Farside offers radio-quiet to probe cosmic Dark Age

Dark Ages Radio Explorer (DARE), utilizing the radio-quiet of the lunar farside to explore the earliest period on the cosmic time line, 200 million years between the primordial Big Bang and the emergence of the earliest luminous sources and the structure of the present universe. "The lunar Farside is potentially the only site in the inner solar system for high precision radio cosmology.” [NLSI].

Anil Ananthaswamy
New Scientist
 
FORTY years after NASA ditched the idea of landing Apollo 17 on the far side of the moon, the forbidden fruit is being sought once again. Not by astronauts this time, but by astronomers seeking a quiet spot from which to observe the universe's "dark ages".

This was an epoch in the development of the cosmos, which lasted for a few hundred million years after the big bang, before stars and galaxies began to form. The only way to observe the dark ages is to look for faint radio signals from neutral hydrogen - single protons orbited by single electrons - which filled the early universe.

Telescopes on Earth, such as the Murchison Widefield Array in Western Australia, are searching for such signals, at frequencies above 100 megahertz. This can probe the universe back to 400 million years after the big bang.

To explore even earlier times, telescopes need to receive radio waves at frequencies below 100 megahertz. Interference from radio sources on Earth such as FM radio and the planet's ionosphere can mess up these signals. "You get to the point where the ionosphere is just a hopeless barrier," says Dayton Jones of NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California. "You have got to go to space, and the most promising location by far is the far side of the moon."

To peer back to the universe's earliest years will need sensitive telescopes in a place where Earth's ionosphere and radio chatter cannot interfere

This is why astronomers were discussing it at an American Astronomical Society meeting in Anchorage, Alaska, this month. Telescopes behind the moon would not have to contend with Earth's ionosphere, and they would also be shielded from our planet's radio chatter. "It is a very pristine environment for low-frequency observation," says Jones.

The first shot at radio astronomy from the moon's far side will probably be a mission called the Dark Ages Radio Explorer, being designed by Jack Burns at the University of Colorado at Boulder, and colleagues.

If selected as a mission by NASA in its review next year, DARE will orbit the moon at an altitude of 200 kilometers. It will collect neutral-hydrogen signals between 40 and 120 megahertz. That corresponds to 80 million to 420 million years after the big bang. Its antenna is designed to pick up signals from the entire sky. The craft will be a little toughie, with parts made from an Astroquartz/Kevlar fibre, which is very thermally stable - particularly handy when moving in and out of sunlight as it orbits the moon.

The DARE team has begun testing the probe's antenna at remote locations on Earth, starting with the National Radio Quiet Zone surrounding the Green Bank telescope in West Virginia. "It may be a radio quiet zone, but it's not quite," says DARE team member Abhirup Datta. "You can still see the FM bands coming in, and of course the ionosphere is a problem."

Not everyone reckons a space-based solution is needed to study the universe's dark ages. "Existing ground-based experiments will yield good progress on this problem at a tiny fraction of the cost of a space mission," says Steven Tingay of Curtin University in Bentley, Western Australia, who headed the construction of the Murchison array.

Burns disagrees. Preliminary tests reveal that the Earth's ionosphere is absorbing signals from space and re-emitting them as noise in frequencies below 80 megahertz. "If we can verify and characterize that, that slams the lid on any attempts to do this kind of experiment from the ground," says Burns.

Once DARE has done its job, his team want to deploy bigger telescopes on the lunar far side to image the first stars and galaxies. These antennas would be made of conducting material imprinted on extremely lightweight films of polyamide, micrometers thick.

In one design, three 100-metre-long arms of such films are attached to a central box of electronics. The arms would be rolled up tight for launch and, once on the moon, a rover sent along with the unit will move it to its required spot and help unfurl the arms. The rover would likely have to be controlled by astronauts orbiting a Lagrange point over the lunar far side.

To test this scenario, Burns's team will work with astronauts based on the International Space Station next year. The astronauts will remotely operate a Mars rover called K-10. It is being outfitted to unwind films of polyamide on a simulated Martian landscape at NASA Ames Research Center in Moffett Field, California.

HDTV still of Tsiolkovskiy, captured by Japan's lunar orbiter SELENE-1 ("Kaguya," 2007-2009). The Naval Research Laboratory, Massachusetts Institute of Technology and  others are refining work on a possible radio telescope array to be deployed in the conspicuous farside crater floor to utilize the radio quiet of the the Moon's farside to probe the cosmic Dark Age [JAXA/NHK/SELENE].

"The ultimate experiment we'd like to do for cosmology on the far side would involve thousands of these antennas," says Burns.

But what if the basic idea proves unfeasible, in terms of cost or in overcoming obstacles in the terrain? At JPL, Jones and his team are working on another solution: rolled-up antennas that inflate like party blowers seconds before they touch the lunar surface. "They are essentially immune to whatever irregularities there are at the surface," says Jones.

Astronomers have their sights set on at least one site for such telescopes: the flat bed of the 180-kilometre-wide Tsiolkovskiy crater, exactly where the Apollo 17 astronauts first wanted to land.

Related Posts:

The Moon as a platform for Astrophysics (April 24, 2012)
MIT to lead development of new radio telescope
array on lunar farside (February 19, 2008)
Naval Research Laboratory to design Farside DALI (March 11, 2008)
What better view? (March 26, 2008)
New model of lunar motion from Apollo LLRR (December 27, 2008)
MacDonald LLR defunded by NSF (June 21, 2009)
The continued importance of lunar laser ranging (August 3, 2009)
Laser Ranging and the LRO (August 12, 2009)
Dust accumulation on Apollo laser reflectors may
indicate a surprisingly fast and more dynamic
lunar exosphere (February 16, 2010)
Long term degradation of optics on the Moon (March 4, 2010)
A Fundamental Point on the Moon (April 13, 2010)
Acquisition Lunokhod-1 (April 27, 2010)

High-speed lunar navigation for crewed and remotely-piloted vehicles

Figure 2 - NASA’s K10 autonomous or teleoperated rover designed for robotic site survey, at speeds up to 0.6 m/s. (Houghton Crater K10 Field Test, 2010) [NASA/ARC/NLSI].

Pedersen & Allan, et al.
NASA Ames Research Center
Carnegie Mellon University
Humboldt University
ETH, Zurich

Increased navigation speed is desirable for lunar rovers, whether autonomous, crewed or remotely operated, but is hampered by the low gravity, high contrast lighting and rough terrain. We describe lidar based navigation system deployed on NASA’s K10 autonomous rover and to increase the terrain hazard situational awareness of the Lunar Electric Rover crew.

Introduction - High speed mobility (by planetary rover standards) is desirable for more efficient exploration of the lunar surface, particularly if human crews are present there.

NASA’s Lunar Electric Rover (LER) can drive at 10km/h (3m/s) on rough terrain, faster on known smooth surfaces. By comparison, the MER vehicles moves at a few cm/s while stopping regularly.

Driving on the Moon is complicated by the low gravity, rough terrain, high contrast lighting and alien environment.

Under the 1/6g lunar gravity a vehicle becomes airborne at relatively modest speeds (driving the Apollo era lunar rover at 7 mph was reportedly like being aboard a rowing boat for this reason). The reduced gravity also lessens vehicle-ground friction. Together these effects increase maneuvering distances.

Astronauts complained of difficulty discerning surface features on the Moon under certain lighting conditions, such as with the sun behind them. The lack of terrestrial depth cues compounds the difficulties of driving.

The 3 sec signal round trip time delay to the Moon permits tele-operating a vehicle from Earth (e.g. Lunakhod) with diffculty (increasing with speed).

This paper describes our robotic rover navigation systems, currently running on NASA’s autonomous or teleoperated K10 rover (Figure 2) and as a crew aid on the LER for increasing pilot situational awareness of the surrounding terrain. We address terrain sensing for 4 different classes of rovers: K10, the Lunar All Terrain Utility Vehicle (LATUV, Figure 3), the LER and the LER operating under lunar gravity and time-delayed tele-operation.

Subsequent sections describe the terrain mapping and hazard detection software, pose estimation, the rover software infrastructure for command and data handling, the graphical user interface and performance figures.

Read the Full Abstract, HERE

Figure 8 - Apollo 17 Station 3 high-resolution pan centered on the south rim of Ballet Crater; frames AS17-138-21155 through 21167 assembled by David Harland for the Apollo Surface Journal [NASA/JSC].

i-SAIRAS 2010. 10th International Symposium on Artificial Intelligence, Robotics and Automation in Space - Sapporo, Japan, August 29 - September 1, 2010

Desert RATS pack for Arizona

Mike Miller demonstrates one of the backpacks his team designed and built for the Desert Research and Technology Studies (Desert Rats) project's upcoming field test in Arizona. Miller led the team that developed the backpacks. The backpacks are equipped with GPS antennas, communications components and cameras. They are meant to show researchers what an astronaut might need to explore an alien world and give designers a look at the hardships the equipment could encounter [NASA/Frank Michaux].

Steven Siceloff
NASA Kennedy Space Center

"A team of astronauts, scientists and engineers from several NASA centers head to Arizona's desert each year to simulate the unique environment of space explorers. The effort is meant to test equipment and people to find out the best way to explore another world.

"Kennedy's engineers develop the communications, navigation and data transmission networks needed, a task that includes a semitrailer set up as a mission operations center, a command vehicle, a specialized RV, a pair of Humvees plus enough communications gear to set up a wireless network for a small crew of explorers to talk back to "Earth" like they will from other planets.

"Equipment from other centers, such as a pair of large rovers, has to work on the same communications network. The rovers, for example, relay the signals from the backpacks to the mission operations center.

"Although the area they test in is not a perfect stand-in for the moon or Mars in terms of having breathable air and normal gravity, the site does a pretty good job of isolating the participants, said Mike Miller, communications research engineer at Kennedy.

"We have to take everything to the site, just like we will to other planet surfaces," Miller said."

Read the full story, HERE.

You decide the Desert RATS' next destination

SEV - Surface Exploration Vehicle (Surface Concept) at Desert RATS Field Test on the Black Point Lava Flow in Arizona. Unveiled in 2007, the latest model began tests in 2009. During the Apollo program, exploration was confined to the distance astronauts could expect to walk back wearing spacesuits if their rovers broke down: about 10 km. The presence of two or more service SEVs on the lunar or Martian surface would extend that potential range to more than 200 km in any direction, greatly increasing the scientific opportunities during missions. Even in the midst of challenging terrain, emergency shelter and support can be less than an hour away. [NASA/ARC/IRG].

NASA is inviting the public to choose the area in northern Arizona where explorers will conduct part of the annual Desert Research and Technology Studies (Desert RATS).

"Desert RATS is an annual test where NASA takes equipment and crews into the field to simulate future planetary exploration missions," said Joe Kosmo, Desert RATS manager at NASA's Johnson Space Center in Houston. "We want the public to be a part of this."

From July 27 until August 8 anyone can vote on where to send the Desert RATS team. To cast your vote, visit HERE.

(http://ti.arc.nasa.gov/desertrats/vote).

The website features interactive panoramic images of lava, rocks and desert for the public to choose as the most interesting destination to explore.

The location that receives the most votes will be announced August 16. Astronauts will visit that site to perform field geology and collect rock samples.

The Intelligent Robotics Group (IRG) at NASA/Ames Research Center (Moffett Field, CA) took the panoramic images of terrain and geologic features at Black Point Lava Flow in Arizona.

"It is essential to involve the public in NASA's exploration program to engage and inspire the next generation of scientists and engineers," said IRG Director Terry Fong. "We want people of all ages to be able to actively participate, contribute and collaborate in meaningful ways to NASA's activities."

The Desert Rats 2010 mission also involves field testing two space exploration vehicles, which could allow astronauts to spend two or more weeks living, working, and traveling across different planets. Astronauts will use two such vehicles to explore a lava flow and test data collection methods, communications protocols, mission operations, and advanced technology. Desert RATS is sponsored by NASA's Exploration Systems Mission Directorate in Washington.

A Glimpse of the Future - Micro-Gravity airless-body exploration will require a play on the SEV without wheels. The Surface Exploration Vehicle (Space Concept) features aspects also undergoing tests [NASA/ARC].

DesertRaTS testing Electrodynamic Dust Shield

Figure 1. shows an example of a lunar architecture that is being evaluated at DesertRaTS.

Calle & Immer, et.al.
Electrostatics and Surface Physics Laboratory
ASRC Aerospace
Florida Institute of Technology
Oklahoma Baptist University

NASA is developing a Habitat Demonstration Unit (HDU) to investigate the feasibility of lunar surface technologies and lunar ground operations. The HDU will define and validate lunar scenario architecture through field analog testing. It will contain a four-port vertical habitat module with docking demonstration capabilities. The Electrodynamic Dust Shield (EDS) is being incorporated into the HDU to demonstrate dust removal from a view-port and from a door prior to docking procedures. In this paper, we will describe our efforts to scale up the EDS to protect a viewport 20 cm in diameter. We will also describe the devel-opment of several 20 cm × 25 cm EDS patches to demonstrate dust removal from one of the HDU doors.

NASA has designed and built a Pressurized Excursion Module (PEM) for a Lunar Habi-tat Demonstration Unit (HDU), a full scale lunar habitat prototype, to perform analog testing of the lunar environment in desert locations. The Desert Research and Technolo-gy Study (RaTS), a series of analog tests that NASA has held at several different desert locations for several years, allows the Agency to run through potential “day in the life” scenarios at a lunar outpost with prototype equipment. These analog tests provide engi-neers and scientists with insights into the utilization of the different systems so that the exploration architecture and the operation concepts can be refined. The HDU will be operated during a 14- to 21-day mission at the 2010 DesertRaTS event planned for Black Point Lava Flow in Arizona.

The PEM has four doors with docking demonstration capabilities. Each door contains a 21-cm diameter viewport. During docking activities with the Lunar Electric Rover (LER), which contains a similar door, the two doors open inward. Any dust accumulating on the surface of these doors must be removed prior to docking.

The Electrodynamic Dust Shield (EDS) technology that NASA has been developing as an active dust removal system during the past several years is being used to demonstrate dust removal from the PEM door. A transparent EDS system has also been installed on one of the viewports to maintain it dust-free during the DesertRaTS activities.

Figure 6. Photographs of the 20-cm diameter transparent EDS for the PEM viewport during laboratory tests. JSC-1A stimulant dust was deposited in a relatively uniform fashion, as shown at the top. The photograph below it shows the EDS after activation. Dust has been removed to the region outside the electrode grid. These tests were performed with the EDS sitting horizontally in a glove box.

In this paper, we describe the development of the different EDS systems installed on the PEM and the demonstration tests planned for DesertRaTS. We also describe scale up plans for future HDU demonstrations.

Review the research (PDF), HERE
Proceedings ESA Annual Meeting on Electrostatics 2010

Habitat Demonstration Unit: An Overview

Figure 1 from "The Habitat Demonstration Unit Project Overview," Illustration of the latest Constellation Lunar Scenario 12.1 "Excursion Configuration." The Pressurized Excursion Module (PEM) depicted at the center will be represented by the "HDU" and tested this summer as part of the 2010 Desert Research and Technologies Simulations ("Desert Rats") test objectives [NASA].

A technique being utilized in NASA's lunar architecture analysis is analog testing of the lunar environment in desert locales. Running through potential "day in the life" scenarios at a lunar outpost with prototype equipment allows designers insight into the utilization of the proposed systems and refines architecture and operations concepts. A series of Desert Research and Technology Studies (Desert-RATS) have been held in locations such as Moses Lake, Washington and Black Point Lava Flow, Arizona, where the most recent test in September 2009 was performed with a Lunar Electric Rover, and a fourteen day excursion was practiced. The 2010 session of Desert-RaTS is planned for Black Point Lava Flow where two LERs will operate together and add a full scale lunar habitat prototype, the Habitat Demonstration Unit to the two LERs to allow for a 14-28 day mission.

(Earth and Space Conference 2010, Honolulu, March 15-17)

Read the full Overview (Adobe .pdf) HERE.

Desert Rats wind up Arizona excursion

NASA has concluded two weeks of technology development tests on two of the agency's prototype lunar rovers.

The Desert RATS -- or Research and Technology Studies -- in the Arizona desert at Black Point Lava Flow allow NASA to analyze and refine technologies and procedures in extreme environments on Earth.

"These tests provide us with crucial information about how our cutting edge vehicles perform in field situations approximating the moon," said Rob Ambrose, Human Robotic Systems project lead at NASA's Johnson Space Center in Houston. "We learn from them, then go back home to refine the technology and plan the next focus of our research."

The annual studies featured an intensive, simulated 14-day mission. Two crew members, an astronaut and a geologist, lived for more than 300 hours inside NASA's prototype Lunar Electric Rover. The explorers scouted the area for features of geological interest, then donned spacesuits and conducted simulated moonwalks to collect samples. The crew also docked to a simulated habitat, drove the rover across difficult terrain, performed a rescue mission and made a four-day traverse across the lava.

Throughout the test, the crew provided updates via Twitter and posted pictures and video online. To see the images and videos and read about the simulated mission, HERE.

Prior to the test, NASA's K10 scout robot identified areas of interest for the crew to explore. NASA's heavy-lift rover Tri-ATHLETE -- or All-Terrain Hex-Legged Extra-Terrestrial Explorer -- carried a habitat mockup to which the rover docked.

The Desert RATS tests have been held for more than a decade, as engineers from NASA centers work with representatives from industry and academia to determine what will be needed for human exploration of the moon and other destinations in the solar system. This year's work built on the investigations of previous years and increased the scope and length of the tests.

Eight NASA centers were involved in the project. Desert RATS participants from outside NASA include the Smithsonian Institution in Washington; the United States Geological Survey in Flagstaff, Ariz.; Arizona State University in Tempe; University of Texas at El Paso; University of Colorado at Denver; Brown University in Providence, R.I.; the Mars Institute at Moffett Field, Calif.; and the Challenger Center for Space Science Education in Alexandria, Va.

For more information about NASA's exploration efforts, visit, http://www.nasa.gov/exploration

- Ashley Edwards, Grey Hautaluoma, Brandi Dean (NASA)

NASA's Desert Rats put LER through paces

Brent Garry with the Suit Port Transport Module.

Lee Allison
State Geologist of Arizona

Arizona Geology: NASA desert rats returning to Arizona to test lunar robot: "According to a press release posted on Reuters, the test will include 'a simulated 14-day mission during which two crew members -- an astronaut and a geologist -- will live inside NASA's prototype Lunar Electric Rover [above]. They will scout the test area for features of geological interest and conduct simulated moonwalks to collect samples.'

Arizona Geology
NASA Exploration Analogs

Testing for the Future

NASA Image of the Day, Friday, Aug. 21, 2009 spotlighted the Lunar Electric Rover (LER), being tested at NASA Johnson Space Center's planetary analog test site. LER will be part of the Desert RATS (Research and Technology Studies) Analog Field Test in Arizona in September. Image Credit: NASA/Franklin Fitzgerald

Suit ports

The Lunar Electric Rover (LER) is equipped with a time and space saving concept called suit ports. The suit ports are located on the aft bulkhead of the LER, and are designed to allow astronauts to quickly go from driving in a shirtsleeve environment to Extravehicular Activity (EVA) in their space suits. The suit port will allow the crew to enter and exit their EVA suits via a rear-entry hatch, while never having to bring the suit inside, keeping the internal cabin mostly free of dust. The suit port will also minimize the loss of consumables when it is depressurized for EVA, extending duration of an LER sortie. The crew uses alignment guides for docking to the suit port, and electromechanical mechanisms to lock and unlock the suit in place and also to open and close hatches. This is an upgrade from last year’s suit port concept that used all mechanically-actuated mechanisms with levers that the crew had to move. This suit port concept also includes an environmental shelter for the suits that will protect them from dust, thermal extremes, and micrometeoroid protection.

From the Desert RATS NASA Blog

Exploration Systems Mission Directorate launches new website

NASA’s Exploration Systems Mission Directorate is developing the concepts and technologies that will be needed to travel to and from the moon and sustain a human presence there.

Because NASA field centers do not have terrain similar to the lunar surface, the agency conducts analog tests in remote field locations. At these locations teams of scientists, engineers and astronauts test robotic equipment, vehicles, habitats, communications, and power generation and storage. They evaluate mobility, infrastructure and effectiveness in the harsh environments.

Test locations include the Antarctic region, oceans, deserts, and arctic and volcanic environments.

Last month, the Pavilion Lake Research Project (Pavilion Lake, Ontario, Canada) and the Haughton Mars Project (Devon Island, Nunavut, Canada) kicked off the 2009 series of exploration analog missions; and later this fall, the Desert RATS team will trek into the deserts of Arizona.

You can stay connected with current and upcoming analog research teams through Blogs, Flickr, Facebook, Twitter, and YouTube, all available through the analogs website, HERE.