Friends of Amateur Rocketry, Inc.
Serving the Amateur Rocketry  Community

Encouraging Amateur Rocketry to Educate the Public

Frequency Asked Questions
1. Are any of these disqualified under the "no active control": throttling, drag parachute, aerobrakes, energy darting, gyro stabilization? The fins need to be fixed. If the fins do not move for any of these, then they are not disqualified. No movable canards either. No boosted darts. The whole rocket must make it to the maximum altitude.

2. Do we have dimensions for the payload or something to design around? Yes. See the Payload Spec page.

3. Is it fair to assume payload must survive landing at ~20ft/s? Yes, but no more than 20ft/s.

4. Does the ignition system need to be methalox? No.

5. Can we use solid motor to start engine? Yes. To follow the California State Fire Marshal rules, ignition needs to be electrically initiated with a key lockout on the pad and same-key used for lockout on the launch controller.

6. Do we have to proof valves at the competition? No.

7. What is the launch rail length? There are two 20-foot rails, one 20-foot rack, one 40-foot rail, two 60-foot rails, or they can bring their own. Look at the FAR website for pictures and dimensions of the launch rails.

8. What are the limitations on control systems E.g. passive vs. active, drag systems, axes of control? No active guidance. The rocket must be rail launched with fixed fins. It can use speed brakes or drogue parachutes to control the maximum altitude.

9. Any dimensions/weight restrictions, material restrictions, payload dimensions and contents (what kind of altimeter)? No, restrictions other than the maximum total-impulse is 9,208-lb-sec. The payload needs to be inserted into a compartment, made from materials that allow reception of of GPS signals.

10. Do we need to submit an application or intent to compete? Intent to compete. Closer to the launch date teams that are ready can sign up for the launch date on a first come first served basis. They will need to have completed a full-duration static firing of their rocket and submit a thrust-versus-time plot and a video of the static firing 30-days prior to the contest first launch date.

11. Is documentation required as part of the competition? (e.g. progress reports like PDR/CDR/FRR) Yes. The qualification and safety sheets need to be filled out. Also, a plot of thrust-versus-time and a video of a full-duration static firing are required.

12. What is the scoring system? First, the rocket must qualify. Second, one-point for every foot over 30,000-feet minus five-points for every foot above 45,000-feet.

13. Is there a design review? No. There will be safety and qualification reviews.

14. Will design decisions affect our score? Yes. If the rocket doesn't have the required safety devices, meet the safety requirements, and meet the qualification requirements; it will not qualify to compete.

15. Is there a documentation score? No. The safety and qualification worksheets are required.

16.
 We plan to use LNG and LOX as our propellants and wanted to inquire about venting. As Liquid Natural Gas displaces the normal oxygen when vented it poses an asphyxiation hazard; our question is whether FAR will be handling venting away from the launch site or is onus on us to set up for safe venting? Yes, methane, helium, and nitrogen are asphyxiants, but are also lighter than air.  We (FAR) do not plan to supply a remote vent for site users.  A good design practice for any vent, which vents propellants or pressurants, is to point them away from people working on the rocket, position them high in the air, and do your operations in open air.  Methane is also highly-explosive.  You should not have anything that creates an open flame or spark while people are working around it. FAR finds that liquid rockets are very safe to build and transport because you can do this without any pressurants or propellants on board.  Once the rocket is at FAR site and on the launch rail, the user can start loading propellants and pressurants.  We recommend that each user does this with a minimum number of people in-proximity of the rocket, to minimize exposure, and handle the pressurants and propellants with the care required by their MSDS sheet.

17. In the competition rules it states that the team must "Consist of college or university students and students that graduated that year." I am confused about the latter part. Are only students that are seniors or 2nd year Masters students eligible? The competitors can be current college students (undergraduate and graduate students) and any college student that has graduated the year of 2018. This means graduating seniors and graduating graduate students.  Graduate students mean masters and doctoral students. I believe this covers almost eight-levels or more of potential college students that can be part of the team.

18. The competition would be May 2018 correct? Correct.

19. Will there be a burn off tower provided for excess methane? No, using a burn stack would be very dangerous. Venting methane above the launch pad, pointing the vent gases away from the launch pad, and prohibiting flames or sparks from the launch pad is the safest way to operate.

20. Is there a LOX / LNG supplier that is partnering with FAR for the competition? We are working on these. We will know closer to the competition.

21. Rule States: "Propellants filled and drained from the bottom of the rocket." Does this mean from the bottom of the rocket next to engine or the bottom of each propellant tank? From the bottom of the rocket near the engine. This is the lowest point on the rocket that guarantees the draining of the most propellant by gravity and does not require a contestant to climb the launch rail or a ladder to access the fill and drain valve.

22. Rules States: “Electromechanical, pneumatic, or lift-off release of pressure umbilicals. (No rope or cable pulls)” Do propellant connections used for propellant loading count under the umbilical rule? This rule does not cover lines for filling propellant tanks with propellants. This rule applies to pressurization lines that will pressurize pressurant and propellant tanks.

23. Can we fill propellants through a self-sealing quick disconnect or do we have to use a ball valve and wrench type fitting? The fill and drain connection to the rocket can be either a self-sealing quick disconnect or a non-self-sealing disconnect or wrench type fitting and a ball valve to close off the line.

24. For the FAR payload, will this have any protrusions in the design (bolts, nubs, antenna, etc)? Or will this be just a smooth cylinder? The payload will be a smooth cylinder.

25. In terms of filling propellants and the rule for filling at the bottom of the rocket. Does this cover pressurization gas meant for pressuring our tanks? Yes. The port for filling the pressurant tank should be accessed from the bottom of the rocket.

26. Say we are doing a pressure fed rocket, can we charge the helium bottle on the ground from the side of the rocket and lift it up, then fill the propellants? " If your pressurization tank is a DOT rated pressure tank and you are not filling beyond its pressure rating; your pressurization tank can be loaded while you stand near it and you can handle and lift your rocket onto the launch rail.

27. FAR's documentation states that the payload: "Must be connected/tethered to the rocket main body." Does that mean that we cannot have the payload in the nose cone because it's not part of the main body? Can there be a line that connects the payload to the main body? The payload can be installed in the nosecone and the nosecone must then be tethered to the main body of the rocket.

28. If we use an off the shelf paintball tank connected to a regulator that is then to our run valve for our pressurant, will it need a remote vent valve? If the pressurant run valve can be opened and closed remotely and there are propellant tank remote controlled vent valves, then you don’t need a vent valve for the pressurant tank. With the pressurant run valve open, the propellant tank vent valves can vent the pressurant tank.

29. Also reading the safety checklist it says recovery arming plug at the bottom of the rocket. Would an off the shelf wireless system work be allowed? No, this is a safety function that needs to be hardwired with access at the bottom of the rocket.

30. For liquid methane and oxygen, what are their Dewar storage temperatures?  It depends on the pressure in the Dewar.  The higher the pressure the warmer the cryogen.

31. Is liquid methane and oxygen stored in the Dewar near boiling or are they like SpaceX and going densified? The liquid methane and oxygen are near boiling point and are not densified.

32. How automated should our GSE be?  It doesn’t need to be automated at all.

33. For liquid methane and oxygen, would we need to bring our own Dewar's? For liquid methane, you may need to bring your own Dewar.  We are considering supplying one, but a liquid methane Dewar has not been found. You do not need to bring a liquid oxygen Dewar, because they can be supplied locally by Praxair. Each group needs to order their own Dewar of liquid oxygen from Praxair.

34. If FAR has Dewars we can use, what size hookups should we expect? The standard liquid oxygen Dewars that can be ordered from Praxair has a CGA fitting.

35. Is gaseous helium considered a common consumable that FAR will provide in it's onsite propellant storage? if so, what pressure is it stored to / pressurization system capable of?  Helium can be ordered from Praxair and delivered to FAR site in 2,200-psi K-bottles; 2,400-psi T-bottles; and 6,000-psi 6K-bottles. Each group must order their own pressurant gases from Praxair.

36. Are there any frequency restrictions for down-linking data or wireless GSE systems and sensors? Use of commercial frequencies like WiFi and Bluetooth are legal. To use amateur radio frequencies and General Radio Mobil Service (GMRS) each group should have at least one member that has a valid radio license for that radio service.

37. Does FAR know of any East-coast test sites that have clearance for 45k altitude? No. The East-coast people come out to FAR site.

38. Can we manually toggle valves on our GSE system without an automated system? Yes.

39. Are there spec sheets for the Dewars FAR plans to use for this competition? The Dewars that can be ordered from Praxair for use at FAR site are typical high-pressure 120, 160, and 180-liter commercial Dewars.

40. Would engine gimbaling or thrust vectoring invalidate the no active guidance rule if it's only effective on powered ascent? Any guidance such as engine gimbaling, thrust vectoring, fins, and canards are not allowed and would violate the no active guidance rule.

41. Can aerobrakes be used for minor flight corrections on ascent, or do they all have to be an on or off deployed state? Any aerobraking utilized for coarse corrections would violate the no guidance rule. Full-aerobraking can be utilized to help attain the desired altitude.

42. What orientation should the fill and drain valves have? These valves can point down or 90º out the sides or any angle in between.

43. Where should the manual vent valves should be located?  These valves should also be located near the base of the rocket such that a contestant does not need a ladder or to climb the launch rail to reach them. This goes with the ability to use gravity to drain the propellant tanks.