1. 1 April 26, 2007 Balloon Workshop on Low Cost Access to Near-Space LCANS:Smith/SwRI L0w Cost Access to Near Space I. Steve Smith, Jr. Southwest Research Institute sismith@swri.edu

2. 2 April 26, 2007 Balloon Workshop on Low Cost Access to Near-Space LCANS:Smith/SwRI 1783 : In the Beginning ( Montgolfier Brothers) Balloon history started on 4 June 1783 with the ascent of the first hot air aerostat followed, on 27 August of the same year, by the launching of the first gas balloon (hydrogen).

3. 3 April 26, 2007 Balloon Workshop on Low Cost Access to Near-Space LCANS:Smith/SwRI Where Do They Fit in the Scheme of Things? balloons

4. 4 April 26, 2007 Balloon Workshop on Low Cost Access to Near-Space LCANS:Smith/SwRI Stratospheric balloons have… –Flown >8000 lb. payloads –Flown large payloads to 160 k-ft. –Flown >700 days duration Stratospheric balloons cannot… –Carry 8000 lb. To 160 k-ft for over 700 days –Perform powered station-keeping (Stratospheric balloons are not airships)

5. 5 April 26, 2007 Balloon Workshop on Low Cost Access to Near-Space LCANS:Smith/SwRI Balloon Altitude Stability Differences Zero-Pressure Balloon (8% ballast mass/night or large altitude excursions) Super-Pressure : No or minimal ballast requirement; Constant density float altitude

6. 6 April 26, 2007 Balloon Workshop on Low Cost Access to Near-Space LCANS:Smith/SwRI Types of Balloons Free Flyers –Gas –Montgolfiers (Hot Air) Powered –Airships

7. 7 April 26, 2007 Balloon Workshop on Low Cost Access to Near-Space LCANS:Smith/SwRI Types of Gas Balloons Zero- Pressure Super - Pressure Hybrid Stratospheric Airships

8. 8 April 26, 2007 Balloon Workshop on Low Cost Access to Near-Space LCANS:Smith/SwRI Zero–Pressure Balloons “Open” system Maintains ~ 0 differential pressure at the base of the balloon Requires 8-10% ballast or dropping of mass each diurnal cycle to maintain altitude Erego…limited durations of 3-5 days in mid-latitudes except in polar regions Typical altitude excursion of 2-10 k- ft day to night Large payload capacity (see following chart) Sizes range from a few thousand ft 3 to ~60 million cubic feet 3 (mcf) Most common balloon in use today RACOON is an unballasted version No ballast Altitude excursions ; 30-50 k-ft Durations dependant of atmospheric lapse rates or gas loss (20-60 days)

9. 9 April 26, 2007 Balloon Workshop on Low Cost Access to Near-Space LCANS:Smith/SwRI ZP Balloon Load Altitude Curves

10. 10 April 26, 2007 Balloon Workshop on Low Cost Access to Near-Space LCANS:Smith/SwRI Super-Pressure Balloons “Closed” system---pressure vessel Maintains differential pressure within balloon Requires no ballast Requires high strength materials Durations weeks or months days anywhere globally (small SP flown fro several hundred days) Typical altitude excursions of 1-2 k-ft Payloads usually a few hundred pounds. ULDB/Pumpkin developing for 2000 lbs Sizes range from a few thousand ft 3 to ~26 mcf Spherical Lobed: “Pumkin” Tetroon

11. 11 April 26, 2007 Balloon Workshop on Low Cost Access to Near-Space LCANS:Smith/SwRI Types of Montgolfiers……Hot Air Balloons “Open” system Lift derived from heated gas Requires heat source to maintain altitude (propane, RTGs, etc) Some make use of thermal radiation sources (ie infrared or solar) Durations limited by availability of heat source Montgolfier Infrarouge & Solar Montgolfiers Typical Hot Air Solar Montgolfiers

12. 12 April 26, 2007 Balloon Workshop on Low Cost Access to Near-Space LCANS:Smith/SwRI Montgolfier Infra-Rouge MIR vehicle (Montgolfiere Infra-Rouge) is a hot air balloon of 36000 to 45000 m3, with natural shape, only heated by radiative fluxes from the sun by daytime and upwelling infrared fluxes during the night.

13. 13 April 26, 2007 Balloon Workshop on Low Cost Access to Near-Space LCANS:Smith/SwRI Stratospheric Airships Nov 2007 Nov 2005 2010 4/99 – 11/01 – 5/03 Stratospheric Airships are powered, streamlined “balloons” designed to station- keep Relatively small payloads (10s-100s lbs) Altitudes usually 60,000 – 75,000 ft Durations : days to weeks Still under intensive development by DoD Only 2 have ever flown successfully under power (HiSentinel20); 20 lb sensor capacity Future is HAA of several thousand pounds HiSentinel

14. 14 April 26, 2007 Balloon Workshop on Low Cost Access to Near-Space LCANS:Smith/SwRI HiSentinel Size Comparisons Nov 2007 Nov 2005 2010 4/99 – 11/01 – 5/03

15. 15 April 26, 2007 Balloon Workshop on Low Cost Access to Near-Space LCANS:Smith/SwRI How Are They Launched? By……….. Land Sea Air Dynamic Static

16. 16 April 26, 2007 Balloon Workshop on Low Cost Access to Near-Space LCANS:Smith/SwRI Where are payloads mounted? Middle Top Bottom

17. 17 April 26, 2007 Balloon Workshop on Low Cost Access to Near-Space LCANS:Smith/SwRI The Environment

18. 18 April 26, 2007 Balloon Workshop on Low Cost Access to Near-Space LCANS:Smith/SwRI Environmental : Variability

19. 19 April 26, 2007 Balloon Workshop on Low Cost Access to Near-Space LCANS:Smith/SwRI Environmental : Extreme Worse than orbiting spacecraft Very long eclipse times (12 hrs possibly) Very localized thermal IR extremes (thunder storms) Primary thermal driver is radiative (convection negligible) Atmosphere changes with time of year and latitude Tropopause temperatures are “generally” colder in summer and higher in altitude and are warmer and lower in winter Temperatures are “generally” warmer towards the poles Temperature of -90C can be seen

20. 20 April 26, 2007 Balloon Workshop on Low Cost Access to Near-Space LCANS:Smith/SwRI Environmental : Winds Jaska 2005 Latitudinal Wind Profiles Winds vary with latitude, altitude and time of year NH winds blow westerly in the summer and easterly in the winter Turn-around occurs in spring and fall when stratospheric winds reverse.

21. 21 April 26, 2007 Balloon Workshop on Low Cost Access to Near-Space LCANS:Smith/SwRI How much can we see? Stratospheric Fields of View Footprint Diameter to the Horizon 692 Miles 520 Miles 80,000 feet 60,000 feet 847 Miles 120,000 feet How much can we see?

22. 22 April 26, 2007 Balloon Workshop on Low Cost Access to Near-Space LCANS:Smith/SwRI What Can We See? Prepared by O. Bruegman & G. Cashin/ITMI Gamma RayX Ray U VOptical I R Altitude (Feet x 1000) Atmospheric Transmittence Problems Wavelength Atmospheric Interference & Water Vapor Absorption of IR. Atmospheric Transmittence Problems Olympus ENABLED SCIENCE 0 35 60 95 130 165 Atmospheric Background Interferes 130 k-ft

23. 23 April 26, 2007 Balloon Workshop on Low Cost Access to Near-Space LCANS:Smith/SwRI Imagination: Let it run wild Venus Titan

24. 24 April 26, 2007 Balloon Workshop on Low Cost Access to Near-Space LCANS:Smith/SwRI Thank-You I. Steve Smith, Jr. Southwest Research Institute sismith@swri.edu 210-522-3587