Northeastern University Scientific Payloads: Atmospheric-Measurement and Controlled-Descent Experiment

Flight Readiness Review

NUSPACE

Final CDLE Design

ATMOS Design and Dimensions

Component on wall

Width Length Height Area

(x2) Raspberry

Pi 2

2.2 in(5.588

cm)

3.35 in(8.509 cm)

0.66 in(1.68 cm)

14.74 in2

(95.1 cm2)

Arduino Mega

2.1 in(5.334

cm)

4.25 in(10.795

cm)

-- 8.925 in2

(57.58 cm2)

9 Volt battery

1 in(2.54 cm)

1.9 in(4.826 cm)

0.6 in(1.524 cm)

1.9 in2

(12.3 cm2)

(x2) Power pack

3.6 in(9.144

cm)

1 in(2.54 cm)

1 in(2.54 cm)

7.2 in2

(46.45 cm2)

ATMOS Components situated on a 5.5” x 4.25” vertical sled

FINAL LAUNCH VEHICLE

Launch Vehicle Specifications● Vehicle Dimensions

○ Length: 120 in.

○ Diameter: 7.5 in.

● Materials○ Fins: G10 Fiberglass

○ Nose cone: Polypropylene

○ Launch Vehicle body: Blue tube

○ Motor Recovery System: Carbon fiber

● Thrust-to-weight ratio: 9.08

● Rail Exit velocity: 68 ft/s

Launch Vehicle FeaturesSection Mass (kg) Mass (lb)

Nose Cone 1.147 2.529

Motor Section + Sheath

8.466 18.664

The CDLE 4.759 10.492

Motor Selection● Predicted Apogee: 5,432 feet● Rationale: Most viable L2 motor to reach

target altitude● Armed Launch Vehicle Weight: 42.2 lbManufacturer Cesaroni

Technologies

Name L1115

Diameter 2.95 in (75 mm)

Average Thrust 1119.0 N

Maximum Thrust

1713.3 N

Total Impulse 5015.0 Ns

Burn Time 4.5 s

Rocket Flight Stability● The stability margin of the final competition launch vehicle is 2.16 calibers● Center of gravity (CG) is located at 74.742 in from the nose cone● Center of pressure (CP) is located at 91.314 in from the nose cone

Parachute Sizes and Decent RatesSection Parachute Size Shock Cord Length Terminal Velocity ft/s

Nose Cone 36 in 20 ft 15.7

Sheath -- -- 8.0

Motor Section 18 in (2) 20 ft (for each) 45.6

Motor Section + Sheath 72 in 40 ft 15.0

The CDLE (emergency parachute)

48 in 20 ft 21.0

Kinetic Energy and Projected DriftsSection Kinetic

EnergyProjected Drift (5, 10, 15, 20 mph wind)

Nose Cone 12.3 ft-lbs 374.1 ft 748.15 ft 1122.3 ft 1496.4 ft

Sheath 4.7 ft-lbs --- --- --- ---

Motor Section 450.4 ft-lbs

--- --- --- ---

Motor Section + Sheath

65.1 ft-lbs 443.0 ft 785.46 ft 1128.0 ft 1470.5 ft

The CDLE (emergency parachute)

71.6 ft-lbs 1842.1 ft 3684.15 ft 5526.5 ft 7368.6 ft

Test Plans and Procedures

● Tests of all electronic bays● Static Piston Tests● Arm Deployment Tests● Quadcopter Flight Test

Recovery System Tests

Motor Section Drogue Deployment Setup and Ejection Test

Full Scale Launch Results● Apogee at 2933 feet

○ Predicted apogee at 2943 feet

● Successful separations of all sections○ All charges energized at programmed altitudes

● Successful deployment of nose cone, mock CDLE, and drogue parachutes

● Main parachute deployed, did not completely unfurl

● All sections successfully recovered with minor damage to the motor section

○ All sections landed within a half mile from the launch rail

Payload Integration● Quadcopter is folded within the sheath

section of the rocket ● The ATMOS payload is within the base of

the CDLE

Interfacing with the Ground Systems● Internal serial data connections

○ Pixhawk to Radio○ Pixhawk to GPS○ MSP430 (auxiliary electronics) to Pixhawk (UART)○ Altimeter to MSP430 (auxiliary electronics) (I2C)

● PWM to motors○ From Pixhawk

● RFD 900 plus radio (915 MHz, 1W max)○ Ground link

Summary of Requirements Verified (LV)Requirement Verification

The launch vehicle shall be designed to be recoverable and reusable.

The vehicle can then be put back together for a relaunch by putting in new nylon shear screws on the parts of the rocket that separate and by re-packing the parachutes, wadding and black powder. During the full scale launch the nose cone parachute and aft motor section parachutes ejected properly. The main parachute, due to improper folding, opened partially thus one of the electronic bays sustained damage.

The vehicle shall deliver the payload to an apogee altitude of 5,280 feet above ground level (AGL).

This was verified through tests of the apogee using the OpenRocket simulation software. This software predicts the apogee at 5,432 feet with all of the components and the L1115 motor; however, there is additional weight due to the epoxy within the sections will make the rocket’s apogee be lower than the predicted height.

Summary of Requirements Verified (LV)The launch vehicle shall use a commercially available solid motor propulsion system using ammonium perchlorate composite propellant.

The team is using a Ceseroni Technology L1115 Motor which is an approved and certified motor. It is a commercially available motor that uses APCP. This is verified through inspection of documents describing the motor. On the data sheet about this particular motor, it was described to follow these qualifications.

The vehicle shall carry one commercially available, barometric altimeter for recording the official altitude used in the competition scoring.

The rocket holds multiple StratoLoggers which are commercially available, barometric altimeters. Any of these could be chosen as the altimeter recording the altitude score. This was verified during tests of the subscale rockets and the full-scale rocket. These StratoLoggers each are able to collect readings based on the atmospheric pressure which was proved during these tests when they each outputted similar apogees depending on their placement within the rocket.

Summary of Requirements Verified (CDLE)Requirement Verification

The CDLE will deploy at apogee Tested during Full scale test. A mock the CDLE with the same weight was released from the rocket at apogee using the piston system.

The CDLE will transmit live flight data to ground A ground test was enacted to ensure that communications working for long distances and during flight. Initial tests with software allowed for proper transmission of GPS, altitude, and velocity data.

Arms will lock into position after deployment Using a one way bearing will ensure that the arms lock into position. Ground tests were performed to verify that the arms deploy with enough force to lock. Arms locked after deployment in arm deployment prototype.

Summary of Requirements Verified (ATMOS)Requirement Verification

Pressure Readings will be taken every ten seconds during descent and then once every minute after landing

Sensor tested on the ground to verify that measurements are taken at the proper time increments. Pressure readings will be compared to accepted pressure vs altitude data.

At least two pictures during descent and three after landing

Images were taken using the Raspberry Pi and taken at specific intervals. This was successfully tested during a software simulation.

Store Data onboard Verify data is on SD card in an easily read format. A data logging system that allows for easy post-processing using tools such as MATLAB was created for this purpose.

Questions?