The thinking behind the GRAIL twins

A useful view of our heterogeneous Moon. A practical illustration of the thinking behind the GRAIL project. From several thousand kilometers above the southern hemisphere and just below the equator of the lunar Farside it’s easier to see our Moon is “lumpy;” perhaps like the asteroids, it's own mass isn't high enough to crush it into a unified solid. From the standpoint of gravity the Moon retains the the memory of the smaller solid and semi-solid bodies from both before and after it's original formation. So nothing stays in close orbit around the Moon for very long without getting a frequent boost, and such boosts need fuel and fuel eventually runs out. This false color map of the lunar surface shows, in low resolution, differences from average elevation, or datum. Mare Orientale is on the right, and just beyond, so a crescent of the Nearside’s is visible. The expanse of the Farside here is defined, by the ancient South Pole Aitken basin, with the Moon's thinnest crusts, below center left, and by the Moon’s highest elevations and thickest crusts in the Farside highlands spread above the SPA rim (yellow box shows field of view in the next illustration [NASA/GSFC/MSFC/LOLA/LMMP/LP].

The Lunar Reconnaissance Orbiter (LRO) has orbited the Moon over 10,000 times since June 2009, mostly in a low and circular polar orbit. It requires a monthly boost to keep its record-breaking mission going. A common demonstration of the Moon's mass concentration (MASCON) problem is a thought experiment. A future astronaut stands on the rim of the Nearside impact basin Mare Imbrium holding a weight suspended a meter below a gloved hand sees that it doesn't hang straight down. Instead it hangs angling slightly toward the center of the basin hundreds of kilometers away. Anything in orbit is alternately tugged or gains slack changing its speed, causing it to eventually crash. This inconvenience, when carefully recorded and studied, is also a good way of mapping the Moon's interior in 3D.

The elevation map above shows how radically different the Moon’s Farside is from the familiar Nearside. In a photographs the extent of the 4 billion year-old SPA basin and the higher ground and its rim don’t stand out nearly as well. The map is plotted from millions of laser points measured from LRO's orbit to and from the lunar surface by the LOLA instrument, shown here using the ILIADS program available from NASA Marshall Space Flight Center. The yellow rectangle shows the field of view shown in an August 2011 release of LOLA science from the Goddard Space Flight Center.

 

NASA/GSFC, August 15, 2011 - Twenty-five years have passed since seven brave astronauts lost their lives in the Challenger accident. As the Shuttle program comes to an end, we are reminded of those who lost their lives in the pursuit of human exploration. Shortly after the accident, the Challenger astronauts were memorialized by having lunar craters named after them. These seven craters, located on the far side of the Moon in the Apollo Basin, expose deep portions of the lunar crust.

This LOLA image reveals that the depths of McNair and Jarvis craters, in particular, reach nearly 7 km below the lunar datum (the Moon's equivalent of 'sea level'). The depth of McNair and Jarvis is due to their placement within the large Apollo Basin (an existing topographic low) as well as the Apollo Basins location in the even larger South Pole-Aitken Basin. When combined with data from other LRO instruments such as LROC and Diviner, and instruments aboard other spacecraft such as the Moon Mineralogy Mapper (M3) aboard Chandrayaan-1, the complex nature of the Challenger craters is revealed. Data from the M3 instrument reveal that Jarvis crater's composition may represents a deep portion of the lunar crust.

References: 

Steigerwald, B. (2010) "Biggest, Deepest Crater Exposes Hidden, Ancient Moon," June 2, 2011.

Robinson, M. (2011) "Challenger Astronauts Memorialized on the Moon," January 28, 2011, LROC

Petro, N., et al. (2010) "Lower Crustal Materials Exposed in the Apollo Basin Revealed Using Moon Mineralogy Mapper (M3) Data," 41st Lunar and Planetary Science Conference, #1802, March 2010.

LOLA original map: small | large 

Japan’s lunar orbiter Kaguya (SELENE-1, 2007-2009) vastly added to our knowledge about the “hidden Moon” originally gathered through the Apollo era and afterward, stitched together by 2005. Along with the first HDTV from lunar orbit, Kaguya was a platform for a variety of instruments, including laser altimetry, like LRO. The Kaguya LALT system itself built up an elevation map that is only very recently being surpassed by LOLA during the past two years.

Using their links with Kaguya, with its sub-satellite R-SAT, and in a manner very much like the mission plan for GRAIL-A and B, JAXA investigators delicately measured Doppler shift and subtle light-speed changes between each orbiting spacecraft and with the ground to built-up a detailed map of the Moon’s "gravimetric anomalies."

Together with the unprecedented detail of the Moon’s crustal thicknesses, seen in maps like the one below, Kaguya presented scientists with new and very much more detailed faces of the Moon. Kaguya investigators also helped refine the elusive center of the Moon, from within 20 to 2 kilometers, much more.

The relative thickness of the lunar crust as teased out by Japan's Kaguya orbiter and its sub-satellite R-SAT. The Moon's MASCONS and 'negative gravity anomalies' don't necessarily manifest themselves in surface features, like the one associated with Mare Imbrium.[JAXA].

GRAIL-A and B will join LRO and the recommissioned ARTEMIS twins for a grand total five American unmanned lunar missions, all orbiting the Moon at the same time by the end of the year. The skies above the Moon will become nearly as crowded as those of Mars.

The GRAIL twins will pick up the task of mapping our lumpy Moon’s mass, ARTEMIS the intricacies of the Moon’s plasma wake and its interaction with Solar wind as the Moon orbits through Earth’s magneto-tail with LRO continuing to map the lunar surface from more lasting, slightly higher polar orbit.

All this latter-day renewed interest in the Moon began as preparation for an eventual return, inspired by the loss of Columbia in 2003. That original timeline for renewed, extended human activity on the Moon may seem much further away once again, for the moment, but these unmanned “precursor missions” set into motion through the vagaries of reaction to tragedy or short-term public policy shifts are well along in the pipeline, on time and under budget.

LROC Wide Angle Camera (WAC) monochrome (604nm) mosaic of northeastern Apollo basin, from observations in LRO orbits 2068 and 2069, December 8, 2009; field of view roughly 120 km, resolution 78 meters per pixel, incidence 70° The depth of the interior floor of Jarvis and McNair, the larger and smaller of the two co-joined craters, respectively, and the largest feature seen above, are roughly 7,000 meters below lunar mean elevation. [NASA/GSFC/Arizona State University].

The Vision Thing

July 20, 1989, National Air & Space Museum, Washington, DC - Celebration of the 20th Anniversary of Apollo 11 and chosen venue for then-President George H.W. Bush's announcement of a proposed Space Exploration Initiative. (Left to Right, Chair of the National Space Council Vice President Dan Quayle, President Bush, Dr. Neil Armstrong, Buzz Aldrin and Michael Collins, the crew of Apollo 11 [NASA Image 89-H-382].

Wayne Hale
NASA Blogs

George Herbert Walker Bush, the 41st President, calls Houston home. He and Barbara can be frequently seen at Astros baseball games, he made his early career in business here, was a congressman from here, even once taught a course as an adjunct professor at my alma mater, Rice University.

As you may recall, Mr. Bush failed in his re-election bid; there were a number of reasons for his loss, but one of the frequently cited reasons was “the vision thing”. The critics felt that he had not clearly articulated his vision for the future of the nation, which is a vital function that an effective chief executive must do. Keep that in mind.

On July 20, 1989 – the 20th anniversary of the first lunar landing – President G. H. W. Bush had made a speech proposing what would come to be known as the Space Exploration Initiative (SEI). This proposal included a permanent return to the Moon and human missions to Mars. In spite of the bold and visionary words, this initiative quickly failed.

Thor Hogan has written an excellent book on the history of the fiasco. His book is “Mars Wars, The Rise and Fall of the Space Exploration Initiative” NASA SP-2007-4410, August 2007. I highly recommend this book for those who are interested in how national space policy is made and how federal agencies can be dysfunctional at times. Dr. Hogan is a Professor of Political Science at the Illinois Institute of Technology in Chicago. Let me reiterate – I highly recommend this book if you are interested in these topics.

When “Mars Wars” was first published in 2007, it was widely circulated in NASA management and caused considerable discussion. Everyone was trying to make sure to avoid the mistakes made in 1989 and create a successful program. There are many lessons to be learned from that earlier experience, and Dr. Hogan hit many of them.

The most frequently cited lesson from SEI is the need to build a “sustainable” program. That is a shorthand way of saying stay within an affordable budget. One of the principle reasons the Space Exploration Initiative failed was its price tag. The SEI package was dead on arrival at Congress because of the high cost. Trying to apply this lesson, the NASA program of the last five years to send crews to the Moon and Mars strove mightily to remain within the budget line announced in 2004.

The notional Lunar Exploration Vehicle that arose from NASA's sketching out, in broad strokes, a frame work for the 1989 Space Exploration Initiative [Report of the 90-Day Study on Human Exploration of the Moon and Mars, November 1989].

But back to 1989, because there are other lessons to be learned there. That year I was a rookie Space Shuttle Flight Director, learning the ropes in Mission Control, and I had no time to be involved in SEI. But I was immersed in the NASA culture of the day and I remember that time with great clarity. Dr. Hogan’s “Mars Wars” book does a wonderful job of capturing the motivations of agency personnel in those days.

It was a bare three years following the Challenger accident and the wound was still raw. Challenger was a driving factor in the SEI story. Remember that widely held beliefs are important whether they are accurate or not. That is because what people believe to be true motivates them. So take the following paragraph not necessarily as historical truth but as the mythos which psychologically undergird folks running SEI.

NASA was not allowed to build the shuttle the “right” way, that is, to make both engineeringly elegant and safe. Lives were lost in Challenger due to basic design choices forced on the agency by severe budgetary restrictions. In the early 1970s, when NASA was authorized to design and build a revolutionary reusable winged space vehicle, the Office of Management and Budget capped the total development cost of the shuttle at $5 billion. (Money went further back then.) This cap was far too low to allow development of several of the more innovative design options. Fly back liquid fueled boosters were out of the question, for example. Operational costs were higher because of choices required to keep the development costs low. Safety was lower. So we got an aero-space plane with a big dumb drop tank and two scaled up JATO bottles.

Read Wayne Hales post, HERE.

Shuttle's past: Time is not on its side

John Kelly
Florida Today

The two dates seem arbitrary because they are. They may seem unrelated, but they're not.

Sept. 30, 2010, is technically the deadline for finishing the last shuttle mission and retiring the fleet.

Feb. 19, 2004, was the deadline for finishing the construction of the International Space Station. But that was before Columbia.

Under intense pressure to keep space station assembly on schedule and within budget, managers harped on that date to the point of installing screensavers on workers' computers counting down the seconds. The message: hurry up, time is running out on your program.

Then, we lost the Columbia astronauts. Investigators blamed the accident in part on schedule pressure, saying it drove people to make bad tradeoffs favoring on-time flights over safety. They wrote, "Most of the shuttle program's concern about Columbia's foam strike were not about the threat it might pose to the vehicle in orbit, but about the threat it might pose to the schedule."

Fast forward to 2009. NASA's shuttle program is again working against the clock. I think managers, engineers and front-line shuttle workers learned the agonizing lessons of Columbia and will not repeat those mistakes on purpose. But, the influence of schedule pressure can be subtle.

In a business demanding perfection, it's the little unnoticed decisions that can add up to a catastrophe. Subtle pressure is there in the form of the 2010 deadline. NASA needs to complete nine more flights to complete the shuttle's mission, which is to finish building and outfitting a space station that can stay in orbit a decade or so.

That's as many as nine missions in about 19 months, or almost six launches per year. Since the return to flight, NASA has flown about three times a year. Even that has required nearly flawless preparation by crews at Kennedy Space Center and some (recent) good luck with the weather.

Nothing is impossible, but flying shuttles every other month or so is as close as it gets. With three orbiters left, stricter safety rules and slim budgets, flying these last missions is going to be difficult enough without the tick-tock of the clock booming in the background. Making matters worse: an exodus of talented people fleeing for more secure jobs.

Read the Rest HERE.

New center honors New Hampshire's Christa McAuliffe and Admiral Shepard

The McAuliffe-Shepard Discovery Center Friday in Concord, New Hampshire, honoring star-crossed "Teacher in Space" Christa McAuliffe (1948-1986) and Admiral Alan Shepard (1923-1998), the first American in space and fifth man to walk on the Moon as commander of Apollo 14.

With its observatory dome and 92-foot full-scale mockup of the rocket and capsule that carried Shepard into space in 1961, the center dwarfs the original planetarium. Its programs do the same.

Director Jeanne Gerulskis says the expansion transforms the planetarium's operations. New programs build on the planetarium presentations, interactive space and science displays and teacher and student workshops.

McAuliffe's mother, Grace Corrigan, said McAuliffe would be proud to be linked with Shepard, whom she considered a hero.

At the cost of the lives of seventeen extraordinarily brave and courageous astronauts

Alamogordo Daily News
By Michael Shinabery
New Mexico Museum of Space History

The tragedies that killed three Apollo astronauts and two space shuttle crews have anniversaries during less than one week's time: Apollo 1 on Jan. 27, 1967; Challenger on Jan. 28, 1986; and Columbia on Feb. 1, 2003.

Apollo 1

Commander Gus Grissom, Ed White and Roger Chaffee were 5 1/2 hours into a simulated countdown at the Kennedy Space Center when White cried, "Fire!"

Chafee shouted, "We're burning up."

In the oxygen-saturated cabin 218 feet in the air atop the Saturn IB rocket at Pad 34, White's hand was seen trying to blow the hatch.

"If Ed couldn't get that hatch off, no one could," Robert Zimmerman quotes astronaut Frank Borman in "Genesis" (Four Walls Eight Windows/1998).

Astronauts and their loved ones were in shock.

"Test pilots died while in the air, which was what all the astronauts and their families braced themselves for. No one at NASA had prepared them for an accident on the ground," Zimmerman wrote.

In "Moon Shot" (Turner Publishing/1994), Alan Shepard and Deke Slayton attributed a chafed wire underneath Grissom's seat as sparking the inferno. Newsweek (Feb. 6, 1967) reported: "With a great whoosh, like the sound of an oven being lit, the pure O2 in the cabin made every combustible item in the ship burn with super intensity. At the same time, no O2 was left to breathe."

"The three astronauts were trapped in their melted suit material, fused with the charred nylon from the inside of the spacecraft," Buzz Aldrin and Malcolm McConnell wrote in "Men From Earth" (Bantam/1989). To remove the hatch, the Web site, www.nasa.gov, states five men struggled in thick smoke, "each forced to make several trips in order to reach breathable air."

Borman, a member of the investigating team, listened to the tape of his friends' screams and crawled into what he called the "fire-blackened charnel house," Zimmerman said. "Borman felt himself getting increasingly angry. Everywhere he and the rest of the investigation committee looked, they found sloppy workmanship by both the contractor and by NASA. Borman decided that he was going to do whatever it took to make sure the Apollo spacecraft flew again. And when it did, it would be the safest spacecraft ever built."

As a result, NASA abandoned the oxygen-rich atmosphere and, Zimmerman cited, "more than 2,500 different items were removed, replaced with nonflammable materials." Engineers redesigned the hatch to open in 10 seconds. The old hatch, according to Zimmerman, took 90 seconds to remove and involved "laboriously unscrewing some lug nuts."

Borman, in his book "Countdown," (Silver Arrow Books/1988), described each NASA staff member who suffered depression, guilt or a breakdown as a "victim of Pad 34."

One man during a meeting suddenly drew an organizational chart of Heaven on a blackboard.

He flew home in a straitjacket. A "NASA official drove onto a Houston expressway and raced his car at speeds of more than 100 mph until the engine caught fire," Borman wrote. "He explained later that he'd seen a metaphysical connection between the pad fire and the one that destroyed his automobile."

The final "victim," Borman said, was White's wife. She "committed suicide" in 1984.

Read the story HERE.

Barbara Morgan returns to Classroom

She waited twenty years for her ride, watched from the ground as back-up for Christa McAuliffe when Challenger exploded nine miles into its doomed mission in 1986, and now Barbara Morgan is retiring from NASA and is headed back to the classroom.

It is unlikely any of her present-day students will remember the explosion of the second Space Shuttle. Instead of appreciating how close Barbara Morgan came to becoming a flaming footnote to the history of NASA or how long she waited for her flight into space, it will be interesting if they will even think its a cool thing to have a "for real astronaut" as their science teacher.

The Story from First Coast News