1April 26, 2007April 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

2April 26, 2007April 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).

3April 26, 2007April 26, 2007

Balloon Workshop on Low Cost Access to Near-Space

LCANS:Smith/SwRI

Where Do They Fit in the Scheme of Where Do They Fit in the Scheme of Things?Things?

balloons

4April 26, 2007April 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)

5April 26, 2007April 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

6April 26, 2007April 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

7April 26, 2007April 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

8April 26, 2007April 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 ft3 to ~60 million cubic feet3 (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)

9April 26, 2007April 26, 2007

Balloon Workshop on Low Cost Access to Near-Space

LCANS:Smith/SwRI

ZP Balloon Load Altitude CurvesSuspended Load vs. Altitude Capabilities

Based on 1962 Standard Atmosphere

90,000

100,000

110,000

120,000

130,000

140,000

150,000

160,000

170,000

0 1000 2000 3000 4000 5000 6000 7000 8000

Suspended Weight (lbs)

Geo

pote

ntia

l Alti

tude

(ft)

59.84 MCF

4.00 MCF 11.82-H MCF

11.82 MCF 29.47 MCF39.57-H MCF

39.57 MCF

ULDB - 21.56 MCF

*Balloon Volumes Noted in Million Cubic Feet (MCF)

10April 26, 2007April 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 ft3 to ~26 mcf

Spherical

Lobed: “Pumkin”

Tetroon

11April 26, 2007April 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

12April 26, 2007April 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.

13April 26, 2007April 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

14April 26, 2007April 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

15April 26, 2007April 26, 2007

Balloon Workshop on Low Cost Access to Near-Space

LCANS:Smith/SwRI

How Are They Launched?

By………..Land Sea Air

Dynamic DynamicStatic

16April 26, 2007April 26, 2007

Balloon Workshop on Low Cost Access to Near-Space

LCANS:Smith/SwRI

Where are payloads mounted?

Middle

TopBottom

17April 26, 2007April 26, 2007

Balloon Workshop on Low Cost Access to Near-Space

LCANS:Smith/SwRI

The Environment

18April 26, 2007April 26, 2007

Balloon Workshop on Low Cost Access to Near-Space

LCANS:Smith/SwRI

Environmental : Variability

19April 26, 2007April 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

20April 26, 2007April 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.

21April 26, 2007April 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 Miles520 Miles

80,000 feet

60,000 feet

847 Miles

120,000 feet

How much can we see?

22April 26, 2007April 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 Ray X Ray U V Optical I R

Alt

itu

de

(Fee

t x

1000

)

Atmospheric

Transmittence

Problems

Wavelength

Atmospheric Interference

& Water Vapor

Absorption of IR.

AtmosphericTransmittence

Problems

Olympus ENABLED SCIENCE

0

35

60

95

130

165

AtmosphericBackground

Interferes

130 k-ft

23April 26, 2007April 26, 2007

Balloon Workshop on Low Cost Access to Near-Space

LCANS:Smith/SwRI

Imagination: Let it run wild

Venus

Titan

24April 26, 2007April 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.edu210-522-3587