Lesson 11 of 11
Objective: Students will be able to build a rocket with a sheet of construction paper and launch their rocket with compressed air.
This lesson is based on California's Middle School Integrated Model of NGSS.
NGSS Performance Expectation (PE): (MS-ETS1-1) Define the criteria and constraints of a design problem with sufficient precision to ensure a successful solution, taking into account relevant scientific principles and potential impacts on people and the natural environment that may limit possible solutions.
Science and Engineering Practice SP1 Asking Questions and Defining Problems. Students are required to build a rocket from household craft material that uses an 'A' Model Rocket Engine and can reach an altitude of 100 meters. Theses design criteria require that students understand the problem and are sufficiently versed in rocket construction plans and applicable scientific principles.
Disciplinary Core Ideas (DCI): ETS1.A Defining and Delimitating Engineering Problems - The more precisely a design task's criteria and constraints can be defined, the more likely it is that the designed solution will be successful. Specification of constraints includes consideration of scientific principles and other relevant knowledge that are likely to limit possible solutions.
Crosscutting Concepts (CCC) Influence of Science, Engineering, and Technology on Society and the Natural World - The uses of technologies and any limitations on their use are driven by individual or societal needs, desires, and values; by the findings of scientific research; and by differences in such factors as climate, natural resources, and economic conditions.
This lesson allows students to build a model rocket from common household materials using a precise set of directions. The criteria for this build is that (a) it must be made from scratch (except engine), (b) reach an altitude of 100 meters, and (c) successfully deploy its flight recovery system (streamer or parachute).
I spend about three days walking the students through the building process step-by-step until they have reached a point where they can work independently. They work in groups of 3-4 students to build the rocket. In their Interactive Science Notebooks they have to create a chart that determines their rocket's altitude using a NASA Altitude Tracker. To calculate altitude the students have to stand a set distance from the rocket launch and measure the angle from that point.
During the construction process I refer back to Newton's 2nd Law (force is dependent on the mass and acceleration of an object). I explain to them that the lighter they can make their rocket the greater the acceleration will be, which results in a higher altitude. By explaining this to the students they are less apt to waste supplies (saves budgetary money).
The students will build a more complicated version of this rocket with Craft Rocket Challenge #1 and Craft Rocket Challenge #2. They follow all the same basic building parameters with the added complexity of computing the rocket's acceleration (Newton's 2nd Law: acceleration = Force/mass) by looking up the average Newtons of force on the rocket engine (force) and weighing the rocket (mass).
How To Build An Air Rocket
- Construction paper (12" X 18")
- 1/2" PVC Blank (9" long)
- Clear tape
To start you will need a 12" X 18" sheet of construction paper. At my school we get sheets that are 24" X 36" and all I need to do is cut them in half. In the past I've allowed each student to pick the color of their choice. This last time I assigned a specific color to a class period. I typically provide 3-4 PVC Blanks and one role of clear tape to each group.
1) Place a 12" X 18" sheet of color construction paper in front of each student.
2) Cut the 12" X 18" sheet of construction paper roughly in half. No need to measure or be exact.
3) Role one half (6" X 9") around a 1/2" PVC Blank. The construction paper should be rolled tightly around the PVC blank, but not so tightly that the PVC blank will not slide out. This PVC blank is the exact same diameter as the launch tube. Secure the rolled construction paper with a single strip of clear tape.
4) Apply clear tape to the entire seam. This will eliminate potential air leaks.
5) With the other half sheet of construction paper, cut an UGLY circle about the size of a fist.
6) Cut a mouth in the UGLY circle to resemble a PAC-MAN.
7) Overlap the bottom lip of PAC-MAN over the top lip to form a cone.
8) Continue the overlapping until the diameter at the base of the cone is the same diameter of the rocket tube. Secure the cone with a single piece of clear tape.
9) Trim the base of the cone flat, so the cone will sit correctly on the rocket tube.
10) Slide the PVC Blank out from the rocket tube.
11) At one end of the rocket tube attach the nose cone. The nose cone needs to be attached with plenty of clear tape, or the nose cone will detach at launch time.
12) Cut 3 or 4 triangle to serve as the rocket fins.
13) Attach the rocket fins to the base of the rocket tube.
14) Admire your new rocket.
The launch system is constructed with 2" PVC pipe and plumbing parts. The complete set of directions from NASA can be found as: Air Rocket Launch System. The launch tube is a 1/2" diameter PVC pipe, the same as the PVC Blank used in construction of a paper rocket. The air value connection is the same connection used for car/bike tires.
I use a small AC air compressor to pressurize the launch system to 60 PSI. I have also used a bicycle pump in the past, but I have found it to be too strenuous for some students. An electric pump is easier and faster to pressurize, you'll just need access to a plug. The launch system has a pressure release value to ensure that this launch system cannot over pressurize and rupture.
Rockets are more stable when their center of gravity is as close to the nose cone as possible. To find a rocket's center of gravity place two index fingers under the rocket and slide them towards the center. Your fingers will stop at the center of gravity every time.
To move the center of gravity towards the nose cone, stuff scrap pieces of paper into the rocket tube and use the PVC Blank to ream these scraps into the nose cone. This should pull the center of gravity towards the nose cone.
To test the rocket's aerodynamic properties, tie a piece of string at the rocket's center of gravity and twirl the rocket around your head. If the rocket flies correctly then the rocket is aerodynamically stable. The center of gravity should be as close to the nose cone as possible and the fins should provide enough air friction to keep the nose cone pointed in the right direction.
I run an extension cord out to a small air compressor that powers the Launch System. You could also fill the Launch System cylinder with a bicycle pump, it would just take longer. I instruct my students that they should turn off the air compressor at about 60 PSI. Once the air compressor is turned off, they can turn the lever to activate the launch. With this design of the Launch System the launch tube can be angled to achieve vertical flight or angled down to produce a parabolic arc, resulting in horizontal distance.
The better the rocket, the higher the altitude that can be achieved.
I instruct my students that they must reset the Launch System to its original setting once they have finished their launch. This speeds up the launches and gets everything ready for the next student. Immediately following a launch, I activate the air compressor and let it fill the Launch System cylinder while the next student is setting up their rocket. I typically launch 35-38 rockets within a class period and need to save time where ever I can. I don't want to run out of class time and still have rockets that need to launch. I can typically launch an entire class of rockets in 45 minutes.
For this activity the students measure their rocket's altitude. They record this data in a chart of their own design in their Science Interactive Notebook. Altitude is determined with a device designed by NASA Education - NASA Altitude Tracker.
Each student has a turn to record the altitude of the rockets. This also has the added benefit of keeping the entire class engaged while the rockets are being launched. I position students at 15 and 30 meters, rotating the students between these two points. Theses two distances are critical to the NASA Altitude Tracker being able to calculate accurate altitudes. Since everyone of my students has made a rocket, I only require them to record data from nine launches.
Student Work Sample