Attachment Narrative

This document pretains to SAT-MOD-20191108-00129 for Modification on a Satellite Space Stations filing.

IBFS_SATMOD2019110800129_2003681

                                    Before the
                      FEDERAL COMMUNICATIONS COMMISSION
                               Washington, D.C. 20554


In the Matter of                                          )
                                                          )
SES AMERICOM, INC.                                        )    File No. SAT-MOD-___________
                                                          )    Call Sign S2415
Application for Modification of NSS-10                    )
Fixed-Satellite Space Station License                     )

                         APPLICATION OF SES AMERICOM, INC.

               SES Americom, Inc. (“SES”) respectfully requests a modification of its license

for the NSS-10 C-band fixed-satellite space station to extend the license term to January 6, 2029.

The requested extension will serve the public interest by enabling SES to continue to offer

services using NSS-10, thus promoting efficient use of satellite and orbital resources. SES also

seeks any necessary further authority to raise the satellite to a disposal orbit at end of life. A

completed FCC Form 312 is attached, and SES incorporates by reference the technical

information previously provided in support of NSS-10.1 In addition, SES is providing an orbital

debris mitigation statement regarding the spacecraft.

               NSS-10 is a C-band satellite that is located at 37.45° W.L. with a license term that

expires April 6, 2020. SES requests an extension of the NSS-10 license term to January 6, 2029.

SES has calculated that there is sufficient fuel onboard NSS-10 for the spacecraft to continue

providing reliable service during the proposed extended license term and to deorbit the

spacecraft to a disposal altitude of at least 292 kilometers above the geostationary arc, as

discussed below.



1
 Columbia Communications Corporation, Call Sign S2415, File No. SAT-LOA-20000407-
00080, grant-stamped Nov. 13, 2001.


                The satellite’s overall health is good, with all satellite subsystems functioning

nominally. There is no single point of failure in the satellite’s design, and there is no problem

with the satellite’s TT&C links, including the back-up TT&C links. As a result, extending the

license term for NSS-10 will serve the public interest by allowing SES to continue to use the

spacecraft to provide service to customers, promoting the efficient use of satellite and orbital

resources.

                Because SES applied for and was granted the NSS-10 license before the

Commission’s orbital debris mitigation disclosure requirements took effect in October 2005 and

has not sought any subsequent modifications of the satellite’s authority, SES has not previously

filed an orbital debris mitigation plan for the satellite. As demonstrated in the plan attached

hereto, SES intends to raise NSS-10 to a disposal altitude with a minimum perigee of

292 kilometers above the geostationary arc, consistent with Section 25.283(a), to vent all excess

propellant and oxidizer, and to passivate the satellite as required by Section 25.283(c), with one

qualification: the helium tanks on the NSS-10 spacecraft will not be fully vented at end-of-life,

but instead have been permanently sealed and isolated following transfer orbit operations.

                SES seeks any necessary waiver of Section 25.283(c) with respect to this residual

helium. Grant of the requested waiver is consistent with Commission policy and precedent:

                The Commission may waive a rule for good cause shown. Waiver
                is appropriate if special circumstances warrant a deviation from the
                general rule and such deviation would better serve the public
                interest than would strict adherence to the general rule. Generally,
                the Commission may grant a waiver of its rules in a particular case
                if the relief requested would not undermine the policy objective of
                the rule in question and would otherwise serve the public interest.2




2
    PanAmSat Licensee Corp., 17 FCC Rcd 10483, 10492 (Sat. Div. 2002) (footnotes omitted).

                                                  2


                In a number of cases involving various spacecraft models with similar limitations,

the Commission has waived Section 25.283(c) to permit launch and operation of spacecraft that

do not allow for full venting of pressure vessels at end of life, based on a finding that modifying

the satellite at a late stage of construction would cause pose an undue hardship.3 SES would

have faced the same hardship if it had been required to alter the design of NSS-10 to conform to

Section 25.283(c) prior to launch of the spacecraft.

                With NSS-10 already in orbit and operational, there is no question of bringing the

satellite into compliance with the rule. The Commission has expressly recognized this, finding a

waiver of Section 25.283(c) to be justified for in-orbit spacecraft that cannot satisfy the rule’s

requirements. For example, in a decision involving the AMC-2 satellite, the Commission waived

the rule on its own motion, observing that venting the spacecraft’s sealed oxidizer tanks “would

require direct retrieval of the satellite, which is not currently possible.”4




3
  See, e.g., EchoStar Satellite Operating Corp., File No. SAT-LOA-20071221-00183, Call Sign
S2746, grant-stamped Mar. 12, 2008, Attachment at ¶ 4 (granting a partial waiver of
Section 25.283(c) for AMC-14, a Lockheed Martin A2100 model spacecraft, on grounds that
requiring modification of satellite would present an undue hardship); DIRECTV Enterprises
LLC, File No. SAT-LOA-20090807-00086, Call Sign S2797, grant-stamped Dec. 15, 2009,
Attachment at ¶ 4 (same for DIRECTV 12, a Boeing 702 model spacecraft); PanAmSat Licensee
Corp., File Nos. SAT-MOD-20070207-00027, SAT-AMD-20070716-00102, Call Sign S2237,
grant-stamped Oct. 4, 2007, Attachment at ¶ 7 (same for Intelsat 11, an Orbital Sciences Star
model spacecraft).
4
  SES Americom, Inc., File No. SAT-MOD-20101215-00261, Call Sign S2134, grant-stamped
Mar. 8, 2011, Attachment at ¶ 4. See also XM Radio Inc., File No. SAT-MOD-20100722-00165,
Call Sign S2616, grant-stamped Oct. 14, 2010, Attachment at ¶ 2 (waiving Section 25.283(c) for
XM-4, a Boeing 702 model spacecraft, because “modification of the spacecraft would present an
undue hardship, since XM-4 is an in-orbit space station and venting XM-4’s helium and xenon
tanks would require direct retrieval of the satellite, which is not currently possible”).

                                                   3


               The same practical obstacle is present here. Because NSS-10 is already in orbit,

SES can do nothing to enable full venting of residual pressure in the helium tanks. Given this

reality, waiver is clearly warranted; there is no possible public interest benefit in requiring strict

adherence to a rule with which the licensee is incapable of complying.

               For the foregoing reasons, SES respectfully requests that the Commission modify

the NSS-10 license to extend the term through January 6, 2029 and authorize retirement of NSS-

10 pursuant to the attached orbital debris mitigation plan.

                                               Respectfully submitted,

                                               SES AMERICOM, INC.

                                               By: /s/ Petra A. Vorwig

Of Counsel                                         Petra A. Vorwig
Karis A. Hastings                                  Senior Legal & Regulatory Counsel
SatCom Law LLC                                     SES Americom, Inc.
1317 F Street, N.W., Suite 400                     1129 20th Street, N.W., Suite 1000
Washington, D.C. 20004                             Washington, D.C. 20036
Tel: (202) 599-0975

Dated: November 8, 2019




                                                   4


                     Annex: NSS-10 Orbital Debris Mitigation Plan


Spacecraft Hardware Design: SES has assessed and limited the amount of debris released in a
planned manner during normal operations of NSS-10 at 37.45° W.L. No debris is generated
during normal on-station operations, and the spacecraft is in a stable configuration. The satellite
is operating with an E-W stationkeeping tolerance of +/- 0.05 degrees.

SES has also assessed and limited the probability of the space station becoming a source of
orbital debris by collisions with small debris or meteoroids that could cause loss of control and
prevent post-mission disposal. SES requires that spacecraft manufacturers assess the probability
of micrometeorite damage that can cause any loss of functionality. This probability is then
factored into the ultimate spacecraft probability of success. Any significant probability of
damage would need to be mitigated in order for the spacecraft design to meet SES’ required
probability of success of the mission. SES has taken the following steps to limit the effects of
such collisions: (1) critical spacecraft components are located inside the protective body of the
spacecraft and properly shielded; and (2) all spacecraft subsystems have redundant components
to ensure no single-point failures. The spacecraft will not use any subsystems for end-of-life
disposal that are not used for normal operations.

Minimizing Accidental Explosions: SES has assessed and limited the probability of accidental
explosions during and after completion of mission operations. As part of the Safety Data
Package submission for SES spacecraft, an extensive analysis is completed by the spacecraft
manufacturer, reviewing each potential hazard relating to accidental explosions. A matrix is
generated indicating the worst-case effect, the hazard cause, and the hazard controls available to
minimize the severity and the probability of occurrence. Each subsystem is analyzed for
potential hazards, and the Safety Design Package is provided for each phase of the program
running from design phase, qualification, manufacturing and operational phase of the spacecraft.
Also, the spacecraft manufacturer generates a Failure Mode Effects and Criticality Analysis for
the spacecraft to identify all potential mission failures. The risk of accidental explosion is
included as part of this analysis. This analysis indicates failure modes, possible causes, methods
of detection, and compensating features of the spacecraft design.

The design of the NSS-10 spacecraft is such that the risk of explosion is minimized both during
and after mission operations. In designing and building the spacecraft, the manufacturer took
steps to ensure that debris generation will not result from the conversion of energy sources on
board the satellite into energy that fragments the satellite. All propulsion subsystem pressure
vessels, which have high margins of safety at launch, have even higher margins in orbit, since
use of propellants and pressurants during launch decreases the propulsion system pressure. Burst
tests were performed on all pressure vessels during qualification testing to demonstrate a margin
of safety against burst. Bipropellant mixing is prevented by the use of valves that prevent
backwards flow in propellant and pressurization lines. All pressures, including those of the
batteries, are monitored by telemetry.

At the end of operational life, after the satellite has reached its final disposal orbit, onboard
sources of stored energy will be depleted or secured, and the batteries will be discharged. The


NSS-10 propulsion system can vent its oxidizer and hydrazine tanks but has no way to vent the
helium tanks, which were sealed following the transfer orbit insertion. After the spacecraft was
placed into its nominal orbit, two valves were permanently closed so that both of the helium
tanks remain isolated.

During and after operational life time, the risk of burst is mitigated to a negligible level for the
following reasons:

        1. The remaining pressure in the Helium (He) tanks (57 bars) is significantly lower than
the design burst pressure (465 bars) and the actual measured burst pressure (638 bars reached
during qualification test). That offers a margin of 1000% with respect to the qualification test and
more than 700% over the design. Furthermore, the main parameter which can increase the
pressure is the temperature. To get the tanks to a pressure above the design rupture pressure
(465 bars), the tank temperature would have to increase to above 146°C (201°C for real burst
pressure). This compares to the thermal analysis conducted for this satellite, which guarantees
operating temperature lower than 40°C, a margin of 1000% with respect to the qualification.
These margins of the actual pressure and temperature versus either the design or qualification
limits indicate that that there is no risk of rupture.

        2. Design of helium tanks: the tank is designed to be “leak before burst.” It is made of a
titanium liner and overwrapped with carbon fiber. Accordingly, whatever the cause of the
unexpected loss of pressure, the tank will leak but not burst and therefore will not generate
debris.

       3. In addition, the helium tanks are surrounded by panels in the satellite which protect
them from thermal flux and external debris.

Based on the foregoing technical design considerations, there is no risk of debris due to burst of
the unvented helium tanks on the satellite, during the satellite’s life through to its disposal.

Safe Flight Profiles: SES has assessed and limited the probability of the space station becoming
a source of debris by collisions with large debris or other operational space stations.
Specifically, SES has assessed the possibility of collision with satellites located at, or reasonably
expected to be located at, the requested orbital location or assigned in the vicinity of that
location. Regarding avoidance of collisions with controlled objects, in general, if a
geosynchronous satellite is controlled within its specified longitude and latitude stationkeeping
limits, collision with another controlled object (excluding where the satellite is collocated with
another object) is the direct result of that object entering the allocated space.

NSS-10 currently operates at the 37.45° W.L. orbital location, and on-station operations require
stationkeeping within the +/- 0.05 degree N-S and +/- 0.05 degree E-W control box, thereby
ensuring adequate collision avoidance distance from other satellites in geosynchronous orbit.
SES is not aware of any other FCC- or non-FCC licensed spacecraft that are operational or
planned to be deployed at 37.45° W.L. or to nearby orbital locations such that there would be an
overlap with the stationkeeping volume of NSS-10. Furthermore, SES is not aware of any other
system with an overlapping stationkeeping volume with NSS-10 that is either in orbit or

                                                  2


progressing towards launch. Based on the preceding, it is concluded that physical coordination
of the NSS-10 satellite with another party is not required at the present time.

SES uses the Space Data Center (“SDC”) system from the Space Data Association to monitor the
risk of close approach of its satellites with other objects. Any close encounters (separation of
less than 10 km) are flagged and investigated in more detail. If required, avoidance maneuvers
are performed to eliminate the possibility of collisions. During any relocation, the moving
spacecraft is maneuvered such that it is at least 30 km away from the synchronous radius at all
times. In most cases, much larger deviation from the synchronous radius is used. In addition,
the SDC system is used to ensure no close encounter occurs during the move. When de-orbit of
a spacecraft is required, the initial phase is treated as a satellite move, and the same precautions
are used to ensure collision avoidance.

Post-Mission Disposal: Post-mission disposal of the satellite from operational orbit will be
accomplished by carrying out maneuvers to a higher orbit. The upper stage engine remains part
of the satellite, and there is no re-entry phase for either component. The fuel budget for
elevating the satellite to a disposal orbit is included in the satellite design. SES plans to
maneuver NSS-10 to a disposal orbit with a minimum perigee of 292 km above the normal GSO
operational orbit. This proposed disposal orbit altitude results from application of the IADC
formula based on the following calculation:

Total Solar Pressure Area “A” = 112.0 m2
“M” = Dry Mass of Satellite = 2352.0 kg
“CR” = Solar Pressure Radiation Coefficient = 1.2
Therefore the Minimum Disposal Orbit Perigee Altitude:
= 36,021 km + 1000 x CR x A / M
= 36,021 km + 1000 x 1.20 x 112.0 / 2352.0
= 36,078 km
= 292 km above GSO (35,786 km)

SES intends to reserve 14.2 kg of propellant in order to account for post-mission disposal of
NSS-10. SES has assessed fuel-gauging uncertainty and has provided an adequate margin of
fuel reserve to address the assessed uncertainty.




                                                 3


                                        DECLARATION


               I, Charles Law, hereby certify under penalty of perjury that I am the technically

qualified person responsible for preparation of the technical information contained in the

foregoing application; that I am familiar with the technical requirements of Part 25; and that I

either prepared or reviewed the technical information contained in the application and that it is

complete and accurate to the best of my knowledge, information and belief.

                                              _/s/__Charles Law__________________
                                              Senior Manager, Flight Dynamics
                                              SES S.A.


Dated: November 8, 2019



Document Created: 2019-11-08 17:49:45
Document Modified: 2019-11-08 17:49:45

© 2024 FCC.report
This site is not affiliated with or endorsed by the FCC