Author Topic: SpaceMobile Constellation (AST & Science)  (Read 56268 times)

Offline Danderman

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Re: SpaceMobile Constellation (AST & Science)
« Reply #40 on: 07/23/2021 03:11 am »
Note that Starlink faced a similar issue, and chose a deployable  array, which is what is causing the problems for astronomers.  AST arrays won’t face the Earth, which is good for astronomy.

The side of the SpaceMobile sats that faces Earth will still reflect light, and these things are huge.

I don’t think there have been many objects in LEO with very large fixed antennas pointing at the Earth. But, I don’t think that the AST phased array antennas are going to cause many problems for astronomers (neither will the solar arrays, but that’s another issue).

First off, I’m not sure how reflective the antennas will be.

Secondly, the beta angles will almost always be very low. Remember that for an object to be visible from the ground, the object must reflect sunlight, and the observer must be in darkness, or at least not in sunlight. This condition can only occur around sunset and sunrise. So, for an observer to see reflection from the phased array, the times of day this happens are short, and the spacecraft antennas must see the sun. Since the antennas are nadir pointing, there are only two points in the orbit when this is possible. And those points must coincide with the time of day when the observer is in darkness. So, it will be rare.

Conversely, Starlink sats have steerable antennas.

Online gongora

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Re: SpaceMobile Constellation (AST & Science)
« Reply #41 on: 07/23/2021 03:42 am »
Conversely, Starlink sats have steerable antennas.

The steerable antennas on the Starlinks don't seem to be the main problem, those are not being shaded (although they were darkened at some point).  It's the flat ESAs that are so reflective on Starlink.  Size also matters a lot.

Offline Danderman

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Re: SpaceMobile Constellation (AST & Science)
« Reply #42 on: 07/24/2021 02:20 pm »
Conversely, Starlink sats have steerable antennas.

The steerable antennas on the Starlinks don't seem to be the main problem, those are not being shaded (although they were darkened at some point).  It's the flat ESAs that are so reflective on Starlink.  Size also matters a lot.

Yikes, I had a brain fade. It’s the steerable solar panels on Starlink that are the problem. AST doesn’t have steerable solar panels, so no such problem.

Online gongora

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Re: SpaceMobile Constellation (AST & Science)
« Reply #43 on: 07/29/2021 03:42 pm »
AST SpaceMobile Announces Launch Services Agreement to Deploy 693-Square-Foot Phased Array Spacecraft for Direct-to-Cell Phone Connectivity Testing

July 29, 2021 08:02 AM Eastern Daylight Time
MIDLAND, Texas--(BUSINESS WIRE)--AST SpaceMobile, Inc. (NASDAQ:ASTS), the company building the first and only space-based cellular broadband network accessible directly by standard mobile phones, today announced an agreement with Space Exploration Technologies Corp. (“SpaceX”) for the launch of its next prototype spacecraft, BlueWalker 3.

BlueWalker 3 is expected to launch aboard a SpaceX mission from Cape Canaveral, Florida, in March 2022. The spacecraft has an aperture of 693 square feet and is designed to communicate directly with cell phones via 3GPP standard frequencies.

“We're pleased to launch with US-based SpaceX, which allows us to deploy BlueWalker 3 from our own backyard,“ said Scott Wisniewski, Executive Vice President and Chief Strategy Officer of AST SpaceMobile. “The spacecraft will be the second prototype to leverage our patented technology.”

AST SpaceMobile's mission is to eliminate the connectivity gaps faced by today's five billion mobile subscribers moving in and out of coverage zones, and bring cellular broadband to approximately half of the world's population who remain unconnected.

Partners in this effort are leading global wireless infrastructure companies, including Rakuten, Vodafone and American Tower. As of June 30, 2021, AST SpaceMobile has entered into agreements and understandings with mobile network operators which collectively cover approximately 1.4 billion mobile subscribers.

Click here to learn more about how the technology works.
« Last Edit: 07/29/2021 03:44 pm by gongora »

Online gongora

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Re: SpaceMobile Constellation (AST & Science)
« Reply #44 on: 07/29/2021 09:05 pm »
SEC filing showing the launch agreement with SpaceX.  Redacted details include the price and the word "Rideshare" wherever it occurred in the document  ::)

https://www.sec.gov/Archives/edgar/data/0001780312/000149315221018041/form424b3.htm

Offline Danderman

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Re: SpaceMobile Constellation (AST & Science)
« Reply #45 on: 08/24/2021 03:23 am »
Did FAA actually give approval for a 693 sq ft antenna?

Online gongora

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Re: SpaceMobile Constellation (AST & Science)
« Reply #46 on: 08/24/2021 05:28 pm »
Did FAA actually give approval for a 693 sq ft antenna?

It would be FCC.

edit:  still pending 1059-EX-CN-2020
« Last Edit: 08/24/2021 11:17 pm by gongora »

Offline panyagua

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Re: SpaceMobile Constellation (AST & Science)
« Reply #47 on: 08/31/2021 06:55 pm »
Did FAA actually give approval for a 693 sq ft antenna?

It would be FCC.

edit:  still pending 1059-EX-CN-2020

This is just for BW3 correct?  They will have to go through this entire process again for the new bluebird satellites with a full constellation correct?

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Re: SpaceMobile Constellation (AST & Science)
« Reply #48 on: 08/31/2021 08:24 pm »
This is just for BW3 correct?  They will have to go through this entire process again for the new bluebird satellites with a full constellation correct?

BW3 will be under an experimental permit.  They also have a pending license application for the constellation:
SAT-PDR-20200413-00034
« Last Edit: 08/31/2021 08:25 pm by gongora »

Online gongora

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Re: SpaceMobile Constellation (AST & Science)
« Reply #49 on: 10/18/2021 04:57 pm »
https://twitter.com/pbdes/status/1450063861193785351

Quote
@gk_launch & @AST_SpaceMobile reach agreement on AST switch from GK's Soyuz to @SpaceX ride-share for BlueWalker3 tech-demo sat when GK's main customer, Korea's #Kari, could not deliver #CAS500-2 Earth obs sat in time. GK will keep $2.7M from AST & use it for future GK launch.

Online gongora

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Re: SpaceMobile Constellation (AST & Science)
« Reply #50 on: 11/20/2021 01:36 am »
https://www.sec.gov/Archives/edgar/data/1780312/000149315221029031/form424b3.htm
Quote
On April 1, 2019, we launched our first test satellite, BlueWalker 1 (“BW1”), which was used to validate our satellite to cellular architecture and was capable of managing communications delays from LEO orbit and the effects of doppler in a satellite to ground cellular environment using the 4G-LTE protocol. We are currently assembling, integrating, and testing the satellite componentry required for our BlueWalker 3 (“BW3”) test satellite. As of September 30, 2021, we have incurred approximately $56.7 million of capitalized costs (including non-recurring engineering) relating to the BW3 test satellite and expect to incur an additional $10.0 to $12.0 million (including non-recurring engineering) to bring this project to completion. The BW3 test satellite will be using SpaceX as a launch services provider. The current available launch window with SpaceX runs from March 2022 through April 2022. However, the exact timing of such launch is contingent on a number of factors, including satisfactory and timely completion of construction and testing of BW3 test satellite. We have the option to select an alternate launch window if we deliver a rebooking notice to SpaceX by December 1, 2021 and pay a rebooking fee. While we have not yet determined if we will provide such rebooking notice and select an alternate mission and launch window, at this time we believe it is likely that we may elect to do so to provide additional time for BW3 testing and final launch preparation. If we exercise the option to rebook, we plan to target a BW3 launch within months of the original launch window; however, any alternate launch window would be subject to mutual agreement and coordination with SpaceX.

We are also in the development and design process of our first constellation phase of 20 satellites (the “BB1 Satellites”). We are currently planning our first commercial satellite launches for the BB1 Satellites to begin during the last quarter of 2022 and continue during the first two or potentially three quarters of 2023. This first phase of satellites is expected to provide satellite coverage in the 49 Equatorial countries, representing a total population of approximately 1.6 billion people, with 20 satellites. We currently plan to achieve full global mobile coverage after the completion of the launches required to deploy an additional 90 satellites which we are targeting to begin launching during the last quarter of 2023 and continue during 2024, assuming the first phase is successfully completed in the anticipated time frame. Assuming we are able to substantially achieve full global mobile coverage, we currently are planning to begin the launches required to deploy an additional 58 satellites with multiple input multiple output (“MIMO”) capabilities beginning in the fourth quarter of 2024 through the third quarter of 2025. While this represents our current planning, our launch plans and timelines are subject to numerous factors, many of which are beyond our control, including, manufacturing timelines and our ability to successfully contract with launch providers that can accommodate the technical specifications of our BB1 Satellites, proposed orbits and resulting satellite coverage, and proposed launch timing and costs and other factors which could impact the determination of launch providers.

(h/t to Peter B. de Selding tweet)
« Last Edit: 11/20/2021 01:36 am by gongora »

Online gongora

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Re: SpaceMobile Constellation (AST & Science)
« Reply #51 on: 11/23/2021 09:37 pm »
https://twitter.com/AST_SpaceMobile/status/1463260467137327109
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The Micron is the building block of our satellites. Each Micron has solar cells on one side, antennas on the other, and a lot of subsystems in-between. Our goal is to mass-produce these at scale to lower costs and deliver the SpaceMobile mission. 🚀 #ASTSpaceMobile #5G

Offline su27k

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Re: SpaceMobile Constellation (AST & Science)
« Reply #52 on: 11/24/2021 02:34 am »
Cool, sandwich tiles like this is used in several Space Solar Power concepts, I was thinking if it can be used in communication satellite too. I wonder which method they'll use to solve the problem of having constant sunlight on the solar side.
« Last Edit: 11/24/2021 02:34 am by su27k »

Offline Asteroza

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Re: SpaceMobile Constellation (AST & Science)
« Reply #53 on: 11/24/2021 02:58 am »
Cool, sandwich tiles like this is used in several Space Solar Power concepts, I was thinking if it can be used in communication satellite too. I wonder which method they'll use to solve the problem of having constant sunlight on the solar side.

I would assume since this isn't a GEO sat, the solar panels aren't sun facing all the time? The SPS sandwich panels did have a heat issue, which can be solved through geometry tricks like Z folds.

Offline Danderman

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Re: SpaceMobile Constellation (AST & Science)
« Reply #54 on: 11/25/2021 02:43 am »
The AST sandwich will have a small issue with limited exposure of the panels to the Sun. They will require lots of batteries.

Offline su27k

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Re: SpaceMobile Constellation (AST & Science)
« Reply #55 on: 11/25/2021 03:20 am »
The AST sandwich will have a small issue with limited exposure of the panels to the Sun.

Yes, this is what I was asking in the previous comment. Although I think the Space Solar Power designs have some ways to mitigate this, by using mirrors and such.

Offline Danderman

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Re: SpaceMobile Constellation (AST & Science)
« Reply #56 on: 11/25/2021 05:57 am »
AST has nothing to do with Space Solar Power.

Mirrors would create additional problems for astronomers, so it’s unlikely that AST will use mirrors.

Offline panyagua

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Re: SpaceMobile Constellation (AST & Science)
« Reply #57 on: 12/02/2021 12:51 pm »

Quote
Due to a change in circumstances, the BlueWalker 3 (“BW3”) test satellite that is associated with the above-noted application will be registered with the United Nations, pursuant to the Registration Convention,1 by the Spanish Ministry of Industry (Subdirección General de Áreas y Programas Industriales -Dirección General de Industria y Pyme). Applicant AST&Science LLC is a subsidiary of AST SpaceMobile, Inc., which has a facility in Spain (AST&Science Iberia, S.L.) that is manufacturing the solar arrays for the BW3 test satellite. In this way, the spacecraft will fully meet the terms of the Registration Convention.

https://fcc.report/ELS/AST-Science-LLC/1059-EX-CN-2020/286939

Is it odd they wont register it in the USA?

Online gongora

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Re: SpaceMobile Constellation (AST & Science)
« Reply #58 on: 12/07/2021 02:49 am »
[Via Satellite] AST SpaceMobile Pushes Back BlueWalker 3 Satellite Launch
Quote
AST SpaceMobile was set to launch with SpaceX between March 1, 2022 and April 30, 2022, and has now submitted a rebooking notice for a revised launch window targeting summer 2022. The final launch timing is dependent on SpaceX.

Online gongora

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Re: SpaceMobile Constellation (AST & Science)
« Reply #59 on: 12/14/2021 04:28 pm »
https://twitter.com/pbdes/status/1470798375872348164
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.@AST_SpaceMobile has reduced by 50%, to 450 m2, the size of the antenna for its operational LEO constellation to provide 4G/5G links to unmodified smartphones, Chief Strategy Officer Scott Wisniewski said at #WSBW.

 

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