Last week sky diver Felix Baumgartner jumped from an altitude of 128,177 feet from a high altitude balloon, breaking the record for the highest altitude jump, which had stood since the 1960’s. The jump was sponsored by Red Bull as part of the “Red Bull Stratos” project.
To be perfectly frank, it was a publicity stunt and it worked quite well in that regard. I have no problem with that, and if it did inspire some additional interest in the physiological effects of high altitudes or the technical capabilities of high altitude ballooning, then that’s all well and good. I doubt that there will be any really compelling scientific data from the event, but there might be some interesting information gathered. If nothing else, it does push the capabilities of flight, which is always worth doing.
But there is one thing that bothers me: It has repeatedly been stated that he jumped from “space” Some call it “near space” and others “near the edge of space.” In fact, high altitude ballooning now seems to be using these terms to pretend it is equivalent to actual space flight. It’s not.
Gas filled balloons can reach the upper atmosphere, but they can’t reach space. They depend on the buoyancy of their gas displacing atmosphere. As such, they can never actually go above the earth’s atmosphere. They may be able to reach altitudes above 99% of air molecules, but that is not space.
What is space, then? That depends on what definition you choose to use. There is no single bright line that indicates where space starts. The atmosphere tapers off slowly and even in outer space, there are gas molecules floating around in a *near* perfect vacuum. But regardless of the definition, whether you use the US Air Force’s arbitrary altitude of 50 statute miles, The Kármán line or the lowest practical altitude at which a satellite can maintain a stable orbit, it is much much higher than what any balloon can reach.
By any accepted definition:
- If an air-breathing jet engine can function, you are not in space.
- If you can remain aloft using aerodynamic lift, you are not in space
- If you can get there using the buoyancy of a lightweight gas, you are not in space
(and sorry to the rest of the world who prefer to think in Metric units. Feet is still the standard, in most circumstances at least, for reporting altitude in aviation. Hence, I shall use feet, conforming to the most widely used international convention.)
1,000-5,000 feet: Standard operating altitude for most general aviation aircraft
10,000 feet: Above this altitude, supplemental oxygen becomes a concern for unpressurized aircraft. Of course, it’s not a single bright line where it is needed, and regulations may allow flights up to 12,500 feet without supplemental oxygen, but as altitude increases the danger of hypoxia becomes more acute.
20,000 – 25,000 feet: Altitude that passenger jets fly at for short regional flights. It is bellow the most efficient altitude for cruising, but if the flight is short, it’s not worth going much higher.
29,000 – 43,000 feet: Normal cruising altitude for passenger jet aircraft. This is approximate and the actual altitude depends on a number of factors, including the wind conditions at altitudes, the duration of the flight and so on.
56,000 feet: The cruising altitude of the Concorde.
70,000 feet: Approximate service ceiling for the U-2.
85,000 feet: Approximate service ceiling of the SR-71.
96,863 feet: Altitude record for stable flight by a non-rocket winged aircraft. This was achieved in 2001 by a NASA solar-electric aircraft. The aircraft was unmanned and built to be extremely lightweight with a very large wingspan, in order to allow such extreme altitudes to be reached.
123,500 feet: Highest manned balloon flight and parachute descent prior to Felix Baumgartner’s October 14 jump. In 1966, Nick Piantanida, an amateur skydiver from the United States reached this altitude in a gas-filled balloon. He was attempting to break the previous record for the highest sky dive. However, he was unable to disconnect his oxygen regulator from the balloons gondola and was forced to detach the balloons gondola and parachute down from within the gondola.
Because he did not pilot his aircraft to the ground, his altitude record was not recognized and because he did not leave the gondola, his parachute descent record was not recognized.
(Personally, I find this notion absurd. The highest altitude record is the highest altitude reached by anyone period. Whether they actually brought the aircraft down is a very stupid technicality. If you go higher than anyone else, you get the record. Similarly, the land speed record should be the fastest recorded speed on land, not the fastest speed by some self-appointed body’s stupid bi-directional protocol.)
123,520 feet: World record for altitude achieved by a manned air-breathing jet aircraft. This altitude was reached by a Mig-25 in 1977. The aircraft could not actually maintain operations at this altitude. Instead, the altitude was reached by putting the aircraft into a zoom climb, achieving the most rapid climb rate possible. The climb carried the aircraft beyond the altitude where its engines could function, but it continued to climb in altitude due to its own momentum.
128,177 feet: Felix Baumgartner’s October 14 jump – although not officially verified (yet) this is the highest parachute jump and highest manned balloon flight to date.
173,900 feet: The highest altitude ever reached by a balloon. In 2002, an unmanned balloon made of an ultra thin membrane reached this altitude, breaking the previous record of approximately 170,000 feet, set in 1972.
264,000 feet: 50 statute miles. This is the altitude that the US Air Force has traditionally used for awarding astronauts wings.
288,000 feet: Approximate maximum altitude of the V-2, the first operational ballistic missile.
328,085 feet: The Kármán line. This altitude is sometimes refereed to as the official line between the atmosphere and outer space, and is recognized as such by the Fédération Aéronautique Internationale for the purpose of differentiating aeronautics from astronautics. The significance of this altitude is that in order of a body to achieve enough lift for level flight, it would need to travel at a speed greater than its orbital velocity. Thus, orbital dynamics becomes the dominant factor in flight and it is not possible to maintain flight by aerodynamics alone.
350,000 feet: Approximate maximum altitude achieved by the X-15.
367,0000 feet: Approximate maximum altitude yet achieved by Virgin Galactic’s SpaceShipOne.
401,280 feet: This is the altitude NASA’s mission control uses as a reference for spacecraft reentry. It is the region where atmospheric drag on a spacecraft becomes significant enough to produce heating and make aerodynamic maneuvering possible. Therefore, when a spacecraft crosses this altitude, it is said to have begun the reentry portion of its flight.
445,000 feet: This is (VERY approximately) the altitude required for a satellite to maintain a stable orbit above earth’s surface. Bellow this altitude, the amount of atmospheric drag will result in rapid orbital decay. Early US spy satellites flew at this approximate altitude during their orbital perigee, in order to make observations as close to the earth’s surface as possible. At this altitude drag is significant enough that a restartable motor was required to keep the satellites orbiting and total flights were short – under two months.
The minimum altitude needed to achieve orbit will depend on the size and aerodynamics of the spacecraft, solar activity and a variety of other factors. However, this represents a good practical example of what has actually been achieved by a functional satellite. The orbit was elliptical and thus it did not spend most of its time at this low an altitude, that was just for the lowest pass.
610,000 feet: Lowest orbit of the Space Shuttle Program. STS-59 and STS-68 were the Space Shuttle missions with the lowest orbital altitude. These flights used space-based radar for earth observation. Much lower than this would cause the Shuttle to rapidly deorbit due to drag.
615,120 feet: The maximum altitude reached by Astronaut Alan Shepard during Mercury-Redstone 3. Shepard is often noted as “the first American in space” for this flight, although he did not enter earth orbit.
800,525 feet: The maximum altitude reached by the Bumper-WAC rocket, an early research rocket used by the United States in the late 1940’s. The Bumber-WAC used a captured German V-2 rocket for the first stage and a WAC Corporal missile for the second stage.
836,286 feet: Reported to be the lowest average altitude of any currently functional satellite and the lowest altitude of any satellite to operate for an extended period of time (years). The European Space Agencies GOCE satellites measure variations in the earth’s magnetic field. Their low altitude means that they are required to fire ion thrusters frequently to fight the effects of atmospheric drag.
No, not space. And not “close to space” or “the edge of space” either. Unless by “the edge” suddenly means “barely halfway there, by the most low-altitude definition possible”
This entry was posted on Wednesday, October 24th, 2012 at 3:30 pm and is filed under Bad Science, Good Science, Misc, Space, media. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
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