from our Hawthorne headquarters command station, to NASA JSC in Houston, across Texas to the TDRSS White Sands Ground Terminal, up to the TDRS 5 Spacecraft in geosynchronous orbit, and back down to the Dragon receiver on the ground in Hawthorne.

The test series demonstrated telemetry and command transmission at a variety of data rates up to 2.1 Mbps, and paves the way for using TDRSS on all fifteen of our Dragon missions for the COTS and Commercial Resupply Services (CRS) programs.

http://www.spacex.com/updates.php

Jim · « **Reply #607 on:** 12/04/2010 08:02 pm »

Quote from: Robotbeat on 12/04/2010 07:55 pm

That's true, however TDRSS has enough bandwidth for video (compressed), and SpaceX has tested TDRSS with the Dragon radio at that bandwidth:

So what is TT&C going to use if video is going to use that bandwith.

Spacex is not going to waste TDRSS bandwith on useless video. TDRSS time is expensive.

Robotbeat · « **Reply #608 on:** 12/04/2010 08:06 pm »

Quote from: Jim on 12/04/2010 08:02 pm

Quote from: Robotbeat on 12/04/2010 07:55 pm
That's true, however TDRSS has enough bandwidth for video (compressed), and SpaceX has tested TDRSS with the Dragon radio at that bandwidth:

So what is TT&C going to use if video is going to use that bandwith

How much bandwidth does TT&C need?
1Mbps is plenty for SD video, if compressed.

mr. mark · « **Reply #609 on:** 12/04/2010 08:11 pm »

One thing that hasn't been mentioned is how great this capsule looks. It's a great achievement for a company with only 1,100 employees. Sometimes we look at the minute details but, sometimes it's nice to look back at the thing and take it all in. A really great job, Spacex employees should be celebrated.

Jim · « **Reply #610 on:** 12/04/2010 08:14 pm »

Quote from: mr. mark on 12/04/2010 08:11 pm

One thing that hasn't been mentioned is how great this capsule looks.

5 person mockup company could do the same work if you are only interested in looks.

Are you only interested in nuclear power plants that only look like they can contain all the radiation or are you interested in ones that can contain the radiation despite looks.

Lee Jay · « **Reply #611 on:** 12/04/2010 08:15 pm »

Quote from: mr. mark on 12/04/2010 08:11 pm

One thing that hasn't been mentioned is how great this capsule looks.

What's so great about it? It's round and pointy on one end.

mr. mark · « **Reply #612 on:** 12/04/2010 08:24 pm »

I guess you guys have no artistic background. If you did you would see the beauty in it. It's like coming home with a new car. I'm not an engineer, I come from an artistic/design based background. So for me, design is something to be admired even when it's simple and functional.

FinalFrontier · « **Reply #613 on:** 12/04/2010 08:30 pm »

Quote from: mr. mark on 12/04/2010 08:24 pm

I guess you guys have no artistic background. If you did you would see the beauty in it. It's like coming home with a new car. I'm not an engineer, I come from an artistic/design based background. So for me, design is something to be admired even when it's simple and functional.

No I agree with you actually. Dragon looks pretty cool!!! I mean its not a delta winged beast like Shuttle, but nothing will ever come close to that again. Still, it looks AWESOME imo.

Lee Jay · « **Reply #614 on:** 12/04/2010 08:38 pm »

I'm sorry for being behind, but does anyone know the expected splash-down point and method of recovery? Don't say "Pacific Ocean" as I don't really consider that a "point".

Lee Jay · « **Reply #615 on:** 12/04/2010 08:46 pm »

Quote from: mr. mark on 12/04/2010 08:24 pm

I guess you guys have no artistic background. If you did you would see the beauty in it. It's like coming home with a new car.

I don't get the analogy - a new car is all about that new car smell.

And I do have an artistic background (photography). I don't see the beauty in Dragon. It's a cone with a hemisphere on top. It's all function, just like is should be.

ugordan · « **Reply #616 on:** 12/04/2010 08:47 pm »

Quote from: mr. mark on 12/04/2010 08:24 pm

So for me, design is something to be admired even when it's simple and functional.

In aerospace and rocketry function often comes before form. Yes, it's sleek looking but mostly because it needs to be. Aerodynamics, etc.

Hey, was it you who "urged" SpaceX to paint the separation bolts and cable trunks white back when the first F9 was rolled out?

ChuckC · « **Reply #617 on:** 12/04/2010 09:01 pm »

Quote from: FinalFrontier on 12/04/2010 08:30 pm

Quote from: mr. mark on 12/04/2010 08:24 pm
I guess you guys have no artistic background. If you did you would see the beauty in it. It's like coming home with a new car. I'm not an engineer, I come from an artistic/design based background. So for me, design is something to be admired even when it's simple and functional.
No I agree with you actually. Dragon looks pretty cool!!! I mean its not a delta winged beast like Shuttle, but nothing will ever come close to that again. Still, it looks AWESOME imo.

One thing that needs to be noted that is at least my opinion gives the Dragon an added coolness and beauty about it is the fact that this is a private sector space craft. Yes, I know that Space X is getting both financial and technical help from NASA but it’s secondary not primary. Space X was going to do this with or with out NASA.

The point is that Space X is moving space flight into the private sector and the day the dragon carries its first crew to orbit it will break the government monopoly on manned space flight. That is a day will celibate.

ChuckC · « **Reply #618 on:** 12/04/2010 09:15 pm »

Quote from: Lee Jay on 12/04/2010 08:46 pm

Quote from: mr. mark on 12/04/2010 08:24 pm
I guess you guys have no artistic background. If you did you would see the beauty in it. It's like coming home with a new car.

I don't get the analogy - a new car is all about that new car smell. And I do have an artistic background (photography). I don't see the beauty in Dragon. It's a cone with a hemisphere on top. It's all function, just like is should be.

Beauty is in the eye of the beholder. Even a pure functional form can be beautiful and while the Dragon is a cone with a hemisphere on top is also more than that. It is the way Space X packaged the function inside and out. The Soyuz is also a case pure functional form but I’ve always thought it was kind of ugly.

HMXHMX · « **Reply #619 on:** 12/04/2010 10:26 pm »

Quote from: ChuckC on 12/04/2010 09:01 pm

Quote from: FinalFrontier on 12/04/2010 08:30 pm
Quote from: mr. mark on 12/04/2010 08:24 pm
I guess you guys have no artistic background. If you did you would see the beauty in it. It's like coming home with a new car. I'm not an engineer, I come from an artistic/design based background. So for me, design is something to be admired even when it's simple and functional.
No I agree with you actually. Dragon looks pretty cool!!! I mean its not a delta winged beast like Shuttle, but nothing will ever come close to that again. Still, it looks AWESOME imo.

One thing that needs to be noted that is at least my opinion gives the Dragon an added coolness and beauty about it is the fact that this is a private sector space craft. Yes, I know that Space X is getting both financial and technical help from NASA but it’s secondary not primary. Space X was going to do this with or with out NASA.

The point is that Space X is moving space flight into the private sector and the day the dragon carries its first crew to orbit it will break the government monopoly on manned space flight. That is a day will celibate.

While in no way diminishing the financial commitment SpaceX's investors have made, the taxpayers have made more. More than 2:1, from published data.

But if it works, it will be a bargain, at less than the price of one or two Delta IVHs.