The short version

• In the United States, amateur rocket laws are mainly set by the FAA in 14 CFR Part 101, Subpart C, which divides rockets into three classes: model rockets, high-power rockets and advanced high-power rockets.
• A small model rocket needs no FAA paperwork, but every amateur rocket must stay suborbital, unmanned, out of foreign territory and must not endanger people, property or aircraft. High-power flights need advance notice to air traffic control, and many need a certificate of waiver applied for at least 45 days ahead.
• A rocket stops being “amateur” once its motors exceed 889,600 newton-seconds of total impulse or it can climb higher than 150 km. Above those limits it needs an FAA commercial space licence or permit.
• In the UK, the Air Navigation Order 2016 sets the thresholds instead: no CAA permission for small rockets up to 10,240 newton-seconds if safety and airspace conditions are met, and a CAA permission, safety case and insurance for anything larger.

Every spring, hundreds of students launch rockets in a field north of NASA’s Marshall Space Flight Center, and some university teams now build vehicles that cross the 100 km line most people treat as the edge of space. So what does the law actually require of someone who wants to launch a rocket?

The short answer is that launching your own rocket is legal in the United States and the UK, within limits. Those limits depend almost entirely on how much energy the motor produces. This explainer sets out the US rules first, then the UK position, and then the other laws that catch hobbyists who only read the aviation rules.

Who regulates amateur rockets in the United States

The Federal Aviation Administration regulates amateur rocketry as an airspace matter, not as a space activity. The rules are in 14 CFR Part 101, Subpart C, the same part that covers moored balloons, kites and unmanned free balloons. The FAA’s amateur rockets page confirms that its Air Traffic Organization handles these flights, with support from the Office of Commercial Space Transportation.

The key definition is in 14 CFR 1.1. An amateur rocket is an unmanned rocket that is propelled by motors with a combined total impulse of 889,600 newton-seconds (200,000 pound-seconds) or less and “Cannot reach an altitude greater than 150 kilometers (93.2 statute miles) above the earth’s surface.” A rocket inside that definition is expressly taken out of the commercial space licensing rules by 14 CFR 400.2, so it never needs the kind of launch licence I described in our explainer on FAA Part 450.

The three classes

Section 101.22 sorts amateur rockets into three classes.

A Class 1 model rocket uses no more than 125 grams of slow-burning propellant, is made of paper, wood or breakable plastic, contains no substantial metal parts and weighs no more than 1,500 grams including propellant. This is the shop-bought kit rocket.

A Class 2 high-power rocket is anything that is not a model rocket and is propelled by motors with a combined total impulse of 40,960 newton-seconds or less. Most club and university competition rockets fall here.

A Class 3 advanced high-power rocket is any other amateur rocket, up to the 889,600 newton-second and 150 km ceiling.

Rules that apply to every amateur rocket

Section 101.23 applies to all three classes. You must operate the rocket so that it is launched on a suborbital trajectory, does not cross into a foreign country’s territory unless the United States has an agreement with that country, is unmanned, and “Does not create a hazard to persons, property, or other aircraft.” The FAA can add further operating limits to protect air traffic and public safety. Section 101.7 separately prohibits operating an amateur rocket, or dropping anything from it, in a way that creates a hazard to other people or their property, and section 101.5 bars flights in prohibited or restricted airspace without permission from the controlling agency.

For a Class 1 model rocket, that is the extent of the FAA’s requirements. There is no notification and no waiver.

What high-power flyers must do

Class 2 and Class 3 rockets carry extra conditions under section 101.25. You must not launch into cloud, where cloud covers more than five-tenths of the sky, or where horizontal visibility is under five miles. You need prior FAA authorisation to fly between sunset and sunrise, within five nautical miles of an airport boundary, or in controlled airspace. You must keep a separation from people and property not associated with the launch of at least a quarter of the expected maximum altitude or 1,500 feet, whichever is greater. A person aged at least 18 must be present with responsibility for safety and final authority to launch, and there must be reasonable precautions to report and control fires.

Section 101.27 requires anyone flying a rocket other than a Class 1 model rocket to give the nearest FAA air traffic control facility the operator’s details, the time, the affected area and the highest affected altitude no less than 24 hours and no more than three days before the launch.

Because much of the United States is controlled airspace, many high-power launches need a certificate of waiver or authorisation. The FAA tells operators to apply on FAA Form 7711-2. The FAA’s airspace manual, Order 7400.2, Chapter 31, says the form must be submitted “at least 45 days prior to the event”, and that all Class 3 requests, and Class 2 requests to enter Class A airspace, go to the Office of Commercial Space Transportation for a safety analysis. Section 101.29 lists what the application must contain. For Class 3 that includes the maximum possible range, the dynamic stability characteristics, nominal impact areas within three standard deviations, launch commit criteria, countdown procedures and mishap procedures. In practice, it is a light-touch safety case.

The other laws that catch hobbyists

The FAA rules only govern the flight. Motors, propellant and the launch site are covered by other regimes.

Explosives law used to be the biggest problem. For years the Bureau of Alcohol, Tobacco, Firearms and Explosives treated ammonium perchlorate composite propellant, the material in most hobby rocket motors, as an explosive. On 16 March 2009 the US District Court for the District of Columbia vacated that classification in Tripoli Rocketry Association v ATF, and the ATF’s 2010 list of explosive materials recorded that the propellant “is no longer regulated under the Federal explosives laws.” Other energetic materials used in recovery systems or igniters can still be regulated, so builders of larger rockets should check each component.

Then there is the safety code system run by the hobby itself. The National Association of Rocketry and the Tripoli Rocketry Association certify flyers at three levels. The NAR’s certification page says Level 1 allows the purchase and use of H and I impulse class motors, Level 2 covers J, K and L, and Level 3 covers M, N and O, and it notes that range safety officers “will require high power certification per NFPA 1127”, the fire safety code for high-power rocketry. These are hobby standards, not federal regulations, but in practice they decide who can fly which motors at organised launches.

Finally, state and local law applies. Fireworks statutes, fire bans, park rules and the consent of the landowner all matter, and they vary a great deal. Ordinary negligence law also applies if a rocket damages someone’s property.

When a rocket stops being amateur

The 150 km ceiling is no longer theoretical. The University of Southern California’s student Rocket Propulsion Laboratory says its Traveler IV reached about 103.6 km after launch from Spaceport America on 21 April 2019, and that its Aftershock II rocket, launched from Nevada’s Black Rock Desert on 20 October 2024, reached 470,000 feet, according to USC’s own account. That is roughly 143 km, close to the regulatory limit. I explained in our piece on the Kármán line why the law has no agreed boundary for space. In the FAA’s amateur rules, though, 150 km is a hard line.

Section 101.21(b) says that a person operating an unmanned rocket that is not an amateur rocket “must comply with 14 CFR Chapter III”, the commercial space transportation rules. That means a Part 450 licence or, for some reusable suborbital vehicles, an experimental permit under Part 437. A team whose rocket might exceed 150 km should treat that as a design constraint, because the step from a waiver to a commercial licence is very large.

Export controls can also apply long before then. Rockets appear in Category IV of the US Munitions List, and teams that share detailed designs or performance data with foreign members or partners should take advice. I covered the general framework in our export controls explainer.

The UK position

In the UK the relevant rules are in article 96 of the Air Navigation Order 2016. The Order defines a “small rocket” as one whose motors have a total impulse of not more than 10,240 newton-seconds, and a “large rocket” as anything above that.

Article 96 applies to small rockets with more than 160 newton-seconds of total impulse and to all large rockets. A small rocket may be launched only if the person launching is satisfied on reasonable grounds that the flight can be made safely and that the airspace will stay clear of obstructions, including aircraft. Flights in controlled airspace need the permission of the relevant air traffic control unit, and flights in an aerodrome traffic zone need permission or information from the aerodrome. A large rocket needs a permission from the Civil Aviation Authority, which may be granted only if the person launching has a safety case showing that risks are as low as reasonably practicable, adequate insurance for each launch, and a level of risk the CAA finds acceptable.

The CAA’s guidance says model rockets up to 160 newton-seconds need no CAA permission and asks for notification of other rockets that are not large, with a minimum of 28 days’ notice requested. Article 96 does not apply to activities covered by the Outer Space Act 1986 or the Space Industry Act 2018, so a vehicle intended to reach space falls into the licensing regime I described in our UK space law explainer.

What I would watch

The first is the 150 km ceiling. University programmes are now flying within about 7 km of it. I would not be surprised to see a team deliberately build to the limit, and the first case where the FAA has to decide whether a rocket “cannot reach” 150 km, as opposed to whether it did, will test how that definition is applied.

The second is airspace pressure. The FAA’s waiver process was built for a relatively small number of club launches. As commercial launch cadence grows and more airspace is reserved for it, I would expect the process for high-altitude amateur flights to get slower and more demanding.

The third is UK notification. The CAA’s 28-day request applies to a wide range of hobby rockets. If launch sites such as those in Scotland and Cornwall bring more airspace restrictions, amateur groups may find their windows narrowing.