IPB

Welcome Guest ( Log In | Register )

9 Pages V  < 1 2 3 4 > »   
Reply to this topicStart new topic
UMSF space history photo of the month
Phil Stooke
post Mar 29 2008, 12:24 PM
Post #16


Senior Member
****

Group: Members
Posts: 5760
Joined: 5-April 05
From: Canada
Member No.: 227



Re: the Pioneer 5 image.

That's quite a Clean Room they've got going there. Just finished milking the cows by the look of it.

Phil


--------------------
... because the Solar System ain't gonna map itself.
Go to the top of the page
 
+Quote Post
imipak
post Mar 29 2008, 02:09 PM
Post #17


Member
***

Group: Members
Posts: 643
Joined: 23-December 05
From: Forest of Dean
Member No.: 617



QUOTE (Phil Stooke @ Mar 29 2008, 12:24 PM) *
That's quite a Clean Room they've got going there. Just finished milking the cows by the look of it.


I love the dustbin in the background of the Pioneer 2 image (post #2). In a parallel universe where NASA was British, the engineers are smoking pipes... I suppose the ashtray must be just out of shot.



--------------------
--
Viva software libre!
Go to the top of the page
 
+Quote Post
Guest_PhilCo126_*
post Mar 29 2008, 06:00 PM
Post #18





Guests






Thanks for pointing out the typo, Apollo 12 indeed: NASA SP-184 & SP-284
http://ares.jsc.nasa.gov/HumanExplore/Expl...Part1/Surv3.htm
Go to the top of the page
 
+Quote Post
dvandorn
post Mar 29 2008, 06:23 PM
Post #19


Senior Member
****

Group: Members
Posts: 3243
Joined: 9-February 04
From: Minneapolis, MN, USA
Member No.: 15



QUOTE (Phil Stooke @ Mar 29 2008, 07:20 AM) *
Surveyor descended on its little 'vernier' thrusters, after braking on a big rocket module mounted under the frame. The rocket and tankage were dropped as the verniers came on, and must lie near each landing site. None were seen in Surveyor images, or by the Apollo 12 crew. But if a Google Lunar X Prize rover were to visit a Surveyor site it might have a chance to search for it.

As highly as I regard your work, Phil, this statement is a teeny-tiny bit misleading. Surveyor's main descent engine was a solid rocket motor; it consisted of little more than a basketball-sized sphere, which held the solid fuel, and a nozzle. After burnout, which occurred about a km over the surface and at a speed of about 100 mph, Surveyor free-fell for a few seconds and then the verniers started up, at which point the descent motor was dropped. The combination of the vernier ignition and descent motor jettison gave maximum separation velocity between lander and motor.

I guess I just would never consider the sphere that held the solid fuel "tankage," just as I would never consider the length of a Shuttle SRB a tank. With solid fuel motors, the device that holds the fuel is more often called a casing than a tank... rolleyes.gif

I'd change the statement to "the burned-out descent motor casing and its nozzle were dropped," with this kind of technology.

I also have to correct another possible mis-speak -- Philco says "Surveyor 1 made the first soft landing on the Moon in June 1966." In point of fact, it made the first lunar soft landing in the Surveyor program. The first "soft" landing (in which an instrument package survived and sent back images and data from the surface) was, of course, made by Luna 9 several months prior to Surveyor 1's achievement.

-the other Doug


--------------------
“The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
Go to the top of the page
 
+Quote Post
Guest_PhilCo126_*
post Mar 29 2008, 07:01 PM
Post #20





Guests






Doug, the 58 cm diameter spheroidal probe Luna 9 "landed" on the Moon in February 1966 and this capsule weighted 100 kg.
It sat ontop the 1440 kg main bus and was ejected up & sideways by springs, the main bus impacted onto the lunar surface... is there somewhere an official definiton of "soft" landing?
Next month's photo = Mariner 4 wink.gif
Go to the top of the page
 
+Quote Post
Phil Stooke
post Mar 29 2008, 07:06 PM
Post #21


Senior Member
****

Group: Members
Posts: 5760
Joined: 5-April 05
From: Canada
Member No.: 227



Quite right, Doug. I had only just got out of bed. Don't tell my wife the first thing I did was check UMSF.

Phil


--------------------
... because the Solar System ain't gonna map itself.
Go to the top of the page
 
+Quote Post
dvandorn
post Mar 29 2008, 07:25 PM
Post #22


Senior Member
****

Group: Members
Posts: 3243
Joined: 9-February 04
From: Minneapolis, MN, USA
Member No.: 15



QUOTE (PhilCo126 @ Mar 29 2008, 02:01 PM) *
Doug, the 58 cm diameter spheroidal probe Luna 9 "landed" on the Moon in February 1966 and this capsule weighted 100 kg.
It sat ontop the 1440 kg main bus and was ejected up & sideways by springs, the main bus impacted onto the lunar surface... is there somewhere an official definiton of "soft" landing?
Next month's photo = Mariner 4 wink.gif

Well -- Pathfinder was dropped onto Mars from about 100 meters and bounced up half a km on its first bounce, and they called that a soft landing... rolleyes.gif

There was an attempt to define such things as the Mars airbag systems, the early Luna landers (which also used airbags) and the attempted-but-never-successful balsawood-packed Ranger surface instrument packages as "hard survivable landers," but the concept never took solid hold. Any system that delivers a reasonably complex instrument package to the surface of a planet seems to be considered a soft landing system, these days. (I would argue that penetrators are in a special class of their own, neither soft landers nor padded/bagged/protected survivable landers.)

-the other Doug


--------------------
“The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
Go to the top of the page
 
+Quote Post
djellison
post Mar 29 2008, 08:06 PM
Post #23


Administrator
****

Group: Chairman
Posts: 13815
Joined: 8-February 04
Member No.: 1



QUOTE (dvandorn @ Mar 29 2008, 07:25 PM) *
Well -- Pathfinder was dropped onto Mars from about 100 meters and bounced up half a km on its first bounce, and they called that a soft landing... rolleyes.gif


The bridle was cut 21.5 m above the ground and impacted at a velocity of 16 m/s (14 m/s vertical and 12 m/s horizontal). It bounced about 12 m.

(paraphrased from http://burro.astr.cwru.edu/stu/advanced/20...pathfinder.html )

Doug
Go to the top of the page
 
+Quote Post
dvandorn
post Mar 29 2008, 09:12 PM
Post #24


Senior Member
****

Group: Members
Posts: 3243
Joined: 9-February 04
From: Minneapolis, MN, USA
Member No.: 15



Really? I clearly recall a much higher bounce estimate at the time of the landing, and a somewhat higher release point...

Perhaps they refined their estimates after the first reports that were reported at the time of the landing.

-the other Doug


--------------------
“The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
Go to the top of the page
 
+Quote Post
DDAVIS
post Mar 29 2008, 10:15 PM
Post #25


Member
***

Group: Members
Posts: 191
Joined: 8-February 04
Member No.: 10




Surveyor 7 (January 1968) was a scientific mission and its TV registered 2 lasers aimed at the spacecraft from observatories in California & Arizona.
I have seen a reproduction of that photo, but the 'laser' specks on the night side of Earth appeared to be retouched onto the photo in the version I saw. Is there an original image of this experiment in existance showing their actual brightnesses?

Don
Go to the top of the page
 
+Quote Post
edstrick
post Mar 30 2008, 10:48 AM
Post #26


Senior Member
****

Group: Members
Posts: 1869
Joined: 20-February 05
Member No.: 174



There used to be a distinction between hard and soft landing and it's certainly valid. A "hard lander" is one that does a controlled crash landing and survives. Even at low speed, like the Venera 7 and 8 landing spheres. A "Soft lander" is one that does not need all-sides protection during landing.. it lands on footpads, like Surveyors, Apollo, Viking, Venera 9 through Vega 2, Hayabusa, NEAR, Huygens, and Phoenix. It's more than just a "landing you can walk away from". Not trivial.

Luna 9 was the first successful landing on the moon. It got the real prize for being first. Surveyor 1 was the first soft landing, a technical quibble, but not a trivial one.
Go to the top of the page
 
+Quote Post
tedstryk
post Mar 30 2008, 02:18 PM
Post #27


Interplanetary Dumpster Diver
****

Group: Moderator
Posts: 4243
Joined: 17-February 04
From: Powell, TN
Member No.: 33



QUOTE (edstrick @ Mar 30 2008, 10:48 AM) *
There used to be a distinction between hard and soft landing and it's certainly valid. A "hard lander" is one that does a controlled crash landing and survives. Even at low speed, like the Venera 7 and 8 landing spheres. A "Soft lander" is one that does not need all-sides protection during landing.. it lands on footpads, like Surveyors, Apollo, Viking, Venera 9 through Vega 2, Hayabusa, NEAR, Huygens, and Phoenix. It's more than just a "landing you can walk away from". Not trivial.

Luna 9 was the first successful landing on the moon. It got the real prize for being first. Surveyor 1 was the first soft landing, a technical quibble, but not a trivial one.


I don't think it is fair to make this distinction with Venus landers in the same way one does with the moon. I mean, the PVO day probe wasn't intended to land and lasted an hour. Also, Venera 8 was a much softer landing that Venera 7, which hit much harder than it was supposed to do to technical problems that would have killed a lander anywhere else. Landing on Venus is definitely not easy, but it is probably the easiest place to slow down, ignoring Titan for the moment.

Back to the moon, part of the reason that landers like Luna 9 and 13 are often dubbed "soft" landers is because the term "hard lander" is often (mis?) applied to missions such as the Rangers and Luna 2.


--------------------
Go to the top of the page
 
+Quote Post
Phil Stooke
post Mar 30 2008, 03:28 PM
Post #28


Senior Member
****

Group: Members
Posts: 5760
Joined: 5-April 05
From: Canada
Member No.: 227



I don't think there should be any distinction, because in principle any combination of methods is possible (was MER hard or soft - ouch!) The only thing that counts is if you survive and transmit afterwards.

Phil


--------------------
... because the Solar System ain't gonna map itself.
Go to the top of the page
 
+Quote Post
NGC3314
post Mar 30 2008, 08:51 PM
Post #29


Junior Member
**

Group: Members
Posts: 86
Joined: 9-November 07
Member No.: 3958



QUOTE (Phil Stooke @ Mar 29 2008, 06:20 AM) *
The Surveyor bacterium story is not generaly accepted today. The people who did the work reported that they probably contaminated it. I think one of them wrote in to the Planetary Report about it years ago.

Surveyor descended on its little 'vernier' thrusters, after braking on a big rocket module mounted under the frame. The rocket and tankage were dropped as the verniers came on, and must lie near each landing site. None were seen in Surveyor images, or by the Apollo 12 crew. But if a Google Lunar X Prize rover were to visit a Surveyor site it might have a chance to search for it.

Phil


Thanks for that tidbit! Never knew that about Surveyor. And I thought designs for crewed landers (on both sides of the moon race) using such "crasher stages" were unnecessarily risky... But then now we find out that Luna 9 used air bags, so I should cease being surprised about anything from UMSF history. Anybody else hear about the tests carried out during the Salyut program to work out the best way for recoating telescope mirrors in orbit?
Go to the top of the page
 
+Quote Post
NGC3314
post Mar 30 2008, 08:58 PM
Post #30


Junior Member
**

Group: Members
Posts: 86
Joined: 9-November 07
Member No.: 3958



QUOTE (DDAVIS @ Mar 29 2008, 04:15 PM) *
Surveyor 7 (January 1968) was a scientific mission and its TV registered 2 lasers aimed at the spacecraft from observatories in California & Arizona.
I have seen a reproduction of that photo, but the 'laser' specks on the night side of Earth appeared to be retouched onto the photo in the version I saw. Is there an original image of this experiment in existance showing their actual brightnesses?

Don


The only printed version I can remember seeing was in "Exploring Space with a Camera" (scanned image here. They don't look retouched in my copy, just that the rendering left gaps between scan lines - is this where you saw it?
Go to the top of the page
 
+Quote Post

9 Pages V  < 1 2 3 4 > » 
Reply to this topicStart new topic

 



RSS Lo-Fi Version Time is now: 31st October 2014 - 09:32 PM
RULES AND GUIDELINES
Please read the Forum Rules and Guidelines before posting.

IMAGE COPYRIGHT
Images posted on UnmannedSpaceflight.com may be copyrighted. Do not reproduce without permission. Read here for further information on space images and copyright.

OPINIONS AND MODERATION
Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators.
SUPPORT THE FORUM
Unmannedspaceflight.com is a project of the Planetary Society and is funded by donations from visitors and members. Help keep this forum up and running by contributing here.