299:, is sometimes used as a lift gas when hydrogen and helium are not available. It has the advantage of not leaking through balloon walls as rapidly as the smaller molecules of hydrogen and helium. Many lighter-than-air balloons are made of aluminized plastic that limits such leakage; hydrogen and helium leak rapidly through latex balloons. However, methane is highly flammable and like hydrogen is not appropriate for use in passenger-carrying airships. It is also relatively dense and a potent
36:
443:
340:). It is non-flammable and much cheaper than helium. The concept of using steam for lifting is therefore already 200 years old. The biggest challenge has always been to make a material that can resist it. In 2003, a university team in Berlin, Germany, has successfully made a 150 °C steam lifted balloon. However, such a design is generally impractical due to high boiling point and condensation.
601:
170:, an amount of gas (and also a mixture of gases such as air) expands as it is heated. As a result, a certain volume of gas has a lower density as the temperature is higher. The temperature of the hot air in the envelope will vary depending upon the ambient temperature, but the maximum continuous operating temperature for most balloons is 250 °F (121 °C).
482:
aerogel material and the air contained within. In 2021, a group of researchers successfully levitated a series of carbon aerogels by heating them with a halogen lamp, which had the effect of lowering the density of the air trapped in the porous microstructure of the aerogel, allowing the aerogel to float.
635:
Because of the enormous density difference between water and gases (water is about 1,000 times denser than most gases), the lifting power of underwater gases is very strong. The type of gas used is largely inconsequential because the relative differences between gases is negligible in relation to the
468:
In a theoretically perfect situation with weightless spheres, a "vacuum balloon" would have 7% more net lifting force than a hydrogen-filled balloon, and 16% more net lifting force than a helium-filled one. However, because the walls of the balloon must be able to remain rigid without imploding, the
591:
This calculation is at sea level at 0 °C. For higher altitudes, or higher temperatures, the amount of lift will decrease proportionally to the air density, but the ratio of the lifting capability of hydrogen to that of helium will remain the same. This calculation does not include the mass of
205:
posed by hydrogen. The extremely high cost of helium (compared to hydrogen) has led researchers to re-investigate the safety issues of using hydrogen as a lift gas, especially for vehicles not carrying passengers and being deployed away from populated areas. With good engineering and good handling
481:
with a density less than air, the lightest recorded so far reaching a density approximately 1/6th that of air. Aerogels don't float in ambient conditions, however, because air fills the pores of an aerogel's microstructure, so the apparent density of the aerogel is the sum of the densities of the
612:
At higher altitudes, the air pressure is lower and therefore the pressure inside the balloon is also lower. This means that while the mass of lifting gas and mass of displaced air for a given lift are the same as at lower altitude, the volume of the balloon is much greater at higher altitudes.
140:
is a gas that has a density lower than normal atmospheric gases and rises above them as a result, making it useful in lifting lighter-than-air aircraft. Only certain lighter than air gases are suitable as lifting gases. Dry air has a density of about 1.29 g/L (gram per liter) at
351:
is lighter than air and could theoretically be used as a lifting gas. However, it is extremely corrosive, highly toxic, expensive, is heavier than other lifting gases, and has a low boiling point of 19.5 °C. Its use would therefore be impractical.
385:
is lighter than air (density 0.900 g/L at STP, average atomic mass 20.17 g/mol) and could lift a balloon. Like helium, it is non-flammable. However, it is rare on Earth and expensive, and is among the heavier lifting gases.
639:
A submerged balloon that rises will expand or even explode because of the strong pressure reduction, unless gas is able to escape continuously during the ascent or the balloon is strong enough to withstand the change in pressure.
283:
has been used as a lifting gas in balloons, but while inexpensive, it is relatively heavy (density 0.769 g/L at STP, average molecular mass 17.03 g/mol), poisonous, an irritant, and can damage some metals and plastics.
374:, which is 7% lighter than air, is technically capable of being used as a lifting gas at temperatures above its boiling point of 25.6 °C. Its extreme toxicity, low buoyancy, and low boiling point have precluded such a use.
193:
Hydrogen is extremely flammable. Some countries have banned the use of hydrogen as a lift gas for commercial vehicles but it is allowed for recreational free ballooning in the United States, United
Kingdom and Germany. The
712:
of earth atmospheric pressure – so a huge balloon would be needed even for a tiny lifting effect. Overcoming the weight of such a balloon would be difficult, but several proposals to explore Mars with balloons have been
271:
and other gases, was also used in balloons. It was widely available and cheap. Disadvantages include a higher density (reducing lift), its flammability and the high toxicity of the carbon monoxide content.
254:
that cannot be practically manufactured from other materials. When released into the atmosphere, e.g., when a helium-filled balloon leaks or bursts, helium eventually escapes into space and is lost.
181:, being the lightest existing gas (7% the density of air, 0.08988 g/L at STP), seems to be the most appropriate gas for lifting. It can be easily produced in large quantities, for example with the
551:= 9.8066 m/s = 9.8066 N/kg; V = volume (in m). Therefore, the amount of mass that can be lifted by hydrogen in air at sea level, equal to the density difference between hydrogen and air, is:
413:
is an unsaturated hydrocarbon that's 3% less dense than air. Unlike nitrogen however, ethylene is highly flammable and far more expensive, rendering use as a lifting gas highly impractical.
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246:
Although abundant in the universe, helium is very scarce on Earth. The only commercially viable reserves are a few natural gas wells, mostly in the US, that trapped it from the slow
620:), must be able to expand enormously in order to displace the required amount of air. That is why such balloons seem almost empty at launch, as can be seen in the photo.
217:
through many materials such as latex, so that the balloon will deflate quickly. This is one reason that many hydrogen or helium filled balloons are constructed out of
402:
and abundantly available, because it is the major component of air. However, because nitrogen is only 3% lighter than air, it is not a good choice for a lifting gas.
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for a human habitat that would float in the atmosphere of Venus at an altitude where both the pressure and the temperature are Earth-like. In 1985, the Soviet
240:
The diffusion issue shared with hydrogen (though, as helium's molecular radius (138 pm) is smaller, it diffuses through more materials than hydrogen).
142:
1414:
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are the most commonly used lift gases. Although helium is twice as heavy as (diatomic) hydrogen, they are both significantly lighter than air.
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363:
is 10% lighter than air and could be used as a lifting gas. Its extreme flammability and low lifting power make it an unattractive choice.
794:, can be filled with helium gas to create a solid which floats when placed in an open top container filled with a dense gas.
1181:
Sun, Haiyan; Xu, Zhen; Gao, Chao (2013-02-18). "Multifunctional, Ultra-Flyweight, Synergistically
Assembled Carbon Aerogels".
100:
72:
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balloon is impractical to construct with any known material. Despite that, sometimes there is discussion on the topic.
1016:
461:
or partial vacuum. As early as 1670, over a century before the first manned hot-air balloon flight, the
Italian monk
119:
774:
for the least dense (lightest) solid. Aerogel is mostly air because its structure is like that of a highly vacuous
519:) rather than upon their ratios. Thus the difference in buoyancies is about 8%, as seen from the buoyancy equation:
745:'s largest moon, has a dense, very cold atmosphere of mostly nitrogen that is appropriate for ballooning. A use of
79:
17:
823:
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A balloon can only have buoyancy if there is a medium that has a higher average density than the balloon itself.
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is lighter than air (density 0.804 g/L at STP, average molecular mass 18.015 g/mol) due to water's low
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828:
627:. A superpressure balloon maintains a higher pressure inside the balloon than the external (ambient) pressure.
57:
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density of water. However, some gases can liquefy under high pressure, leading to an abrupt loss of buoyancy.
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is the second lightest gas (0.1786 g/L at STP). For that reason, it is an attractive gas for lifting as well.
86:
53:
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236:
A major advantage is that this gas is noncombustible. But the use of helium has some disadvantages, too:
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is about 50% denser than Earth air, ordinary Earth air could be a lifting gas on Venus. This has led to
650:(upside down bags) that they fill with air to lift heavy items like cannons and even whole ships during
68:
548:
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A different approach for high altitude ballooning, especially used for long duration flights is the
182:
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890:(No. FAA-H-8083-11A). Washington, D.C.: Federal Aviation Administration. 2008. pp. 3-9–3-10.
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295:(density 0.716 g/L at STP, average molecular mass 16.04 g/mol), the main component of
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251:
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771:
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deployed two helium balloons in Venus's atmosphere at an altitude of 54 km (34 mi).
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914:
8:
214:
195:
93:
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1128:
Sean A. Barton (21 October 2009). "Stability
Analysis of an Inflatable Vacuum Chamber".
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311:
It is also possible to combine some of the above solutions. A well-known example is the
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The lifting power in air of hydrogen and helium can be calculated using the theory of
312:
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1012:
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507:
Thus helium is almost twice as dense as hydrogen. However, buoyancy depends upon the
348:
210:
428:
it is however a major safety hazard, on a scale even greater than that of hydrogen.
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1004:
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833:
732:
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Therefore, the amount of mass that can be lifted by helium in air at sea level is:
371:
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424:
is slightly lighter than molecular nitrogen with a molecular mass of 27.7. Being
268:
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1242:"Light-induced levitation of ultralight carbon aerogels via temperature control"
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is due primarily to the large proportion of air within the solid and not the
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are a type of deep-sea submersibles that use gasoline as the "lifting gas".
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of radioactive materials within Earth. By human standards, helium is a
146:
1419:
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1240:
Yanagi, Reo; Takemoto, Ren; Ono, Kenta; Ueno, Tomonaga (2021-06-14).
903:"Long Permanence High Altitude Airships: The Opportunity of Hydrogen"
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360:
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and the buoyant force for one m of hydrogen in air at sea level is:
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when compared with typical atmospheric gases such as nitrogen gas (N
35:
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and the buoyant force for one m of helium in air at sea level is:
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1089:"HeiDAS UH – Ein Heissdampfaerostat mit ultra-heiss-performance"
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or pumped through a hose from the diver's ship on the surface.
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which combines a core of helium with an outer shell of hot air.
149:, and so lighter-than-air gases have a density lower than this.
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Bonnici, Maurizio; Tacchini, Alessandro; Vucinic, Dean (2014).
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Speight, James G. (2000). "Fuels, Synthetic, Gaseous Fuels".
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964:(Thesis). OPUS Augsburg, University at Augsburg. p. 30.
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use ballast tanks and trim tanks with air to regulate their
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While not a gas, it is possible to synthesize an ultralight
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Theoretically, an aerostatic vehicle could be made to use a
791:
699:
693:
583:
Thus hydrogen's additional buoyancy compared to helium is:
382:
318:
961:
Permeation
Barrier for Lightweight Liquid Hydrogen Tanks
616:
A balloon that is designed to lift to extreme heights (
900:
1252:(1). Springer Science and Business Media LLC: 12413.
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683:
757:
proposal included a balloon to circumnavigate Titan.
27:
Gas used to create buoyancy in a balloon or aerostat
60:. Unsourced material may be challenged and removed.
786:construction materials. Taking advantage of this,
702:has a very thin atmosphere – the pressure is only
608:that has been able to reach a height of 36 km
206:practices, the risks can be significantly reduced.
145:(STP) and an average molecular mass of 28.97
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1387:SEAgel Aerogel lighter than air solid. Not a UFO
143:standard conditions for temperature and pressure
1001:Kirk-Othmer Encyclopedia of Chemical Technology
213:hydrogen molecule is very small, it can easily
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790:, in the same family as aerogel but made from
1358:
579:1 m × 1.114 kg/m × 9.8 N/kg= 10.9 N
563:1 m × 1.202 kg/m × 9.8 N/kg= 11.8 N
162:Heated atmospheric air is frequently used in
1336:"NASA's 'frozen smoke' named lightest solid"
465:envisioned a ship with four vacuum spheres.
595:
592:the envelope need to hold the lifting gas.
1359:Administrator, NASA Content (2015-04-15).
957:
189:, but hydrogen has several disadvantages:
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976:"Balloon flight - Historical development"
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587:11.8 / 10.9 ≈ 1.08, or approximately 8.0%
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201:is frequently cited as an example of the
152:
120:Learn how and when to remove this message
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319:Gases theoretically suitable for lifting
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1038:The Boston Medical and Surgical Journal
1009:10.1002/0471238961.0701190519160509.a01
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555:(1.292 - 0.090) kg/m = 1.202 kg/m
14:
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1361:"Aerogels: Thinner, Lighter, Stronger"
1118:Tom D. Crouch (2009). Lighter Than Air
672:, essentially making them underwater "
571:(1.292 - 0.178) kg/m = 1.114 kg/m
1300:"Is There an Atmosphere on the Moon?"
1031:
630:
1068:Colorado Aviation Historical Society
696:because it has almost no atmosphere.
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58:adding citations to reliable sources
29:
1064:"Timothy S. Cole - Honored in 1995"
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24:
907:European Transport Research Review
684:Balloons on other celestial bodies
658:. The air is either supplied from
25:
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1334:Stenger, Richard (May 9, 2002).
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1394:from the original on 2021-12-21
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1032:Terry, Herbert (14 July 1881).
824:Buoyancy compensator (aviation)
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1415:Lighter-than-air - An overview
1314:"Exploring Mars With Balloons"
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844:Vacuum airship/Vacuum balloon
398:has the advantage that it is
1130:Journal of Applied Mechanics
692:Balloons cannot work on the
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7:
1094:. Aeroix.de. Archived from
1050:10.1056/NEJM188107141050202
958:Schultheiß, Daniel (2007).
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755:Titan Saturn System Mission
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267:, a mixture of hydrogen,
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1189:(18). Wiley: 2554–2560.
864:"Air - Molecular Weight"
778:. The lightness and low
596:High-altitude ballooning
183:water-gas shift reaction
980:Encyclopedia Britannica
888:Balloon Flying Handbook
463:Francesco Lana de Terzi
377:
164:recreational ballooning
1203:10.1002/adma.201204576
723:atmosphere. Because CO
652:underwater archaeology
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486:Hydrogen versus helium
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330:gaseous state of water
252:non-renewable resource
153:Gases used for lifting
1440:Hydrogen technologies
1384:Grommo (2008-06-20),
772:Guinness World Record
625:superpressure balloon
603:
445:
1034:"Coal-Gas Poisoning"
543:= Buoyant force (in
243:Helium is expensive.
138:lighter-than-air gas
54:improve this article
1420:Airship Association
1195:2013AdM....25.2554S
1152:2008JAM....75d1010B
919:2014ETRR....6..253B
656:shipwreck salvaging
511:of the densities (ρ
166:. According to the
1445:Airship technology
1246:Scientific Reports
1183:Advanced Materials
814:Balloon (aircraft)
631:Submerged balloons
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1160:10.1115/1.2912742
349:Hydrogen fluoride
344:Hydrogen fluoride
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168:ideal gas law
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71: –
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69:"Lifting gas"
66:
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41:
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1465:Mass density
1396:, retrieved
1386:
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1364:
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1339:
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867:
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733:Vega program
687:
678:Bathyscaphes
664:
648:lifting bags
642:
638:
634:
622:
618:stratosphere
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504:as follows:
499:
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327:
324:Water vapour
310:
307:Combinations
291:
279:
262:
235:
229:
209:Because the
203:safety risks
196:
187:electrolysis
177:
161:
137:
133:
131:
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110:October 2012
107:
97:
90:
83:
76:
64:
52:Please help
47:verification
44:
297:natural gas
248:alpha decay
219:Mylar/BoPET
134:lifting gas
1429:Categories
1398:2018-01-16
1370:2018-01-16
1345:2018-01-16
1320:2012-10-21
1105:2012-10-21
985:2021-08-17
873:2018-01-16
850:References
666:Submarines
509:difference
426:pyrophoric
334:molar mass
197:Hindenburg
80:newspapers
1435:Aerostats
1268:2045-2322
1227:205248394
1211:0935-9648
1168:118896629
1073:17 August
945:255617917
937:1866-8887
770:held the
766:In 2002,
729:proposals
604:MAXIS: a
535:) × g × V
361:Acetylene
356:Acetylene
1450:Buoyancy
1392:archived
1286:34127746
1219:23418099
819:Buoyancy
804:Aerostat
798:See also
751:proposed
747:aerobots
719:has a CO
674:airships
670:buoyancy
502:buoyancy
491:Hydrogen
422:Diborane
417:Diborane
411:Ethylene
406:Ethylene
396:nitrogen
390:Nitrogen
265:coal gas
259:Coal gas
211:diatomic
199:disaster
179:Hydrogen
174:Hydrogen
1277:8203743
1191:Bibcode
1148:Bibcode
915:Bibcode
809:Airship
784:silicon
780:density
768:aerogel
707:⁄
606:balloon
547:); g =
539:Where F
479:aerogel
473:Aerogel
293:Methane
288:Methane
281:Ammonia
276:Ammonia
215:diffuse
158:Hot air
94:scholar
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788:SEAgel
776:sponge
762:Solids
753:. The
743:Saturn
644:Divers
545:Newton
515:) − (ρ
495:helium
459:vacuum
453:(1670)
432:Vacuum
231:Helium
226:Helium
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1455:Gases
1223:S2CID
1164:S2CID
1138:arXiv
1099:(PDF)
1092:(PDF)
941:S2CID
739:Titan
717:Venus
713:made.
400:inert
394:Pure
147:g/mol
101:JSTOR
87:books
1365:NASA
1282:PMID
1264:ISSN
1215:PMID
1207:ISSN
1075:2021
1013:ISBN
933:ISSN
792:agar
700:Mars
694:Moon
654:and
646:use
527:= (ρ
493:and
446:The
383:Neon
378:Neon
328:The
73:news
1272:PMC
1254:doi
1199:doi
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