Happy HoJo Day (National Honest John Day)

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.


A.K.A. 'Mr. HoJo'
TRF Supporter
Dec 4, 2016
Reaction score
Birmingham, AL
Happy HoJo Day! 69 years ago today on June 29, 1951 Test Round #1 was launched at the New Mexico Joint Guided Missile Test Range (now called the White Sands Missile Range). The Honest John was a free-flight (unguided) missile and also America's first tactical nuclear weapon delivery device. Until it's development, delivery of nuclear weapons was possible only via bomber aircraft.

The Honest John was rushed into development to meet the needs of the US Army, just as war was breaking out in Korea. The weapon was the ultimate "kit bash" rocket--compromised of a Navy JATO rocket motor with fins and a warhead attached. It was nearly scraped several times during its development and the first five test flights turned out to be vital.

The first flights were wildly successful. The rocket turned out to have more than acceptable range and accuracy--both of which improved over it's lifetime. After seeing the successful tests, funding for the project was accelerated.

The rocket had two major variants as well. The "Demi John" (pictured below) was an attempt to reduce the range of the weapon, giving battlefield commanders more flexibility in how it was deployed. There were seven test flights, but an operational version was never produced. There was also the "Father John" which was developed to lift a heavier payload. It featured the main JATO rocket motor, and six or eight smaller rocket motors strapped outside of the main motor for more lift.

The M31 version with the larger fins is the better known of the rockets, and a favorite of modelers to this day.

Post photos of your favorite HoJo (prototype) or model and celebrate National Honest John Day!


    501.5 KB · Views: 30
Happy HoJo day to you lowga!
I'm thinking you should change your username to Mr.HoJo!
I'll post a pic of my latest HoJo build later.
It's in the filler stage right now.
Still working on the Demi-John project, but it is nearly complete. Love the nickname.

Out today (coincidently timed with National Honest John Day?) news that Scott Binder will soon be releasing a new 5.5"/8" Honest John kit that is among the most detailed version of the weapon ever! It weights in around 10lbs with a 75mm Motor Mount, just over 7 feet tall. Perfect for L3 project. And it's coming this summer!

The news broke during an interview with Scott on "The Rocketry Show" podcast. Patrons got access to it early. If you're not a patron of this amazing podcast--why not?


Scott also talked about how he developed his Honest John kits...getting access to an Army Depot and permission to "climb all over" their static display. Measuring, taking photographs, etc.

He then used Corel Draw to trace over the photographs, outlining key details of the weapon. The new L3 version comes with a 3-D printed nose cone, and lots of other 3D details.

Now I have to figure out how to talk Scott out of a copy of those photos and measurements! With three great Honest John kits released in the past year, SBR Rocketry is making HoJo dreams come true.

Combine that with the great kits from Boyce Aerospace and the reissue of the MMX HoJo for a banner year for America's first nuclear weapon. Can't wait to see what the 70th anniversary brings.SBR 5:8 Honest John L3.jpeg