Gorge Rocket Club Section 790

NRC events for the 2019-2020 Contest Year

Per rules 13.1.1 through 13.1.2 of the United States Model Rocket Sporting Code (USMRSC), the NAR Contest Board has selected the following 6 NRC events for the 2019-2020 contest year, including NARAM 62:

1/2A B/G

1/2A SD

1/2A HD

1/2A PD

1/2A ALT

B Payload

Per the USMRSC, NRC launches with scores to qualify for Event Specialist and National Awards for the 2019-2020 contest year can be held from August 4, 2019 (the day after NARAM-61) until June 30, 2020.

Approved Altimeters

Contest Advice


For information on the new contest book, here is the link:


  • Dates for the GRC 790 2019 Season Wyeast Middle School Launch dates: 

 Times for launch dates are from 9 am to 12 pm at the Northwest Small field.  Better known as the baseball field in front of the parking area where the soccer fields are located behind the WyEast Middle School Football field.

October                               19th         Saturday-NRC Contest 2019/20_1

November                          16th         Saturday - NRC Contest 2019/20_2

December                           14th           Saturday - NRC Contest 2019/20_3

If you have any questions please feel free to contact me: Thompsonje@gmail.com

Bring your rocket and your own engines.
There are two per month and will be at either three locations. Wyeast (which is a larger field and can accommodate larger engines and rockets),  Westside for A to C motors, or Parkdale.

If you know you are coming, it helps to RSVP via email so in case there is a last minute change due to weather or launch site change beyond our control, we can let you know. Otherwise, most launches are scheduled to go regardless of all but impossible launch weather. If it is windy, we suggest using smaller engines (A) and cutting a hole in the shoot or using streamer recovery.

Fees: If you would like to join, you can come to the shop or  launch and fill out a waiver and it is $15 per family or $10 per person for the whole season (bring cash or check or if you need to pay by credit card please go through HR Community Ed because 100% of the fees go to them to pay for launch site). A parent or guardian is expected to be present for children, these are not supervised launches.  https://hoodriver.cr3.rschooltoday.com/public/costoption/class_id/3557/public/1/sp/

Daniel Peirce did a remarkable job with the Semroc Saturn 1B rocket

Check out the rocketry show at https://www.therocketryshow.com/
Check out the rocketry show at



Hercules up on a G75-4
Photo provided by Jim Reed
Photo provided by Jim Reed

"Congratulations to Daniel Peirce for Certifying Level 1"

Daniel successfully launched his Mad Cow Honest John rocket on an H128-10W with great results:

Welcome to the Gorge Rocket Club Section 790 website.

If you have any questions please feel free to contact me: Thompsonje@gmail.com

  My Background

What is Thrust to weight ratio?

To safely launch a rocket the thrust to weight ratio should be at least 5 to 1

For example, if a rocket weighs 0.4 kg, and the motor has a thrust of 15 Newtons, is this safe?

Answer: The weight of the rocket is 0.4 x 9.8 = 3.9 N. Thrust is 15 N. The thrust to weight ratio is thus 15:3.9, or 3.8:1. This is less than 5:1 so the launch would be unsafe.


NAR http://www.nar.org/



Its a beautiful place for the hobby of rocketry

Its a beautiful place for the hobby of rocketry

Dans Snake Jumper Rocket

Rocket History Quiz:


For the answers, email me:-)

If you have any questions please feel free to contact me: Thompsonje@gmail.com

High Powered Organization for those interested is:



What is this thing called World Space Modeling Championships:

Intro to rocketry part 1:

intro to rocketry part 2:

intro to rocketry part 3:

Propellant Types:

igniter installation:

Interesting site called "The Orbital Mechanics"


Rocket Engineering and Science Technologies

Slide Rule Museum

1 Newton = 0.2248 pounds

1 Pound = 4.448 Newtons