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Developing Responsive and Agile Space Systems - Space-Library

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AeroCube-3 Takes Flight<br />

The Aerospace Corporation’s third CubeSat, AeroCube-3, was<br />

launched from Wallops Isl<strong>and</strong>, Virginia, on May 19, 2009, as a<br />

secondary payload on the TacSat-3 mission. The picosatellite measures<br />

10 × 10 × 10 centimeters <strong>and</strong> weighs about 1 kilogram, in<br />

keeping with the CubeSat specification. It is more complex than<br />

its two predecessors <strong>and</strong> has several improvements; most notable is<br />

the new solar power subsystem that replaced the one that failed on<br />

AeroCube-2. AeroCube-3 also has a two-axis sun sensor <strong>and</strong> an<br />

Earth sensor, as well as a deorbit device that includes an inflatable<br />

balloon that doubles as a tracking aid.<br />

During the first phase of its<br />

mission, AeroCube-3 remained<br />

attached to the upper stage of the<br />

Minotaur launch vehicle by means<br />

of a 200-foot long tether, snapping photos of the upper stage with<br />

a wide-angle Video Graphics Array (VGA) camera to simulate an<br />

orbital inspection mission. In the second phase, AeroCube-3 cut<br />

its tether to become a free-flying spacecraft. At that point, magnets<br />

mounted on the satellite helped align it with Earth’s magnetic field,<br />

enabling various attitude control experiments to be performed.<br />

Aerospace Serves Panel Reviewing Human <strong>Space</strong>flight<br />

Aerospace President <strong>and</strong> CEO W<strong>and</strong>a Austin served as one of 10<br />

panel members charged with reviewing NASA’s Constellation human<br />

spaceflight program. The Human <strong>Space</strong> Flight Review Committee<br />

conducted an independent review of U.S. human spaceflight<br />

plans <strong>and</strong> programs, including available alternatives. The goal was to<br />

identify <strong>and</strong> characterize a range of options for continuing U.S. human<br />

space activities beyond the retirement of the space shuttle.<br />

The committee assessed ways of expediting U.S. capability to<br />

transport equipment <strong>and</strong> personnel to the International <strong>Space</strong> Station,<br />

examined ways to support missions to the moon <strong>and</strong> other<br />

destinations beyond low Earth orbit, <strong>and</strong> considered ways<br />

of stimulating commercial spaceflight. It also made recommendations<br />

on how these goals can best be achieved within NASA’s<br />

projected budget.<br />

The committee, whose charter was signed June 1, summarized<br />

its findings in a final report presented Aug. 31. Former Lockheed<br />

Martin CEO Norman Augustine chaired the committee. Sally<br />

Ride, a member of the Aerospace board of trustees <strong>and</strong> a former<br />

astronaut, also served on the panel. “I am pleased to have had the<br />

opportunity to assist in planning the future U.S. human spaceflight<br />

program at this critical juncture,” Austin said. Aerospace provided<br />

much of the analysis to the committee.<br />

Astronauts Repair Hubble <strong>Space</strong> Telescope<br />

The Atlantis space shuttle with seven<br />

astronauts aboard launched into space<br />

on a mission to repair the 19-year-old<br />

Hubble <strong>Space</strong> Telescope on May 11,<br />

2009. The STS-125 mission was destined<br />

for a 14-day trip in which astronauts<br />

replaced or fixed everything from<br />

cameras to gyros to insulation on the<br />

ailing telescope.<br />

Astronauts conducted five spacewalks,<br />

totaling nearly 37 hours. They<br />

installed a science instrument comm<strong>and</strong><br />

<strong>and</strong> data h<strong>and</strong>ling unit, replaced<br />

the wide-field camera 2, installed six<br />

new gyros, <strong>and</strong> replaced three of the<br />

telescope’s six nickel-hydrogen batteries.<br />

They also installed a “soft capture” mechanism designed to help<br />

with the future disposal of Hubble by a crewed or robotic mission.<br />

Astronauts also installed a cosmic origins spectrograph, which<br />

will allow scientists to better study the universe <strong>and</strong> how planets<br />

formed <strong>and</strong> evolved. This new tool is designed to examine dark<br />

matter, which may provide insights into how the universe began.<br />

Hubble’s Advanced Camera Survey was also revitalized when<br />

outfitted with four new circuit boards <strong>and</strong> a new power supply.<br />

The camera is credited with sending back some of Hubble’s most<br />

stunning imagery. The <strong>Space</strong> Telescope Imaging Spectrograph was<br />

also repaired; it was installed during a 1997 servicing mission but<br />

stopped working in August 2004 because of a power supply failure.<br />

STS-125 astronauts navigate the exterior of the Hubble<br />

<strong>Space</strong> Telescope on the end of the remote manipulator system<br />

arm, controlled from inside Atlantis’ crew cabin.<br />

Courtesy of NASA<br />

Lastly, the astronauts installed a new<br />

thermal material. It will protect Hubble’s<br />

external blankets, preventing further degradation<br />

of the insulation, <strong>and</strong> will help<br />

maintain normal operating temperature of<br />

electronic equipment. With all of the new<br />

additions <strong>and</strong> repairs, Hubble is expected<br />

to last through 2014, when the James<br />

Webb Telescope is scheduled to take its<br />

place.<br />

During the initial ascent phase of this<br />

mission, a piece of foam was liberated <strong>and</strong><br />

struck some tile forward of the starboard<br />

wing of the Atlantis orbiter. Aerospace had<br />

previously developed an analytical tool for<br />

NASA that evaluates foam debris risk. This<br />

tool was built to predict foam debris risk as part of the return-toflight<br />

effort following the failure of the Columbia orbiter caused<br />

by thermal protection system damage from a foam debris strike.<br />

R<strong>and</strong>y Williams, senior project leader, <strong>Space</strong> Launch Projects, said,<br />

“Aerospace determined the velocity <strong>and</strong> angle of impact for the<br />

STS-125 debris strike, which allowed the debris assessment team<br />

to conclude the tile damage had minimal depth <strong>and</strong> precluded the<br />

need for a more detailed inspection that would likely have reduced<br />

the timeframe for the astronauts to conduct their primary mission<br />

objectives.” The astronauts returned to Earth, l<strong>and</strong>ing at Edwards<br />

Air Force Base in California on May 24, 2009.<br />

Crosslink Summer 2009 • 3

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