December 12, 1996

Mr. Corey Mack

Space Business Group

Bristol Aerospace Limited

660 Berry Street

Winnipeg, MB R3C 2S4

Fax: (204) 786-2745

Dear Corey:

Thank you for your fax concerning the weight budget and preliminary layout. It is instructive to see the weight breakdown.

I just talked with Mr. Dale Sommerfeldt of Scientific Instrumentation Limited (S.I.L.), here in Saskatoon, about the possibilities for testing the NiteOwl payload and parachute operation by means of a balloon flight.

The relevant Appendix of the Small Payloads Program Announcement of Opportunity indicates that for a 218 kg payload (science + bus + ballast) flown to 37 km for a 24-hour mission, the total cost is about $70K for a first flight, and $27K for a second flight. Dale indicated a ROM cost of about half the first number for a hand launch of a smaller payload (I estimated <50 kg exclusive of ogive, skin sections, and ejection springs) to about 36 km (120,000 ft) with no float time, but immediate descent on the parachute. If the total mass flown were to exceed 50 kg a hand launch would no longer be possible, and with a truck launch the costs would increase appreciably.

We also discussed the question of maintaining the payload spin at an appropriate value per our requirement. He mentioned the possibility of using a decoupler between the parachute and the payload. Is there a reason why such a device could not work in our altitude/pressure/temperature regime? If it could work, we could then think about using a small reaction wheel to spin the payload up to the desired spin rate. The spin rate could also be independent of the descent speed, which would not be the case with a spin parachute, according to our reading of the Silbert paper in your earlier fax. Admittedly, this would not help us with the basic weight issue we currently have.

Best regards,

David Steele

NiteOwl P.I.