Feeds

Space soldiers save satellite from FLAMING DEATH

The little engine that could rescues $2bn military bird

Securing Web Applications Made Simple and Scalable

Enter the unrehearsed understudies

The team then sealed up the LAE's tanks, which had the advantage of safety but which also kept about 1,000 pounds of oxidizer bottled up, adding to the vehicle's weight.

With the LAE unusable, Madden and his team turned to the two other thrusters available to them: hydrazine-fueled reaction engines (REAs) and extremely low-thrust xenon-fueled Hall Current Thrusters (HCTs), which pumped out a miniscule 0.05 pounds of push.

If the comparatively powerful REAs could get the vehicle out of its unstable orbit relatively quickly, the HCTs – weak as they may be – had one tremendous advantage that could save the mission: they could be fired for thousands of hours with no ill effects.

The team needed to work fast, seeing as how the vehicle was losing about three miles of altutude per day, and its 140-mile-or-so perigee took it through a band of dangerous orbiting space junk. "That's a pretty nasty area," says Madden.

SV-1 orbital adjustments

What a long, strange trip it's been (credit: Air Force Magazine – click to enlarge)

On August 29, the team fired up the REAs – which had been intended to stabilize the satellite, not change its orbital location – and by early September the vehicle had been nudged into a far safer perigee of 600 miles. By September 22, the perigee had risen to over 2,900 miles.

It was then the HTCs turn. One problem, however: the HTCs require electricity to operate, and at this altitude the vehicle was encountering radiation from the Van Allen Belts, radiation that could damage the satellite's solar-power panels, source of the HTCs' needed electricity.

The team plotted a course to get through the Van Allen Belts as quickly as possible – and they made it with little or no damage to the solar panels, which would be needed to power the AEHF satellite during its 14-year planned mission.

The HTCs continued firing, modifying the vehicle's orbit for 10 to 12 hours per day from October until the next June. Since they had never been intended for such use, Madden and his team continued to learn about their peccadilloes. "They're like a finicky old car," he said, "one that you’ve got to constantly adjust to get it to optimize. There’s no instruction manual for how to do that. It’s basically an art."

After boosting the perigee, the final step was to nudge the apogee down from its top altitude of 32,145 miles while continuing to boost the perigee up to the required geosynchronous altitude. The perigee reached its geosynchronous-altitude goal in early August, and the apogee matched it in on October 24.

At that point, the AEHF satellite was released from the SV-1, and an extensive "How y'doing?" checkout period of all its systems began. The Air Force now says that the communications satellite will be operational this March.

"All of the telemetry we're getting on the vehicle says we didn't violate any parameters," Madden says. "Our solar panels are doing great. We didn’t do any damage that would hurt us in full operation. We've got a full mission life planned for this vehicle."

SV-2 is planned for launch this April. Needless to say, there has been quite a bit of investigation of its LAE design since the SV-1's choked on August 17, 2010. ®

HP ProLiant Gen8: Integrated lifecycle automation

More from The Register

next story
ALIEN BODY FOUND ON MARS: Curiosity rover snaps extraterrestrial
And NASA kept evidence to itself for over a month
Malaysian Airlines flight MH17 claimed lives of HIV/AIDS cure scientists
Researchers, advocates, health workers among those on shot-down plane
Mwa-ha-ha-ha! Eccentric billionaire Musk gets his PRIVATE SPACEPORT
In the Lone Star State, perhaps appropriately enough
Diary note: Pluto's close-up is a year from … now!
New Horizons is less than a year from the dwarf planet
Forty-five years ago: FOOTPRINTS are FOUND ON MOON
NASA won't be back any time soon, though
NASA: ALIENS and NEW EARTHS will be ours inside 20 years
ETs, habitable planets will soon pop up with our new 'scopes
prev story

Whitepapers

Top three mobile application threats
Prevent sensitive data leakage over insecure channels or stolen mobile devices.
The Essential Guide to IT Transformation
ServiceNow discusses three IT transformations that can help CIO's automate IT services to transform IT and the enterprise.
Mobile application security vulnerability report
The alarming realities regarding the sheer number of applications vulnerable to attack, and the most common and easily addressable vulnerability errors.
How modern custom applications can spur business growth
Learn how to create, deploy and manage custom applications without consuming or expanding the need for scarce, expensive IT resources.
Consolidation: the foundation for IT and business transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.