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Lord Jubjub
2011-Jun-23, 09:08 PM
I think this question has been asked before but if you take a balloon to the altitude of Kittinger's freefall and launched a rocket into NEO, what would the launch look like from terms of angle of launch, size of rocket, etc.

Could you launch a bottle rocket into orbit?

csmyth3025
2011-Jun-24, 04:12 AM
I think this question has been asked before but if you take a balloon to the altitude of Kittinger's freefall and launched a rocket into NEO, what would the launch look like from terms of angle of launch, size of rocket, etc.

Could you launch a bottle rocket into orbit?
I can't give you the exact numbers for a launch at ~103, 000 ft (~31.3 Km) since it would require some additional information like desired payload, specific impulse of the rocket, dry weight of the rocket, weight of fuel and oxidizer, number of rocket stages (if more than one), etc.

In general, you have to consider that you're launching at an altitude of about 31 km. The minimum altitude you would need to attain for Earth orbit would be about 6 times this altitude:

Re-entry is assumed to occur when the satellite has descended to an altitude of 180 km. In all but the heaviest satellites (those with a mass to area ratio well in excess of 100 kilogram per square metre), the actual lifetime from an altitude of less than 180 km is only a few hours.
(ref. http://www.ips.gov.au/Category/Educational/Space%20Weather/Space%20Weather%20Effects/SatelliteOrbitalDecayCalculations.pdf )

In addition to the rocket power you'll need to raise your payload ~150 km vertically against gravity, you'll also have to accelerate it to a "horizontal" orbital velocity of about 7,800 m/s (~17,500 mph):

Atmospheric and gravity drag associated with launch typically adds 1,5002,000 m/s to the delta-v launch vehicle required to reach normal LEO orbital velocity of around 7,800 m/s (17,448 mph).
(ref. http://en.wikipedia.org/wiki/Low_Earth_orbit )

It's safe to say that you're going to need a lot more than a bottle rocket if you want to achieve even a very short-lived Earth orbit.

For comparison, the Patriot surface-to-air missle weighs in at about 700 kg (~1500 lb) and has a payload (warhead) of about 90 kg (~200 lb). It can achieve a speed of ~mach 5. Orbital velocity, however, is about mach 25.4:
(ref. http://en.wikipedia.org/wiki/Patriot_missle#Patriot_Guided_Missile )

Chris

cjl
2011-Jun-24, 09:25 AM
Honestly, it would be pretty much like launching from the ground. You might need a few percent less delta V, since gravity loss would be very slightly reduced and drag loss would be very significantly reduced, but the main problem (getting from a standstill up to over 7 kilometers per second) is completely unaffected. Something like a bottle rocket wouldn't have a prayer of making it even to the edge of space from a hundred thousand feet, much less all the way to orbit.

Kiwi
2011-Jun-24, 09:33 AM
There were rocket launches from balloon platforms in the late 1950s - you might want to follow them up.

Manawatu Daily Times, Thursday 19 September 1957, page 7
U.S. plans ultra-high altitude rocket project
(Received 10:30 p.m.) Baltimore, September 18
The United States Air Force announced today it would fire a four-stage rocket from a balloon-supported platform 100,000 feet above the earth late this month.
The rocket shot, the second phase of the Air Force research project "Far Side," would be aimed at obtaining data 1000 to 1400 miles above the earth, an altitude of the upper atmosphere never before pierced by man, the announcement said.
The Air Research and Development Command said the rocket would be launched from above Eniwetok atoll in the Pacific during the latter part of this month. No specific date was announced.
A tiny but powerful radio transmitter located in the last stage of the rocket would send back to earth data on cosmic rays, the earth's magnetic field and other fields of air force scientific interest, the announcement added.
The ARDC said this exploratory research effort had no nuclear aspects, and the Atomic Energy Commission was not participating in the project, although its Pacific proving ground would be used. The first phase of project "Far Side" was accomplished on June 28 when what the Air Force described as the world's largest balloon — 200 feet in diameter — successfully lifted nearly two tons of equipment to an altitude of more than 104,000 feet.


Manawatu Evening Standard, Tuesday 8 October 1957, page 15
High hopes for American satellite
Washington, October 7
A United States rocket designed to plunge further into space than the Soviet satellite "could go at any minute," a United States Air Force spokesman said today.
He said the four-stage rocket, expected to climb 1000 to 4000 miles to the highest point ever reached by a man-made object, had been ready for firing since September 30. The only thing delaying it was the weather.
The Air Force spokesman said the launching, known as "Project Far Side," would take place at Eniwetok Atoll at the Pacific. The rocket would be carried 100,000 feet by a balloon-supported platform before being fired into outer space.


Manawatu Daily Times, Friday 25 October 1957, page 7
Rocket launched from balloon — Scientists obtain extensive data
(10 p.m.) Washington, October 24
The Defence Department said tonight that a rocket was launched from a balloon high over the Pacific Ocean at the Eniwetok proving grounds on Monday in operation "Far Side."
The department said the firing was "successful" and that "extensive data" was obtained, but it said the data has not yet been evaluated. It was hoped the data can be ready by Friday, the brief announcement said. The department said that until the material was evaluated, it cannot confirm or deny any reported results.
The department would not confirm reports that the air force rocket was fired nearly 4000 miles above the earth from a balloon platform 100,000 feet up.
A high air force spokesman said, however, that scientists were almost certain the rocket exceeded 1000 miles. The spokesmen said scientists themselves would not know whether the rocket reached 4000 miles until they had evaluated technical records of the flight.
An officer familiar with the tests said it was possible it soared well beyond the 4000-mile goal. This would be far higher than anything ever sent skyward by man. The Soviet Union's earth satellite was shot to a maximum height of about 500 miles.
One published report said the rocket carried an instrument package consisting of a 3スlb collection of counters and sensitive indicators in a six-by-four-inch container in the nose cone of the fourth stage of the rocket.
The announced aim of the "Far Side" project was to launch a research rocket to take readings of interplanetary radiations and the earth's magnetic field at various altitudes. The Air Force has emphasised that this was no attempt to place a satellite in space and had no relation to that programme.

slang
2011-Jun-24, 11:36 AM
A high air force spokesman

"Launching rockets from a balloon!? Yeah, he must have been high."


said, however, that scientists were almost certain the rocket exceeded 1000 miles. [...] This would be far higher than anything ever sent skyward by man. The Soviet Union's earth satellite was shot to a maximum height of about 500 miles.

Funny, the historical context of this article. So proud they achieved double the altitude of "[t]he Soviet Union's earth satellite", but everyone remembers Sputnik, yet very few remember these balloon tests.

ETA: About horizontal take-off: air-to-air missiles are launched horizontally, as is the Pegasus rocket. Not quite the same as from a balloon of course, but maybe the similarity can help answer questions.

Kiwi
2011-Jun-24, 12:35 PM
"Launching rockets from a balloon!? Yeah, he must have been high."

What sort of balloon are you thinking of? The first article says "balloon-supported platform" and refers to a balloon that lifted nearly two tons to over 104,000 feet.


"everyone remembers Sputnik, yet very few remember these balloon tests.

Plenty of people worldwide saw Sputnik 1, including me (or, more likely the spent rocket that launched it) because it orbited the earth, but very few would have seen non-orbiting rockets launched from 100,000 feet above Eniwetok Atoll in its sparsely-populated part of the Pacific.

There was a little more in my local newspaper, so I imagine many others around the world would have similar information or even more:--

Manawatu Daily Times, Saturday 26 October 1957, page 7
Rockets reach 17,000 M.P.H. — Thrilling experience says director
The scientist in charge of "Operation Far Side" said last night that the rocket's instrument package was in flight an hour and a quarter and reached a velocity of 17,000 miles per hour.
Dr Morton Alperin said the fourth-stage rocket and instrument package burnt up when it entered the denser atmosphere. He declined to tell the exact altitude reached by the rockets. The Air Force announced yesterday that two experimental far side rockets — designed to reach up to 1000 miles or more — had been successful. Six tests were made in all. The rockets were launched from balloons 100,000 feet above Eniwetok in the Pacific.
"It was a thrilling experience," said the 39-year-old director of advanced studies of the Air Force Office of Scientific Research. "In my opinion," he said, "all six tests were successful. We learnt something from each one."
Instruments in the nose of the rockets radioed back information on cosmic radiation and magnetic field variations.
The rockets had a corkscrew spin of five revolutions per second, he said. Further details, including the exact altitudes reached, must come from Washington, he said. In his opinion the United States could send a rocket to the moon within a year if high Government officials thought it should be done, Dr Alperin said.


Manawatu Daily Times, Monday 28 October 1957, page 5
"Fake stunt" when Russian launched earth satellite
Redlands, California, October 25
Mr Charles Bartley, a scientist taking part in the United States "far side" rocket range programme, said in a speech made public yesterday, that the Soviet Union might have "pulled off a fake stunt" when it launched the earth satellite. Mr Bartley said the satellite could have been launched from a high-flying balloon, just as the United States' far side rocket was launched recently in the Pacific. The far side rocket, it was announced on Wednesday, may have soared to a height of 4000 miles or more. Mr Bartley gave his evaluations to 15 scientists from the University of Redlands at a meeting on Tuesday night. His remarks were made public yesterday.
"As propaganda, The Russian launching is undeniably superb," Mr Bartley told the university scientists. "By innuendo, it supports Soviet claims to an intercontinental ballistic missile. But objective analysis raises several questions. Sputnik could easily have been launched from a balloon. This would have been possible without employing a large rocket.

slang
2011-Jun-24, 06:24 PM
What sort of balloon are you thinking of? The first article says "balloon-supported platform" and refers to a balloon that lifted nearly two tons to over 104,000 feet.

It was a joke on the usage of the word "high", that has some other connotations especially after the sixties.


Plenty of people worldwide saw Sputnik 1, including me (or, more likely the spent rocket that launched it) because it orbited the earth, but very few would have seen non-orbiting rockets launched from 100,000 feet above Eniwetok Atoll in its sparsely-populated part of the Pacific.

I know. And understand. It's still interesting to me, in the context of the space-race, and how it played out over time. Most people know what Sputnik was, but even many space enthousiasts don't know about these balloon rocket tests. I didn't. Thanks for the articles, fun to read the reporting of the time.

Project Far Side is briefly mentioned in the Balloon part of "Aeronautics and astronautics: An American chronology of science and technology in the exploration of space, 1915-1960 (http://hdl.handle.net/2060/19790079963)" PDF 12.3 MB, 1961.

JustAFriend
2011-Jun-26, 03:48 AM
You dont need to go up to 103,000ft.

In the 80s, F-15s were used to launch a 20ft long 1-ton rocket up to 350miles high as a satellite killer:
http://en.wikipedia.org/wiki/ASM-135_ASAT

Bit bigger than a 'bottle rocket' but not that big....

csmyth3025
2011-Jun-26, 07:54 AM
You dont need to go up to 103,000ft.

In the 80s, F-15s were used to launch a 20ft long 1-ton rocket up to 350miles high as a satellite killer:
http://en.wikipedia.org/wiki/ASM-135_ASAT

Bit bigger than a 'bottle rocket' but not that big....
Getting something up to an altitude of 350 miles is one thing. Getting something into Earth orbit is another problem entirely - you still need to accelerate your payload to a tangental speed of about 17,500 mph.

The ASM-135 30 lb "warhead" had a speed of ">15,000 mph" according to the Wikipedia article. Anything short of a tangental speed of about 17,500 mph will not put even this small payload into Earth orbit

Chris

cjl
2011-Jun-26, 09:42 PM
The wikipedia article quick spec is wrong about the speed too - if you look farther down in the article, 15k mph is the closing speed with the satellite, not the speed of the warhead itself.