|
Author
|
Topic: Closest to the Moon with stepping on it?
|
Blackarrow
Member Posts: 3120
From: Belfast, United Kingdom
Registered: Feb 2002
|
posted 08-20-2009 04:51 PM
  
Who has come closest to the Moon without actually stepping onto its surface?You might think the answer is obvious, but think again. I'm not 100% sure of the answer but I can make a strong case for this individual. Any suggestions? |
Rick Mulheirn
Member Posts: 4167
From: England
Registered: Feb 2001
|
posted 08-20-2009 04:55 PM
Tom Stafford and Gene Cernan being the obvious answer... but clearly Blackarrow knows something contrary. Do tell. |
AstroAutos
Member Posts: 803
From: Co. Monaghan, Republic of Ireland
Registered: Mar 2009
|
posted 08-20-2009 05:03 PM
Well, if it isn't either Cernan or Stafford, I'll make a wild guess and go for Al Worden...Please tell us...  |
Rick Mulheirn
Member Posts: 4167
From: England
Registered: Feb 2001
|
posted 08-20-2009 05:22 PM
I was going to say Wallace and Gromit... but they landed! |
FFrench
Member Posts: 3161
From: San Diego
Registered: Feb 2002
|
posted 08-20-2009 05:33 PM
Gene Shoemaker... |
Blackarrow
Member Posts: 3120
From: Belfast, United Kingdom
Registered: Feb 2002
|
posted 08-20-2009 05:42 PM
Gene Cernan? I seem to remember he DID walk on the Moon.Francis, if human DNA counted, I suspect it would be some nameless Russian who worked on Lunik 2 or Luna 9. Or the nameless American who sneezed on the Surveyor 3 camera. |
FFrench
Member Posts: 3161
From: San Diego
Registered: Feb 2002
|
posted 08-20-2009 06:50 PM
Out of respect to the late, great Gene Shoemaker, I wouldn't personally equate his ashes to a sneeze - but each to their own... |
Delta7
Member Posts: 1505
From: Bluffton IN USA
Registered: Oct 2007
|
posted 08-20-2009 08:17 PM
Stuart Roosa. |
Blackarrow
Member Posts: 3120
From: Belfast, United Kingdom
Registered: Feb 2002
|
posted 08-20-2009 08:56 PM
At about 95 hours GET on Apollo 15, the spacecraft reached a low point of 13.9 Km (about 45,000 feet in English) above the landing-site. But it had to cross the Apennine mountains which rose to around 15,000 feet in places. Scott and Irwin would later set foot on the Moon, but on 30th July Al Worden was probably little more than 30,000 feet (9.2 km) above the mountain tops. That's about the height of a short-haul commercial airliner above the Earth. I can't be certain, but I doubt whether Stuart Roosa, Ken Mattingly or Ron Evans came that close. Worden might have got even closer: at one point Houston was predicting that mascons would lower the orbit to around 33,000 feet "plus or minus 9,000 feet" which raised the prospect of Apollo 15 clearing the mountain-tops by only 9,000 feet. I have heard Al Worden say that would have been "close enough to count rocks." Not surprisingly, Houston ordered an engine burn to correct the downward drift. |
328KF
Member Posts: 1234
From:
Registered: Apr 2008
|
posted 08-20-2009 09:44 PM
I'm going to give it to Cernan and Schmitt.According to the mission reports from each flight, the LM landing gear struts "stroked": - Apollo 11 - less than 1 inch
- Apollo 12 - all less than 2.5 inches
- Apollo 14 - did not stroke significantly
- Apollo 15 - forward strut stroked 3 inches
- Apollo 16 - 0 inches (not bad for a Navy pilot)
- Apollo 17 - some stroking on the aft strut, but it also rested in a 3-4 meter diameter crater.
So given that the Challenger rested at an angle back into that crater, I would assume that the base of the LM was closer to contacting the ground than any other LM. So Cernan and Schmitt came closest to the moon without walking on it... even though they did walk on it later in the day.Now where is that "You might be a space geek if..." thread? |
ilbasso
Member Posts: 1522
From: Greensboro, NC USA
Registered: Feb 2006
|
posted 08-20-2009 10:36 PM
Ah, but wasn't there a rock that came close to contacting the descent engine bell on Apollo 15? |
328KF
Member Posts: 1234
From:
Registered: Apr 2008
|
posted 08-20-2009 10:55 PM
Well, both Falcon and Challenger came to rest partially within craters. Apollo 15's engine bell was buckled due to a suspected buildup of pressure, due to a newly extended bell's interaction with the surface, not any direct contact. This was anticipated pre-flight.Now if we take descent rates into consideration... I think 15 gets it there (6.8 ft/sec). Anyway, without direct measurements by the crews, it's impossible to tell. The information in the mission reports is not presented in a consistent manner. I was just trying to look at the question from a different angle. |
LCDR Scott Schneeweis
New Member Posts:
From:
Registered:
|
posted 08-20-2009 11:59 PM
Its apparent from this image that Falcon's LMDE nozzle deformation was the result of compression/direct contact with the lunar surface (click on picture for higher resolution image). ------------------
Scott Schneeweis
http://www.SPACEAHOLIC.com/ |
328KF
Member Posts: 1234
From:
Registered: Apr 2008
|
posted 08-21-2009 09:31 AM
Nice shot, but without that extra 10 inch extension to the bell (the gray area?) the apparent contact would not have happened. Either way, it doesn't put the ascent stage and the crew any closer to the surface...only the combination of strut compression and terrain slope (or cratering) would affect that. |
Blackarrow
Member Posts: 3120
From: Belfast, United Kingdom
Registered: Feb 2002
|
posted 08-21-2009 11:49 AM
We seem to have diverted into some weird parallel universe. The 12 Moonwalkers don't count (obviously) as they DID walk on the Moon. The question related to the CMP who came closest. |
328KF
Member Posts: 1234
From:
Registered: Apr 2008
|
posted 08-21-2009 01:48 PM
My fault entirely...you're original question did not specify CMP's. With tongue firmly in my cheek, I took an alternate approach to the issue, and tried to figure out who got closest prior to becoming a moonwalker (i.e. "without actually stepping on its surface")But I like FFrench's answer too... |
AstroAutos
Member Posts: 803
From: Co. Monaghan, Republic of Ireland
Registered: Mar 2009
|
posted 08-22-2009 11:31 AM
quote:
Originally posted by AstroAutos:
Well, if it isn't either Cernan or Stafford, I'll make a wild guess and go for Al Worden...
The real question is... what do I get for being right?  |
Blackarrow
Member Posts: 3120
From: Belfast, United Kingdom
Registered: Feb 2002
|
posted 08-22-2009 02:06 PM
The respect of your fellow cSers. Worth its weight in gold. |
AstroAutos
Member Posts: 803
From: Co. Monaghan, Republic of Ireland
Registered: Mar 2009
|
posted 08-22-2009 03:15 PM
That'll do me just fine... |
spaceheaded
Member Posts: 147
From: MD
Registered: Feb 2003
|
posted 08-27-2009 07:45 PM
Looking at the original question a different way, I'd say closest without walking would be Jim Lovell and Fred Haise. Oh, so close. |
moorouge
Member Posts: 2454
From: U.K.
Registered: Jul 2009
|
posted 10-09-2009 01:27 PM
Having given some thought to the matter and knowing Black Arrow's profession, one has to read the question very carefully and then interpret what is meant by 'stepping'. It can be argued that 'stepping' equates with 'standing'.Therefore, the closest astronaut to the Moon without 'standing' on it has to be Charlie Duke when he fell over!! As to limiting it to CMP's - "The 12 Moonwalkers don't count (obviously) as they DID walk on the Moon" - this is changing the parameters of the original query which specifies 'stepping'. Further, it doesn't quantify the length of time that anyone doen't have to either step or stand. So, I stand (pun intended) by my answer - Charlie Duke. |
mjanovec
Member Posts: 3811
From: Midwest, USA
Registered: Jul 2005
|
posted 10-09-2009 01:29 PM
Anybody who has handled a lunar rock in their hands, but hasn't stepped on it.  |
Blackarrow
Member Posts: 3120
From: Belfast, United Kingdom
Registered: Feb 2002
|
posted 10-10-2009 09:20 AM
Dear me! I wish I had never asked the question. It wasn't a trick question. It would have been reasonable (but wrong) to suggest Fred Haise, Jack Swigert or Tom Stafford. Nine others orbited without landing. One out of those twelve came closest to the surface of the Moon, and it had to be a CMP on one of the missions with a planned 9 mile low-point (Apollos 14, 15, 16 and 17). As per my Aug. 20th post, it was almost certainly Al Worden, who got as close to the mountain-tops as a passenger in a commercial jet at cruising altitude. QED |
garymilgrom
Member Posts: 1966
From: Atlanta, GA
Registered: Feb 2007
|
posted 10-10-2009 10:11 AM
Apollo 10 paved the way and the CMPs on the landing missions are a group unto themselves. Certainly Apollo 13 is another unique crew. But Blackarrow's finding of Al Worden seem correct. What a great thread for a rainy day in Atlanta! Thanks Blackarrow. |
moorouge
Member Posts: 2454
From: U.K.
Registered: Jul 2009
|
posted 10-13-2009 04:01 PM
May I throw a large stone to muddy the waters of this discussion.
First - how do you define altitude above the Moon's surface. In the mission reports NASA gives three different versions.
1. Altitude is the perpendicular distance from the reference body surface to the point of orbit intersect. (Apollo 10)
2. Altitude, when the reference body is the Moon, it is the distance measured from the radius of the landing site to the spacecraft along a vector from the centre of the Moon to the spacecraft. (Apollo 14)
3. When the reference body is the Moon, it is the distance measured from the spacecraft along the local vertical to the surface of a sphere having a radius equal to the distance from the centre of the Moon to the landing site. (Apollo 15)With this in mind the actuaql numbers for the missions are -
Apollo 10 (the most comprehensive data) - LM inserted into a 46.5 x 11.0 mile orbit. Pericynthion is given as 8.5 miles (44880ft) on p6-11 of the report. However, on p6-20 the report states altitude over landing site 2 was 56783ft; lowest approach was 47400ft; and the lowest point above the mean radius was 40411ft (7.6 miles)at 100hr 43min into the flight.
Apollo 14 - altitude at CSM/LM separation was 7.8 miles (41184ft). In table 6-V-3 it calls this 'Forcythian' (?). Pericythian at this point is given as 9.1 miles (48048ft)
Apollo 15 - the mission summary gives the CSM/LM orbit as 58.5 x 9.6 miles (50688ft). However, it does mention the trim burm which sent the combination lower but the numbers are unreadable. From another source the lowest point is given as 14.5km which translates to 9.01 miles (47574ft)
Apollo 16 - the report is very sparse on detail but it states in table 3-V that the lowest point of CSM/LM orbit was 10.9 miles (57552ft)
Apollo 17 - again, very sparse on detail but the summary on p3-8 says lowest point for the CSM/LM was 14.5 miles (76560ft). This leads me to ask where Black Arrow got his 13.9km (8.6 miles - 45605ft) number from? A source would be helpful. Also, it is a big leap of faith to assume that the CSM passed directly over the highest point of the Appenines. This would seem to make Tom Stafford as the closest with a claim carrying the weight of a Mission Report to support it. |
Blackarrow
Member Posts: 3120
From: Belfast, United Kingdom
Registered: Feb 2002
|
posted 10-13-2009 06:18 PM
Some interesting points, but I stand by my conclusions. First, you ask for a reference. Go to the Apollo 15 Flight Journal and check the PAO announcement (which appears in green type) after GET 95 hours 01m 43s. That is the reference to 13.9 Km altitude.I think it over-complicates the issue to get into detail about the mean radius of the Moon. It's no use telling an astronaut that he's still a mile above the surface allowing for the mean radius of the Moon if he has actually flown into a mountain. We're talking about height above the local surface. You say Snoopy's lowest approach above Landing Site 2 was 47,400 feet. Fair enough, but that's over the Sea of Tranquillity, which is basically flat. That's why it was selected. When Apollo 15 got down to about 13.9 Km (45,000 feet) it was over the Hadley-Apennine site, which necessarily involved flying over the mountains.(Look at pictures of the site: you can't fly over it without flying over the Apennines). I agree that you can't be sure of the height of the mountains at the precise point where the spacecraft flew over, but I'm fairly certain it must have been at least 10,000 feet, and on viewing the video I think they probably fly over (or close to) Mount Hadley. In any event, Al Worden almost certainly passed no higher than 35,000 feet above the mountains, and probably as low as 30,000 feet. There's no way Tom Stafford got that close. But that's the best counter-argument so far! |
moorouge
Member Posts: 2454
From: U.K.
Registered: Jul 2009
|
posted 10-14-2009 01:50 AM
Might it not be said that a PAO announcement is 'hearsay' evidence? Would it be allowed in a law court?Interestingly, the table giving orbits after the various burns is missing from the Apollo 15 report. The numbers I quote are from elsewhere in the report. It will be interesting to see what other cS's have to say. Meanwhile, I have heard that Stafford flew over Mt. Snoopy on the blind side of the Moon, having to sidestep it on the way. |
moorouge
Member Posts: 2454
From: U.K.
Registered: Jul 2009
|
posted 10-15-2009 07:04 AM
Done a little more research into this. First, the RLS (Radius of the landing site) is an important factor as we'll see later. The mean Moon radius is 1080 miles. Second, it is necessary to know the height difference between the landing site and the Apennines. This is given as about 11155ft. The summit of Hadley Delta is quoted as being 11000ft above the valley floor. What follows are heights (converted to feet) for Apollo 15 taken from the flight journal - - 81:33:09 - expecting a 58359ft pericynthion
- 83:17:59 - onboard readout 60698ft pericynthion
- 83:22:20 - revised to 57745ft with a comment that Apennines reach ALMOST a quarter of this or a 43309ft possible altitude.
- 85:14:54 - s/c at 55120ft decaying to 52823ft at wake up call.
- 93:32:50 - s/c at 46261ft. However, at this point it is decided that there could be a 9000ft error in the height due to uncertainty about the exact RLS landing site figure.
- 95:01:43 - PAO announces a 45605ft pericynthion but this is not confirmed in the transcript.
- 96:30:23 - s/c onboard readout gives 62666ft pericynthion confirmed five minutes later by FIDO
- 99:29:40 - final CSM/LM pericynthion given as 57089ft.
So, it could be that Worden was closest but there is sufficient uncertainty not to rule out Stafford in particular, especially if one takes the 40000ft figure of his height above the mean radius into account. |
Blackarrow
Member Posts: 3120
From: Belfast, United Kingdom
Registered: Feb 2002
|
posted 10-15-2009 05:05 PM
I did say at the outset that I couldn't be 100% sure. That's still true. But I still think it was Worden. Stafford didn't fly over high mountains.By the way, if they're reading this, they're probably rolling on the floor in fits of laughter. |
moorouge
Member Posts: 2454
From: U.K.
Registered: Jul 2009
|
posted 10-16-2009 01:33 AM
That is very true. But the research kept me occupied whilst my partner was having an operation.It only remains to discover which astronaut achieved the fastest roll rate! |
advertisement