Skip to Sidebar Skip to Content

National Association of Rocketry

  • Home
  • Join NAR
  • Site Map
  • Contact Us
  • My Membership
  • About NAR
    • Overview
    • Organization Awards
    • Organization Contacts
  • Donate

Altitude

« Altitude Events
  • NAR Rocketry Competition
  • Altitude Events
  • Craftsmanship Events
  • Duration Events
  • Miscellaneous Events
  • Techniques and Tips
  • Altitude
  • Cluster Altitude
  • Eggloft
  • Payload Altitude
  • Random Altitude
  • Super-Roc Altitude

  • OVERVIEW
    This event is about pure altitude! Who’s rocket can go the highest on a specified amount of total impulse?

    The rocket may be single or multi-staged. It must have a recovery device. The model does not have to be returned unless there is a question from the Range Safety Officer (RSO) about whether it had a rules issue in its flight (ejected engine, etc.). If the event is flown with altimeter-based tracking, then the rocket must contain an altimeter and must be returned after flight for the altimeter to be read.

    For the full rules for this event, please see the Altitude rules in the Model Rocket Sporting Code.

    SCORING
    Score is the higher of the altitudes from the two allowed official flights. If the trackers cannot see the rocket and a “track lost” is recorded on a flight, that flight may be reflown.

     

    GENERAL TIPS
    by Trip Barber, NAR 4322

    The keys to this event are minimum body size, minimum drag, proper motor selection, and optimum weight.

    Minimum Body Size. Always use the smallest body diameter that will contain the motor or (if staged) motors that you use. Then use the minimum body length that will ensure a straight boost with good dynamic stability — generally about 10 times the body diameter. This will minimize the frontal area and wetted surface area of the rocket, minimizing its drag.

    Minimum Drag. Put the best surface finish on rockets for this event that you know how to do. Use a nose cone that is parabolic in shape with a length-diameter ratio of 2 or 3 to 1. If the nose cone is balsa, user filler coat, sanding sealer, or Elmer’s wood-filling paste to completely fill the grain and polish it with at least 600 grit sandpaper to make the finish mirror-smooth. Pay close attention to the nose-body joint to ensure that it is smooth. Sand the surface of the body tube to ensure there are no ridges from any spiral winding. Use thin waferglass for the fins or, if you use balsa, use the same techniques as the nose to ensure a smooth surface finish and put a good symmetrical airfoil on the fins. Use a fin jig to put the fins on absolutely straight so the rocket does not spin during its upward flight. Make the shock cord mount internal so there are no protrusions on the surface of the body. Use a piston launcher or a tower launcher (or a piston inside a tower) to permit leaving off the draggy launch lug or rail buttons.

    Motor Selection. The best motor selection for this event is one with low average thrust, the smallest possible diameter, the highest total impulse that fits within the power class being flown, and a long delay time. If you have a choice between a 13mm motor and an 18mm motor for this event, always use the 13mm motor. Staging is generally not advantageous unless it permits you to use a smaller body diameter than single-staging, without sacrificing total impulse (i.e. staging two 13mm diameter “A” motors vs single-staging one 18mm diameter B motor with the same total impulse as the two A’s together). The optimum thrust for maximum altitude is twice the weight of the rocket, i.e. very low; an F10 will go much higher than an F50 of equal total impulse because the rocket with the F10 will travel at a lower average velocity and drag goes up as the square of velocity so low velocity equals lower drag equals higher altitude for the same total impulse. Altitude models tend to need long coasting times after motor burnout in order to reach their maximum feasible altitude, so always use the longest available delay time for the motor type you choose. In some power classes, particularly “A”, the longest delay time currently available for the smallest-diameter available A, the Estes A3-4T, is far too short for maximum altitude but you don’t have any alternative choice.

    Optimum Weight. Every rocket has a weight that leads to optimum altitude performance for that design. If the rocket is too light, it will not have enough momentum to coast as far as it could have after motor burnout, as it turns the velocity it achieved during motor burn into altitude. If the rocket is too heavy, it will not reach as high a burnout velocity as it might have done if lighter, and therefore will not coast as far. Flight simulation programs such as Rocksim or Open Rocket permit you to determine what this “optimum” liftoff weight is for your particular design and this is what your rocket should weigh, if possible. In general, this optimum weight is lower that it is possible to achieve for A power class and below altitude designs, while for C power class and above you may actually need to add weight (such as extra tracking powder) to the basic rocket in order to hit the optimum and achieve maximum altitude.

    Other Considerations. For recovery, use a small aluminized mylar streamer, narrow and long. The mylar takes up little room, and it can reflect sunlight to make it easier to see coming down and after landing on the ground. If optical tracking is being used to determine altitude, use lots of tracking powder (keeping the optimum liftoff weight in mind) so that the people doing the tracking can see the point of ejection, which is what they track to. See the section on “tracking powder” elsewhere on this website. If altimeters are being used to determine altitude score, use the lightest available altimeter that is approved for contest use by the NAR Contest Board, particularly in C and below power classes where optimum weight is a concern.

    KITS
    –Gone I kit (1/4A through A) – Qualified Competition Rockets

    PLANS AND ARTICLES
    A Altitude, C Payload, and Flying Altitude Events by Dan Wolf

    Flying 1/2 A Altitude, Thoughts, Ideas, Strategy, and a Plan  by Dan Wolf

    Related Documents:

    Altitude & Payload Events (Wolf) PDF May 28, 2014, 5:24 am 3 MB
    • Return to home
    • Join the NAR
      • Home
      • Join NAR
      • Site Map
      • Contact Us
      • My Membership
      • About NAR
      • The American Rocketry Challenge
      • Model Rocket Info
        • The Sport Rocketry Hobby
        • Model Rocket Safety Code
        • Understanding FAA Regulations
      • High Power Rocketry
        • High Power Rocketry Certifications
        • High Power Rocket Safety Code
        • Understanding FAA Regulations
        • Filing for FAA Launch Authorization
        • High Power Resources
          • High Power Technical Reports
          • NAR HPR Certified Member Search
        • The NAR Rocket Science Achievement Award
      • Educational Resources
        • Online Mentoring Resources
        • NARTREK Skills Program
        • The NARTREK Cadet Program
        • 4-H
        • Air Force JROTC
        • Civil Air Patrol
        • Rocket Teacher Certification Program
        • Grants, Scholarships, and Recipients
        • Educator’s Newsletter Archive
      • Find a Launch
        • General Launch Information
        • Launch Calendar
        • Find a Contest
        • Register an NAR Launch
      • Local Clubs
        • NAR Club Locator
        • Find an NAR Club Launch
        • Submit a Local Club / Submit Changes
        • Section FAQ’s
        • Section Guidebook
      • Insurance Questions/Claims
      • Safety
        • Safety Codes
        • Model Rocket Safety Code
        • High Power Rocket Safety Code
        • Radio Control Rocket Glider Safety Code
      • Rocket Motor Information
        • Certified Motors
          • Motor Related Lists
        • NAR Motor Testing
          • NAR Motor Testing Notices
        • Manufacturer Notifications
        • Report a Malfunctioning Motor
      • Contest Flying – NAR Competition
        • National Scoreboard
        • US Team Selection Scoreboard
        • Find a Contest
        • Register an NAR Launch
        • Competition Results Entry
        • Team Registration
        • Teams List
        • Contest Events
        • Competition Meets
        • US National Model Rocket Performance Records – 8/2/19
        • International Competition
        • Competition Guide
        • U.S. Model Rocket Sporting Code
        • Rules Revision Process
      • Sport Rocketry Magazine
        • Magazine Submissions
        • Write It and Get Paid
        • Advertise in Sport Rocketry
        • Sample Issue
        • Contact Sport Rocketry
      • Member Resources
        • Members Only Forum
        • Magazine Archives
          • Sport Rocketry Magazine
          • eRocketeer Digital Editions
          • Member Guidebook Archive
          • American Spacemodeling Magazine
          • The Model Rocketeer Magazine
          • Model Rocketry Magazine
        • NARTREK Skills Program
        • R&D Reports
        • Technical Bibliography
        • NAR Insurance
          • Insurance Questions
          • Proof of Insurance
          • NAR Insurance Claim Form
        • NAR Association Documents
        • Promotional Materials
      • NAR Products
      • Website Fixes
      • Donate
      • What’s My NAR Number?
      • Log out

    • High Power Rocket Certification

      Design and Fly High Power Rocket Vehicles Learn More

    • Local Rocketry Clubs

      Connect with Proven Rocketry Experts Find A Club Today

    • Members-Only Forum

      Engage in meaningful conversations about rocketry topics that matter. Get Connected!

    • Sport Rocketry Magazine

      Six 48 Page Issues a year with NAR Membership!


    • Contact Nar

      National Association of Rocketry
      P.O. Box 407
      Marion, IA 52302

      Call: 319-373-8910

    • Join NAR

      The best way to get more out of the exciting hobby of rocketry is to connect with other flyers. The National Association of Rocketry can get you connected to the cutting edge of the hobby so you can learn how to fly higher, faster, and better. As an NAR member you will get:

      • Access to launch sites through local NAR clubs
      • The bimonthly color magazine "Sport Rocketry"
      • Insurance coverage for your flights
      • Certification for high power rocket flying

      Join Nar

      © Copyright YEAR National Association of Rocketry | Privacy Notice

      • Home
      • Join NAR
      • Site Map
      • Contact Us
      • My Membership
      • About NAR
      • The American Rocketry Challenge
      • Model Rocket Info
        ▼
        • The Sport Rocketry Hobby
        • Model Rocket Safety Code
        • Understanding FAA Regulations
      • High Power Rocketry
        ▼
        • High Power Rocketry Certifications
        • High Power Rocket Safety Code
        • Understanding FAA Regulations
        • Filing for FAA Launch Authorization
        • High Power Resources
          ▼
          • High Power Technical Reports
          • NAR HPR Certified Member Search
        • The NAR Rocket Science Achievement Award
      • Educational Resources
        ▼
        • Online Mentoring Resources
        • NARTREK Skills Program
        • The NARTREK Cadet Program
        • 4-H
        • Air Force JROTC
        • Civil Air Patrol
        • Rocket Teacher Certification Program
        • Grants, Scholarships, and Recipients
        • Educator’s Newsletter Archive
      • Find a Launch
        ▼
        • General Launch Information
        • Launch Calendar
        • Find a Contest
        • Register an NAR Launch
      • Local Clubs
        ▼
        • NAR Club Locator
        • Find an NAR Club Launch
        • Submit a Local Club / Submit Changes
        • Section FAQ’s
        • Section Guidebook
      • Insurance Questions/Claims
      • Safety
        ▼
        • Safety Codes
        • Model Rocket Safety Code
        • High Power Rocket Safety Code
        • Radio Control Rocket Glider Safety Code
      • Rocket Motor Information
        ▼
        • Certified Motors
          ▼
          • Motor Related Lists
        • NAR Motor Testing
          ▼
          • NAR Motor Testing Notices
        • Manufacturer Notifications
        • Report a Malfunctioning Motor
      • Contest Flying – NAR Competition
        ▼
        • National Scoreboard
        • US Team Selection Scoreboard
        • Find a Contest
        • Register an NAR Launch
        • Competition Results Entry
        • Team Registration
        • Teams List
        • Contest Events
        • Competition Meets
        • US National Model Rocket Performance Records – 8/2/19
        • International Competition
        • Competition Guide
        • U.S. Model Rocket Sporting Code
        • Rules Revision Process
      • Sport Rocketry Magazine
        ▼
        • Magazine Submissions
        • Write It and Get Paid
        • Advertise in Sport Rocketry
        • Sample Issue
        • Contact Sport Rocketry
      • Member Resources
        ▼
        • Members Only Forum
        • Magazine Archives
          ▼
          • Sport Rocketry Magazine
          • eRocketeer Digital Editions
          • Member Guidebook Archive
          • American Spacemodeling Magazine
          • The Model Rocketeer Magazine
          • Model Rocketry Magazine
        • NARTREK Skills Program
        • R&D Reports
        • Technical Bibliography
        • NAR Insurance
          ▼
          • Insurance Questions
          • Proof of Insurance
          • NAR Insurance Claim Form
        • NAR Association Documents
        • Promotional Materials
      • NAR Products
      • Website Fixes
      • Donate
      • What’s My NAR Number?
      • Log out