[HN Gopher] FCC Partially Grants SpaceX Gen2 Broadband Satellite...
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FCC Partially Grants SpaceX Gen2 Broadband Satellite Application
Author : rntn
Score : 67 points
Date : 2022-12-02 18:13 UTC (4 hours ago)
(HTM) web link (www.fcc.gov)
(TXT) w3m dump (www.fcc.gov)
| shagie wrote:
| The section on orbital tolerances:
|
| 79. Collision Risk at Specific Operational Altitudes. Viasat and
| Kuiper assert that the 468 satellites SpaceX proposes to operate
| in the 604 km and 614 km shells will not comply with the
| Commission's individual satellite collision risk metric of
| 0.001.305 Viasat also expresses concern with satellites planned
| for operations at 360 km.306 Since we do not authorize satellites
| planned for operations at these altitudes in this grant, we do
| not reach these issues.
|
| 80. Orbital Tolerances. The satellites authorized in this grant
| are planned for operations in orbital shells centered at
| altitudes from 525 km to 535 km. SpaceX has requested orbital
| tolerances of +70 km and -50 km, i.e., the satellites in any
| orbital shell can be maintained for regular operations anywhere
| within an altitude range of 70 kilometers above or 50 kilometers
| below the center altitude. The Gen2 Starlink satellites in the
| authorized shells would, if this request is granted, be
| authorized for regular operations at altitudes ranging from as
| low as 475 km to as high as 605 km.307 This represents a
| substantially larger range of altitudes than for the Gen1
| Starlink satellites. SpaceX states that this orbital tolerance
| will allow the satellites in Gen2 Starlink to retain their
| operational life in periods of high drag and maintain low passive
| decay times in the event the satellite becomes non-
| maneuverable.308
|
| 81. If we were to authorize SpaceX's operations with the orbital
| tolerance requested, Gen2 Starlink satellite operations would be
| permitted at altitudes within the altitudes at which Kuiper's
| constellation will operate, beginning at altitudes around 580 km
| and above. Kuiper requests that we require SpaceX to limit the
| orbital tolerances of its satellites to keep its operations below
| 580 km.309 Kuiper does not object to orbital overlap with smaller
| systems and agrees with SpaceX that nothing in the Commission's
| rules limits which orbits an operator may choose, but Kuiper
| emphasizes the risks posed by the overlap of two systems
| operating at the scale of Kuiper's and SpaceX's proposed
| operations and requests that the Commission require SpaceX to
| operate all Gen2 Starlink satellites at or below 580 km
|
| 82. The record does not reflect with any specificity a need for
| Gen2 Starlink satellite operations at altitudes above 580 km, as
| opposed to the +45 to +55 km tolerance that can be achieved if
| operations are maintained below 580 km. We also note that one of
| the reasons for larger orbital tolerances that SpaceX identifies
| --effects of solar radiation on the orbits of spacecraft--is less
| pronounced for the particular orbital shells authorized by this
| grant than for lower altitudes. We will follow the approach of
| the SpaceX Third Modification Order,311 and require SpaceX to
| restrict its Gen2 Starlink operations to below 580 km. We
| condition this authorization accordingly. However, this action is
| without prejudice to any determination we may make with respect
| to requirements such as orbital separation or coordination for
| large constellations as is currently under consideration in a
| separate rule making proceeding.
| foota wrote:
| TIL "The drag force on satellites increases during times when
| the Sun is active. When the Sun adds extra energy the
| atmosphere the low density layers of air at LEO altitudes rise
| and are replaced by higher density layers that were previously
| at lower altitudes. As a result, the spacecraft now flies
| through the higher density layer and experiences a stronger
| drag force. When the Sun is quiet, satellites in LEO have to
| boost their orbits about four times per year to make up for
| atmospheric drag. When solar activity is at its greatest over
| the 11-year solar cycle, satellites may have to be maneuvered
| every 2-3 weeks to maintain their orbit [1]."
| shagie wrote:
| This can be an issue and cause real losses. From much earlier
| this year: https://www.smithsonianmag.com/smart-news/solar-
| storm-knocks...
|
| These were still in the lower staging orbit and hadn't been
| moved up to where they would be in a final configuration.
| They're at that orbit so that if anything goes wrong, they
| burn up quickly... the geomagnetic storm made them burn up
| that much more quickly (days rather than a month or so).
|
| (edit - found it!)
|
| You can see the orbital history of a satellite at
|
| https://in-the-sky.org/spacecraft.php?id=44282
|
| That was an early one... probably for testing.
|
| A recently launched one looks like https://in-the-
| sky.org/spacecraft.php?id=44713
|
| You cases the initial insertion altitude, and then taking it
| up to 550 km where it remains operational.
|
| In trying to find the specific ones that burned up...
| https://in-the-
| sky.org/search.php?searchtype=Spacecraft&s=&s...
|
| You can see that 03 Feb 2022 didn't have many that still have
| an Operational Status.
|
| Ahh! Found one... its the funny letter names that (likely)
| indicate the stack that they're sent up in.
|
| https://in-the-sky.org/spacecraft.php?id=51470
| foota wrote:
| Really interesting, so it sounds like they want to be able
| to move up enough to dodge those times?
| shagie wrote:
| Exactly - the expanded atmosphere with a geomagnetic
| storm can "puff" up the atmosphere.
|
| https://www.nasa.gov/mission_pages/sunearth/news/solarsto
| rm-...
|
| > During the heating impulse, the thermosphere puffed up
| like a marshmallow held over a campfire, temporarily
| increasing the drag on low-orbiting satellites. This is
| both good and bad. On the one hand, extra drag helps
| clear space junk out of Earth orbit. On the other hand,
| it decreases the lifetime of useful satellites by
| bringing them closer to the day of re-entry.
| dmix wrote:
| I was curious what Gen2 offers:
|
| > Gen2 satellites are expected to feature inter-satellite laser
| links that will enable communication with one another to transfer
| data at a much faster rate. The FCC filing says the Gen2 System
| will also feature other new capabilities and be launched by
| Starship. "[...] The satellites will be somewhat larger and
| generate more power, enabling them to support expanded
| capabilities now and accommodate additional payloads in the
| future..." - meaning, SpaceX could plan to offer companies and
| organizations the capability of hosting their antennas, sensors,
| or cameras, etc. aboard the Starlink satellite chassis. This will
| be useful to get the most out of the satellites' life.
|
| https://www.tesmanian.com/blogs/tesmanian-blog/starlink-orbi...
|
| I'm curious what that means for performance and capacity.
|
| Also only 7500 of the 28k satellites were approved (1/4th),
| apparently out of concern for interference.
| MrRadar wrote:
| One of the already-announced features of the Gen 2 satellites
| is the ability to connect directly to standard 4G LTE handsets
| to send emergency messages (similar to the SOS feature on the
| latest iPhone, but not limited to any specific phone model). In
| the US they will be partnering with T-Mobile to offer the
| service (probably using their band 25 spectrum).
|
| https://www.androidauthority.com/t-mobile-starlink-satellite...
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(page generated 2022-12-02 23:00 UTC)