Deployingtiny probes to inspect or service spacecraft in distress and flying satellitesthat can operate with limited human touch are the chief goals behind astate-of-the-art technology demonstration mission successfully launched into Earthorbit this morning.
The Air Force Research Laboratory'sExperimental Satellite System-11 craft reached space aboard a four-stage, $18million Orbital Sciences Minotaur rocket. Liftoff occurred at 1335 GMT (6:35a.m. local time; 9:35 a.m. EDT) from the Space Launch Complex 8 pad on thesouthern edge of California'sVandenberg Air Force Base.
Officials confirm that theXSS-11 spacecraft separated from the launcher as planned and has begun itsinitial activities.
"Everything looksgood," an Orbital spokesman said. "Early preliminary indications looklike (the satellite) is healthy. It was an accurate launch, right in the middleof the box."
Over the coming weeks,controllers will conduct a fundamental checkout of the satellite's mainsystems.
The first real test of theXSS-11's rendezvous sensors and technology is expected sometime in the nextthree to six weeks when the craft revisits the Minotaur fourth stage.
"That is really wherewe get the basic performance parameters for the sensors," said HaroldBaker, XSS-11 program manager at the Air Force Research Lab.
The mission will last 12 to18 months as XSS-11 demonstrates new autonomous satellite features duringencounters with six or seven spent rocket stages and dead U.S.satellites. The microsatellite project is designed totest technologies that could allow quick visual examinations or maintenance ofspacecraft in orbit.
"This satelliterepresents a significant advance of what's ever been done in spacebefore," Baker said. "Proving these technologies could haveconsiderable impact on the amount of money it takes to operate a satellite, tolaunch a satellite, to build a satellite."
At the heart of XSS-11 is aradiation-hardened Power PC 750 processor that serves as the master avionicsbox, enabling onboard autonomous operations and mission planning by thesatellite itself.
"The real technologyis in the autonomous planner onboard and the logic algorithms that are requiredto do that mission, as well as the ground tools," Baker said.
The U.S. militaryhas spent $56 million creating the XSS-11 spacecraft. Another $6 million hasgone into mission operations over the life of the program.
Ground controllers will beactively involved in the early rendezvous attempts, but hope to gradually weanXSS-11 from human intervention.
"From the beginning,safety has been foremost in our minds. If we collide with an object, we fail.So initially we let the planner plan, but it has many, many ground decisionpoints that have to be reached before it can proceed on its own," Bakersaid.
"Aswe proceed through the mission, we take some of those points out as we get moreconfidence that the planner is doing the right thing and it's agreeing withwhat we are seeing on the tools on the ground. As we go through the mission, wewill take more and more of those go/no go decision points out that are givenfrom the ground. The objective by the end of the program is have as many ofthose, if not all those, out and tell it what you want it to do and haveconfidence it is going to succeed."
In selecting the targets,the objects must be American and within roughly the same orbit.
"All of the objectsare U.S.-owned, dead or inactive space objects. We have several rocket bodiesthat have been expended for other space vehicles and two or three satellitesthat are no longer operating....I believe one of them is a dead NOAAsatellite," Baker explained.
The exact mission lengthwill be determined as the mission proceeds.
"It really depends howthe objects work out as we go along," Baker said. "Fuel is thelimiting factor on the flight."
Some space watchers havesuggested that XSS-11 is actually testing anti-satellite, or space weapon,concepts to disable enemy craft.
"Our job at the Lab isto develop technology," Baker said. "This is really a demonstrationof autonomy technology, not weapons."
"We can saycategorically, there's nothing that ejects out of the satellite," saidCol. Richard White, commander of Space and Missile System Center's Detachment 12."There's no battering ram. The entire purpose of the software, the entirepurpose of the mission, is to make sure -- I repeat -- not bump intosomething."
During the rendezvousevents with the target objects, XSS-11 will close within 1.5-miles of a rocketbody or satellite but will never touch them.
"To fulfill ourrequirements, we can do that from two-and-a-half kilometers away. Obviously, wemove in somewhat closer just to validate some of the technologies and how wellthey perform," Baker said.
"If we collide withsomething, we fail. We have multiple layers of safety on this satellite, literally we have three or four layers of safetyto make sure we don't collide with an object."
How the technology will beused in operational missions of the future is yet to be seen.
"There is no specificor direct military application. This is a technology demonstration. That iswhat the Lab is for. We're really looking at the technologies, tools,algorithms, how the onboard planner performs and validate those so that theycan be put into future plans," Baker said.
XSS-11 is one in a line ofdemonstration test satellites. Air Force leaders will decide whether thereneeds to be a follow-up to this particular mission.
"I think if thisflight is successful, we move some of this technology forward for futuremission planning. There are other areas to be developed, so there may be a follow-on. But that is not really how we do our programs.
"Thisis one in a series of experimental satellites. Currently, we are planning thenext one. We receive proposals from different organizations on what they wouldlike to see and done in space. That goes to our high-level officers in the AirForce and at Space Command, they get vetted and they select a newdemonstration. It doesn't have to be in the same area as this one, it could bein a totally different area. We are right in the middle of that process now. Inthe next three or four months, they will come out with what the nextdemonstration is going to be."
Today's mission was thirdfor the Orbital Sciences-managed Minotaur rocket, which uses decommissionedMinuteman 2 first and second stages and the upper two stages from commercialPegasus boosters. The first stage that propelled the six-story vehicle skywardat sunrise this morning was built in 1967; the second stage dates to 1981.
"It's a great reuse ofold ICBM assets, taking those out of missile holes and using that to launch asmall satellite," White said.
Minotaur successfullydebuted in 2000, carrying out a pair of missions that lofted five smallsatellites.
Schedules call for two moreMinotaur launches this year -- in July and December -- from Vandenberg. Thefirst will deploy the STP-R1 research satellite for the Air Force; the secondwill carry spacecraft in the joint Taiwan-U.S. project called COSMIC to studythe atmosphere.
ForVandenberg Air Force Base, today's launch was the site's first space mission in2005. Next up is Orbital Sciences' air-launched Pegasus rocket with NASA's DARTtechnology satellite slated for flight on Friday.