September 2008 Archives

14 Sep 2008 LOIRP Status

Keith Cowing: Here is the document that shows that there is a SECOND demodulator system and even outlines how the data is written to the tape drives.

The Lunar Orbiter Telecommunications System, NASA LaRC, 1965

6 Sep 2008 LOIRP Status

The first image you see here is the explanation from the original documentation showing what a single line of lunar orbiter video looks like.  The second, is the machine fully locked up and reproducing the correct structure.  The image is inverted as it gets flipped with a jumper select on the board that we just have another board that has the jumper but we weren't using it.

If you look at the oscilloscope, you can see the fiducial marks in their proper position before and after the sync pulse.  If you look at the lower right part of the screen, you will see the notation (200us).  That is the amount of time per division.  If you count the divisions to the next sync pulse, you will see that it exactly matches the number for a single scan line below.  The voltage scale is correct as well except that the drawing below is wrong.  The signal is 1 volt, not five volts.  We have confirmation that 1 volt is the correct number from the audio tapes where the engineers recorded the voltage levels on the tape.  It is these kinds of discrepancies that we have had to research and overcome.  We have reached that magic milestone.  We now have to put those lines together into an image and we are working that now.  However, the two critical questions that were in everyones mind when we started this have been answered.  Are the tapes good?  Yes.  Can the drive be brought back to operational status? Yes.  

We are at a crossroads here and I will put together a formal report and seek input on where to go from here.  As a result of our work we have found a few things that were not in the documentation that effects which way we go forward from here.  Our original plan for digitizing the images is no longer tenable and we are doing a near term work around for the image milestone.

Keith Cowing: The Image we think we have - detective story

Keith Cowing: This is part of the detective work I used to help narrow down what image we may have found.

1. If you listen to this audio [ http://images.spaceref.com/news/2008/loirptest5.mp3] from a data tape you will hear the technician state that it is an analog copy of an earlier tape - but that it is only a copy of the portion with the Earth and moon on it and that it was originally recorded on GMT date 237.

2. In 1966 day 237 was 25 August. Lunar Orbiter 1 was launched on 10 August 1966 and imaged the moon from 18-29 August 1966.

3. This image of a page from a Lunar Orbiter planning document [ page 70 of Lunar Orbiter I - Photography NASA-CR-847 http://hdl.handle.net/2060/19670023005] clearly shows an image of the Earth from the moon being planed for Lunar Orbiter 1 on day 237.

http://images.spaceref.com/news/2008/day237.earth.moon.jpg

4. Apparently this was attempted more than once. Recall that Lunar Orbiter 1 was the first mission and they had a lot of bugs to work out with the imaging system.

5. According to http://nssdc.gsfc.nasa.gov/imgcat/html/object_page/lo1_h102_123.html Lunar Orbiter 1 took the first two remote images of earth from the distance of the Moon, August 23rd 1966."

6. This is the series of three images stitched togetehr showing Earthrise above the lunar surface taken on 23 August 1966

http://images.spaceref.com/news/2008/lo1_h102_123.gif

Location & Time Information
Date/Time (UT): 1966-08-23 T 16:36:23
Distance/Range (km): 1476
Central Latitude/Longitude (deg): -14.68/104.34
Orbit(s): N/A

Imaging Information
Area or Feature Type: crater, global view
Instrument:  High-resolution Camera
Instrument Resolution (pixels): N/A
Instrument Field of View (deg): 20.4 x 5.16 
Filter: Clear
Illumination Incidence Angle (deg): 21.30
Phase Angle (deg): 95.07
Instrument Look Direction: N/A
Surface Emission Angle (deg): 80.94

Ordering Information
CD-ROM Volume: N/A
NASA Image ID number: L01-102; H1, H2, H3
Other Image ID number: N/A
NSSDC Data Set ID (Photo): 66-073Z-01D
NSSDC Data Set ID (CD): N/A
Other ID: N/A

7. Apparently there was some controversy about doing things like this with the spacecraft:

"Despite the malfunctions in the photographic subsystem the spacecraft succeeded in taking many historic pictures. Command and maneuver requirements were developed to take, [241] in near real-time, such pictures as those of the morning and evening terminator on the lunar surface, the Earth as seen from the Moon's vicinity, numerous farside pictures, and additional photographs of sites of interest on the near side. Lunar Orbiter I photographed such areas as potential targets for Mission B, major craters, and mare and upland areas useful as Apollo navigation landmarks and was mostly able to satisfy the requirements to take these photographs.

Of all the pictures which Lunar Orbiter I made, one of the most spectacular was the first photograph of the Earth taken from the vicinity of the Moon. This picture was not included in the original mission plan, and it required that the spacecraft's attitude in relation to the lunar surface be changed so that the camera's lenses were pointing away from the Moon. Such maneuvering meant a calculated risk and, coming early in the flight, the unplanned photograph of Earth raised some doubts among Boeing management about the safety of the spacecraft.

Robert J. Helberg, Boeing's Program Manager for Lunar Orbiter, opposed such a hazardous unnecessary risk. The spacecraft would be pointed away from the Moon so that [242] the camera's lenses could catch a quick view of Earth tangential to the lunar surface. Then, once the pictures were made (flight controllers would execute two photo sequences on two different orbits), Lunar Orbiter I would disappear behind the Moon where it would not be in communication with ground control. If, for some reason ground control failed to reestablish communications with it, the Apollo-oriented mission photography would probably remain undone, Moreover, Boeing had an incentive riding on the performance of the spacecraft, and Heiberg did not think it prudent to commit the spacecraft to a series of maneuvers for which no plans had been made.30

The understandably conservative Boeing stance was changed through a series of meetings between top NASA program officials, including Dr. Floyd L. Thompson, Clifford H. Nelson, and Lee R. Scherer. They convinced Heiberg that the picture was worth the risk and that NASA would make compensation in the event of an unexpected mishap with the spacecraft. After agreement had been reached, Lunar Orbiter flight controllers executed the necessary maneuvers to point the spacecraft's camera away from the lunar surface, and on two different orbits (16 and 26) it recorded two unprecedented, very useful photographs.

[243] The Earth-Moon pictures proved valuable for their oblique perspective of the lunar surface. Until these two photographs, all pictures had been taken along axes perpendicular or nearly perpendicular to the Moon's surface. On subsequent Lunar Orbiter missions oblique photography was planned and used more often.31"

8. We know that we have an image on this particular tape.

3 September 2008 LOIRP Status

Dennis Wingo: Progress has been good since the last report. We have obtained audio from tapes from all of the ground stations, from Woomera, Goldstone, Madrid, as well as from NASA Langely where some of the tapes were re-recorded, which brings up and issue to discuss in a minute. What we have proven in playing audio and video data from these random tapes is that we can conclusively state that one of the two questions that were paramount at the beginning of the project (are the tapes any good), can be conclusively answered affirmative. Audio clips will be put on the net with a link. I think that they will fit in this email without overcoming anyone's mail box. You already have the Woomera tape.

-- This audio excerpt is from a tape being recorded at Goldstone wherein the tech talks about "seeing some sky" i.e. deep space above the moon's horizon http://images.spaceref.com/news/2008/goldstone-g3-58lo3.mp3

-- This audio excerpt from a data tape has features a technican with a spanish accent recording identifiying information on a tape being downlinked in Madrid. http://images.spaceref.com/news/2008/loirptest08madrid.mp3

We continue to find small problems with the drive. Most of them now is because the pins on the back of one of the connectors has many broken coax wires and it is taking a while to track down but we almost have a fully locked up video signal that we have recorded on a new test tape that Ken brought in. We are still looking for information and this past week we received many aperture cards, some of them with procedures on them that we are applying to align the electronics and mechanics of the drive.

Also, since we know that we are going to have the money soon for the head refurbishment, I have delayed some expenditures to expedite the head refurbishment. We have sent a large check and two heads (they have three heads now) to VMI to get them started with the refurbishment process and they are getting started.

We expect to receive by the end of the week, refurbished pinch rollers that are critical to the tape moving at the proper speed through the tape transport system. This week we sent a sample of the belts for the motors to a company in New Jersey and they are going to be able to make brand new belts for the reel motors and the capstan drive motors. It will take them about 6 weeks to provide us with new belts but the cost is fairly modest, about $1k for all the belts that we need, made from scratch, along with plenty of spare belts. That is the good news. However, not all news in this area is good.

A couple of weeks ago we sent the capstan motors and the reel motors from the two parts donor drives to get the bearings replaced. We have received their estimate of the costs. It is going to cost about $30k to get the primary and secondary drive motors completely refurbished. Ouch. This is not completely unexpected as the bearings are not the typical ones you buy at Auto Zone for a V-8 engine. They are bearing with the highest quality classifications in the books. They require being dunked in liquid nitrogen to remove or install, a rubber mallet just won't do. So, we are holding off in this area for now though we will pay the $3k needed just to order the bearings that we need so that if we go forward to full production, we won't loose any schedule there.

We are growing very concerned now on the schedule for the demodulator and are monitoring the progress there. We are also looking at our alternative for software demodulation or other hardware solutions. We are still investigating whether or not the demodulator on the drive is one that we can use. Still not sure and are still investigating. It will take us fixing a couple of final problems with the electronics before we know for sure.

One thing that we found this past week is a tape from Langley that is of the famous shot of the Earth from the Moon. This tape looks like it may have been demodulated prior to writing back out to the tape. We are writing the software now in Labview to record this data and put it back together and see if it is that image. If it is, and if the tape is demodulated already, we will know for sure whether or not the tape drive is fully functional for an entire hour of playback, which is different than a few minutes of audio. If we can do this, then we will have met our next major milestone of proving that the drive can be refurbished to the point of reliably playing a tape back.

The demodulator is external to the drive (assuming for a second that the on board demodulator is not the right one) and so we will be able to show that the drive is fully operational. The system, which is the tapes, the drive, the demodulator, the software, and the computer is in progress and we will at least put to bed the continuing issue of exactly what the bandwidth of the original signal from the spacecraft was.

We are also trying to contact Lee Scherer, who was the Lunar Orbiter program manager for NASA and the former center director of Dryden and KSC. We are trying to track down some Boeing people who were working on the ground support equipment at that time to ask some questions.

Audio and pictures attached.

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