Brief:
This is another of the rocket trio that I won from EMRR's Quarterly Rocket Giveaway. Thanks Nick!

The Discovery is a 'modular concept rocket', that features three interchangeable fin units. It is part of HotRod's Educators Series and is intended either builders who have previously built a rocket or newbies under the guidance of an experienced builder. It flies on 18mm motors and recovers via a 'chute. You can always make additional fin units too.

Construction:
This is a simple 3FNC rocket, but it includes a lot of parts:

• balsa nose cone
• 24mm main body
• three 24mm fin can tubes
• two sets of laser cut balsa fins
• one sheet of balsa stock for the 3rd fin pattern
• long 18mm motor tube
• 5 rings and a motor block
• Kevlartwine and elastic cord
• screw eye and snap swivel
• 1/8" lug
• 10" plastic 'chute

The instructions for this 'educator series' kit are simple and intended for either builders who have previously built a rocket or newbies under the guidance of an experienced builder. They have plenty of illustrations and were perfectly adequate.

You also get a fin marking template and a fin pattern for the 3rd set of fins. It's a neat idea to provide the removable fin units.

New builders can start with pre-cut fins and then move to DIY patterns. I will only present one fin can.

The 18mm motor tube is built first. Two thin fiber rings are used to mount it in the main body and three wider rings are used to support the removable fin units. The kit only includes a motor block but it would be easy to add a motor clip if you were so interested.

The Kevlarleader is tied to the mount behind the forward ring, which has to be notched to pass the line. You tie elastic to that and to the hefty screw eye. Good stuff.

There are two sets of 3 laser cut fins and a sheet of balsa for you to make a third. Each set is attached to their own tube. A fin guide is provided to help with alignment. To attach a fin set, you slide it over the motor tube and use a piece of tape to help hold the two tubes together.

Finishing:
Finishing of this kit would be typical for a kit with balsa parts...but I flew mine nekkid.

Construction Rating: 5 out of 5

Flight:
I first secured the fin unit to the main body with a couple of wraps of masking tape. The kit's motor mount protrudes about 1/2" below the lower body tube. Instead of wrapping the motor with tape and cramming it into the motor tube, the instructions say to install the motor and then tape it to the motor tube. This should make removing the spent engine easier, so I gave it a try. My motor of choice was a C6-5.

I used a couple of sheets of Quest wadding and some dog barf to protect the 'chute and it was ready.

It ripped off the pad, never to be seen again. :(

Recovery:
I won't fault the kit for getting lost. Based on its construction, there is no reason to think that the kit isn't robust for it's size. The only change I'd make is to include a motor hook.

Flight Rating: 4 out of 5

Summary:
This is a simple kit with nice quality parts and clear instructions. The main distinguishing feature is the swappable fin units. I think this is a great idea for beginners to let them experience different fin styles and move from pre-cut to cut-your-own. In fact, it's an interesting idea for larger modular rockets.

Overall Rating: 4 out of 5