-
#20 by deruch on 11 Nov, 2018 16:35
-
https://forum.nasaspaceflight.com/index.php?topic=46726.msg1874328#msg1874328
gongora, I appreciate that you're sharing highlights and that you're linking to direct source info, but I don't think it's actually an appropriate use of screen captures. Using screen caps instead of copy/pasting the text means that the included text isn't searchable. So, for instance, if someone in the future was trying to find something they only vaguely remembered from one of those posts and using the site search function, they're going to be SOL. It's a bit more work, but please copy/paste future text quotes. Of course, for included images, diagrams, and charts, screen cap away. -
#21 by gongora on 11 Nov, 2018 17:10
-
On some pages I couldn't select the text from the pdf file, so I just ended up doing all of them the same way.
-
#22 by Nehkara on 15 Nov, 2018 16:14
-
Text from: https://forum.nasaspaceflight.com/index.php?topic=46726.msg1874328#msg1874328
Moreover, as its own launch provider, SpaceX is fully integrating its satellite design with the launch vehicle - the groundbreaking Falcon 9 rocket. This integration allows SpaceX to optimize the satellites' specifications to the capacity and thrust available with Falcon 9 to plan for highly efficient launches that maximize the speed of deployment.
---
SpaceX learned how to initiate the move towards mass production by beginning with a single-band antenna using Ku-band spectrum and how to operate a portion of the system at a lower orbital altitude to capture a variety of operational and service-related benefits described below. Now, SpaceX is poised to build upon the lessons learned from these satellites to advance into the next stage in development.
---
By operating closer to the Earth, SpaceX would also reduce the latency of its communications signals to as low as 15 milliseconds, at which point it would be virtually unnoticeable to almost all users.(9) In addition, operating at lower altitude reduces the degree to which satellite beams will spread before they reach the Earth. As discussed in the technical analysis, SpaceX‘s ability to use even tighter beams will achieve more efficient re-use of spectrum
resources.
Despite these well-known advantages, this altitude does pose significant trade-offs, which may be why most other NGSO providers choose to operate at higher orbits.
(9) By contrast, SpaceX expected to target latency of approximately 25-35 ms from the 1,150 km altitude
---
I have a program that pulls text from images. Hope this was helpful.
-
#23 by Nehkara on 15 Nov, 2018 16:40
-
Text from: https://forum.nasaspaceflight.com/index.php?topic=46726.msg1874320#msg1874320
In the initial phase, SpaceX will launch and operate first-generation satellites that it has designed specifically to support a faster pace of deployment with a simplified design to streamline the construction process and continuously add features to subsequent generations of spacecraft. For example, SpaceX initially will use Ku-band spectrum for communications between satellites and both gateways and user terminals, and then incorporate dual Ku/Ka-band chipsets and other supporting technologies to phase in the use of Ka-band spectrum for gateway communications as it populates its constellation. Similarly, SpaceX initially will use parabolic antennas for its gateway earth stations, and introduce phased array alternatives as the system evolves. The frequency usage during these two phases is
summarized in Table A.2-2 below.
---
Operating this shell at lower altitude will significantly decrease each satellite's footprint on the Earth. To maintain suitable coverage during the very early stages of initial deployment, SpaceX may periodically use a minimum elevation angle as low as 25 degrees for this initial shell. Then, as further satellites are deployed to populate the remainder of the constellation, SpaceX will revert to a 40 degree minimum elevation angle for all user and gateway beams.
---
In its Original Applications, SpaceX planned to transition its satellites from approximately 400 km to the 1,150 km orbital shell. For its proposed operations at 550 km, SpaceX expects the insertion altitude for the modified 1,584 satellites generally to be 300-350 km, depending on solar activity. Even with this slightly lowered insertion altitude, the total orbit raise required to reach operating altitude is dramatically less than for the 1,150 km destination of the original shell. Correspondingly, this altitude requires less fuel for orbit raising and leaves more propellant to maintain orbit once the satellite arrives at its new maximum altitude. In fact, even though the thrust to overcome ongoing atmospheric drag at 550 km is significantly higher than at 1,150 km, SpaceX has been able to decrease the overall work required by the Hall-effect electric propulsion system by at least 50% with respect to the original design.
---
Second, by far the biggest change is the addition of steel reaction wheels, which were not a potential source of human casualty risk in the prior analysis. SpaceX plans to deploy two versions of its initial satellites with slightly different configurations and each will only carry a subset of the components identified above. (34)
(34) The first version includes the iron thruster and steel reaction wheels, whereas later iterations will add a silicon carbide component, while replacing the wheels with a fully demisable alternative. Even a worst-case configuration that includes all three components (a configuration that SpaceX does not intend to deploy) yields a risk of 1:10,700, which still meets the NASA requirement.
-
#24 by gongora on 23 Nov, 2018 21:06
-
This is just a summary of Starlink information to get it all in one place...
NSF Threads for Starlink:
SpaceX FCC filing for a 4425 satellite constellation providing Internet service (original thread for discussion of the FCC filings)
SpaceX - now a satellite manufacturer (Starlink) (general Starlink discussion)
SpaceX New FCC Filings for Starlink (use this thread going forward for discussion specifically related to the FCC filings)
SAT-LOA-20161115-00118
SAT-LOA-20170301-00027
These are the Starlink Ku/Ka-band filings. Approved March 29, 2018
SAT-LOA-20170726-00110
This is the Starlink V-band filing. It has 7000 additional satellites in a VLEO constellation and adds V-band frequencies to the original 4425 satellite Ku/Ka-band constellation. Adopted November 15, 2018 (document released November 19, 2018.)
SAT-MOD-20181108-00083
This modification would allow the initial deployment (~1600 sats) of the Ku/Ka-band constellation to be deployed in a lower orbit. The filing has not been officially accepted/posted for public notice yet as of Nov. 23, 2018. Once the notice of the filing is posted it will kick off a (30 day?) time period for comments/oppositions to the filing, followed by more time periods for rounds of responses. Don't expect any resolution on this before mid-2019. -
#25 by gongora on 15 Dec, 2018 22:26
-
Accepted for filing, now the comment periods can start.Quote
SAT-MOD-20181108-00083 E S2983/3018
Modification
Date Filed: 11/08/2018 11:22:07:27300
Space Exploration Holdings, LLC
Space Exploration Holding, LLC (SpaceX) requests modification of the authorization for its previously authorized 4,425 non-geostationary orbit satellite constellation using Ku- and Ka-band spectrum (IBFS File Nos. SAT-LOA-20161115-00118 and SAT-LOA-20170726-00110). Specifically, SpaceX to seeks to: (1) reduce the number of satellites in the constellation from 4,425 to 4,409; (2) relocate 1,584 satellites authorized to operate at an altitude of 1,150 km to an altitude of 550 km; and (3) make related changes to the operations of the satellites in this new lower shell of the constellation. SpaceX also addresses three conditions included in its existing authorization related to orbital debris mitigation, compliance with applicable limits on equivalent power flux-density, and protection of fixed services in the Ka-band. SpaceX requests waivers, to the extent necessary, of Sections 25.157(c) and 25.146(a) of the Commission's rules, as well as of various limitations in the Commission's Schedule S software, in connection with this request. -
#26 by mgeagon on 16 Dec, 2018 06:32
-
Accepted for filing, now the comment periods can start.
QuoteSAT-MOD-20181108-00083 E S2983/3018
Modification
Date Filed: 11/08/2018 11:22:07:27300
Space Exploration Holdings, LLC
Space Exploration Holding, LLC (SpaceX) requests modification of the authorization for its previously authorized 4,425 non-geostationary orbit satellite constellation using Ku- and Ka-band spectrum (IBFS File Nos. SAT-LOA-20161115-00118 and SAT-LOA-20170726-00110). Specifically, SpaceX to seeks to: (1) reduce the number of satellites in the constellation from 4,425 to 4,409; (2) relocate 1,584 satellites authorized to operate at an altitude of 1,150 km to an altitude of 550 km; and (3) make related changes to the operations of the satellites in this new lower shell of the constellation. SpaceX also addresses three conditions included in its existing authorization related to orbital debris mitigation, compliance with applicable limits on equivalent power flux-density, and protection of fixed services in the Ka-band. SpaceX requests waivers, to the extent necessary, of Sections 25.157(c) and 25.146(a) of the Commission's rules, as well as of various limitations in the Commission's Schedule S software, in connection with this request.This modification would allow the initial deployment (~1600 sats) of the Ku/Ka-band constellation to be deployed in a lower orbit. The filing has not been officially accepted/posted for public notice yet as of Nov. 23, 2018. Once the notice of the filing is posted it will kick off a (30 day?) time period for comments/oppositions to the filing, followed by more time periods for rounds of responses. Don't expect any resolution on this before mid-2019.
If the satellites were ready to launch before final approval, there is nothing preventing SpaceX from putting them into the 550 km orbit, correct? Worst case is the satellites couldn't be turned on for commercial use until approval was secured. AIUI, the company would be free to do all the testing it would like, as long as it simply files a temporary bandwidth request, just like it did for Tintin and all other vehicles. Do I understand this correctly? -
#27 by oldAtlas_Eguy on 16 Dec, 2018 20:46
-
30 day period ends 15 Jan. Now give FCC up to 5 months to consider the mod and that puts it May. Even if the mod is not approved, SpaceX is likely to have 3 months before the earliest launch date possible Aug 2019 to then redo the orbit and launch trajectory plans/calcs.
-
#28 by gongora on 16 Dec, 2018 21:06
-
30 day period ends 15 Jan. Now give FCC up to 5 months to consider the mod and that puts it May. Even if the mod is not approved, SpaceX is likely to have 3 months before the earliest launch date possible Aug 2019 to then redo the orbit and launch trajectory plans/calcs.
There is more than one round of comments and replies, and there isn't really a maximum time for it to take. OneWeb's modification is at about 9 months now and hasn't received a ruling. -
#29 by RedLineTrain on 16 Dec, 2018 21:24
-
And I still think that the ITU hasn't fully reviewed and approved the original constellation, this modified constellation, or the VLEO constellation. SpaceX is asking the FCC for a waiver to launch until the ITU finishes the review, but the FCC has declined to grant such a waiver yet.
Disclaimer: I do not know much about how ITU regulations work. -
#30 by meberbs on 16 Dec, 2018 21:59
-
If the satellites were ready to launch before final approval, there is nothing preventing SpaceX from putting them into the 550 km orbit, correct? Worst case is the satellites couldn't be turned on for commercial use until approval was secured. AIUI, the company would be free to do all the testing it would like, as long as it simply files a temporary bandwidth request, just like it did for Tintin and all other vehicles. Do I understand this correctly?
I don't think so, FCC approvals are required for any communication with a satellite, not just commercial use. Just launching a satellite at all requires approval first. The FCC has ended up as the body that regulates things like orbital debris and some other hazards, just out of convenience, since someone has to be the regulatory gatekeeper. This means that just launching them to a different orbit than originally planned without approvals first could get you in trouble.
Submitting a redundant but limited application shortly before launch to allow the launch to take place is just one more approval you are going to have to wait for and is going to end up just slowing things down for you overall anyway. -
#31 by deruch on 18 Dec, 2018 15:33
-
If the satellites were ready to launch before final approval, there is nothing preventing SpaceX from putting them into the 550 km orbit, correct? Worst case is the satellites couldn't be turned on for commercial use until approval was secured. AIUI, the company would be free to do all the testing it would like, as long as it simply files a temporary bandwidth request, just like it did for Tintin and all other vehicles. Do I understand this correctly?
No. They need bandwidth access for all communications with the satellites. This includes any commanding or even satellite status signals. I don't believe it would be an appropriate use of the FCC's Special Temporary Authority granting mechanism (or of their shorter-term licensing mechanism) to cover communications with the constellation regardless of whether it was in commercial operation or not. Nor do I believe that the FCC would ever agree to grant/license bandwidth to such a constellation on those terms. -
#32 by gongora on 30 Jan, 2019 00:40
-
The first round of comments/oppositions is coming in (I think they were due to be filed today.) So far we've got Kepler, Astro Digital, Planet, Spire, and the Commercial Smallsat Spectrum Management Association complaining that SpaceX decided to move their constellation to an area where all of the cubesat constellations are to be found, and potentially increase interference in Ku-band since SpaceX wants to initially switch their gateways from Ka to Ku.
FCC Filings related to the SpaceX Modification -
#33 by gongora on 08 Apr, 2019 21:22
-
SpaceX filed for STA to communicate with their first set of stats during orbit raising (this is because of a gap in the FCC rules for NGSO sats). They say they're targeting early May for the launch, it doesn't say how many sats are being launched.
SAT-STA-20190405-00023
-
#34 by gongora on 16 Apr, 2019 22:49
-
Quote
...SpaceX has filed applications for just six Ku-band gateways in the U.S. – and has no current plans to request more.
SpaceX made clear in its modification application that only a limited number of first generation satellites will use the Ku-band for gateway communications for a discrete period of time, until it transitions to Ka-band for gateways communications. Specifically, SpaceX anticipates that it will deploy fewer than 75 satellites that use Ku-band spectrum for gateway operations.
-
#35 by Robotbeat on 17 Apr, 2019 04:35
-
That's some spicy commentary in there about OneWeb...Quote...SpaceX has filed applications for just six Ku-band gateways in the U.S. – and has no current plans to request more.
SpaceX made clear in its modification application that only a limited number of first generation satellites will use the Ku-band for gateway communications for a discrete period of time, until it transitions to Ka-band for gateways communications. Specifically, SpaceX anticipates that it will deploy fewer than 75 satellites that use Ku-band spectrum for gateway operations. -
#36 by gongora on 17 Apr, 2019 04:39
-
That's some spicy commentary in there about OneWeb...
The commentary between SpaceX and OneWeb tends to be like that (in both directions). -
#37 by strawwalker on 09 May, 2019 20:18
-
0388-EX-CN-2019
Form 442 for Starlink test user terminals in Washington.
Description:QuoteEXPERIMENTAL DESCRIPTION
Space Exploration Technologies Corp. (“SpaceX”) seeks an experimental license to
deploy a limited number of user terminals in fixed locations to gather operational data regarding
the performance of SpaceX’s user terminals with the initial deployment of the Starlink
constellation.1 These operations will use the following subset of frequencies for which SpaceX
has already obtained appropriate space station authorizations, and for which applications for
gateway earth station operations are currently pending:
Downlink: 10.2 – 12.7 GHz
Uplink: 14.0 – 14.5 GHz
SpaceX will use a total of no more than 256 user terminals, distributed among five test
locations. The terminals will be deployed in clusters at each location at the coordinates listed on
the associated Form 442. At each location, all user terminals involved in the experiment will be
deployed on rooftops such that they are spatially isolated from any other earth stations operating
in this band.
Docs -
#38 by strawwalker on 28 Jun, 2019 15:36
-
Two more new experimental license requests:
0517-EX-CN-2019 Space Exploration Holdings, LLC, posted Wednesday morning.
0515-EX-CN-2019 Space Exploration Technologies Corporation, posted Friday morning.
0517 - Testing of 70 user terminals distributed nationwide and 200 in Washington at SpaceX employee homes. Phased array and 1 meter parabolic antennas. Up to one year. Description | Radiation Hazard Analysis
0515 - Aircraft borne antenna operation from distributed US airfields. Appears to be for Starlink related testing, possibly related to 0153-EX-CM-2018. Public Note
edit: FCC just posted the exhibits link for 0515 but I don't have time now to look through it if someone else wants to cut and paste the purpose. -
#39 by intelati on 28 Jun, 2019 15:49
-
edit: FCC just posted the exhibits link for 0515 but I don't have time now to look through it if someone else wants to cut and paste the purpose.
QuoteIn this application, SpaceX seeks an experimental authorization to test activities undertaken with
the federal government. The tests are designed to demonstrate the ability to transmit and receive
information (1) between five ground sites (“Ground-to-Ground”) and (2) between four ground
sites and an airborne aircraft (“Ground-to-Air”). Nothing about the operation of and
transmissions from the satellites will change under this modification. This application seeks only
to use an earth station to transmit signals to the SpaceX satellites first from the ground and later
from a moving aircraft. For this purpose, SpaceX will use the same antenna used in the earlier
experiments with Microsat-2a and Microsat-2b. As discussed below, these proposed operations
will not adversely affect any other authorized spectrum user, including geostationary orbit
(“GSO”) satellite systems.
E: page 3 of exhibit
