A little over a week before NASA’s MAVEN spacecraft fired its rockets to successfully enter orbit around Mars, MESSENGER performed a little burn of its own – the second of four orbit correction maneuvers (OCMs) that will allow it to remain in orbit around Mercury until next March. Although it is closing in on the end of its operational life it’s nice to know we still have a few more months of images and discoveries from MESSENGER to look forward to!
The first OCM burn was performed on June 17, raising MESSENGER’s orbit from 115 kilometers (71.4 miles) to 156.4 kilometers (97.2 miles) above the surface of Mercury. That was the ninth OCM of the MESSENGER mission, and at 11:54 a.m. EDT on Sept. 12, 2014, the tenth was performed.
At the time of this most recent maneuver, MESSENGER was in an orbit with a closest approach of 24.3 kilometers (15.1 miles) above the surface of Mercury. With a velocity change of 8.57 meters per second (19.17 miles per hour), the spacecraft’s four largest monopropellant thrusters (with a small contribution from four of the 12 smallest monopropellant thrusters) nudged the spacecraft to an orbit with a closest approach altitude of 94 kilometers (58.4 miles). This maneuver also increased the spacecraft’s speed relative to Mercury at the maximum distance from Mercury, adding about 3.2 minutes to the spacecraft’s eight-hour, two-minute orbit period.
OCM-10 lasted for 2 1/4 minutes and added 3.2 minutes to the spacecraft’s 8-hour, 2-minute-long orbit. (Source)
The next two burns will occur on October 24 and January 21.
After its two final successful burns MESSENGER will be out of propellant, making any further OCMs impossible. At the planned end of its mission MESSENGER will impact Mercury’s surface in March of 2015.
Built and operated by The Johns Hopkins University Applied Physics Laboratory (JHUAPL), MESSENGER launched from Cape Canaveral Air Force Station on August 3, 2004. It entered orbit around Mercury on March 18, 2011, the first spacecraft ever to do so. Since then it has performed countless observations of our Solar System’s innermost planet and has successfully mapped 100% of its surface. Check out the infographic below showing some of the amazing numbers racked up by MESSENGER since its launch ten years ago, and read more about the MESSENGER mission here.
Watch here live, below, for the Mars orbital insertion of the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft, on Sunday, September 21 (or early Sept. 22 depending on your time zone) from 9:30 to 10:45 p.m. EDT, 01:30 to 02:45 UTC). The NASA TV broadcast feed will originate from the Lockheed Martin Facility in Littleton, Colorado, and will feature live camera views of mission control, interviews with senior NASA officials and mission team members, and mission video footage. The spacecraft’s mission timeline will place the spacecraft in orbit at approximately 9:50 p.m. EDT (01:50 UTC).
Coverage will wrap up with a post-orbit insertion news conference, targeted for about two hours after orbital insertion begins.
Members of the public are invited to follow the day-long NASA Social event on Sunday by following the hashtags #MAVEN and #JourneytoMars on social media channels including Twitter, Instagram and Facebook. Twitter updates will be posted throughout on the agency’s official accounts @NASA, @MAVEN2Mars and @NASASocial.
MAVEN launched Nov. 18, 2013, from Cape Canaveral Air Force Station in Florida, carrying three instrument packages. It is the first spacecraft dedicated to exploring the upper atmosphere of Mars. The mission’s goal is to determine how the loss of atmospheric gas to space played a role in changing the Martian climate through time.
SpaceX Falcon 9 erect at Cape Canaveral launch pad 40 awaiting launch on Sept 20, 2014 on the CRS-4 mission.
Credit: Ken Kremer – kenkremer.com
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KENNEDY SPACE CENTER, FL – SpaceX is on the cusp of launching the company’s fourth commercial resupply Dragon spacecraft mission to the International Space Station (ISS) shortly after midnight, Saturday, Sept. 20, 2014, continuing a rapid fire launch pace and carrying NASA’s first research payload – RapidScat – aimed at conducting Earth science from the stations exterior.
Final preparations for the launch are underway right now at the Cape Canaveral launch pad with the stowage of sensitive late load items including a specially designed rodent habitat housing 20 mice.
Update 20 Sept: Poor weather scrubs launch to Sept. 21 at 1:52 a.m.
Fueling of the two stage rocket with liquid oxygen and kerosene propellants commences in the evening prior to launch.
If all goes well, Saturday’s launch of a SpaceX Falcon 9 rocket would be the second in less than two weeks, and the fourth over the past ten weeks. The last Falcon 9 successfully launched the AsiaSat 6 commercial telecom satellite on Sept. 7 – detailed here.
“We are ready to go,” said Hans Koenigsmann, SpaceX vice president of mission assurance, at a media briefing at the Kennedy Space Center today, Sept. 19.
Liftoff of the SpaceX Falcon 9 rocket on the CRS-4 mission bound for the ISS is targeted for an instantaneous window at 2:14 a.m. EDT from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida at the moment Earth’s rotation puts Cape Canaveral in the flight path of the ISS.
You can watch NASA’s live countdown coverage which begins at 1 a.m. on NASA Television and NASA’s Launch Blog: http://www.nasa.gov/multimedia/nasatv/
The weather forecast is marginal at 50/50 with rain showers and thick clouds as the primary concerns currently impacting the launch site.
The Dragon spacecraft is loaded with more than 5,000 pounds of science experiments, spare parts, crew provisions, food, clothing and supplies to the six person crews living and working aboard the ISS soaring in low Earth orbit under NASA’s Commercial Resupply Services (CRS) contract.
The CRS-4 missions marks the start of a new era in Earth science. The truck of the Dragon is loaded Dragon with the $30 Million ISS-Rapid Scatterometer to monitor ocean surface wind speed and direction.
RapidScat is NASA’s first research payload aimed at conducting Earth science from the stations exterior. The stations robot arm will pluck RapidScat out of the truck and attach it to an Earth-facing point on the exterior trusswork of ESA’s Columbus science module.
Dragon will also carry the first 3-D printer to space for studies by the astronaut crews over at least two years.
The science experiments and technology demonstrations alone amount too over 1644 pounds (746 kg) and will support 255 science and research investigations that will occur during the station’s Expeditions 41 and 42 for US investigations as well as for JAXA and ESA.
“This flight shows the breadth of ISS as a research platform, and we’re seeing the maturity of ISS for that,” NASA Chief Scientist Ellen Stofan said during a prelaunch news conference held today, Friday, Sept. 19 at NASA’s Kennedy Space Center.
After a two day chase, Dragon will be grappled and berth at an Earth-facing port on the stations Harmony module.
The Space CRS-4 mission marks the company’s fourth resupply mission to the ISS under a $1.6 Billion contract with NASA to deliver 20,000 kg (44,000 pounds) of cargo to the ISS during a dozen Dragon cargo spacecraft flights through 2016.
This week, SpaceX was also awarded a NASA contact to build a manned version of the Dragon dubbed V2 that will ferry astronauts crews to the ISS starting as soon as 2017.
NASA also awarded a second contact to Boeing to develop the CST-100 astronaut ‘space taxi’ to end the nation’s sole source reliance on Russia for astronaut launches in 2017.
Dragon V2 will launch on the same version of the Falcon 9 launching this cargo Dragon
Stay tuned here for Ken’s continuing SpaceX, Boeing, Sierra Nevada, Orbital Sciences, commercial space, Orion, Mars rover, MAVEN, MOM and more planetary and human spaceflight news.
NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) orbiter is oh-so-close to its destination after a 10-month journey. It’s scheduled to arrive in orbit Sunday (Sept. 21) around 9:50 p.m. EDT (1:50 a.m. UTC) if all goes well, but there are a few things that need to happen, in order, first.
One big obstacle is already out of the way. MAVEN controllers had expected to do final engine burn tweaks to put it on the right trajectory, but the mission is so on-target that it won’t be needed.
“#MAVEN orbit insertion sequence has been activated on the s/c. No additional ground intervention is needed to enter #Mars’ orbit on Sunday,” the official account tweeted yesterday (Sept. 18).
So what does the sequence entail? MAVEN will need to turn on its six thruster engines for a 33-minute braking maneuver to slow it down. This will allow the gravity of Mars to “capture” the spacecraft into an elliptical or oval-shaped orbit.
Should that all go safely, MAVEN still has a lot of work to do before being ready to capture information about the upper atmosphere of the Red Planet. All spacecraft go through a commissioning phase to ensure their instruments are working correctly and that they are in the correct orbit and orientation to do observations.
Controllers are interested in learning about the comet and its effect on the upper atmosphere, so they will stop the commissioning to make those measurements. MAVEN will also be oriented in such a way that its solar panels are protected as much as possible from the dust, although scientists now believe the risk of strikes is very low.
MAVEN is expected to work at Mars for a year, but investigators are hoping it will be for longer so that the atmosphere can be tracked through more of a solar cycle. The Sun’s activity is a major influencer on the atmosphere and the “stripping” of molecules from it over time, which could have thinned Mars’ atmosphere in the ancient past.
The spacecraft will also serve as a backup communications and data relay for the Opportunity and Curiosity rovers on the surface, which might be needed if some of the older NASA Mars spacecraft that fulfill that function experience technical difficulties.
While NASA often speaks about the power of Earth observation from the International Space Station, the picture above from one of the astronauts on board now shows something else — you can get an awesome view of the Milky Way.
With the view unobscured by the atmosphere, the picture from Expedition 41 European astronaut Alexander Gerst shows that his perch on the ISS is pretty amazing. We wonder how it compares to some of the desert or mountaintop observatories here on Earth! And there are astronomical experiments on board, such as this one that may have found dark matter.
Below we’ve handpicked some of the best recent pictures from Gerst and NASA astronaut Reid Wiseman, a crewmate, as they take in the wonder of our planet and the universe.
What are these thick dune-like features on Mars, and how were they formed? Scientists are still trying to puzzle out these ridges, which you can see above in a more tropical region of the Red Planet called Iapygia, which is south of Syrtis Major. The thick ridges were captured from orbit by the Mars Reconnaissance Orbiter’s High Resolution Imaging Science Experiment (HiRISE), and we’ve included some more intriguing pictures below the jump.
“Called transverse aeolian ridges, or TARs, the features stand up to 6 meters tall and are spaced a few tens of meters apart. They are typically oriented transverse to modern day wind directions, and often found in channels and crater interiors,” read an update on the University of Arizona’s HiRISE blog.
“The physical process that produces these features is still mysterious. Most TARs display no evidence of internal structure, so it is difficult to discern exactly how they were formed.”
This picture from the NASA spacecraft was taken in Iapygia, which is south of Syrtis Major. While scientists say these look similar to TARs in other parts of the Red Planet, the features have layers on the northwest faces and a paucity on the southern side.
Scientists suggest it’s because these TARs may have had wedge-shaped layers, which hints that they would have gotten taller as material was added to the ridges. They hope to do further studies to learn more about how TARs formed in other regions on Mars.
We’ve included other recent releases from the HiRISE catalog below, so enjoy the Martian vistas!
NASA’s Dawn spacecraft experienced technical problems in the past week that will force it to arrive at dwarf planet Ceres one month later than planned, the agency said in a statement yesterday (Sept. 16).
Controllers discovered Dawn was in safe mode Sept. 11 after radiation disabled its ion engine, which uses electrical fields to “push” the spacecraft along. The radiation stopped all engine thrusting activities. The thrusting resumed Monday (Sept. 15) after controllers identified and fixed the problem, but then they found another anomaly troubling the spacecraft.
Dawn’s main antenna was also disabled, forcing the spacecraft to send signals to Earth (a 53-minute roundtrip by light speed) through a weaker secondary antenna and slowing communications. The cause of this problem hasn’t been figured out yet, but controllers suspect radiation affected the computer’s software. A computer reset has solved the issue, NASA added. The spacecraft is now functioning normally.
“As a result of the change in the thrust plan, Dawn will enter into orbit around dwarf planet Ceres in April 2015, about a month later than previously planned. The plans for exploring Ceres once the spacecraft is in orbit, however, are not affected,” NASA’s Jet Propulsion Laboratory stated in a press release.
Dawn is en route to Ceres after orbiting the huge asteroid Vesta between July 2011 and September 2012. A similar suspected radiation blast three years ago also disabled Dawn’s engine before it reached Vesta, but the ion system worked perfectly in moving Dawn away from Vesta when that phase of its mission was complete, NASA noted.
Among Dawn’s findings at Vesta is that the asteroid is full of hydrogen, and it contains the hydrated mineral hydroxyl. This likely came to the asteroid when smaller space rocks brought the volatiles to its surface through low-speed collisions.
Spacecraft can experience radiation through energy from the Sun (particularly from solar flares) and also from cosmic rays, which are electrically charged particles that originate outside the Solar System. Earth’s atmosphere shields the surface from most space-based radiation.
With a newly cleared memory, it’s time for Opportunity to resume the next stage of its long, long Martian drive. The next major goal for the long-lived rover is to go to Marathon Valley, a spot that (in images from orbit) appears to have clay minerals on site. Clay tends to form in the presence of water, so examining the region could provide more information about Mars’ wet, ancient past.
A NASA planetary senior review panel from early September, which was evaluating the science value of several extended missions, said there are “software and communication issues that afflict the rover” that could affect its ability to send data. (This was written before the memory reformat.)
The major goal of Opportunity’s latest extended mission, the review continued, is to find out what habitability conditions existed on Mars. This includes looking at the water, the geology and the environment.
“This will be achieved by measurements of rocks and soils, as well as atmospheric observations, as it traverses from Murray Ridge to Cape Tribulation,” the report read.
“This extended mission will focus on the orbitally detected phyllosilicate deposits near Endeavour crater, which are considered to represent deposits from the ancient Noachian period. This would represent the first time that such ancient deposits have been analyzed on the Martian surface.”
The report further cautioned that there is no proof yet that the phyllosilicates (which are sheet salt silicate materials made of silicon and oxygen) are from the Noachian era, which represents geology that is more than 3.5 billion years old (depending on which source you consult). It added, however, that Opportunity is expected to be able to complete the science.
Meanwhile, enjoy these pictures from the rim of Endeavour Crater that Opportunity sent in the past few days.
Here’s Hydra! The New Horizons team spotted the tiny moon of Pluto in July, about six months ahead of when they expected to. You can check it out in the images below. The find is exciting in itself, but it also bodes well for the spacecraft’s search for orbital debris to prepare for its close encounter with the system in July 2015.
Most of Pluto’s moons were discovered while New Horizons was under development, or already on its way. Mission planners are thus concerned that there could be moons out there that aren’t discovered yet — moons that could pose a danger to the spacecraft if it ended up in the wrong spot at the wrong time. That’s why the team is engaging in long-range views to see what else is lurking in Pluto’s vicinity.
“We’re thrilled to see it, because it shows that our satellite-search techniques work, and that our camera is operating superbly. But it’s also exciting just to see a third member of the Pluto system come into view, as proof that we’re almost there,” stated science team member John Spencer, of the Southwest Research Institute.
Hydra was spotted using the spacecraft’s Long Range Reconnaissance Imager (LORRI), which took 48 images of 10 seconds apiece between July 18 and July 20. Then the team used half the images, the ones that show Hydra better, to create the images you see above.
The spacecraft was still 267 million miles (430 million kilometers) from Pluto when the images were taken. Another moon discovered around the same time as Hydra — Nix — is still too close to be seen given it’s so close to Pluto, but just wait.
Meanwhile, scientists are busily trying to figure out where to send New Horizons after Pluto. In July, researchers using the Hubble Space Telescope began a full-scale search for a suitable Kuiper Belt Object, which would be one of trillions of icy or rocky objects beyond Neptune’s orbit. Flying past a KBO would provide more clues as to how the Solar System formed, since these objects are considered leftovers of the chunks of matter that came together to form the planets.
Wow! See that bright streak in the photo above? That’s a shot of the Expedition 40 crew making a flawless return from the International Space Station yesterday (Sept. 10) … a shot taken from space itself.
“Our view of the picture perfect reentry of TMA-12M,” wrote Expedition 41 astronaut Reid Wiseman, who just hours before bid farewell to Steve Swanson (NASA), Alexander Skvortsov (Roscosmos) and Oleg Artemyev (Roscosmos). The re-entry was in fact so perfect that TV cameras caught the parachute immediately after deployment, which doesn’t always happen.
As you can see in the video replay below, the Soyuz made a bulls-eye landing near Dzhezkazgan, Kazakhstan at 10:23 p.m. EDT (2:23 a.m. UTC). There are now only three people tending to the space station until the rest of the Expedition 41 crew launches, which is expected to happen Sept. 25.