October 10, 2013
LADEE Probe Enters Orbit Around The Moon
[ Watch the Video: LADEE Is Now In Orbit Around The Moon ]
redOrbit Staff & Wire Reports - Your Universe Online
LADEE blasted off from Wallops Island, Virginia on September 6, beginning the first leg of a month-long journey to the moon aboard a Minotaur 5 rocket. The probe entered Earth’s atmosphere in a highly elliptical orbit, circling the planet three times. Finally, on Sunday, LADEE was in position to fire its breaking rocket, which helped slow the probe down enough for it to be captured by the moon’s gravity.
The spacecraft, which is just under eight feet tall and less than five feet in diameter, fired its liquid-fueled engine at 6:57am EDT for a period of four minutes, said Stephen Clark of Spaceflight Now. The first of two major orbit adjustment burns, designed to lower LADEE’s orbit and eventually resulting in a near-circular orbit approximately 155 miles over the moon's equator, was scheduled to take place on Wednesday. The other is set for Saturday.
“The timing was not ideal,” Reuters reporter Irene Klotz pointed out on Monday. “The ongoing partial shutdown of the US government has sidelined about 97 percent of the NASA's 18,000 employees. But among those still on the job were LADEE's flight controllers, who monitored the do-or-die maneuver, said deputy project scientist Greg Delory, with NASA's Ames Research Center in Moffett Field, California.”
“Thanks to NASA’s foresight and good project management within the LADEE team, essential personnel were immediately exempted from the shutdown and operations have continued normally,” Delory told Discovery News in an email. “The spacecraft team continues to keep a close eye on LADEE’s systems to ensure that we’re in a good position to close in on our final science orbit as the mission progresses.”
He added that the US government shutdown is not expected to affect a laser communications exhibition LADEE is scheduled to put on later this month. Once it reaches the 155-mile orbit mark, ground control will begin operations using the three scientific instruments on the probe, as well as deploying aperture covers from the sensor and activating the laser for that forthcoming 30-day high-speed optical communications demonstration.
During the display, the spacecraft will be communicating with ground stations in New Mexico, California and the Canary Islands. Once the systems are linked, LADEE will be able to receive tens of megabits of data per second from the Earth or send hundreds of megabits per second from the moon back to the Earth.
Those speeds are unattainable with most current radio communications systems, according to Don Cornwell, the laser communication demonstration mission manager from the Goddard Space Flight Center in Greenbelt, Maryland. NASA is looking for a way to increase download speeds for data originating from space, he told Spaceflight Now. Ideally, the US space agency is hoping to be able to transmit high-resolution images and 3D video footage from satellites that orbit the Earth, as well as from vehicles that travel to the moon or into deep space.
“After LADEE's one-month commissioning and laser demo phase, controllers will put the probe in an orbit closer to the moon for a 100-day research mission exploring the dust environment just above the lunar surface and measuring the composition of the moon's ultra-thin atmosphere,” Clark said. “LADEE's science instrumentation will study the dynamics of the lunar exosphere, measuring its response to sunlight, especially around the terminator where the night and day side of the moon meet.”
“We know from Apollo that there's a gas called argon-40," Delory added. “It's an isotope that probably comes from the interior of the moon. There's argon gas hanging around the moon, and when the moon rotates into night, the argon gets cold and it goes down to the surface, and then as it rotates again into sunlight, it comes leaping off the surface because of the heat. There is literally an argon wind over the terminator of the moon, if you can imagine. That is an example of a component of the lunar atmosphere.”