APOD and General Astronomy Discussion Forum
https://asterisk.apod.com/
Having to make rockets that are more powerful isn't a detail, but a deal killer.JohnD wrote:Look, I'm not criticising anyone, I've no agenda,I want this mission to work, but if there had been tests of such an innovative system, wouldn't NASA have been proud to make them available? But they show cartoons. I can see that the rockets that work on Mars would not on Earth, so they would have to be more powerful, but that's a detail. It's the guidance system that is important. Lots of evidence that such systems DO work, see my previous.
I don't think any missions have failed because of inadequate testing, except maybe for Phobos-Grunt, and we don't really know the details of that yet.JohnD wrote:But Chris, Mars is the Cursed Planet! Overall, half the probes have not worked!
I offer Beagle II, before someone else does, and then Phobos-Grunt, and NASA has a better record with landers, but 'simulation is so effective'?
Because you are immediately testing a different system then you will actually use. On Earth, with a different gravity and an atmosphere, all the dynamics change. I think you will get better results from a properly designed simulator (and I'm not limiting this to pure numerical simulation; you can test an attitude control system by putting it on an attitude table- no need for actual rockets).Please explain, Chris, why the need for more powerful rockets is the 'deal killer'?
NASA's Mars Science Laboratory spacecraft successfully refined its flight path Wednesday with the biggest maneuver planned for the mission's journey between Earth and Mars.
"We've completed a big step toward our encounter with Mars," said Brian Portock of NASA's Jet Propulsion Laboratory, Pasadena, Calif., deputy mission manager for the cruise phase of the mission. "The telemetry from the spacecraft and the Doppler data show that the maneuver was completed as planned."
The Mars Science Laboratory mission will use its car-size rover, Curiosity, to investigate whether the selected region on Mars inside Gale Crater has offered environmental conditions favorable for supporting microbial life and favorable for preserving clues about whether life existed.
Engineers had planned today's three-hour series of thruster-engine firings to accomplish two aims: to put the spacecraft's trajectory about 25,000 miles (about 40,000 kilometers) closer to encountering Mars and to advance the time of the encounter by about 14 hours, compared with the trajectory following the mission's Nov. 26, 2011, launch.
"The timing of the encounter is important for arriving at Mars just when the planet's rotation puts Gale Crater in the right place," said JPL's Tomas Martin-Mur, chief navigator for the mission.
The mission's second trajectory correction maneuver, expected to be about one-sixth the magnitude of this first one, is scheduled for March 26. Up to four additional opportunities for fine-tuning, as needed, are scheduled before the arrival at Mars on Aug. 5, 2012, PDT (Aug. 6, EDT and Universal Time).
The spacecraft's initial trajectory resulting from the launch included an intentional offset to prevent the upper stage of the launch vehicle from hitting Mars. That upper stage was not cleaned the way the spacecraft itself was to protect Mars from Earth's microbes.
The Mars Science Laboratory spacecraft rotates in flight at about two revolutions per minute. Today's maneuver included two different components: one that changed velocity in the direction of the axis of the spacecraft's rotation, and one that changed velocity in a direction perpendicular to that.
The maneuver used the eight thruster engines on the cruise stage of the spacecraft, grouped into two sets of four. It began with a thrust lasting about 19 minutes, using just one thruster in each set and affecting velocity along the direction of the axis of rotation. Then, to affect velocity perpendicular to that line, each set of thrusters was fired for 5 seconds when the rotation put that set facing the proper direction. These 5-second bursts were repeated more than 200 times during a period of about two hours for a total of about 40 minutes.
The maneuver was calculated to produce a net change in velocity of about 12.3 miles per hour (5.5 meters per second), combining a slight increase in speed with a small change in direction of travel.
As of 9 a.m. PST (noon EST) on Thursday, Jan. 12, the spacecraft will have traveled 81.2 million miles (130.6 million kilometers) of its 352-million-mile (567-million-kilometer) flight to Mars. It will be moving at about 10,300 mph (16,600 kilometers per hour) relative to Earth, and at about 68,700 mph (110,500 kilometers per hour) relative to the sun.
Helicopter Helps Test Radar for 2012 Mars LandingJohnD wrote:Re: my above of Dec 18th.
The largest solar particle event since 2005 hit the Earth, Mars and the Mars Science Laboratory spacecraft travelling in-between, allowing the onboard Radiation Assessment Detector (RAD) to measure the radiation a human astronaut could be exposed to en route to the Red Planet.
On Sunday, a huge coronal mass ejection erupted from the surface of the sun, spewing a cloud of charged particles in our direction, causing a strong "S3" solar storm. A NASA Goddard Space Weather Lab animation of the CME illustrates how the disturbance impacts Earth, Mars and several spacecraft. Solar storms can affect the Earth's aurorae, satellites, air travel and GPS systems; no harmful effects to the Mars Science Laboratory have been detected from this solar event.
"We only have a few hours of data downloaded from the RAD so far, but we clearly see the event, said RAD Principal Investigator Don Hassler, science program director in the Space Studies Department at Southwest Research Institute. The Mars Science Laboratory, launched Nov. 26, will land a sophisticated car-sized rover called Curiosity on the surface of the planet in August. Loaded with 10 instruments including RAD, Curiosity will traverse the landing site looking for the building blocks of life and characterizing factors that may influence life, such as the harsh radiation environment expected on Mars. "This SPE encounter is particularly exciting in light of the alignment between the Earth, MSL and Mars right now and for the next few months. It will be very interesting to compare the RAD data, collected from inside the capsule, with the data from other spacecraft."
This event has also been seen by the Solar Dynamics Observatory, Geostationary Operational Environment Satellites, the Advanced Composition Explorer, and the twin Solar Terrestrial Relations Observatory spacecraft in Earth orbit as well as the Solar Heliospheric Observatory flying between Earth and the sun.
"RAD was designed to characterize radiation levels on the surface of Mars, but an important secondary objective is measuring the radiation during the almost nine-month journey through interplanetary space to prepare for future human exploration," said Hassler. "RAD is an important bridge between the science and exploration sides of NASA.
"Not only will this give us insight into the physics of these giant clouds, but like an astronaut, RAD is tucked inside the MSL 'spacecraft,'" Hassler continued. "Measurements from RAD will give us insight about the shielding provided by spacecraft for future manned missions in deep space."
RAD will collect data nearly continuously during cruise and will downlink data every 24 hours. Positioned in the front-left corner of the rover, the instrument is about the size of a coffee can and weighs about three pounds, but has capabilities of an Earth-bound instrument nearly 10 times its size. When MSL arrives at Mars, RAD will detect charged particles arriving from space and will measure neutrons and gamma rays coming from Mars' atmosphere above, or the surface material below, the rover.
The camera at the end of the robotic arm on NASA's Mars rover Curiosity has its own calibration target, a smartphone-size plaque that looks like an eye chart supplemented with color chips and an attached penny.
When Curiosity lands on Mars in August, researchers will use this calibration target to test performance of the rover's Mars Hand Lens Imager, or MAHLI. MAHLI's close-up inspections of Martian rocks and soil will show details so tiny, the calibration target includes reference lines finer than a human hair. This camera is not limited to close-ups, though. It can focus on any target from about a finger's-width away to the horizon.
Curiosity, the rover of NASA's Mars Science Laboratory mission, also carries four other science cameras and a dozen black-and-white engineering cameras, plus other research instruments. The spacecraft, launched Nov. 26, 2011, will deliver Curiosity to a landing site inside Mars' Gale Crater in August to begin a two-year investigation of whether that area has ever offered an environment favorable for microbial life.
The "hand lens" in MAHLI's name refers to field geologists' practice of carrying a hand lens for close inspection of rocks they find. When shooting photos in the field, geologists use various calibration methods.
"When a geologist takes pictures of rock outcrops she is studying, she wants an object of known scale in the photographs," said MAHLI Principal Investigator Ken Edgett, of Malin Space Science Systems, San Diego. "If it is a whole cliff face, she'll ask a person to stand in the shot. If it is a view from a meter or so away, she might use a rock hammer. If it is a close-up, as the MAHLI can take, she might pull something small out of her pocket. Like a penny."
Edgett bought the special penny that's aboard Curiosity with funds from his own pocket. It is a 1909 "VDB" cent, from the first year Lincoln pennies were minted, the centennial of Abraham Lincoln's birth, with the VDB initials of the coin's designer - Victor David Brenner -- on the reverse.
"The penny is on the MAHLI calibration target as a tip of the hat to geologists' informal practice of placing a coin or other object of known scale in their photographs. A more formal practice is to use an object with scale marked in millimeters, centimeters or meters," Edgett said. "Of course, this penny can't be moved around and placed in MAHLI images; it stays affixed to the rover."
The middle of the target offers a marked scale of black bars in a range of labeled sizes. While the scale will not appear in photos MAHLI takes of Martian rocks, knowing the distance from the camera to a rock target will allow scientists to correlate calibration images to each investigation image.
Another part of MAHLI's calibration target displays six patches of pigmented silicone as aids for interpreting color and brightness in images. Five of them -- red, green, blue, 40-percent gray and 60-percent gray -- are spares from targets on NASA Mars rovers Spirit and Opportunity. The sixth, with a fluorescent pigment that glows red when exposed to ultraviolet light, allows checking of an ultraviolet light source on MAHLI. The fluorescent material was donated to the MAHLI team by Spectra Systems, Inc., Providence, R.I.
A stair-stepped area at the bottom of the target, plus the penny, help with three-dimensional calibration using known surface shapes.
Curiosity also carries calibration materials for other science instruments on the rover. "The importance of calibration is to allow data acquired on Mars to be compared reliably to data acquired on Earth," said Mars Science Laboratory Project Scientist John Grotzinger, of the California Institute of Technology, Pasadena.
The MAHLI calibration target, with its penny and a miniscule cartoon of a character named "Joe the Martian," serves an additional function: public engagement.
"Everyone in the United States can recognize the penny and immediately know how big it is, and can compare that with the rover hardware and Mars materials in the same image," Edgett said. "The public can watch for changes in the penny over the long term on Mars. Will it change color? Will it corrode? Will it get pitted by windblown sand?"
The Joe the Martian character appeared regularly in a children's science periodical, "Red Planet Connection," when Edgett directed the Mars outreach program at Arizona State University, Tempe, in the 1990s. Joe was created earlier, as part of Edgett's schoolwork when he was 9 years old and NASA's Mars Viking missions, launched in 1975, were inspiring him to dream of becoming a Mars researcher.
Edgett said, "The Joe the Martian on Curiosity really is a 'thank you' from the MAHLI team to the folks who have provided us with the opportunity to study Mars, the U.S. taxpayers. He is also there to encourage children around the world to set goals that will help them achieve their dreams in whatever interests they pursue."
With a pair of bug-eyes swiveling on a stalk nearly 8 feet off the ground, the 6-wheeled, 1800-lb Mars rover Curiosity doesn’t look much like a human being. Yet, right now, the mini-Cooper-sized rover is playing the role of stunt double for NASA astronauts.Click to play embedded YouTube video.ScienceCasts: Curiosity, The Stunt Double
“Curiosity is riding to Mars in the belly of a spacecraft, where an astronaut would be,” explains Don Hassler of the Southwest Research Institute in Boulder, Colorado. “This means the rover experiences deep-space radiation storms in the same way that a real astronaut would.”
Indeed, on Jan. 27th, 2012, Curiosity’s spacecraft was hit by the most intense solar radiation storm since 2005. The event began when sunspot AR1402 produced an X2-class solar flare. (On the “Richter Scale of Solar Flares,” X-flares are the most powerful kind.) The explosion accelerated a fusillade of protons and electrons to nearly light speed; these subatomic bullets were guided by the sun’s magnetic field almost directly toward Curiosity.
When the particles hit the outer walls of the spacecraft, they shattered other atoms and molecules in their path, producing a secondary spray of radiation that Curiosity both absorbed and measured.
“Curiosity was in no danger,” says Hassler. “In fact, we intended all along for the rover to experience these storms en route to Mars.”
Unlike previous Mars rovers, Curiosity is equipped with a Radiation Assessment Detector. The instrument, nicknamed “RAD,” counts cosmic rays, neutrons, protons and other particles over a wide range of biologically-interesting energies. RAD’s prime mission is to investigate the radiation environment on the surface of Mars, but researchers have turned it on early so that it can also probe the radiation environment on the way to Mars as well.
Curiosity’s location inside the spacecraft is key to the experiment.
“We have a pretty good idea what the radiation environment is like outside,” says Hassler, who is the principal investigator for RAD. “Inside the spacecraft, however, is still a mystery.”
Even supercomputers have trouble calculating exactly what happens when high-energy cosmic rays and solar energetic particles hit the walls of a spacecraft. One particle hits another; fragments fly; the fragments themselves crash into other molecules.
“It’s very complicated. Curiosity is giving us a chance to actually measure what happens.”
Even when the sun is quiet, Curiosity is bombarded by a slow drizzle of cosmic rays—high-energy particles accelerated by distant black holes and supernova explosions. In the aftermath of the Jan. 27th X-flare, RAD detected a surge of particles several times more numerous than the usual cosmic ray counts. Hassler’s team is still analyzing the data to understand what it is telling them about the response of the spacecraft to the storm.
More X-flares will help by adding to the data set. Hassler expects the sun to cooperate, because the solar cycle is trending upward toward a maximum expected in early 2013.
As of February 2012, “we still have 6 months to go before we reach Mars. That’s plenty of time for more solar storms.”
A stunt double’s work is never done.
At 10:31 p.m. PDT April 27, (1:31 p.m. EDT), NASA's Mars Science Laboratory, carrying the one-ton Curiosity rover, will be within 100 days from its appointment with the Martian surface. At that moment, the mission has about 119 million miles (191 million kilometers) to go and is closing at a speed of 13,000 mph (21,000 kilometers per hour).
"Every day is one day closer to the most challenging part of this mission," said Pete Theisinger, Mars Science Laboratory project manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Landing an SUV-sized vehicle next to the side of a mountain 85 million miles from home is always stimulating. Our engineering and science teams continue their preparations for that big day and the surface operations to follow."
On Sunday, April 22, a week-long operational readiness test concluded at JPL. The test simulated aspects of the mission's early surface operations. Mission planners and engineers sent some of the same commands they will send to the real Curiosity rover on the surface of Mars to a test rover used at JPL.
"Our test rover has a central computer identical to Curiosity's currently on its way to Mars," said Eric Aguilar, the mission's engineering test lead at JPL. "We ran all our commands through it and watched to make sure it drove, took pictures and collected samples as expected by the mission planners. It was a great test and gave us a lot of confidence moving forward."
The Mars Science Laboratory spacecraft, launched Nov. 26, 2011, will deliver Curiosity to the surface of Mars on the evening of Aug. 5, 2012, PDT (early on Aug. 6, Universal Time and EDT) to begin a two-year prime mission. Curiosity's landing site is near the base of a mountain inside Gale Crater, near the Martian equator. Researchers plan to use Curiosity to study layers in the mountain that hold evidence about wet environments of early Mars.
NASA has narrowed the target for its most advanced Mars rover, Curiosity, which will land on the Red Planet in August. The car-sized rover will arrive closer to its ultimate destination for science operations, but also closer to the foot of a mountain slope that poses a landing hazard.Image Credits: NASA/JPL-Caltech/ESA/DLR/FU Berlin/MSSS
"We're trimming the distance we'll have to drive after landing by almost half," said Pete Theisinger, Mars Science Laboratory project manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "That could get us to the mountain months earlier."
It was possible to adjust landing plans because of increased confidence in precision landing technology aboard the Mars Science Laboratory spacecraft, which is carrying the Curiosity rover. That spacecraft can aim closer without hitting Mount Sharp at the center of Gale crater. Rock layers located in the mountain are the prime location for research with the rover.
Curiosity is scheduled to land at approximately 10:31 p.m. PDT Aug. 5 (1:31 a.m. EDT, Aug. 6). Following checkout operations, Curiosity will begin a two-year study of whether the landing vicinity ever offered an environment favorable for microbial life.
Theisinger and other mission leaders described the target adjustment during an update to reporters on Monday, June 11, about preparations for landing and for operating Curiosity on Mars.
The landing target ellipse had been approximately 12 miles wide and 16 miles long (20 kilometers by 25 kilometers). Continuing analysis of the new landing system's capabilities has allowed mission planners to shrink the area to approximately 4 miles wide and 12 miles long (7 kilometers by 20 kilometers), assuming winds and other atmospheric conditions are as predicted.
Even with the smaller ellipse, Curiosity will be able to touch down at a safe distance from steep slopes at the edge of Mount Sharp.
"We have been preparing for years for a successful landing by Curiosity, and all signs are good," said Dave Lavery, Mars Science Laboratory program executive at NASA. "However, landing on Mars always carries risks, so success is not guaranteed. Once on the ground we'll proceed carefully. We have plenty of time since Curiosity is not as life-limited as the approximate 90-day missions like NASA’s Mars Exploration Rovers and the Phoenix lander.”
Since the spacecraft was launched in November 2011, engineers have continued testing and improving its landing software. Mars Science Laboratory will use an upgraded version of flight software installed on its computers during the past two weeks. Additional upgrades for Mars surface operations will be sent to the rover about a week after landing.
Other preparations include upgrades to the rover's software and understanding effects of debris coming from the drill the rover will use to collect samples from rocks on Mars. Experiments at JPL indicate that Teflon from the drill could mix with the powdered samples. Testing will continue past landing with copies of the drill. The rover will deliver the samples to onboard instruments that can identify mineral and chemical ingredients.
"The material from the drill could complicate, but will not prevent analysis of carbon content in rocks by one of the rover's 10 instruments. There are workarounds,” said John Grotzinger, the mission’s project scientist at the California Institute of Technology in Pasadena. "Organic carbon compounds in an environment are one prerequisite for life. We know meteorites deliver non-biological organic carbon to Mars, but not whether it persists near the surface. We will be checking for that and for other chemical and mineral clues about habitability."
Curiosity will be in good company as it nears landing. Two NASA Mars orbiters, along with a European Space Agency orbiter, will be in position to listen to radio transmissions as Mars Science Laboratory descends through Mars' atmosphere.
CURIOSITYgeckzilla wrote:The music in that video reminds me of the soundtrack for Inception. And why, oh why, did I read some of the comments that have been posted?
BMAONE23 wrote:Orca wrote:
Roughly 1 day to go!
- 13+ Hours
http://www.washingtonpost.com/national/health-science/mars-rover-curiosity-on-course-to-land-monday/2012/08/04/896a28c8-de3b-11e1-af1d-753c613ff6d8_story.html wrote:
Mars rover Curiosity on course to land Monday
By Marc Kaufman, Washington Post, August 4, 2012
<<Anxious engineers and scientists will be waiting for a touchdown “beep” — which comes as computer code — that will report a safe landing. It could come as early as 1:31 a.m. Several hours of silence from Curiosity are quite possible, officials said, since the rover’s signals can be received only if the Mars orbiters that will relay its messages are in precisely the correct location. But if nothing is heard from the orbiters or through the Deep Space Network after about 18 hours, said MSL deputy project manager Richard Cook, then it’s time to start worrying about the fate of the mission.>>
