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The Planetary Society BlogBy Emily LakdawallaLRO & LCROSS Up-Close TourMay. 18, 2009 | 21:58 PDT | May. 19 04:58 UTC
Planetary Society volunteer Ken Kremer is reporting for us from the Kennedy Space Center, where he witnessed the launch of Space Shuttle Atlantis to the Hubble Space Telescope on May 11. Kremer is a research scientist and freelance journalist who spends his spare time giving public outreach presentations on behalf of The Planetary Society as a volunteer and NASA's Jet Propulsion Laboratory as a Solar System Ambassador. He also enjoys creating Mars mosaics. Thanks Ken!  by Ken Kremer
The Lunar Reconnaissance Orbiter, or LRO, is NASA's next science flight dedicated to explore and survey Earth's moon and pave the way to return a human presence. In fact, it's actually two robotic pathfinder missions in one. Riding piggyback is the co-manifested Lunar Crater Observation and Sensing Satellite, or LCROSS.
The two spacecraft will provide complimentary data from different vantage points in unprecedented detail and are set to launch no earlier than June 17. Whereas LRO will study the lunar composition and environment from polar orbit, LCROSS is designed to impact a crater near the lunar polar region, hunt for water ice and provide ground level composition data. I observed the integrated LRO and LCROSS combination spacecraft stack up close on Friday, May 15, at the Astrotech Space Operations Facility, Titusville, FL, located a few miles west of KSC. I participated in a media tour sponsored by NASA for a pre-launch photo opportunity and Q&A with mission scientists and engineers.
LRO is managed by NASA Goddard Spaceflight Center. LCROSS is the responsibility of the NASA Ames Research Center in Moffett Field, CA. The LRO/LCROSS mission hopes to discover what the moon has to offer for future moon dwellers. This includes searching for safe landing sites and life sustaining elements such as water and constitutes a major step by NASA towards returning humans to the moon by 2020. The spacecraft are undergoing final processing before launching aboard an Atlas V rocket from Cape Canaveral Air Force Station (CCAFS), FL. CCAFS lies adjacent to the Kennedy Space Center.
Craig Tooley, LRO Project Manager at NASA‘s Goddard Spaceflight Center said, "We are essentially ready to launch from a spacecraft standpoint. They are stacked, they're cleaned and they're fueled". NASA decided to delay LRO/LCROSS from a June 2 launch window so as to allow the LCROSS team additional time to mitigate a ‘potential thrust disturbance associated with the Atlas V Centaur fill/drain valves'. LCROSS is using the spent Centaur rocket as a lunar impactor. The Centaur was designed as an upper stage to launch spacecraft and has never been used in this manner before. Its use as an impactor enables new science discoveries but also poses numerous technical challenges. "LRO is the first mission to use a Centaur second stage of the Atlas rocket for useful science", Tooley added. Access to the spacecraft is strictly regulated. Everyone's camera equipment was wiped clean by contamination-control specialists. Our shoes were thoroughly brushed. We entered the garment room and were furnished with full clean room attire, known as "bunny suits," which includes full body suits, face masks, gloves and shoe covers all of which must be worn. As a research scientist myself, I wear this attire to protect myself from toxic chemicals. In this case of role reversal, the purpose is to protect the spacecraft from contamination by us humans.
After passing through an airlock we finally entered the clean room for the photoshoot and technical briefing & interviews. We observed the LRO/LCROSS sitting adjacent to and sandwiched between the twin halves of the 4 meter diameter Atlas V payload fairing and nose cone, barely a few hours prior to their encapsulation. The two fairing sections were joined together later that same day. The lower portion is lined with black colored panels for acoustic and thermal protection of the spacecraft, said Nick Virmani, an LRO Systems Manager at NASA Goddard. "This mission is all about taking us back to the moon. LRO has 6 science instruments and is the size of a mini-couper. We are looking for water ice and will get a totally comprehensive look at the moon", says LRO Deputy Project Manager Catherine Peddie of NASA Goddard. "LRO is scheduled for a one year primary mission. Then the plan is to fly LRO for at least 2 or 3 years and even longer, until we run out of fuel", according to Peddie. "The moon has an irregular gravity field. We will trim the orbit every month to avoid crashing". Tooley told me that, "After achieving orbit, LRO will undergo a two month commissioning phase, orbiting at 216 x 30 km. During the primary mission phase, LRO will be at a 50 km (30 mi) circular orbit. This orbit requires thruster firings". What's next I asked? He said that "although they haven't yet made their final plans, they will likely return to the elliptical commissioning orbit because it costs very little fuel to stay in the commissioning orbit, which is why it was chosen as the commissioning orbit. There is very little fuel use. The commissioning orbit is tuned to the variations in the lunar gravity. The perturbations are periodic so you don't have to correct for them. When the perturbations are not periodic, you end up having to do propulsive burns as we do in our 50 km orbit. And you start running out of fuel. Pretty soon your perigee winds up getting really low and the spacecraft has to correct for that". After the primary mission is complete, management responsibilities for the spacecraft will be handed over to NASA's Science Mission Directorate. "A new science mission phase will then begin that will be operationally very different then our primary mission". Traditionally, new project management "will then be assigned by NASA to oversee the day to day operations. How they fly LRO exactly and which instruments and observations they choose to use and to do could be very different", explained Tooley. NASA hopes to operate LRO for perhaps 5 years and hopefully even longer.
"We will look to photograph [one or more of] the Apollo landing sites with 0.5 meter resolution", said Tooley. The high resolution camera will also be targeted to find other US and Russian unmanned robotic landers and rovers. "Initial images may be available during the first month. The lower half of the Lunar Module (LM) should be easily visible as well as the lunar rover tracks and perhaps the science instruments". "A microchip with 1 million names has been installed on LRO", says Nick Virmani. The Planetary Society assisted in collecting names for the highly successful "Send Your Name to the Moon" project which enabled everyone, including me and many of you, to participate in this great lunar adventure. Planetary Society President Jim Bell, Cornell U, is a participating scientist on LRO. The spacecraft will be delivered to the launch pad at Complex 41 at Cape Canaveral which is managed by United Launch Alliance (ULA), where it will be integrated with and bolted atop the Centaur upper stage. |
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