Team DSROCritical Design Review

Taylor BoeAndrew BucknerAndrew GilbertEmily HowardGrace Harsha

Bobby StillwellOctober 14, 2008

Mission Overview• The primary mission of Operation H.A.L.O. is to find

the optimal altitude at which one can take quality telescopic images of celestial bodies from a high altitude observatory. By taking light readings of ambient light intensity (all wavelengths) at various altitudes up to 30,000 meters using a photometer, and comparing this to past data we shall achieve an understanding of where ambient light remains constant above our stratosphere, no longer interfering with telescopic imagery, so that future missions can attempt to obtain quality images of celestial bodies at a lower cost compared to current ground based or orbiting telescopes.

Requirement Flow Down• 1.0 Mission requirements:

The H.A.L.O. payload shall provide evidence that it is feasible to capture high quality images of celestial bodies from a near space environment. The payload will be functioning no later than November 15, 2008 and will follow all proposal requirements concerning the weight (1000g) and price ($150) budgets.

• 2.0 Objective Requirements: 2.1 Operation H.A.L.O. will take light intensity readings throughout the ascent to an altitude of 30 km. 2.2 The payload will be logging the internal and external temperature for the duration of the flight as well as humidity to ensure that the environment is not to extreme for a high altitude observatory.

• 3.0 System Requirements: 3.1 The payload will gather light intensity readings through a photometer, and store the voltage data onboard the payload via a microcontroller. 3.2 The photometer shall be calibrated and tested prior to November 15, 2008, to ensure its proper functionality. 3.3 We shall use an internal heating device to keep our power source at an optimum level. 3.4 A “cold finger” will be implemented into our photometer design to conduct heat away from our photometer circuit to ensure that the photodiode stays cool and does not record false data due to excess energy in the form of heat.

How

• We plan to build a photometer to take light readings, via a photodiode, that shall provide data about sky brightness at different altitudes up to 30 kilometers.

• The data shall be stored on a microcontroller.• The photometer is Kyle Kemble’s design which is

based upon the design of Dr. Yorke Brown.• The altitude, at which we took our readings, shall

be obtained using math and our understanding of the rate of ascent after the balloon flight.

Given Parts• Camera

• HOBO Data Logger • Temp Probes • 9V Batteries x 3

• Heater • Tube

• Foam Core • Aluminum Tape • Switches x 3 • American Flag

Photometer Parts

Photometer Schematic

Mass Contingency

Price Budget

Functional Block Diagram

Schedule• October 1: Start work on the first test shell of the satellite. • October 4: First test of Satellite shell (drop test, whip test, and stair test).• October 13: Start Work on our photometer. • October 20: Start construction of final satellite shell.• October 22: Final shell of satellite shall be finished. • October 25: First cold test of working components in test box with

heater. • October 29- November 8: Component Testing (photometer tests and

more cold tests).• November 4: In class mission simulation.• November 6: In class mission simulation. • November 12: Design shall be finished. All tests shall have been

performed. • November 15: Launch Day• November 17: Gather raw flight data. Begin work of final presentation.• November 18: In-Class Launch Recap• November 19- 29: Repair satellite.• November 29: Team Video shall be finished.• December 2: Final team Presentation

Testing• Drop test• Stair test• Whip test

• Cold Test of basic electronics• Cold/Light test of Photometer

• Functionality tests• Memory/Data test

• Capacitor/Electronics test (final)• Imaging test

Expected Results

• We expect to prove that there is in fact an altitude above which ambient light (light from the atmosphere) stabilizes enough to image stars.

• The data collected will provide evidence that it is possible to take high quality telescopic images of celestial bodies from near space.

Biggest Worries

• Photometer working• Photometer pointing at the sun

• Thermal• Time