Question being answered: "I'm more interested in international laws/treaties and U.S. spaceflight laws"
Thanks to called2voyage - https://www.congress.gov/114/plaws/publ90/PLAW-114publ90.pdf
The only constraint I see is the License to perform the launch. IF SpaceX gets that I do not see anything that constrains a Trip TO the Moon or around it.
In addition I did NOT see anything that constrained the reentry of the HUMAN passengers.
From an international perspective as long as no language attempting to show ownership, sovereignty etc exist then International Law does not apply.
IF some one can show evidence of an International Law prohibiting an American Corporation Launching Humans on a trip around the Moon I would like to see it and what Roscosmos did to get permission to take Space Tourist to the ISS.
EDITED:
There may be an exception here, IF SpaceX decides to send the tourist to see the ISS at less than 200 meters then there would be an issue.
If all goes according to plan, at approximately 5:30AM ET, Dragon will be permitted to enter the Keep-Out Sphere (KOS), an imaginary circle drawn 200 meters (656 feet) around the station that prevents the risk of collision, and continue its approach to the capture point
https://nssphoenix.wordpress.com/tag/keep-out-sphere/
Edited: IF the requirement for an answer is what is a Launch License https://www.faa.gov/about/office_org/headquarters_offices/ast/licenses_permits/launch_reentry/
A launch- or reentry-specific license authorizes you to conduct one or
more launches or reentries having the same operational parameters of
one type of launch or reentry vehicle operating at one launch or
reentry site. The license identifies, by name or mission, each
activity authorized under the license. Your authorization to operate
terminates when you complete all launches or reentries authorized by
the license or the expiration date stated in the license, whichever
occurs first.
Edit: Add History of the LAW ... https://en.wikipedia.org/wiki/Private_spaceflight
The Commercial Space Launch Act of 1984 required encouragement of
commercial space ventures, adding a new clause to NASA's mission
statement: (c) Commercial Use of Space.--Congress declares that the
general welfare of the United States requires that the Administration
seek and encourage, to the maximum extent possible, the fullest
commercial use of space.
Yet one of NASA's early actions was to effectively ban private space
flight through a mountain of red tape. From the beginning, though,
this met significant opposition not only by the private sector, but in
Congress.
In 1962, Congress passed its first law pushing back the prohibition on
private involvement in space, the Communications Satellite Act of
1962. While largely focusing on the satellites of its namesake, this was described by both the law's opponents and advocates of private
space, as the first step on the road to privatization.
While launch vehicles were originally bought from private contractors,
from the beginning of the Shuttle program until the Challenger
disaster in 1986, NASA attempted to position its shuttle as the sole
legal space launch option.But with the crash came the suspension of
the government-operated shuttle flights, allowing the formation of a
commercial launch industry.
On 30 October 1984, United States President Ronald Reagan signed into
law the Commercial Space Launch Act. This enabled an American industry
of private operators of expendable launch systems. Prior to the
signing of this law, all commercial satellite launches in the United
States were restricted by Federal regulation to NASA's Space Shuttle.
On 5 November 1990, United States President George H. W. Bush signed
into law the Launch Services Purchase Act. The Act, in a complete
reversal of the earlier Space Shuttle monopoly, ordered NASA to
purchase launch services for its primary payloads from commercial
providers whenever such services are required in the course of its
activities.
Commercial launches outnumbered government launches at the Eastern
Test Range in 1997.
The Commercial Space Act was passed in 1998 and implements many of the
provisions of the Launch Services Purchase Act of 1990.
Nonetheless, until 2004 NASA kept private space flight effectively
illegal. But that year, the Commercial Space Launch Amendments Act of
2004 required that NASA and the Federal Aviation Administration
legalize private space flight. The 2004 Act also specified a "learning
period" which restricted the ability of the FAA to enact regulations
regarding the safety of people who might actually fly on commercial
spacecraft through 2012, ostensibly because spaceflight participants
would share the risk of flight through informed consent procedures of
human spaceflight risks, while requiring the launch provider to be
legally liable for potential losses to uninvolved persons and
structures.
To the end of 2014, commercial passenger flights in space has remained
effectively illegal, as the FAA has refused to give a commercial
operator's license to any private space company.
The United States updated US commercial space legislation with the
passage of the SPACE Act of 2015 in November 2015. The full name of
the act is Spurring Private Aerospace Competitiveness and
Entrepreneurship Act of 2015 The update US law explicitly allows "US
citizens to engage in the commercial exploration and exploitation of
'space resources' [including ... water and minerals]." The right does
not extend to biological life, so anything that is alive may not be
exploited commercially. The Act further asserts that "the United
States does not [(by this Act)] assert sovereignty, or sovereign or
exclusive rights or jurisdiction over, or the ownership of, any
celestial body."
The SPACE Act includes the extension of indemnification of US launch
providers for extraordinary catastrophic third-party losses of a
failed launch through 2025, while the previous indemnification law was
scheduled to expire in 2016. The Act also extends, through 2025, the
"learning period" restrictions which limit the ability of the FAA to
enact regulations regarding the safety of spaceflight participants.
Indemnification for extraordinary third-party losses has, as of 2015,
been a component of US space law for over 25 years, and during this
time, "has never been invoked in any commercial launch mishap."