https://techcrunch.com/2017/06/25/watch-spacex-launch-10-satellites-into-orbit-with-a-falcon-9-live-right-here/
Scheduled for Jun 25, 2017 SpaceX is targeting launch of Iridium-2 from Space Launch Complex 4E (SLC-4E) at Vandenberg Air Force Base in California. The instantaneous launch window is at 1:25 p.m. PDT, or 20:25 UTC, on Sunday, June 25. A backup launch opportunity opens at 1:19 p.m. PDT, or 20:19 UTC, on Monday, June 26.
SpaceX’s Falcon 9 rocket will deliver 10 satellites to low-Earth orbit for Iridium, a global leader in mobile voice and data satellite communications. This is the second set of 10 satellites in a series of 75 total satellites that SpaceX will launch for Iridium’s next generation global satellite constellation, Iridium® NEXT. The satellites will begin deployment about an hour after launch.
Maybe I'm over simplifying things, but it seems like the constellation that Elon wants to put up will do everything that the Iridium constellation already does, and even better. Is there something that the Iridium constellation does that his won't?
This Gabbard diagram shows debris orbits at altitudes are near the orbits of SpaceX, OneWeb, Kuiper, Telesat, and Guowang SatNet.
https://preview.redd.it/9hzhp8vles081.jpg?width=1703&format=pjpg&auto=webp&s=7804aa29d1e9a3d1488ee59421f5d852185dc429
This Tom Choi guy from October has several interviews in this link where he places emphasis on GEO and not LEO constellations, but now is creating a LEO one himself. https://www.satellitetoday.com/business/2021/03/16/outspoken-leo-critic-tom-choi-details-plans-for-new-curvanet-constellation/. If you read through the second older article (Tom Choi: OneWeb’s Failure Will Dent New Space Investments) talks about connectivity to the "unconnected" and costs among 3rd world populations, may provide some food for thought. https://www.satellitetoday.com/business/2020/03/31/tom-choi-onewebs-failure-will-dent-newspace-investment/. His LEO constellation still requires a dish, so no competition to AST, but interesting to see an opponent of LEO constellations is now trying to create their own. I beleive those unconnected 3rd world countries will only be able to afford internet from cell phones and not $100 dishes. We bypass all the terminal equipment and electricity cost with AST business model and things look bright when they execute.
This is a follow-up to my original post on this topic. Please see HERE.
This last weekend, I embarked on an effort that I initially thought was just “due diligence”. I wasn’t expecting any surprises or revelations.
Along with each capture of a Starlink downlink signal, I also wanted to deduce exactly which Starlink satellite I was receiving at that precise moment in time. I was able to accomplish this using NORAD TLE datasets from CelesTrak. These datasets contain orbital model parameters that can be used to project the position of a satellite at a given time. In conjunction with an observer’s latitude and longitude, the azimuth and altitude can be calculated.
I did not know exactly the altitude/azimuth of my dish. Nonetheless, given its 24° offset angle, I had a “reasonable” guess of 60° / 25°. This “guess” and my latitude/longitude were inputs into my code. Upon detecting a signal, my code would estimate the altitude/azimuth of all Starlink satellites at the exact moment of start of reception. Then, I would convert to a 3-D unit vector and compute the error with respect to my “guess” observer unit vector. I record the 5 “most probable” satellites.
I added this new feature to my receive processing pipeline, and I let it run Sunday-Monday.
This was quite successful! My dish has a 3° beam width, and the timestamp used to project the Starlink orbits wasn’t exactly at the peak of the capture. This data would imply that the dish is pointing at ~ 56° / 33°.
However, not ALL signals I received could be explained by the Starlink NORAD dataset. 26 captures were clearly identifiable as specific Starlink satellites. 11 were unexplained.
As can be seen from the table above, the (5) "most probably" satellites aren't anywhere near where my dish is pointing.
A couple observations:
- The “identified” satellites were only transmitting at 11.325, 11.575 GHz. The “unidentified” satellites were ALSO transmitting at 11.075 GHz.
- All the “identified” signals
Last week I was out of cell reception and found myself nearly stuck (couldn't back up an incredibly steep road, but proceeding was too dangerous given the loose rock). I have a Garmin InReach but have never used it in an emergency. To be honest, I dreaded having to use it - it's unclear when someone will answer a distress call, and the thought of texting someone during an emergency terrifies me. This made me look into getting an Iridium satphone, as you can quickly talk to someone, which is helpful in a complex emergency. Price for a 200 minute prepaid plan seems to be $1600 including the phone, which seems well-worth the price of getting help when time is of the essence. The thing is, I never hear of anyone who has one of these.
Anyone here have one and has had to use it in an emergency? Any recs on the device/subscription type? Thanks!
- TL/DR AST SpaceMobile constellation will boast the largest ever deployed area of antenna in space. Powerful enough to do what no one else does: Connect directly to smartphones. Price Target: 45 USD per share. 3.8 x current share price.
- I am not a financial advisor. This is analysis, not financial advice.
Background. The Communication Services Sector, CSS, Telecommunications addressable market and stepwise evolution of telecom sector.
- Alphabet (Google) and Facebook make up half of the S&P 500 CSS. Telecommunications companies is one fifth (21%) of sector, and about 2% of the S&P 500 total value. Internet infrastructure is not part of CSS, it is part of Information Technology sector.
- The Total (global) telecom addressable market in 2021 is 1,000 Bn USD. Growing at CAGR 40% annually. This means the entire Telecom sector is by definition in hypergrowth. A company just maintaining its market share is, thereby, also in hypergrowth. This is largely driven by 5g rollout. And fueled by new technological concepts and evolvong standards.
- Mainstream consumer telecom started as wire connected telegraphs, then phones, evolved into cellphones and terrestrial towers further subdivided into 2g, 3g, 4g LTE and now 5g. Research and development has started for another leap: Connecting to satellites.
- 🦅 Incorporated in 3GPP release 16 and 17, 5g standards. For Example Qualcomm x65 release 16 chip, manufactured by Samsung, and in cellphones from early 2022 is engineered to improve its satellite connectivity. Regular cellphones has already started adapting for AST type constellations.
🦢🦢🦢🦢🦢🦢🦢🦅 Low Earth Orbit Satellite constellations. A whole lot of swans.
- There are a lot of Low Earth Orbit communications Constellations planned and operational.
How numerous some leading LEO constellations are planned to become. (correct for AST is 336 sats).
🦅 SpaceMobile constellation. Bigger antenna than any other.
[Ellis Island. Originally only 3.5 acres in size, today Ellis Island covers nearly 27.5 acres. Or 111.000 square meters. This is the size of the total phased array antenna that AST SpaceMobile constellation will deploy when it
... keep reading on reddit ➡
TL/DR Imagery show AST SpaceMobile is building things associated with testing and the production of their test satellite and constellation. Some of these investments serve to extensively test the technology before launch. This is part of a philosophy of keeping it simple in space and do as much as possible of the difficult stuff down on earth. This process is a step in de-risking the technology. Imagery shows timely progress leading up to satellite launches in 2022.
BACKGROUND
In a previous writeup I outline the company and what makes it unique. This post is recommended background reading if you are not familiar with the company: AST SpaceMobile. The Black Swan of Low Earth Orbit satellite communication constellations. 🦢🦢🦢🦢🦢🦢🦢🦢🦢🦢 🦅 Why is it so different?
CONSTRUCTION AT MIDLAND - Imagery
- u/Peeloosy spotted an updated aerial photo of AST Space Mobile Midland facility.Original post is available here and the link he provides to MS Bing maps shows shots from different angles slightly time differentiated.
CONSTRUCTION AT MIDLAND -what it looks like now.
- The image above is captured from u/peeloosys link. Found here.
Bluewalker 3 network architecture. This is the single experimental satellite.
CONSTRUCTION AT MIDLAND. Lets zoom in. Phased array radome/climate chamber.FLIPPED SAUCER
[Image shows a 4 wheel crab-steered telehandler with telescopic reach enough to need front support legs servicing the building while its service doors are op
... keep reading on reddit ➡For background, campers and people otherwise traveling to remote areas would like internet access to update others in real time. This includes bloggers in the forests trying to update others, broadcasting the Northern lights from a remote part of Alaska, broadcasting starry nights in a desert, having world wide internet access in the north and south poles, Scouting troops with the adults needing internet, etc. The ideas for improving existing smartphone and standalone cameras to video record moonless starry nights should be implemented but that's a separate issue.
I've seen research papers about full duplex radio communications. It's possible. Part of why I bring up the question in the title is that all modern smartphones with 5G (including mm wave) use MIMO configurations and high order QAM schemes (256 or higher). My concern with the L band is that the width of the RF range is not as high and would require a higher order QAM scheme. It could defeat the purpose of the lower frequency. My concern with the Ka band is how it's more sensitive to rain fade and could lower the speed thus defeating the purpose of the ultra wide frequency range.
What are your thoughts and why?
