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Author
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Topic: Fastest circumnavigation (orbit) of Earth
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Blackarrow
Member Posts: 3484
From: Belfast, United Kingdom
Registered: Feb 2002
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posted 03-04-2005 01:31 PM
  
The success of Steve Fossett, who has circled the Earth, non-stop in about 67 hours, leads me to wonder who holds the record for the fastest circumnavigation of Earth.Obviously, it must be an astronaut, or cosmonaut, or multi-member crew in Earth orbit. It must have been a low orbit, since the lower you orbit, the faster you fly. Does anyone know who made the fastest ever orbit? |
Rodina
Member Posts: 836
From: Lafayette, CA
Registered: Oct 2001
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posted 03-04-2005 03:13 PM
That's entirely a function of what the lowest orbit has been, so I'd guess Gagarin, since Vostok-1 and, then, Vostok-2's orbits were designed to degrade on their own in two days if anything went wrong with the retro-package. |
FFrench
Member Posts: 3275
From: San Diego
Registered: Feb 2002
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posted 03-04-2005 03:50 PM
If we were being very picky, it could not be Gagarin. He did not make a completely full orbit of the Earth - he was about 900 miles short of his starting point. |
Rodina
Member Posts: 836
From: Lafayette, CA
Registered: Oct 2001
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posted 03-04-2005 06:15 PM
A point often overlooked! |
ejectr
Member Posts: 1921
From: Killingly, CT
Registered: Mar 2002
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posted 03-04-2005 06:33 PM
So then technically, Gherman Titov was the first to "orbit Earth." |
Ben
Member Posts: 1917
From: United States
Registered: May 2000
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posted 03-04-2005 06:56 PM
I forget the name of it but some organization (probably biased to the US) lists John Glenn as the first person to orbit the earth. Because cosmonauts in Vostoks had to eject before landing, they say they didn't 'complete' the orbit. |
Robert Pearlman
Editor Posts: 48760
From: Houston, TX
Registered: Nov 1999
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posted 03-04-2005 07:40 PM
It's a French, internationally recognized organization: the Féderation Aéronautique Internationale (FAI), the same group that just certified GlobalFlyer's round-the-world solo journey as record setting. The Soviets lied in their press release following Gagarin's landing with the FAI (and their rules) in mind: they said he landed in his Vostok spacecraft. When it was later discovered that he had parachuted, the record was said to be quietly re-assigned to Glenn (though Gagarin is still considered the first person in space by the FAI [and rightly so]). |
MrSpace86
Member Posts: 1618
From: Gardner, KS
Registered: Feb 2003
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posted 03-04-2005 11:22 PM
Wow, Gagarin not being the first to orbit? Interesting. Doesn't the Apollo 10 or 13 crew have the record for fastest speed (well, around the moon)? |
Robert Pearlman
Editor Posts: 48760
From: Houston, TX
Registered: Nov 1999
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posted 03-04-2005 11:42 PM
I think the FAI distinction wouldn't carry as much weight had the Soviets not obviously cared so much about it to lie. One could easily justify that its splitting hairs to define the first orbit as the one who lands inside the same craft he departed in, but the FAI rules were written before anyone ever attempted to do such a thing and were clearly understood by the participants so as to inspire a 20-year deception. Since the Soviets placed so much importance on gaining the FAI approval, perhaps we should not disrespect their wishes by not doing the same... |
Blackarrow
Member Posts: 3484
From: Belfast, United Kingdom
Registered: Feb 2002
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posted 03-05-2005 12:03 PM
Regarding Gagarin, I don't think it is fair or reasonable to try to deprive him of his position in history. Technically, he did not complete a full orbit, but there is no doubt that Vostok 1 achieved orbital velocity, and Gagarin was "in orbit." That's good enough for me. As for parachuting to the ground, it is nit-picking to suggest that this robs him of the record. I would be amazed if John Glenn disagrees about this.Back to my original question: there must be statistics of orbital periods indicating which spacecraft orbited in how many minutes. An orbit usually takes around 90 minutes. Anything less than 90 ought to stand out in the statistics. |
Aztecdoug
Member Posts: 1405
From: Huntington Beach
Registered: Feb 2000
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posted 03-05-2005 12:54 PM
I recall reading that one of the weight saving functions of Apollo 15 was to put the Apollo system into a lower Earth orbit before TLI.By using less fuel/weight to achieve this lower orbit, they could pack the LM with all the extra goodies like the Lunar Rover. I imagine the same was true for Apollo 16 and 17. A lower orbit should equate to a faster orbit. But, this is all conjuncture on my part. I was just a Business Major at SDSU, not an Orbital Mechanics Post Grad at MIT. |
kyra
Member Posts: 589
From: Louisville CO US
Registered: Aug 2003
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posted 03-05-2005 09:06 PM
I'd have to haul out the archives on this one, but the next rainy day someone could look for the data to find the apogees and perigees for all the piloted missions and average those two. (or the orbital period if available). The lowest averages will be the fastest orbits. Sounds like a bland answer, but true. |
Blackarrow
Member Posts: 3484
From: Belfast, United Kingdom
Registered: Feb 2002
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posted 03-06-2005 03:38 PM
I think Doug may have hit the nail on the head. From memory, Apollo lunar missions were put into very low orbits. No need to worry about orbital decay - they were only sitting temporarily in Earth orbit. This might be the makings of an answer. |
trajan
Member Posts: 111
From: Chester, Cheshire, UK
Registered: May 2004
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posted 03-06-2005 04:13 PM
No idea if this merits a "record" but STS-51F/Spacelab 2 performed an Abort to Orbit after failure of one of the SSME's. Was its initial orbit a low orbital record before it re-adjusted via the OMS? |
Blackarrow
Member Posts: 3484
From: Belfast, United Kingdom
Registered: Feb 2002
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posted 03-08-2005 05:22 PM
I think I have the answer. It's a fairly simple matter to check all of the Apogee "NASA Mission Reports" for the Apollo missions. Each has a Post-Mission Report which gives the parameters of the initial parking orbit for each flight. (Thanks also to the BIS "Spaceflight" magazine's "Satellite Digest" for orbital periods).The answer to my own question ("Who has made the fastest circumnavigation of Planet Earth?") can now be revealed. In second place, with orbital parameters of only 92.5 x 91.5 nautical miles, is Apollo 15, with an orbital period of 87.87 minutes. In first place, and therefore the holders of the record for the fastest circumnavigation of our planet in all human history, is the crew of Apollo 17, with orbital parameters of 92.5 x 91.2 nautical miles and an orbital period of 87.82 minutes. It's only a difference of three seconds, but that means that Gene Cernan is not only one of the three fastest men alive (Apollo 10) but also one of the two fastest circumnavigators of Earth alive. |
Aztecdoug
Member Posts: 1405
From: Huntington Beach
Registered: Feb 2000
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posted 03-08-2005 07:10 PM
Upon reflection I am reasonably certain that I read about the lower orbit for Apollo 15 in the Apogee Book for that flight. Those Apogee books are great source material if you have the dedication to read them all end to end. |
Blackarrow
Member Posts: 3484
From: Belfast, United Kingdom
Registered: Feb 2002
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posted 03-09-2005 04:32 PM
Doug, it's perfectly true that the Apollo 15 Saturn V was modified to allow a greater payload (lunar rover,etc). This is confirmed at page 70 of the Apogee "Apollo 15" volume, under the heading "Significant Vehicle Changes." This is in the Apollo 15 Press Kit reprint. It confirms that the Earth parking orbit is reduced from 100 nautical miles (Apollo 14 and earlier) to 90 n.m.But, and this is the main point, Apollo 15 entered a 92.5 x 91.5 orbit. Orbital period was 87.87 minutes. On Apollo 17, the parking orbit was fractionally lower (92.5 x 91.2 nm) meaning that the orbital period was about three seconds faster (87.82 minutes). The orbital periods are confirmed in "Spaceflight" magazine's "Satellite Digest" (Jan. 1972 and June 1973 issues). |
Gkitman
New Member Posts: 9
From: Houston, TX
Registered: May 2002
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posted 03-25-2005 10:29 AM
I think Apollo did not have the lowest orbit and highest orbital velocity. But, we'd have to verify the precise time Gemini 3 did the OAMS burn that lowered its orbit to a 72 km perigee. This was a failsafe maneuver in case the retrorockets failed to fire after service module jettison. But depending upon the timing of the burn and the speed from that burn to retrofire and landing, the final orbit of Gemini 3 was probably the lowest and fastest to date. |
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