Lunar Lost & Found

[Rykster]

Lunar Lost & Found: The Search for Old Spacecraft

By Leonard David

Senior Space Writer

posted: 27 March 2006

12:08 am ET

One look at Earth's Moon is all it takes. It has been mussed up by scads of incoming celestial objects that produced lots of craters.

But our Moon has also been on the receiving end of artificial impacts over the last few decades. Moon probes and leftover rocket stages have contributed to the crater population—albeit too small to see from our planet. Robotic lunar landers from the United States and the former Soviet Union dot the Moon too.

Add in hardware castaways from human adventurers who made their way to the Moon from 1969 through 1972 as part of NASA's Apollo program, and you've got a lot of junk on the Moon.

Pinpointing old spacecraft and artificial impact craters is not only a curatorial courtesy, but also can generate important science.

That's the report from Philip Stooke, an associate professor within the department of geography at the University of Western Ontario in London, Ontario, Canada. Stooke described his lunar detective story in a paper released at the 37th Lunar and Planetary Science Conference (LPSC), held March 13-17 in Houston.

Precise locales

Starting in the 1960s, the "space race" between the Soviet Union and the United States was on full-speed. And the Moon was a place to demonstrate one-upmanship.

NASA's Ranger, Surveyor and Lunar Orbiter spacecraft set the stage for the piloted Apollo landers. For the Soviet Union, it was the robotic Luna-series that plowed into the desolate landscape, as well as soft-landed, roved around, and even shot samples back to Earth across cis-lunar space.

NASA's Lunar Reconnaissance Orbiter (LRO), to be sent moonward in 2008, will be able to spot some of this Space Age flotsam. LRO's camera system has enough resolving power for the task.

But there is uncertainty in targeting LRO's imaging hardware to scout out the precise locales of all that gear that has plopped down on the aged Moon.

Tighter coordinates

"I've devoted almost all my time in the last five years to my Atlas of Lunar Exploration, which is in the final stages now," Stooke told SPACE.com. Part of his research is focused on tracking down the whereabouts of decades-old mooncraft and identifying craters caused by human-made objects. One might think the locations would be well-charted.

But spacecraft were "lost" because they were never found initially, Stooke said. There are those craft that came to rest on the lunar surface, with their positions known to within about 6 or 12 miles (10 or 20 kilometers), figured out by tracking a spacecraft's signals during descent.

However, if future astronauts want to do a pinpoint landing near a piece of equipment, or wheel over to examine an old lander, they'll need much tighter coordinates.

In some instances, the imagery taken by landed spacecraft from the surface is a big help.

"That is also important for establishing the geological context of surface observations. So whenever something lands...people try to locate it precisely," Stooke pointed out. "The well established method for doing this is by comparing horizon relief features—hills or crater rims—on panoramas with the same features on orbital images. If you can match them you can locate the lander precisely."

Surveying for Surveyor

This method was basically invented, Stooke explained, by Ewen Whitaker of the Lunar and Planetary Laboratory at the University of Arizona in Tucson. He used it with Surveyor 1 and subsequent Surveyor craft that set down on the Moon between 1966 and 1968.

"But it does depend on being able to match features," Stooke added. "In very flat areas there may be nothing to match." Surveyor 5 is such a case.

"If you have only low resolution orbital images you may not be able to make a match either—that applies partly to Surveyor 5 as well, but especially to all the Soviet landers," Stooke said. "No Soviet spacecraft has ever been located precisely in this way because they didn't land in areas of good orbital photography."

Even with photos taken from the Moon's surface, questions can remain. For example, is the Soviet Luna 9 landing area on the Moon back in 1966 in mare or highland terrain? "The argument has continued since it landed," Stooke said.

Part of the interest is purely historical.

"It would be nice to know where Luna 9 is, the first successful lander," Stooke said. "We may want to set up a register of historic sites, not to be disturbed by future missions or hardware impacts. To do that we need accurate locations."

Search for Lunokhod

One nifty exercise that's now being considered is attempting to bounce a laser beam off a lost-on-the-Moon Soviet rover: Lunokhod 1. That eight-wheel robotic lunar buggy is outfitted with laser "retroreflectors" and rolled about within the Moon's Sea of Rains for nearly a year after landing in November 1970.

Lunokhod 1 may still have value as a laser ranging target. That's if it can be located precisely.

The Soviet machinery is sitting silent at the most northerly of all landings on the Moon to date, "and would be a vital part of understanding the Moon's exact rotation for geophysical purposes," Stooke said.

However, the robot's position is uncertain by at least 3 miles (5 kilometers), and stabs at getting laser returns all failed since early in the Lunokhod 1's mission.

"We don't know if it is still clean or oriented suitably...if not there's no hope. But if it is, we still need a good position," Stooke said.

Tantalizing target

"The recovery of Lunokhod 1 is on my wish list," said Jim Williams of the Jet Propulsion Laboratory (JPL) in Pasadena, California. He and fellow investigators are part of a Lunar Laser Ranging (LLR) data analysis group at JPL.

Williams told SPACE.com that there are four laser retroreflector arrays on the Moon that get ranged: the Apollo 11, 14, and 15 sites plus the other Russian moonbuggy, Lunokhod 2. "As a result of the ranging, we know those positions to better than one-meter accuracy" or roughly three feet, he said.

The arrays of 14 prisms on Lunokhods 1 and 2 were built by the French. The Lunokhod 2 retroreflector has been ranged, so the design works, Williams noted. The Lunokhod would rove during daylight, but was parked at night so that the array was oriented properly for Earth-to-Moon laser ranging.

Lunokhod 1 is a tantalizing target, Williams said.

"A few laser observations were reported early in the mobile Lunokhod 1's journey and later after it stopped moving, but those observations have never been publicly distributed or processed with a data analysis program of modern accuracy," Williams explained. "It is unclear whether the effectiveness of the Lunokhod 1 array has been compromised or whether position uncertainty and weak signal conspired to prevent its acquisition by standard ranging stations...but a modern search is in order."

Apache Point Observatory

The sole U.S. LLR station in the early 1970s tried to range Lunokhod 1, Williams said, but did not find it.

"The task is more difficult than it sounds," Williams said. "The return signal should be very weak and only a limited spread of distance and angle could be searched...for a sequence of shots. The position may have been too poor or the Lunokhod 1 retroreflector may be obscured somehow."

There is a new LLR station now undergoing checkout at Apache Point Observatory in New Mexico.

"Once the new station is operational and returning data, then a Lunokhod 1 search will be practical," Williams said. This new equipment at the facility will be a good instrument for the search, he added, but will still require a major effort.

Location uncertainties

Meanwhile, Stooke is on the lunar lookout trail.

Early Apollo Moon landing craft and the moonwalkers themselves scuffed up areas of the lunar surface. These disturbances are visible in orbital imagery taken by later Apollo missions.

A number of discarded Apollo rocket stages and lunar module ascent stages were tracked to narrow the search area. So those which fell in areas subsequently imaged were identified fairly easily, Stooke reported in his LPSC paper.

Ranger 6's impact area may now have been found in Clementine images taken by that U.S. Defense Department Moon-orbiting spacecraft in 1994, Stooke stated. On the other hand, many impact craters made by orbiters at the end of their missions—or by failed landers—will be difficult to find because of location uncertainties.

NASA Lunar Orbiter impact sites, for example, are uncertain by hundreds of kilometers and would be very difficult to distinguish from natural fresh impacts.

On the other hand, craters formed by camera-carrying Ranger probes were found easily because images taken during their plunge toward the lunar terrain allowed impact sites to be predicted. Two of the three successful kamikaze-like Ranger missions imaged their impact points for comparison with later images.

Hiten, a Japanese lunar orbiter, should be located easily using Earth-based tracking data and observation of the impact, Stooke said.

Protection of sites

In his lunar work, Stooke noted that several challenges remain.

Can the site of Russia's Luna 2 impact be located? If it is, will visual observers be vindicated after years of doubt? Can Luna 9 or Surveyor 5 be located at last? Can the craters caused by the hits of spent rocket stages from the Apollo 15, 16 and 17 missions be found?

"The scientific value of this work includes placing lander data in better context, refining seismic results from Apollo [rocket stage] impacts, or planning future visits to old sites for study of old hardware, as Apollo 12 did for Surveyor 3," Stooke says. "If in the future it is decided to confer special designations or protection on these sites, finding them is essential."

View: Full Article | Source: Space.com

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Perhaps we will be able to image an Apollo era vehicle and put the conspiracy baloney forever to rest. Naw, the HBs will just say we faked the pictures!

Edited March 27, 2006 by Rykster

[Bella-Angelique]

Does seem very important to study if planning to build a base there to see long term effects.

Nice article.

Edited March 27, 2006 by Bella-Angelique

[zandore]

Good find Rykster.

Perhaps now we can start putting questions to rest. *Did we go to the moon or not*

[Rykster]

Thanks folks!

I knew this was a good one the minute I saw it. I thought of several UMers I wanted to PM with it!

[Rykster]

An interesting addendum to this topic...

NASA Considers Stowaway Finalists for LRO Launch

By Brian Berger
Space News Staff Writer

With extra room available on the rocket that will launch the Lunar Reconnaissance Orbiter in late 2008, NASA is evaluating four proposals for low-cost spacecraft small enough to be stowaways on the mission.

NASA plans to launch the Lunar Reconnaissance Orbiter on either an Atlas 5 or Delta 4 rocket in October 2008. Mark Borkowski, director of NASA's Robotic Lunar Exploration Program, said either rocket should have room for another 1,000 kilograms worth of secondary payloads.

Not wanting to waste what essentially amounts to a free ride to the Moon for one lucky spacecraft, NASA asked its 10 regional field centers in late January to submit proposals for low-cost hitchhiker missions beneficial to the U.S. space agency's lunar exploration goals.

"There are a lot of pieces of information we'd like to have about the Moon and if we can get any of that information sooner and at a lower cost, that would be an advantage," Borkowski said.

NASA received 19 "pretty freakin' exciting" proposals within a matter of weeks, according to Borkowski, and by late February had selected four finalists for a closer look. The finalists were due to present additional information to NASA the week of March 20. Borkowski said NASA intends to make its selection by early April and give the chosen team authority to proceed.

If that seems like a rather fast turnaround for soliciting and selecting a space mission, Borkowski said that is the point.

"We want to see if the quick-response, low-cost way of doing business will work for the exploration initiative," he said.

While the Lunar Reconnaissance Orbiter's launch vehicle will have room for multiple secondary payloads, Borkowski said only one of the four finalists - if that - can expect to make the cut.

"It's ambitious to free up budget for one," he said. "Freeing up budget for two might be a bridge to far."

Borkowski said the field center-led teams were given a budget target of $50 million and an "absolute upper limit" of $80 million for doing their proposed mission. NASA would fund the mission out of the Robotic Lunar Exploration Program budget, which would grow to $272 million in 2007 under the agency's spending request now before Congress.

Neither Borkowski nor the field centers would say much

A Feb. 23 e-mail that NASA's associate administrator for exploration, Scott "Doc" Horowitz, sent to NASA field center directors identified the four finalists as: the Lunar Crater Observation and Sensing Satellite; the Lunar Explorer for Elements and Hazards; Lunar Explorer; and Lunar Impactor.

NASA's Moffett Field, Calif.-based Ames Research Center proposed the first two missions on the list. The last two missions were proposed by Goddard Space Flight Center and the Jet Propulsion Laboratory respectively.

Borkowski said three of the four candidate missions would be focused in whole or in part on "the water question." If water ice is present in the permanently shadowed craters at the lunar poles as NASA suspects, it would be a valuable resource for extended stays, making it possible to produce potable water, breathable air and rocket propellant on the Moon.

Hunting for water ice is one of the main objectives of the Moon-mapping Lunar Reconnaissance Orbiter.

While details about the proposed missions are being closely held, Borkowski did say that all four of the finalists would make use of a secondary payload adapter ring that the U.S. Air Force developed for the Atlas 5 and Delta 4.

The EELV Secondary Payload Adapter, or ESPA, has accommodations for up to six small satellites. The structure was developed by the U.S. Air Force Laboratory but has yet to fly.

But that is expected to change later this year. The Atlas 5 rocket slated to launch the U.S. Defense Advanced Research Project Agency's Orbital Express spacecraft from Cape Canaveral, Fla., also will be carrying an ESPA ring laden with five small experimental satellites.

Borkowski said one of the four finalists is proposing to turn the ESPA ring into a satellite by outfitting the structure with the necessary subsystems. That idea, while untested, is not new. The U.S. Air Force Research Laboratory has a project called the Deployable Structures Experiment in development that would use the ESPA ring as the hub of an Earth-orbit satellite equipped with multiple instruments.

At least some of the proposed missions NASA is considering would leave room for the ESPA ring to carry additional secondary payloads.

"There are several options, some of which might leave room and mass available for others, and some which do not" Borkowski said. "After we make our decisions, we would then consider other opportunities on a case-by-case basis. Until then, we don't know enough to offer potentially open 'slots' to other users."

View: Article | Source: Space.com