Author Topic: General Falcon and Dragon discussion (Thread 14)  (Read 156799 times)

Offline Jim

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Re: General Falcon and Dragon discussion (Thread 14)
« Reply #40 on: 09/26/2016 03:23 PM »
Don't understand that.  The Air Force, the owner of the range, still has to give them clearance and it doesn't matter what Spacex's system says

Maybe it's an a la carte service they buy from the Air Force and they could provide data from their own radar to the AF safety officers instead?  I know nothing about the pricing and options for AF launch range services.

It isn't a service.  The Air Force isn't going to allow a launch unless it says the range is clear
Will that also be true for Texas? I've wondered how range safety will be managed when they get that site online.

Spacex will manage their own range in TX

Online RonM

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Re: General Falcon and Dragon discussion (Thread 14)
« Reply #41 on: 09/26/2016 04:44 PM »
Don't understand that.  The Air Force, the owner of the range, still has to give them clearance and it doesn't matter what Spacex's system says

Maybe it's an a la carte service they buy from the Air Force and they could provide data from their own radar to the AF safety officers instead?  I know nothing about the pricing and options for AF launch range services.

It isn't a service.  The Air Force isn't going to allow a launch unless it says the range is clear
Will that also be true for Texas? I've wondered how range safety will be managed when they get that site online.

Spacex will manage their own range in TX

Maybe SpaceX wants to test a system at the Cape before setting one up in Texas. See how the commercial radars compare to the Air Force system (Garmin 2526 only costs $9000). Of course, the Air Force would still have the final say on whether the range is clear.

Offline Jim

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Re: General Falcon and Dragon discussion (Thread 14)
« Reply #42 on: 09/26/2016 04:52 PM »
Also, I would wonder about how spacecraft feel about being that close to those radars.

Offline Nomadd

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Re: General Falcon and Dragon discussion (Thread 14)
« Reply #43 on: 09/26/2016 05:11 PM »
Also, I would wonder about how spacecraft feel about being that close to those radars.
They could have them up to 3 miles from the pad north or south. An antenna on a broom handle would be enough for a line of sight comms link anywhere on the island. Maybe a mobile 100' tower or two for the radar antenna. One at either end of the beach could double for a security point.

Offline Jim

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Re: General Falcon and Dragon discussion (Thread 14)
« Reply #44 on: 09/26/2016 05:14 PM »
Also, I would wonder about how spacecraft feel about being that close to those radars.
They could have them up to 3 miles from the pad north or south. An antenna on a broom handle would be enough for a line of sight comms link anywhere on the island. Maybe a mobile 100' tower or two for the radar antenna. One at either end of the beach could double for a security point.

I am talking about the proposed ones on 40 and 39

Offline Space Ghost 1962

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Re: General Falcon and Dragon discussion (Thread 14)
« Reply #45 on: 09/26/2016 05:27 PM »
Also, I would wonder about how spacecraft feel about being that close to those radars.
They could have them up to 3 miles from the pad north or south. An antenna on a broom handle would be enough for a line of sight comms link anywhere on the island. Maybe a mobile 100' tower or two for the radar antenna. One at either end of the beach could double for a security point.

I am talking about the proposed ones on 40 and 39

They don't "illuminate" them.

As to AF range securing, isn't it about an AF officer with the duty to protect against assessed threats, including those created by incorrect surveillance of the range by whatever means it is done, and thus acting as the gate keeper to keep the AF station's operating liability to its established norms?

We've seen a back-off of how this duty has been accomplished at both ranges over the years, as AF personnel used to handle all aspects, and for cost reasons the "divisional wedge"  has shrunk. Eventually an operator will perform all of this function, but as long as its an AFS you'll have a responsible officer a decision rolls up to, at a minimum.

Offline oldAtlas_Eguy

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Re: General Falcon and Dragon discussion (Thread 14)
« Reply #46 on: 09/26/2016 05:46 PM »
The Garmin 2526 marine radars have a 96nm range and a 1.1 degree beam width. Comes with software to plot detection's onto a GPS map. Operational out of the box once installed. Will need extra length cabling from radars to control center. Comes with all the features SpaceX needs including ability to to have a transmit exclusion zone such as not transmitting onto the LV.

https://buy.garmin.com/en-US/US/on-the-water/radar/gmr-2526-xhd2-open-array-radar-and-pedestal/prod531409.html

Offline Herb Schaltegger

Re: General Falcon and Dragon discussion (Thread 14)
« Reply #47 on: 09/26/2016 06:19 PM »
Also, I would wonder about how spacecraft feel about being that close to those radars.
They could have them up to 3 miles from the pad north or south. An antenna on a broom handle would be enough for a line of sight comms link anywhere on the island. Maybe a mobile 100' tower or two for the radar antenna. One at either end of the beach could double for a security point.

I am talking about the proposed ones on 40 and 39

They don't "illuminate" them.


Not directly, no. I'm sure Jim's concern is more about sidelobe radiation and RF interference with payload systems. At least, that would be my concerns until some on-site tests are done.

Of course, maybe they have done a few tests like that on exemplar units already and are satisfied there's no need for concern.
Ad astra per aspirin ...

Offline Space Ghost 1962

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Re: General Falcon and Dragon discussion (Thread 14)
« Reply #48 on: 09/26/2016 06:55 PM »
Also, I would wonder about how spacecraft feel about being that close to those radars.
They could have them up to 3 miles from the pad north or south. An antenna on a broom handle would be enough for a line of sight comms link anywhere on the island. Maybe a mobile 100' tower or two for the radar antenna. One at either end of the beach could double for a security point.

I am talking about the proposed ones on 40 and 39

They don't "illuminate" them.


Not directly, no. I'm sure Jim's concern is more about sidelobe radiation and RF interference with payload systems. At least, that would be my concerns until some on-site tests are done.

Of course, maybe they have done a few tests like that on exemplar units already and are satisfied there's no need for concern.

FCC regulates these very well these days. And FWIW you can add to the product a few things that can decrease spill another 20-30db.

A non-issue issue.

Offline Nomadd

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Re: General Falcon and Dragon discussion (Thread 14)
« Reply #49 on: 09/26/2016 09:00 PM »
 Would you turn off the exclusion zone radars when you launch? Good antennas can have sidelobes more than 40db down if they're worried about the rocket on the pad. Even less off the back. Radar dishes closer to the rocket can be less interference that farther ones if the point is farther off.

Offline Space Ghost 1962

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Re: General Falcon and Dragon discussion (Thread 14)
« Reply #50 on: 09/26/2016 09:09 PM »
Would you turn off the exclusion zone radars when you launch? Good antennas can have sidelobes more than 40db down if they're worried about the rocket on the pad. Even less off the back. Radar dishes closer to the rocket can be less interference that farther ones if the point is farther off.

I believe the "issue" is not SX's rocket on the pad, but other payloads in/on/adjacent nearby. Accidentally wrecking sensitive ... receptors.

And yes your threat assessment can tell you close rates for next assessment.

Offline gongora

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Re: General Falcon and Dragon discussion (Thread 14)
« Reply #51 on: 09/26/2016 09:17 PM »
Would you turn off the exclusion zone radars when you launch? Good antennas can have sidelobes more than 40db down if they're worried about the rocket on the pad. Even less off the back. Radar dishes closer to the rocket can be less interference that farther ones if the point is farther off.

I believe the "issue" is not SX's rocket on the pad, but other payloads in/on/adjacent nearby. Accidentally wrecking sensitive ... receptors.

And yes your threat assessment can tell you close rates for next assessment.

I think their application says they will mask it in the direction of the other pads.  Don't have the link to look it up right now.

Offline AnalogMan

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Re: General Falcon and Dragon discussion (Thread 14)
« Reply #52 on: 09/26/2016 11:20 PM »
Would you turn off the exclusion zone radars when you launch? Good antennas can have sidelobes more than 40db down if they're worried about the rocket on the pad. Even less off the back. Radar dishes closer to the rocket can be less interference that farther ones if the point is farther off.

I believe the "issue" is not SX's rocket on the pad, but other payloads in/on/adjacent nearby. Accidentally wrecking sensitive ... receptors.

And yes your threat assessment can tell you close rates for next assessment.

I think their application says they will mask it in the direction of the other pads.  Don't have the link to look it up right now.

This is what the FCC application says about angles and masking:

SLC-40 Radar
Width of beam in degrees at half power point: 1.1 degrees horizontal, 23 degrees vertical closest airport is the shuttle landing strip on CCAFS. This radar will be attached to a camera tower (similar to scaffolding) and is masked to radiate between 0 to 154 degrees azimuth. Radar emission is masked to avoid illuminating land and in particular other launch and spacecraft processing facilities. Please note this antenna has an FCC equipment authorization: -- FCC Identifier: IPH-A2552 -- Date of Grant: 10/02/2015

LC-39A Radar
Width of beam in degrees at the half power point: 1.1 degrees horizontal, 23 degrees vertical. This radar will be attached to a horizontal structural member on the pad 39A water tower and emission will be masked to radiate only between 328 to 135 degrees azimuth (over the Atlantic Ocean). Please note that this radar has an FCC equipment authorization: -- FCC Identifier: IPH-A2552 -- Date of Grant: 10/02/2015

https://apps.fcc.gov/oetcf/els/reports/442_Print.cfm?mode=current&application_seq=73850&license_seq=74568
« Last Edit: 09/26/2016 11:29 PM by AnalogMan »

Offline alamo

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Re: General Falcon and Dragon discussion (Thread 14)
« Reply #53 on: 09/28/2016 08:19 AM »
I will try to seriously..
It would allow the use of Falcon 9 in to "downgrade mode",
normal LOX, normal preasurized helium.. not used reusability..
F9 for clasical EELV, it would allow start in November?

Offline hkultala

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Re: General Falcon and Dragon discussion (Thread 14)
« Reply #54 on: 09/28/2016 08:36 AM »
Helium in F9 second stage has nothing to do with reusability. The second stage is not reusable.

And they cannot launch any rocket no matter what the rocket contains until they have a pad that works.
Currently they do not have a pad that works because LC40 is damaged and not yet fixed and LC-39A is not yet ready
« Last Edit: 09/28/2016 08:38 AM by hkultala »

Offline alamo

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Re: General Falcon and Dragon discussion (Thread 14)
« Reply #55 on: 09/28/2016 08:58 AM »
Helium in F9 second stage has nothing to do with reusability. The second stage is not reusable.
reusability brings a loss of capacity, it was necessary to increase the performance of the second stage..
without reusability, there is no need to increase the performance of the second stag

Online jpo234

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Re: General Falcon and Dragon discussion (Thread 14)
« Reply #56 on: 09/28/2016 09:07 AM »
Helium in F9 second stage has nothing to do with reusability. The second stage is not reusable.
reusability brings a loss of capacity, it was necessary to increase the performance of the second stage..
without reusability, there is no need to increase the performance of the second stag

It's not even known that the anomaly was caused by the Full Thrust changes.

Offline alamo

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Re: General Falcon and Dragon discussion (Thread 14)
« Reply #57 on: 09/28/2016 11:04 AM »
if the failure investigation, take too long time..
will be "downgrade", fallback plan?
money to burn..
http://www.nytimes.com/2016/09/05/business/spacexs-explosion-reverberates-across-space-satellite-and-telecom-industries.html?_r=0

Offline Toastmastern

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Re: General Falcon and Dragon discussion (Thread 14)
« Reply #58 on: 09/28/2016 11:13 AM »
if the failure investigation, take too long time..
will be "downgrade", fallback plan?
money to burn..
http://www.nytimes.com/2016/09/05/business/spacexs-explosion-reverberates-across-space-satellite-and-telecom-industries.html?_r=0

Doesn't matter. SpaceX needs to find out why the rocket exploded. That is not a very cleaver backup plan if the explosion had nothing to do with the changes made to the FT version.

Offline mclumber1

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Re: General Falcon and Dragon discussion (Thread 14)
« Reply #59 on: 09/28/2016 12:23 PM »
Helium in F9 second stage has nothing to do with reusability. The second stage is not reusable.

And they cannot launch any rocket no matter what the rocket contains until they have a pad that works.
Currently they do not have a pad that works because LC40 is damaged and not yet fixed and LC-39A is not yet ready

They still have Vandenberg that they can launch out of.  Yes, this means only polar and retrograde launches, but they still *do* have an operational launch site, although not as useful as LC40.

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