NASA’s New Horizons mission is returning to normal science operations after a July 4 anomaly and remains on track for its July 14 flyby of Pluto.
The investigation into the anomaly that caused New Horizons to enter “safe mode” on July 4 has concluded that no hardware or software fault occurred on the spacecraft. The underlying cause of the incident was a hard-to-detect timing flaw in the spacecraft command sequence that occurred during an operation to prepare for the close flyby. No similar operations are planned for the remainder of the Pluto encounter.
“I’m pleased that our mission team quickly identified the problem and assured the health of the spacecraft,” said Jim Green, NASA’s Director of Planetary Science. “Now – with Pluto in our sights – we’re on the verge of returning to normal operations and going for the gold.”
Preparations are ongoing to resume the originally planned science operations on July 7 and to conduct the entire close flyby sequence as planned. The mission science team and principal investigator have concluded that the science observations lost during the anomaly recovery do not affect any primary objectives of the mission, with a minimal effect on lesser objectives. “In terms of science, it won’t change an A-plus even into an A,” said New Horizons Principal Investigator Alan Stern of the Southwest Research Institute, Boulder.
Adding to the challenge of recovery is the spacecraft’s extreme distance from Earth. New Horizons is almost 3 billion miles away, where radio signals, even traveling at light speed, need 4.5 hours to reach home. Two-way communication between the spacecraft and its operators requires a nine-hour round trip.
Status updates will be issued as new information is available.
The New Horizons spacecraft, which will fly past Pluto on July 14th, went into safe mode on Saturday. This happens occasionally with most spacecraft. It is like a reboot on a computer. Something unexpected happened, for example a memory bit flipping its value due to a cosmic ray hitting a RAM chip, and the control system is programmed to shut everything down and run only the most essential components including the communications gear.
The ground system team then re-establishes contact with the spacecraft and downloads data regarding why the system went into safe mode. After diagnosing what happened, the team will carefully restart one subsystem after another and will try to either fix or route around any component, e.g. a bad section of memory, that has a problem that could result in another safe mode incident.
[ Update 6:20 EDT July.5.15: No further updates yet from the New Horizons team on the recovery of the spacecraft from Safe Mode. Here are some articles about the incident:
This brief “Random Space Fact” video from the Planetary Society’s Bruce Betts was made before the Safe Mode incident but he provides some scale for the speed and distances involved in the mission:
]
Here is a statement on Saturday from the New Horizons team about the incident:
The New Horizons spacecraft experienced an anomaly this afternoon that led to a loss of communication with Earth. Communication has since been reestablished and the spacecraft is healthy.
The mission operations center at the Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, lost contact with the unmanned spacecraft — now 10 days from arrival at Pluto — at 1:54 p.m. EDT, and regained communications with New Horizons at 3:15 p.m. EDT, through NASA’s Deep Space Network.
During that time the autonomous autopilot on board the spacecraft recognized a problem and – as it’s programmed to do in such a situation – switched from the main to the backup computer. The autopilot placed the spacecraft in “safe mode,” and commanded the backup computer to reinitiate communication with Earth. New Horizons then began to transmit telemetry to help engineers diagnose the problem.
A New Horizons Anomaly Review Board was convened at 4 p.m. EDT to gather information on the problem and initiate a recovery plan. The team is now working to return New Horizons to its original flight plan. Due to the 9-hour, round trip communication delay that results from operating a spacecraft almost 3 billion miles (4.9 billion kilometers) from Earth, full recovery is expected to take from one to several days; New Horizons will be temporarily unable to collect science data during that time.
Status updates will be issued as new information is available.
– look fantastic and would clearly be places where many people would live if they existed today. The problem, of course, is that they do not exist and it’s difficult to convince people that it’s possible to ever build such gigantic habitats. But there are in fact ways to get from here to there.
When I fly into a big city and look out the window as the plane descends, I’m always amazed at just how enormous such places are. How could mere mortals create such a vast landscape of houses, buildings, skyscrapers, roads, bridges, harbors, and more? The answer, of course, is a city starts as a small settlement and over many decades the incremental efforts of thousands upon tens of thousands of people and their machines working in parallel day after day, year after year, create such massive metropolises.
Such a process can create cities in space as well. New Rome in orbit doesn’t have to be built in a day. We just need to get small “starter” settlements off the ground, so to speak.
That’s easy to say but what about the high cost of getting to space?
Fully reusable space transports like that being developed by SpaceX, Blue Origin, and other companies can bring down the cost of getting to space by factors of 10-100. The cost of propellants is a less than a half percent of the cost of an orbital rocket launch. The rest of, say, the $60M cost of Falcon 9 goes for the vehicle, which currently is thrown away on each flight.
What about the detrimental effects of microgravity and radiation on human health?
Rotation of a habitat can provide artificial gravity and bulk materials such as water and structural metals can shield people in a habitat just as the atmosphere shields people on earth.
The toughest question is how to get started. When giant habitats like those above were being designed in the 1970s, it was assumed that most of the material would be sent from the Moon. All of this would be paid for by huge investments from governments who would appreciate the construction of in-space solar power stations feeding energy via microwave to the earth.
Excavation activities on the Moon, space base solar power, and big government funding do not look likely to happen anytime soon, to say the least. Is there any other way to get space settlement underway?
Yes, it can still happen if the process can start small and pay its own way. Al Globus, who works as a contractor at NASA Ames Research Center in Mountain View, California, describes in a set of three documents listed below a plan for small affordable space habitats in low earth equatorial orbit that will provide 1 g gravity and enjoy sufficient radiation protection for residents to live a healthy life. Space tourism will be a primary industry similar to the way many island economies on earth rely on tourism.
* Space Settlement the Easy Way, Al Globus and Stephen Covey, presentation at ISDC 2015, May 2015.
“This presentation shows how the results of the next two papers — “Space Settlement Population Rotation Tolerance” and “Orbital Space Settlement Radiation Shielding” — when combined suggest that small space settlements in equatorial LEO with little or no radiation shielding may be viable. Hopefully, this will be turned into a paper in the not-too-distant-future.”
* Space Settlement Population Rotation Tolerance, Al Globus and Theodore Hall, preprint, June 2015.
“This paper reviews the literature to find that space settlement residents and visitors can tolerate at least four, and proabaly six, rotations per minute to achieve 1g of artificial gravity. This means settlements can be radically smaller, and thus easier to build, than previously believed. Combined with the next paper on radiation shielding, the first space settlements can be two orders of magnitude less massive and closer to Earth than previous designs making launch from Earth practical.”
* Orbital Space Settlement Radiation Shielding, Al Globus and Joe Strout, preprint, May 2015.
“The major result of this paper is that settlements in low (~500 km) Earth ***equatorial*** orbits may not require any radiation shielding at all based on a careful analysis of requirements and extensive simulation of radiation effects. This radically reduces system mass and has profound implications for space settlement as extraterrestrial mining and manufacturing are no longer on the critical path to the first settlements, although they will be essential in later stages. It also means the first settlements can evolve from space stations, hotels, and retirement communities in relatively small steps.”
Yes, there is methane on Pluto, and, no, it doesn’t come from cows. The infrared spectrometer on NASA’s Pluto-bound New Horizons spacecraft has detected frozen methane on Pluto’s surface; Earth-based astronomers first observed the chemical compound on Pluto in 1976.
The latest New Horizon image sequence of Pluto and its moon Charon.
“We already knew there was methane on Pluto, but these are our first detections,” said Will Grundy, the New Horizons Surface Composition team leader with the Lowell Observatory in Flagstaff, Arizona. “Soon we will know if there are differences in the presence of methane ice from one part of Pluto to another.”
Methane (chemical formula CH4) is an odorless, colorless gas that is present underground and in the atmosphere on Earth. On Pluto, methane may be primordial, inherited from the solar nebula from which the solar system formed 4.5 billion years ago. Methane was originally detected on Pluto’s surface by a team of ground-based astronomers led by New Horizons team member Dale Cruikshank, of NASA’s Ames Research Center, Mountain View, California.
Come Fly with New Horizons on its Approach to Pluto
Images from New Horizons show the view from aboard the spacecraft closes in on the Pluto system for a July 14 flyby.
This time-lapse approach movie was made from images from the Long Range Reconnaissance Imager (LORRI) camera aboard New Horizons spacecraft taken between May 28 and June 25, 2015. During that time the spacecraft distance to Pluto decreased almost threefold, from about 35 million miles to 14 million miles (56 million kilometers to 22 million kilometers). The images show Pluto and its largest moon, Charon, growing in apparent size as New Horizons closes in. As it rotates, Pluto displays a strongly contrasting surface dominated by a bright northern hemisphere, with a discontinuous band of darker material running along the equator. Charon has a dark polar region, and there are indications of brightness variations at lower latitudes.
Same sequence as above but with some extra information included
The New Horizons spacecraft has made a critical observation in preparation for its upcoming observations of Pluto’s tenuous atmosphere. Just hours after its flyby of Pluto on July 14, the spacecraft will observe sunlight passing through the planet’s atmosphere, to help scientists determine the atmosphere’s composition. “It will be as if Pluto were illuminated from behind by a trillion-watt light bulb,” said Randy Gladstone, a New Horizons scientist from Southwest Research Institute, San Antonio. On June 16, New Horizons’ Alice ultraviolet imaging spectrograph successfully performed a test observation of the sun from 3.1 billion miles away (5 billion kilometers), which will be used to interpret the July 14 observations.
This spectrum of the Sun obtained by New Horizons’ Alice instrument on June 16, 2015, will be used to interpret the spacecraft’s upcoming observations of Pluto’s atmosphere.
Credits: Photo credit: NASA/Johns Hopkins Applied Physics Laboratory/Southwest Research Institute
New Horizons is now less than 11 million miles (18 million kilometers) from the Pluto system. The spacecraft is healthy and all systems are operating normally.
The Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, designed, built, and operates the New Horizons spacecraft, and manages the mission for NASA’s Science Mission Directorate. The Southwest Research Institute, based in San Antonio, leads the science team, payload operations and encounter science planning. New Horizons is part of the New Frontiers Program managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama.
Follow the New Horizons mission on social media, and use the hashtag #PlutoFlyby to join the conversation. The mission’s official NASA Twitter account is @NASANewHorizons. Live updates will be available on Facebook at: www.facebook.com/new.horizons1
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Here is a separate notice about a course correction for the spacecraft:
With just two weeks to go before its historic July 14 flight past Pluto, NASA’s New Horizons spacecraft tapped the accelerator late last night and tweaked its path toward the Pluto system.
The 23-second thruster burst was the third and final planned targeting maneuver of New Horizons’ approach phase to Pluto; it was also the smallest of the nine course corrections since New Horizons launched in January 2006. It bumped the spacecraft’s velocity by just 27 centimeters per second – about one-half mile per hour – slightly adjusting its arrival time and position at a flyby close-approach target point approximately 7,750 miles (12,500 kilometers) above Pluto’s surface.
While it may appear to be a minute adjustment for a spacecraft moving 32,500 miles per hour, the impact is significant. New Horizons Mission Design Lead Yanping Guo, of the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, says without the adjustment, New Horizons would have arrived 20 seconds late and 114 miles (184 kilometers) off-target from the spot where it will measure the properties of Pluto’s atmosphere. Those measurements depend on radio signals being sent from Earth to New Horizons at precise times as the spacecraft flies through the shadows of Pluto and Pluto’s largest moon, Charon.
In fact, timing and accuracy are critical for all New Horizons flyby observations, since those commands are stored in the spacecraft’s computers and programmed to “execute” at exact times.
This latest shift was based on radio-tracking data on the spacecraft and range-to-Pluto measurements made by optical-navigation imaging of the Pluto system taken by New Horizons in recent weeks. Using commands transmitted to the spacecraft on June 28, the thrusters began firing at 11:01 p.m. EDT on June 29 and stopped 23 seconds later. Telemetry indicating the spacecraft was healthy and that the maneuver went as designed began reaching the New Horizons Mission Operations Center at APL, through NASA’s Deep Space Network at 5:30 a.m. EDT on June 30.
“We are really on the final path,” said New Horizons Project Manager Glen Fountain, of APL. “It just gets better and more exciting every day.”
“This maneuver was perfectly performed by the spacecraft and its operations team,” added mission principal investigator Alan Stern, of Southwest Research Institute, Boulder, Colorado. “Now we’re set to fly right down the middle of the optimal approach corridor.”
New Horizons is now about 10 million miles (16 million kilometers) from the Pluto system – some 2.95 billion miles (4.75 billion kilometers) from Earth
![nh-6-30-15_pluto_movie_nasa_jhuapl_swri[1]](http://hobbyspace.com/Blog/wp-content/uploads/2015/07/nh-6-30-15_pluto_movie_nasa_jhuapl_swri1.gif "Pluto")
