Waiver of Launch Collective Risk Limit for a Near-Orbital Trajectory, 88338-88340 [2024-25851]

Agencies

• Federal Aviation Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 89, Number 216 (Thursday, November 7, 2024)]
[Notices]
[Pages 88338-88340]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-25851]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration


Waiver of Launch Collective Risk Limit for a Near-Orbital 
Trajectory

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation.

ACTION: Notice of waiver.

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SUMMARY: This notice concerns a petition for waiver submitted to the 
Federal Aviation Administration (FAA) by Space Exploration Technologies 
Corporation (SpaceX) to waive the launch collective risk limit of 1 x 
10-4 expected casualties (Ec) for Starship Super 
Heavy missions that utilize a near-orbital trajectory. The near-orbital 
Starship Super Heavy missions have been deemed suborbital such that a 
single launch collective risk limit of 1 x 10-4 
Ec has been applied to cover the aggregate of the risks from 
the suborbital launch and suborbital reentry phases of each mission. 
The SpaceX petition requests an increase to the collective risk limit, 
to not exceed 2 x 10-4 Ec, with the condition 
that neither the suborbital launch nor suborbital reentry risks exceed 
1 x 10-4 Ec individually. The FAA grants the 
petition for near-orbital Starship Super Heavy missions to allow a risk 
budget that parallels but remains consistent with an orbital mission 
profile that has a separate risk limit of 1 x 10-4 
Ec for both the launch and reentry phases.

DATES: Issued in Washington, DC, on July 31, 2024.

FOR FURTHER INFORMATION CONTACT: For technical questions concerning 
this waiver, contact Paul Wilde, Senior Technical Specialist, 
Commercial Space Transportation--Office of Operational Safety, 800 
Independence Avenue SW, Washington, DC 20591; telephone: (202) 267-
5727; email: [email protected].

SUPPLEMENTARY INFORMATION: 

Background

    On April 18, 2024, SpaceX submitted a waiver petition to the 
Federal Aviation Administration's (FAA's) Office of Commercial Space 
Transportation (AST) requesting relief from 14 CFR

[[Page 88339]]

450.101(a)(1)(i) for a unique near-orbital trajectory SpaceX designed 
for the initial Starship Super Heavy launches from Boca Chica in Texas. 
SpaceX requested an increase to the collective risk criteria, to not 
exceed 2 x 10-4 Ec, with neither suborbital 
launch nor suborbital reentry risks exceeding 1 x 10-4 
Ec. SpaceX requested that the waiver be effective for 
Starship Super Heavy launches starting with Flight 4 and beyond that 
utilize a near-orbital trajectory, where the maximum perigee altitude 
is less than +130 km and greater than -50 km. Additionally, SpaceX 
requested a waiver of the 60-day requirement for submission of waiver 
petitions per Sec.  404.5(a). SpaceX updated its request on May 17, 
2024. with additional rationale to support the waiver petition. On June 
4, 2024, the FAA notified SpaceX that the waiver request was still 
under evaluation and there would be no determination prior to the 
planned launch of Flight 4 on June 6, 2024. SpaceX requested the FAA 
consider the waiver for the next flight, namely Flight 5. The request 
to waive the procedural requirements set forth in Sec.  404.5(a) is no 
longer applicable as SpaceX since requested the waiver to apply 
starting with Flight 5.

Near-Orbital Trajectory of Starship Super Heavy Missions

    SpaceX's initial developmental test missions are for launches 
conducted on a near-orbital trajectory, where the nominal trajectory 
does not achieve orbital insertion as defined in Sec.  401.7.\1\ 
Therefore, the FAA has considered each mission a suborbital launch that 
includes a suborbital reentry, and has applied a single launch 
collective risk limit of 1 x 10-4 Ec in 
accordance with Sec.  450.101(a)(1)(i). Per Sec.  450.3(b)(3)(iii), for 
a suborbital launch that includes a suborbital reentry, launch ends 
after reaching apogee.
    The Ec criteria identified in Sec.  450.101 apply to 
flight. SpaceX, in its waiver petition, divides the phases of Starship 
Super Heavy flight into two distinct phases. First, SpaceX identifies 
the launch phase \2\ to be from ignition of the Super Heavy booster 
(first stage) to the initial second engine cutoff (SECO-1) of the 
Starship upper stage. In addition, the launch phase includes stage 
separation, followed by the Super Heavy booster performing a boostback 
burn to return to the launch site or a designated landing area 
offshore. After stage separation, Starship ignites its engines until 
SECO-1. Due to the shallow perigee of the Starship trajectory after 
SECO-1, Earth's gravity will cause the Starship to passively enter the 
Earth's atmosphere in either a controlled or uncontrolled suborbital 
reentry. For a controlled suborbital reentry, Starship may perform a 
landing burn prior to ocean splashdown. An uncontrolled suborbital 
reentry of Starship would almost certainly result in an in-air breakup 
with debris expected to land within published hazard areas.\3\ In both 
scenarios, Starship hazardous debris \4\ would impact the open ocean 
between Madagascar and Australia. SpaceX identifies the suborbital 
reentry phase of the Starship flight to be from SECO-1 of the Starship 
to its final impact or landing because the perigee only decreases in 
the post-SECO-1 phases of flight.

Waiver Criteria

    Chapter 509 allows the FAA to waive a license requirement if the 
waiver (1) will not jeopardize public health and safety, safety of 
property; (2) will not jeopardize national security and foreign policy 
interests of the United States; and (3) will be in the public interest. 
See 51 U.S.C. 50905(b)(3); 14 CFR 404.5(b).

Section 450.101(a)(1)(i) Waiver Petition

    Section 450.101(a)(1)(i) requires that the risk to all members of 
the public, excluding persons in aircraft and neighboring operations 
personnel, must not exceed 1 x 10-4 Ec. For a 
suborbital launch, or a suborbital launch with a suborbital reentry,\5\ 
the 1 x 10-4 Ec in Sec.  450.101(a)(1)(i) applies 
from liftoff through final impact or landing. SpaceX's waiver petition 
is for its Starship Super Heavy missions from Boca Chica that involve a 
near-orbital trajectory, where the Starship almost obtains the 
necessary position and velocity to achieve orbital insertion (i.e., 
make it into orbit). Because Starship does not achieve orbital 
insertion, the FAA considers the near-orbital Starship Super Heavy 
missions to be suborbital in which a single launch collective risk 
limit of 1 x 10-4 Ec is applied to cover the sum 
or aggregate of the risks from the suborbital launch and suborbital 
reentry phases of each mission. SpaceX seeks relief from the 
application of a single launch collective risk limit required by Sec.  
450.101(a)(1)(i) and requests that the FAA allow for two separate 1 x 
10-4 Ec risk limits, one for the suborbital 
launch phase and one for the suborbital reentry phase, similar to what 
is allocated to an orbital mission when a vehicle achieves orbital 
insertion and then reenters from Earth orbit.
    In making a waiver determination, the FAA must analyze whether the 
waiver: (1) would jeopardize public health and safety or safety of 
property; (2) would jeopardize national security and foreign policy 
interests of the United States; and (3) is in the public interest. See 
51 U.S.C. 50905(b)(3); 14 CFR 404.5(b).

i. Public Health and Safety and Safety of Property

    The FAA finds that the trajectory proposed by SpaceX is more like 
an orbital trajectory than a suborbital trajectory. Because suborbital 
trajectories do not involve separate, licensable reentries, they are 
afforded one risk budget. By contrast, orbital trajectories with a 
return result in a separate and licensable reentry which necessitates a 
risk budget for launch and a risk budget for reentry. For future 
flights of the Starship Super Heavy that use this trajectory and end in 
the Indian Ocean, SpaceX has identified a trajectory that would allow 
the FAA to apply two separate risk budgets without jeopardizing public 
health and safety. This increase in the collective risk threshold from 
1 x 10-4 to 2 x 10-4 Ec, with neither 
launch nor reentry exceeding 1 x 10-4 Ec, exposes 
the public to overall less risk than that of an orbital mission 
followed by a separate reentry, given the current Starship flight 
history. SpaceX demonstrated that utilizing the near-orbital trajectory 
targeting an Indian Ocean landing, which avoids random reentry risk 
from failures that may occur while on-orbit and provides near certainty 
that any hazardous debris would impact locations in the Indian Ocean, 
will not jeopardize public health and safety. The FAA independently 
found that the public risk associated with a random reentry of the 
Starship, at this stage in its development, would be 40 to 50 times 
higher than the collective risk threshold of 1 x 10-4 
Ec. Forcing Starship engine cut-off to occur just prior to 
reaching orbital perigee (and thus maintaining a suborbital trajectory) 
allows SpaceX to predict with high certainty debris impact locations 
given a failure.
    For an orbital launch, the criteria in Sec.  450.101(a) apply from 
liftoff through orbital insertion. For a suborbital launch, or a 
suborbital launch and reentry, the criteria in Sec.  450.101(a) apply 
from liftoff through final impact or landing. To determine whether a 
launch is orbital or suborbital, the FAA determines whether the 
trajectory is a suborbital trajectory or achieves orbital insertion. 
The near-orbital trajectory targeting an Indian Ocean landing as 
proposed by SpaceX does not fully meet the definition of suborbital 
trajectory per Sec.  401.7, nor does the operation achieve orbital 
insertion. Specifically, the near orbital trajectory does not fully 
meet the definition of suborbital

[[Page 88340]]

trajectory because under Sec.  401.7, a suborbital trajectory is when 
the vacuum instantaneous impact point (IIP) of a vehicle's flight path 
does not leave the surface of the Earth. Starship's nominal IIP leaves 
the earth for a few seconds. Secondly, the near orbital trajectory is 
not an orbital trajectory because it does not lead to orbital 
insertion. Orbital insertion is defined in Sec.  401.7 as the point at 
which a vehicle achieves a minimum 70-nautical mile perigee based on a 
computation that accounts for drag. In this case, the Starship Super 
Heavy does not achieve a 70-nautical mile perigee. Because Starship 
does not achieve orbital insertion, it conducts a suborbital reentry, 
which is different from a reentry from Earth orbit that involves a 
final health check prior to initiating deorbit. The near-orbital 
trajectory presents a unique circumstance as it relates to the 
application of the safety criteria outlined in Sec.  450.101.
    The FAA finds that granting SpaceX a waiver to Sec.  
450.101(a)(1)(i) with the following terms and conditions would not 
jeopardize public health and safety or safety of property:
     The risk to all members of the public, excluding persons 
in aircraft and neighboring operations personnel, must not exceed 1 x 
10-4 Ec for the phases of flight from the lift-
off of the Super Heavy first stage to the initial SECO-1 of Starship.
     The risk to all members of the public, excluding persons 
in aircraft and neighboring operations personnel, must not exceed 1 x 
10-4 Ec for the phases of flight from the initial 
SECO-1 to final impact or landing.
     The risk to all members of the public, excluding persons 
in aircraft and neighboring operations personnel, must not exceed 2 x 
10-4 Ec for all phases of flight from lift-off 
through final impact or landing.
     The Starship mission profile utilizes a near-orbital 
trajectory where maximum perigee is less than positive 130 km and 
greater than negative 50 km, and the normal trajectory limits predicted 
debris impacts to broad ocean areas in the Indian Ocean.

ii. National Security and Foreign Policy Implications

    The FAA has identified no national security or foreign policy 
implications associated with granting this waiver.

iii. Public Interest

    On June 20, 2024, the FAA received a letter from the National 
Aeronautics and Space Administration (NASA) Human Landing System (HLS) 
program conveying the importance and criticality of the Starship Super 
Heavy system and rapid iterations of flight test operations to NASA and 
its Artemis program. The Starship program, and these test flights, are 
essential to further the technology required to support the NASA 
Artemis program and key to returning U.S. Government astronauts to the 
moon, as reinforced by the letter from NASA. For these reasons, the FAA 
finds that granting this waiver will be in the public interest.

Endnotes

    \1\ Sec.  401.7 states that ``Orbital insertion means the point 
at which a vehicle achieves a minimum 70-nautical mile perigee based 
on a computation that accounts for drag.'' Seventy nautical miles 
equals 130 km.
    \2\ The FAA notes that this is different from the FAA's 
definition of launch in 14 CFR 401.7, which encompasses certain pre- 
and post-flight activities when the launch occurs from a U.S. site.
    \3\ This is because the loads on the Starship would exceed its 
structural limits.
    \4\ Sec.  401.7 states that ``Hazardous debris means any object 
or substance capable of causing a casualty or loss of functionality 
to a critical asset. Hazardous debris includes inert debris and 
explosive debris such as an intact vehicle, vehicle fragments, any 
detached vehicle component whether intact or in fragments, payload, 
and any planned jettison bodies.''
    \5\ The FAA introduced suborbital reentry in its experimental 
permit final rulemaking in 2007 and reaffirmed its position in the 
Streamlined Launch and Reentry License Requirements final rule (85 
FR 79566, 79583 (2020)). The CSLAA describes suborbital rockets as 
reentering. See 51 U.S.C. 50905(b)(4) and 50906. Congress made clear 
that a suborbital rocket can ``reenter'' for purposes of licensing 
or permitting. It is not necessary to reach orbit to be in outer 
space. Although a suborbital rocket does not reach the velocity 
necessary to orbit the Earth, the vehicle can reach altitudes 
sufficient to be considered outer space.

James Hatt,
Space Policy Division Manager, Commercial Space Transportation, Federal 
Aviation Administration.
[FR Doc. 2024-25851 Filed 11-6-24; 8:45 am]
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