Brief:
The Corona-2 is a separate kit that compliments the FlisKits Corona creating a 2-stage rocket. What also makes this stand out is that it takes the tube fin design of the Corona one step further.

Construction:
Before starting the Corona-2, you must have a built FlisKits Corona kit. If you built your Corona with the motor retention clip, you will need to cut it off the rocket so that you can direct stage the motors in the Corona and Corona-2.

The kit contains:

• 3 laser cut plywood fins
• 1 BT-70 ring
• 1 BT-101 ring
• 1 BT-50 body tube
• 1 BT-20 motor tube
• 2 CR5020 centering rings
• 1 BT-50 coupler
• Instruction manual

The instructions are very simple. First, you must have a fully built FlisKits Corona kit as it is needed to place the forward (smaller) ring and align the 3 fins.

The motor mount is typical LPR: a couple of centering rings with a motor tube glued together and then inside the larger body tube. That is followed by a coupler glued halfway into the forward end of the body tube to connect to the Corona kit.

That assembly is slid into the aft end of the Corona. The small ring is slid around the Corona's ring fin and taped into place to keep it from moving. Lines are drawn on the Corona-2 body tube to match the fins of the Corona. The perfectly cut plywood fins are glued onto the body tube and forward ring with plenty of attention needed to ensure that they are lined up with the Corona's fins. Once all of the fins are dry, fillets are applied.

The last step is to glue and fillet the BT-101 ring onto the fins.

Finishing:
Filling the grain of the fins was arguably the most difficult part of the entire build--and it wasn't even that hard. It merely required patience more than anything. I used diluted Elmer's Fill 'n' Finish along with an epoxy spreader to help press the filler into the grain of the wood while also wiping away as much excess as possible (and reduce the amount of sanding I needed to do!) I sanded the fins smooth with 320 grit sandpaper.

Painting was less of a challenge than I originally anticipated. I was concerned about getting overspray on the coupler or inside the motor mount as well as potential runs when trying to paint the inside of the large aft ring fin. [NOTE: You do not want to paint the inside of the forward ring as this may cause the overall fit to be too snug when attaching the stages together!] My fears turned out to be unfounded--or maybe I just plain got lucky! A couple coats of Krylon white primer with some light sanding in between followed by Krylon Sun Yellow Gloss had it matched up perfectly with the paint job on the Corona. I added some silver automotive pinstriping tape as an accent.

Construction Rating: 5 out of 5

Flight:
The Corona-2 was mated up with my fully prepped Corona. Using clear tape, a C6-0 was mated up with a C6-7. A little masking tape was needed on each motor to make sure that neither would kick undesirably. With the motors loaded up in the rocket, I set it up on the pad.

It left the pad with plenty of thrust pushing the rocket up to about 400 feet before successfully staging the Corona sustainer. The Corona is a very sleek rocket so it got some altitude when staged C6 to C6! Don't try this on a small field. I pushed the limits of the schoolyard I was at causing the sustainer to drift on the way down across the street into some neighboring woods. Thankfully the sustainer didn't get caught up in a tree and was recovered successfully.

Recovery:
The Corona-2 booster has a tumble recovery typical of BP staged designs. It backflipped all the way down (much like the CD spool rockets I have built) to land safely within 40 feet of the pad.

Flight Rating: 5 out of 5

Summary:
The already unique FlisKits Corona kit is definitely enhanced by the very complimentary design of the Corona-2 booster. I dig tube fin and ring fin rockets so what could be cooler than a 2-stage ring fin design?!? Any existing Corona owners can add the Corona-2 to their fleet after modifying the Corona's motor clip. If staging with a pair of C6 motors though, be sure to have plenty of room at your launch site!

Overall Rating: 5 out of 5