November 7, 2011 

By Electronic Mail and Express Mail

Office of Commercial Space Transportation 

Federal Aviation Administration (FAA/AST-200) 

Room 331 

800 Independence Avenue, S.W. 

Washington, DC 20591 

SUBJECT: Petition to Amend Commercial Space Transportation Regulations

To the Office of Commercial Space Transportation: 

Further to the September 29, 2011 meeting between representatives of Space Exploration 

Technologies Corp. (“SpaceX”) and FAA/AST, SpaceX respectfully proposes six changes to the 

Commercial Space Transportation Regulations, 14 CFR §§ 400-460, as described in detail below. 

As required by 14 CFR § 404.3(b), this letter sets forth the text or substance of each regulation or 

amendment proposed and contains facts, views, and data that we believe supports the action 

requested. 

1. Acceptable Risk for a Launch License

A. Current Requirements 

14 CFR Part 415 prescribes requirements for obtaining a license to launch a launch vehicle. With 

respect to the acceptable level of risk, 14 CFR § 415.35(a) states in pertinent part: 

(a) Flight risk through orbital insertion or impact. Acceptable flight risk 

through orbital insertion for an orbital launch vehicle, and through 

impact for a suborbital launch vehicle, is measured in terms of the 

expected average number of casualties (Ec) to the collective members of 

the public exposed to debris hazards from any one launch. To obtain 

safety approval, an applicant must demonstrate that the risk level 

associated with debris from an applicant's proposed launch meets the 

public risk criteria of §417.107(b)(1) of this chapter for impacting inert 

and impacting explosive debris. 

14 CFR § 417.107(b)(1) provides as follows with respect to the Ec criterion for launch vehicles: 

(b) Public risk criteria. A launch operator may initiate the flight of a 

launch vehicle only if flight safety analysis performed under paragraph 

(f) of this section demonstrates that any risk to the public satisfies the 

following public risk criteria: 
(1) A launch operator may initiate the flight of a launch vehicle 

only if the risk associated with the total flight to all members of 

the public, excluding persons in waterborne vessels and aircraft, 

does not exceed an expected average number of 0.00003 

casualties (Ec ≤ 30 × 10−6

) from impacting inert and impacting 

explosive debris, (Ec ≤ 30 × 10−6) for toxic release, and (Ec ≤ 30 × 

10−6

) for far field blast overpressure. The FAA will determine 

whether to approve public risk due to any other hazard 

associated with the proposed flight of a launch vehicle on a caseby-case basis. The Ec criterion for each hazard applies to each 

launch from lift-off through orbital insertion, including each 

planned impact, for an orbital launch, and through final impact 

for a suborbital launch. 

B. Proposed Requirements 

SpaceX respectfully suggests that 14 CFR § 417.107(b)(1) be amended to read as follows: 

(b) Public risk criteria. A launch operator may initiate the flight of a 

launch vehicle only if flight safety analysis performed under paragraph 

(f) of this section demonstrates that any risk to the public satisfies the 

following public risk criteria: 

(1) A launch operator may initiate the flight of a launch vehicle 

only if the risk associated with the total flight to all members of 

the public, excluding persons in waterborne vessels and aircraft, 

does not exceed an expected average number of 0.0001 

casualties (Ec ≤ 100 × 10−6

). The Ec criterion applies to each 

launch from lift-off through orbital insertion, including each 

planned impact, for an orbital launch, and through final impact 

for a suborbital launch.

C. Rationale for Proposed Change 

The proposed change would replace the separate Ec criterion for each hazard in the current 

version of 14 CFR § 417.107(b)(1) with a single Ec criterion for the mission. Since the 

overarching concern is with public safety, the regulation should focus on the overall Ec. For 

example, the allocation of Ec between the various hazards identified in the current 14 CFR § 

417.107(b)(1) could result in a scenario where a launch vehicle with an overall Ec of 87 × 10−6

(assuming Ec of 29 × 10−6

 from impacting debris plus 29 × 10−6 for toxic release plus 29 × 10−6

for far field blast overpressure) met the safety approval standard, but a launch vehicle with an 

overall Ec of 31 × 10−6

 (assuming 31 × 10−6 from impacting debris plus no risk of toxic release or 

far field blast overpressure) did not despite posing only one third of the risk to the public. The 

proposed change would eliminate this potential inconsistency while maintaining an appropriate 

focus on overall public safety. 

The proposed change also would make FAA requirements consistent with other U.S. Government 

standards. The suggested Ec value of Ec ≤ 100 × 10−6

 is currently used in U.S. Government 
Orbital Debris Mitigation Standard Practices, Range Commanders Council Document 321 10 

(Common Risk Criteria for National Test Ranges), Air Force Instruction 91-217 (2010 Space 

Safety and Mishap Prevention Program), and NASA Technical Standard NASA-STD 8719.14 

(Process for Limiting Orbital Debris). To SpaceX’s knowledge, the FAA is the only government 

agency, including international agencies, that applies the 30 × 10−6

 value. Thus, a change to 

require Ec ≤ 100 × 10−6 would provide consistency. 

In addition, both the 30 × 10−6

 and 100 × 10−6 values are indicative of extremely low risk to the 

public. As noted in FAA Advisory Circular No. 431-35-1, these values are orders of magnitude 

less than the background risk to the public of fatalities due to non-occupational accidents, which 

has been estimated at 2 × 10−4

. Moreover, the background risk only accounts for fatalities, not 

serious injuries, whereas Ec measures both fatalities and serious injuries. 

2. Acceptable Risk for a Reentry License

A. Current Requirements 

14 CFR Part 435 prescribes requirements for obtaining a license to reenter a reentry vehicle. 

With respect to the acceptable level of risk, 14 CFR § 435.35 states as follows: 

To obtain safety approval for reentry, an applicant must demonstrate that 

risk for the proposed reentry, when assessed in combination with launch 

of the reentry vehicle, does not exceed acceptable risk for the conduct of 

an RLV mission as defined in paragraphs (a) and (b) of §431.35 of this 

subchapter. 

14 CFR § 431.35(b)(1)(i) similarly provides as follows with respect to the Ec criterion for reentry 

vehicles: 

(b) Acceptable risk for a proposed mission is measured in terms of the 

expected average number of casualties (Ec). 

(1) To obtain safety approval, an applicant shall 

demonstrate: 

(i) For public risk, the risk level to the collective 

members of the public exposed to vehicle or vehicle 

debris impact hazards associated with a proposed 

mission does not exceed an expected average number of 

0.00003 casualties per mission (or Ec criterion of 30 × 

10−6

) to members of the public from the applicant's 

proposed activity; and ... 

B. Proposed Requirements 

SpaceX respectfully suggests that 14 CFR § 435.35 be amended to read as follows: 
To obtain safety approval for reentry, an applicant must demonstrate that 

risk for the proposed reentry does not exceed acceptable risk for the 

conduct of an RLV mission as defined in paragraphs (a) and (b) of 

§431.35 of this subchapter. 

In addition, SpaceX respectfully suggests that 14 CFR § 431.35(b)(1)(i) be 

amended to read as follows: 

(b) Acceptable risk for a proposed mission is measured in terms of the 

expected average number of casualties (Ec). 

(1) To obtain safety approval, an applicant shall 

demonstrate: 

(i) For public risk, the risk level to the collective 

members of the public exposed to vehicle or vehicle 

debris impact hazards associated with a proposed 

mission does not exceed an expected average number of 

0.0001 casualties per mission (or Ec criterion of 100 × 

10−6

) to members of the public from the applicant's 

proposed activity; and 

C. Rationale for Proposed Changes 

The proposed change in 14 CFR § 435.35 would eliminate the “combined” Ec requirement for 

launch and reentry and separate the Ec calculations into two discrete events: launch and reentry. 

Although the FAA initially decided to use a single aggregate risk threshold for a mission 

involving the launch and reentry of a reentry vehicle, the FAA also acknowledged that there 

could be circumstances where it would be appropriate to separate launch from reentry risk, such 

as where different operators were involved and could be apportioned allowable risk thresholds, or 

where intervening events or time made reentry risks sufficiently independent of launch risks as to 

warrant separate consideration. Commercial Space Transportation Reusable Launch Vehicle and 

Reentry Licensing Regulations, NPRM, 64 FR 19626, 19635 (Apr. 21, 1999). 

SpaceX believes it would be more logical to routinely separate launch from reentry risk since the 

two events are distinct. This would replicate the approach taken by the U.S. Air Force, which 

imposes a requirement of Ec ≤ 100 × 10−6

 on launch and a separate requirement of Ec ≤ 100 × 10−6

on reentry per Air Force Instruction 91-217 (2010 Space Safety and Mishap Prevention Program). 

This logically consistent methodology also would eliminate some of the potential infelicities that 

may result from combining launch and reentry risk under the FAA’s current approach. Under the 

current system, for example, a reentry vehicle could have an Ec = 0 for the reentry portion of its 

mission but still fail to meet the safety standard for obtaining a reentry license if the launch Ec > 

30 × 10−6

. Accordingly, SpaceX recommends that the FAA treat launch and reentry risk 

separately, which would both be a more logical approach to the subject and consistent with the 

approach taken by the U.S. Air Force. 

Similarly, the proposed change in 14 CFR § 431.35(b)(1)(i) would make FAA requirements 

consistent with other U.S. Government standards. The suggested Ec value of Ec ≤ 100 × 10−6

 is 
currently used in U.S. Government Orbital Debris Mitigation Standard Practices, Range 

Commanders Council Document 321 10 (Common Risk Criteria for National Test Ranges), Air 

Force Instruction 91-217 (2010 Space Safety and Mishap Prevention Program), and NASA 

Technical Standard NASA-STD 8719.14 (Process for Limiting Orbital Debris). To SpaceX’s 

knowledge, the FAA is the only government agency, including international agencies, that applies 

the 30 × 10−6

 value. Thus, a change to require Ec ≤ 100 × 10−6 would provide consistency. 

In addition, both the 30 × 10−6

 and 100 × 10−6 values are indicative of extremely low risk to the 

public. As noted in FAA Advisory Circular No. 431-35-1, these values are orders of magnitude 

less than the background risk to the public of fatalities due to non-occupational accidents, which 

has been estimated at 2 × 10−4

. Moreover, the background risk only accounts for fatalities, not 

serious injuries, whereas Ec measures both fatalities and serious injuries. 

3. Definition of “Launch”

A. Current Requirements 

14 CFR § 401.5 defines “Launch” in pertinent part as follows: 

Launch means to place or try to place a launch vehicle or reentry vehicle 

and any payload from Earth in a suborbital trajectory, in Earth orbit in 

outer space, or otherwise in outer space, and includes preparing a launch 

vehicle for flight at a launch site in the United States. Launch includes 

the flight of a launch vehicle and includes pre- and post-flight ground 

operations as follows: 

(1) Beginning of launch. (i) Under a license, launch begins with the 

arrival of a launch vehicle or payload at a U.S. launch site. 

B. Proposed Requirements 

SpaceX respectfully suggests that 14 CFR § 401.5 be amended to read as 

follows: 

Launch means to place or try to place a launch vehicle or reentry vehicle 

and any payload from Earth in a suborbital trajectory, in Earth orbit in 

outer space, or otherwise in outer space, and includes preparing a launch 

vehicle for flight at a launch site in the United States. Launch includes 

the flight of a launch vehicle and includes pre- and post-flight ground 

operations as follows: 

(1) Beginning of launch. (i) Under a license, launch begins at the moment 

when the vehicle is fully integrated and fueled in preparation for lift-off 

from a U.S. launch site. 

Alternatively, 14 CFR § 401.5 could be amended to read as follows: 
Launch means to place or try to place a launch vehicle or reentry vehicle 

and any payload from Earth in a suborbital trajectory, in Earth orbit in 

outer space, or otherwise in outer space, and includes preparing a launch 

vehicle for flight at a launch site in the United States. Launch includes 

the flight of a launch vehicle and includes pre- and post-flight ground 

operations as follows: 

(1) Beginning of launch. (i) Under a license, launch begins at the moment 

when the vehicle is first fully fueled in its ready-for-flight configuration 

at a U.S. launch site. 

C. Rationale for Proposed Changes 

The current definition of launch requires a launch operator to obtain license (or a waiver) prior to 

the delivery of the major components of the launch vehicle to the launch site. Consequently, a 

launch operator may be required to obtain a license (or waiver) for an action as benign as 

transporting empty tanks or other major components of the launch vehicle to the launch site six 

months or more before launch. This creates an unnecessary administrative burden on the launch 

operator and the FAA, without providing any corresponding benefit to public safety. In the same 

way that a launch provider is not required to have an FAA license to perform ground tests (such 

as static fires), a launch provider should not be required to have a launch license (or waiver) to 

perform standard ground operations well in advance of the planned mission. 

4. Definition of “Mission” for a Reusable Launch Vehicle (RLV)

A. Current Requirements 

14 CFR § 431.35(a) defines “Mission” in pertinent part as follows: 

To obtain safety approval for an RLV mission, an applicant must 

demonstrate that the proposed mission does not exceed acceptable risk as 

defined in this subpart. For purposes of this section, the mission 

commences upon initiation of the launch phase of flight and consists of 

launch flight through orbital insertion of an RLV or vehicle stage or 

flight to outer space, whichever is applicable, and reentry or descent 

flight, and concludes upon landing on Earth of the RLV. 

B. Proposed Requirements 

SpaceX respectfully suggests that 14 CFR § 431.35(a) be amended to read as 

follows: 

 To obtain safety approval for an RLV mission, an applicant must 

demonstrate that the proposed mission does not exceed acceptable risk as 

defined in this subpart. For purposes of this section, the mission 

commences upon initiation of the launch phase of flight and consists of 

launch flight through orbital insertion of an RLV or vehicle stage or 
flight to outer space, whichever is applicable, and suborbital descent 

flight, and concludes upon landing on Earth of the suborbital stages of 

the RLV. Reentry from orbit by any portion of the RLV shall be treated 

as a reentry by a reentry vehicle and governed by Part 435 of this 

subchapter. 

C. Rationale for Proposed Changes 

The proposed change in 14 CFR § 431.35 would retain the “combined” Ec requirement for launch 

and suborbital descent flight, but it would treat the reentry of any orbital stage as a separate event 

subject to its own Ec calculation. The FAA previously has acknowledged that there could be 

circumstances where it would be appropriate to separate launch from reentry risk, such as where 

different operators were involved and could be apportioned allowable risk thresholds, or where 

intervening events or time made reentry risks sufficiently independent of launch risks as to 

warrant separate consideration. Commercial Space Transportation Reusable Launch Vehicle and 

Reentry Licensing Regulations, NPRM, 64 FR 19626, 19635 (Apr. 21, 1999). 

As with the acceptable risk for a reentry license discussed in Section 2 above, SpaceX believes it 

would be more logical to routinely separate launch and suborbital descent risk from reentry risk 

since the two events are distinct. Similarly, the reentry of any of the RLV’s orbital stages should 

be treated as separate reentries since intervening events and/or the passage of time will make the 

reentries sufficiently independent to warrant separate consideration. 

5. Autonomous Reentry of a Reentry Vehicle or Reusable Launch Vehicle

A. Current Requirements 

14 CFR § 431.43(e)(2) provides as follows with respect to whether reentry can be initiated 

autonomously: 

(e) Any RLV that enters Earth orbit may only be operated such that the 

vehicle operator is able to— 

(1) Monitor and verify the status of safety-critical systems before 

enabling reentry flight to assure the vehicle can reenter safely to 

Earth; and 

(2) Issue a command enabling reentry flight of the vehicle. 

Reentry flight cannot be initiated autonomously under nominal 

circumstances without prior enable. 

Although 14 CFR Part 431 prescribes requirements for obtaining an RLV 

mission license, the above language also governs reentry vehicles as it is 

incorporated by reference per 14 CFR § 435.33 into the part that prescribes 

requirements for obtaining a license to reenter a reentry vehicle. 

 
B. Proposed Requirements 

SpaceX respectfully suggests that 14 CFR § 431.43(e)(2) be amended to read as 

follows: 

(e) Any RLV that enters Earth orbit may only be operated such that the 

vehicle operator is able to— 

(1) Monitor and verify the status of safety-critical systems before 

enabling reentry flight to assure the vehicle can reenter safely to 

Earth; and 

(2) Issue a command enabling reentry flight of the vehicle. 

Reentry flight cannot be initiated autonomously under nominal 

circumstances without prior enable. Reentry flight can be 

initiated autonomously under other than nominal circumstances 

if the criteria that govern the autonomous reentry decision have 

been approved by the FAA. 

C. Rationale for Proposed Changes 

As the FAA acknowledged when it granted a waiver permitting a potential autonomous reentry of 

the Dragon spacecraft on its maiden flight, allowing autonomous reentry rather than permitting 

the vehicle to continue circling the Earth until it reentered randomly due to natural orbital decay 

would reduce risk to the public in many cases. Notice of Waiver, 75 FR 75621 (Dec. 6, 2010). 

The proposed change would continue to require the capability for human intervention in nominal 

circumstances but would eliminate the requirement of a waiver for any autonomous reentry 

capability. Instead, the proposed autonomous reentry capability would be evaluated as part of the 

application package for a reentry license. SpaceX believes that such a change would reduce risk 

to the public by allowing autonomous reentry in appropriate circumstances. 

6. Tailored Requirements

A. Current Requirements 

All FAA requirements related to commercial space launch operations can be found at 14 CFR 

Parts 400-460. 

B. Proposed Requirements 

SpaceX respectfully suggests that the FAA adopt a tailorable requirements document that can be 

adapted for each launch or reentry operator rather than publishing detailed technical requirements 

in the Code of Federal Regulations. 

 
C. Rationale for Proposed Changes 

Due to the extremely diverse nature of space vehicles, regulations that are suitable for one type of 

vehicle may be entirely inappropriate for another type of vehicle. In order to change any of the 

regulations governing commercial space activities, the FAA must go through the standard 

rulemaking process, which is time consuming and administratively burdensome for both the FAA 

and industry. Moreover, the standard rulemaking process is inadequate when faced with rapidly 

changing technology and a dynamic commercial environment. Thus, it is highly desirable that the 

FAA develop a more flexible way to update its requirements and tailor them to individual 

vehicles. 

SpaceX recommends that the FAA minimize the technical requirements in the regulations and 

instead incorporate by reference a separate tailorable document that would contain the more 

detailed requirements. This would be similar to the approach the U.S. Air Force takes with the 

Air Force Space Command Manual 91-710, which has resulted in fast response times and 

efficient operations at Federal launch ranges. It has also allowed the range to customize its rules 

for a diverse group of launch vehicles, reentry vehicles, and RLVs. SpaceX further notes that this 

approach would be similar to the way that the Federal Highway Administration handles design 

standards for highways under 23 CFR Part 625, which incorporates relevant design and safety 

standards by reference. 

Conclusion

For the reasons set forth above, SpaceX respectfully requests that the FAA implement the 

proposed changes. SpaceX believes the proposed changes would be in the public interest and 

would not jeopardize public health and safety, the safety or property, or any national security or 

foreign policy interest of the United States. 

Please contact either me at 202-649-2704 (tim.hughes@spacex.com) or David Harris (202-649-

2708; david.harris@spacex.com) with any questions or concerns. 

 Sincerely, 

 Timothy R. Hughes 

 SVP & General Counsel