Four hundred thousand kilometers away, a cargo ferry arrives at the Moon. It spots an orbiting depot, makes its approach and mates flawlessly, offloading drill heads, solar panels and other supplies for a frontier outpost at the Moon's south pole.
Meanwhile, down on the the lunar surface, mining buggies trundle along a "sensor highway" between the outpost and some nearby hills. They're harvesting lunar ice hidden in the shadows of a deep, cold crater.
Oh yeah – there's not a single human operator in this hypothetical scenario.
It's not as far-out as it sounds. All of these spacecraft and satellites, even the mining buggies, could one day operate on their own, guided not by humans but by automated rendezvous and docking technologies now in development by NASA and its partners.
Some of those technologies are about to get a field test onboard Orbital Express--a space mission managed by the Defense Advanced Research Projects Agency (DARPA) and a team led by engineers at NASA's Marshall Space Flight Center. Slated for launch this week, March 8, on an Atlas V rocket, Orbital Express will deploy two test satellites: the Autonomous Space Transport Robotic Operations (ASTRO) service vehicle, and the Next-generation serviceable satellite (NextSat).
"Our goal is to demonstrate on-orbit refueling, component exchange and satellite repair--all without a human operator," says James Lee, the MSFC Automated Rendezvous and Docking Projects Lead.
In a nutshell, ASTRO will dock with NextSat and service it.
Who will pilot ASTRO? The answer is not
who but
what: the Advanced Video Guidance Sensor or AVGS for short. Mounted on ASTRO, the AVGS shoots infrared laser beams, which bounce off a pattern of retroreflectors on NextSat. By analyzing the reflections, ASTRO adjusts its speed and angle of approach to safely close the distance and make contact.
Eight test series will be conducted during the three-month mission. ASTRO and NextSat will conduct approach and docking maneuvers from starting points up to 4.3 miles (6.9 km) away. Once docked, they'll also swap propellants and trade and install batteries--the first unassisted component exchange in space history. Tests will be conducted at different times of day to see if darkness on Earth's night side confuses the imaging system.
If Orbital Express is a success, use of autonomous rendezvous and docking systems could become a viable alternative to human-piloted missions in the next decade.
"Automated systems will take ship-to-ship mating duties off the hands of busy flight crews," says AVGS flight software project leader Keith Cornett of Marshall. "They can solve issues associated with tricky repairs and provide cost-effective options for servicing permanent satellites in orbit around the Moon or Mars."
Automated systems could also benefit surface operations, Lee notes, particularly on the airless moon where global positioning systems won't work without relays. That "sensor highway," dotting the surface with reflective markers to shine the way, could one day guide robots from place to place – surveying, sampling and laying the groundwork for human expeditions to come.
"When it comes to exploring new worlds, robots can't beat human beings for capturing the experience," Lee says. "But to make those human missions possible, we need to set the stage as completely as we can. Automation is crucial."
For more information about the Orbital Express mission,
click here.
Source: Science@NASA, by Rick Smith
Related stories:
Cosmic Cloudshine: Its Beauty Is More Than Skin Deep
Hubble's iconic images include many shots of cosmic clouds of gas and dust called nebulae. For example, the famous "Pillars of Creation" mark the birthplace of new stars within the Eagle Nebula. Yet despite their beauty, visible-light images show only the nebulae surfaces. Baby stars may hide beneath, invisible even to Hubble's powerful gaze.
Study Puts Solar Spin on Asteroids, their Moons & Earth Impacts
Asteroids with moons, which scientists call binary asteroids, are common in the solar system. A longstanding question has been how the majority of such moons are formed. In this week's issue of the journal
Nature, a trio of astronomers from Maryland and France say the surprising answer is sunlight, which can increase or decrease the spin rate of an asteroid.
NASA Satellite Finds Interior of Mars Is Colder
New observations from NASA's Mars Reconnaissance Orbiter indicate that the crust and upper mantle of Mars are stiffer and colder than previously thought.
Meet Nexi, MIT Media Lab's latest robot and Internet star
A new experimental robot from the MIT Media Lab can slant its eyebrows in anger, or raise them in surprise, and show a wide assortment of facial expressions to communicate with people in human-centric terms. Called Nexi, it is aimed at a range of applications for personal robots and human-robot teamwork.
Newly discovered galaxy cluster in early stage of formation is farthest ever identified
UC Irvine scientists have discovered a cluster of galaxies in a very early stage of formation that is 11.4 billion light years from Earth – the farthest of its kind ever to be detected. These galaxies are so distant that the universe was in its infancy when their light was emitted.
Meteorites a rich source for primordial soup
The organic soup that spawned life on Earth may have gotten generous helpings from outer space, according to a new study. Scientists at the Carnegie Institution have discovered concentrations of amino acids in two meteorites that are more than ten times higher than levels previously measured in other similar meteorites.
Small 'helper' stars needed for massive star formation
In order for a rare, massive star to form inside an interstellar cloud of gas and dust, small "helper" stars about the size of the sun must first set the stage, according to a new theory proposed by astrophysicists at the University of California, Berkeley, and Princeton University.
Tiny radioactive spheres effectively treat cancer that has spread to the liver
Placing tiny radioactive spheres directly into the liver through its blood supply halted growth of tumors that had spread to the organ in 71 percent of patients tested in a small clinical trial, researchers from Mayo Clinic Jacksonville report.
