The two architectures (top to bottom), "fly-back" and "glide-back" configurations. Credit: Balesdant, M., et al. (2023)
Reusable launch vehicles have been a boon for the commercial space industry. By recovering and refurbishing the first stages of rockets, launch providers have dramatically reduced the cost of sending payloads and even crew to space. Beyond first-stage boosters, there are efforts to make rockets entirely reusable, from second stages to payload fairings. There are currently multiple strategies for booster recovery, including mid-air retrieval using helicopters and nets. Still, the favored method involves boosters returning to a landing pad under their own power (the boost-back and landing maneuver).
This strategy requires additional rocket propellant for the booster to land again, which comes at the expense of payload mass and performance for the ascent mission. As an alternative, researchers from the National Office Of Aerospace Studies And Research (ONERA) propose two new types of strategies that would allow boosters to return to their launch site. These are known as “glide-back” and “fly-back” architectures, both of which involve boosters with lifting surfaces (fins and wings) performing vertical takeoff and horizontal landing (VTVL) maneuvers.
Artist's impression of the IDEFIX rover on Phobos, with the MMX spacecraft in the background. Credit: DLR
At this very moment, eleven robotic missions are operating in orbit or on the surface of Mars, more than at any point during the past sixty years. These include the many orbiters surveying the Red Planet from orbit, the handful of landers and rovers, and one helicopter (Ingenuity) studying the surface. In the coming years, many more are expected, reflecting the growing number of nations participating in the exploration process. Once there, they will join in the ongoing search for clues about the planet’s formation, evolution, and possible evidence that life once existed there.
However, there’s also the mystery concerning the origin of Phobos and Deimos, Mars’ two satellites. While scientists have long suspected that these two moons began as asteroids kicked from the Main Belt that were captured by Mars’ gravity, there is no scientific consensus on this point. This is the purpose of the Martian Moons eXploration (MMX) mission currently under development by the Japan Aerospace Exploration Agency (JAXA), which will explore both moons with the help of a Phobos rover provided by the German Aerospace Center (DLR) and the French National Center of Space Studies (CNES).
This artist's concept depicts the InSight lander on Mars after the lander's robotic arm has deployed a seismometer and a heat probe directly onto the ground. InSight is the first mission dedicated to investigating the deep interior of Mars. The findings will advance understanding of how all rocky planets, including Earth, formed and evolved. NASA approved a new launch date in May 2018. Credits: NASA/JPL-Caltech
This artist’s concept depicts the InSight lander on Mars after the lander’s robotic arm has deployed a seismometer and a heat probe directly onto the ground. InSight is the first mission dedicated to investigating the deep interior of Mars. The findings will advance understanding of how all rocky planets, including Earth, formed and evolved. NASA approved a new launch date in May 2018. Credits: NASA/JPL-Caltech
Top NASA managers have formally approved the launch of the agency’s InSight Lander to the Red Planet in the spring of 2018 following a postponement from this spring due to the discovery of a vacuum leak in a prime science instrument supplied by France.
The InSight missions goal is to accomplish an unprecedented study of the deep interior of the most Earth-like planet in our solar system.
NASA is now targeting a new launch window that begins May 5, 2018, for the Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight). mission aimed at studying the deep interior of Mars. The Mars landing is now scheduled for Nov. 26, 2018.
InSight had originally been slated for blastoff on March 4, 2016 atop a United Launch Alliance (ULA) Atlas V rocket from Vandenberg Air Force Base, California.
But the finding of a vacuum leak in its prime science instrument, the French-built Seismic Experiment for Interior Structure (SEIS), in December 2015 forced an unavoidable two year launch postponement. Because of the immutable laws of orbital mechanics, launch opportunities to the Red Planet only occur approximately every 26 months.
InSight’s purpose is to help us understand how rocky planets – including Earth – formed and evolved. The science goal is totally unique – to “listen to the heart of Mars to find the beat of rocky planet formation.”
The revised launch date was approved by the agency’s Science Mission Directorate.
“Our robotic scientific explorers such as InSight are paving the way toward an ambitious journey to send humans to the Red Planet,” said Geoff Yoder, acting associate administrator for NASA’s Science Mission Directorate, in Washington, in a statement.
“It’s gratifying that we are moving forward with this important mission to help us better understand the origins of Mars and all the rocky planets, including Earth.”
NASA’s InSight Mars lander spacecraft in a Lockheed Martin clean room near Denver. As part of a series of deployment tests, the spacecraft was commanded to deploy its solar arrays in the clean room to test and verify the exact process that it will use on the surface of Mars.
Since InSight would not have been able to carry out and fulfill its intended research objectives because of the vacuum leak in its defective SEIS seismometer instrument, NASA managers had no choice but to scrub this year’s launch. For a time its outlook for a future revival seemed potentially uncertain in light of today’s constrained budget environment.
The leak, if left uncorrected, would have rendered the flawed probe useless to carry out the unprecedented scientific research foreseen to measure the planets seismic activity and sense for “Marsquakes” to determine the nature of the Red Planet’s deep interior.
“The SEIS instrument — designed to measure ground movements as small as half the radius of a hydrogen atom — requires a perfect vacuum seal around its three main sensors in order to withstand harsh conditions on the Red Planet,” according to NASA.
The SEIS seismometer instrument was provided by the Centre National d’Études Spatiales (CNES) – the French national space agency equivalent to NASA. SEIS is one of the two primary science instruments aboard InSight. The other instrument measuring heat flow from the Martian interior is provided by the German Aerospace Center (DLR) and is named Heat Flow and Physical Properties Package (HP3). The HP3 instrument checked out perfectly.
NASA Jet Propulsion Laboratory (JPL) was assigned lead responsibility for the “replanned” mission and insuring that the SEIS instrument operates properly with no leaks.
JPL is “redesigning, developing and qualifying the instrument’s evacuated container and the electrical feedthroughs that failed previously. France’s space agency, the Centre National d’Études Spatiales (CNES), will focus on developing and delivering the key sensors for SEIS, integration of the sensors into the container, and the final integration of the instrument onto the spacecraft.”
“We’ve concluded that a replanned InSight mission for launch in 2018 is the best approach to fulfill these long-sought, high-priority science objectives,” said Jim Green, director of NASA’s Planetary Science Division.
The cost of the two-year delay and instrument redesign amounts to $153.8 million, on top of the original budget for InSight of $675 million.
NASA says this cost will not force a delay or cancellation to any current missions. However, “there may be fewer opportunities for new missions in future years, from fiscal years 2017-2020.”
Back shell of NASA’s InSight spacecraft is being lowered onto the mission’s lander, which is folded into its stowed configuration. The back shell and a heat shield form the aeroshell, which will protect the lander as the spacecraft plunges into the upper atmosphere of Mars. Launch now rescheduled to May 2018 to fix French-built seismometer. Credit: NASA/JPL-Caltech/Lockheed Martin
Lockheed Martin is the prime contractor for InSight and placed the spacecraft in storage while SEIS is fixed.
InSight is funded by NASA’s Discovery Program of low cost, focused science missions along with the science instrument funding contributions from France and Germany.
Mars has the same basic internal structure as the Earth and other terrestrial (rocky) planets. It is large enough to have pressures equivalent to those throughout the Earth’s upper mantle, and it has a core with a similar fraction of it’s mass. In contrast, the pressure even near the center of the Moon barely reach that just below the Earth’s crust and it has a tiny, almost negligible core. The size of Mars indicates that it must have undergone many of the same separation and crystallization processes that formed the Earth’s crust and core during early planetary formation. Credit: JPL/NASA
Learn more about OSIRIS-REx, InSight Mars lander, SpaceX missions, Juno at Jupiter, SpaceX CRS-9 rocket launch, ISS, ULA Atlas and Delta rockets, Orbital ATK Cygnus, Boeing, Space Taxis, Mars rovers, Orion, SLS, Antares, NASA missions and more at Ken’s upcoming outreach events:
Sep 6-8: “OSIRIS-REx lainch, SpaceX missions/launches to ISS on CRS-9, Juno at Jupiter, ULA Delta 4 Heavy spy satellite, SLS, Orion, Commercial crew, Curiosity explores Mars, Pluto and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings
Back shell of NASA's InSight spacecraft is being lowered onto the mission's lander, which is folded into its stowed configuration. The back shell and a heat shield form the aeroshell, which will protect the lander as the spacecraft plunges into the upper atmosphere of Mars. Launch now rescheduled to May 2018 to fix French-built seismometer. Credit: NASA/JPL-Caltech/Lockheed Martin
Back shell of NASA’s InSight spacecraft is being lowered onto the mission’s lander, which is folded into its stowed configuration. The back shell and a heat shield form the aeroshell, which will protect the lander as the spacecraft plunges into the upper atmosphere of Mars. Launch now rescheduled to May 2018 to fix French-built seismometer. Credit: NASA/JPL-Caltech/Lockheed Martin
The Insight Mars lander has been saved from mission termination and will live to launch another day two years from now, NASA managers just announced following a thorough three month investigation into the causes of the last moment snafu involving the failure of its French-built seismometer science instrument that last December forced the agency to cancel its planned liftoff this month.
NASA is now targeting a new launch window that begins May 5, 2018, for the Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) mission aimed at studying the deep interior of Mars.
The May 2018 launch amounts to an unavoidable 26 month launch delay from the originally planned launch on March 4, 2016. Because of the immutable laws of orbital mechanics, launch opportunities to the Red Planet only occur every 26 months.
Since InSight would not have been able to carry out and fulfill its intended research objectives because of a vacuum leak in its defective seismometer instrument, NASA managers had no choice but to scrub this year’s launch and its outlook for a future revival seemed potentially uncertain at best in today’s constrained budget environment.
“The spacecraft had been on track to launch this month until a vacuum leak in its prime science instrument prompted NASA in December to suspend preparations for launch,” said NASA officials.
The leak, if left uncorrected, would have rendered the flawed probe useless to carry out the unprecedented scientific research foreseen to measure the planets seismic activity and sense for “Marsquakes” to determine the nature of the Red Planet’s deep interior.
“The science goals of InSight are compelling, and the NASA and CNES plans to overcome the technical challenges are sound,” said John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington.
“The quest to understand the interior of Mars has been a longstanding goal of planetary scientists for decades. We’re excited to be back on the path for a launch, now in 2018.”
Artist rendition of NASA’s Mars InSight (Interior exploration using Seismic Investigations, Geodesy and Heat Transport) Lander. InSight is based on the proven Phoenix Mars spacecraft and lander design with state-of-the-art avionics from the Mars Reconnaissance Orbiter (MRO) and Gravity Recovery and Interior Laboratory (GRAIL) missions. Credit: JPL/NASA
InSight is now slated for a Mars landing on Nov. 26, 2018.
The seismometer instrument is named Seismic Experiment for Interior Structure (SEIS) and was provided by the Centre National d’Études Spatiales (CNES) – the French national space agency equivalent to NASA. SEIS is one of the two primary science instruments aboard InSight. The other instrument measuring heat flow from the Martian interior is provided by the German Aerospace Center (DLR) and is named Heat Flow and Physical Properties Package (HP3).
“InSight project managers recently briefed officials at NASA and France’s space agency, Centre National d’Études Spatiales (CNES), on a path forward; the proposed plan to redesign the science instrument was accepted in support of a 2018 launch,” said NASA.
JPL will assume lead responsibility for insuring that the SEIS instrument operates properly with no leak.
The cost of the 2 year delay is still being assessed but expected to be in the tens of millions of dollars, likely over $100 million. How that will be payed for has yet to be determined.
Lockheed Martin is the prime contractor for InSight and will place the spacecraft in storage while SEIS is fixed and until the 2018 launch date nears.
“We’re delighted that NASA has approved the launch of the InSight mission in May 2018,” Stu Spath, Lockhhed Martin spacecraft program manager told Universe Today.
“Currently, we are preparing the spacecraft to go into storage at our Space Systems facility near Denver.”
“Our team worked hard to get the InSight spacecraft built and tested, and although InSight didn’t launch this year as planned, we know ultimately the scientific knowledge it will bring us is crucial to our understanding of how Mars and other rocky planets formed.”
NASA’s InSight Mars lander spacecraft in a Lockheed Martin clean room near Denver. As part of a series of deployment tests, the spacecraft was commanded to deploy its solar arrays in the clean room to test and verify the exact process that it will use on the surface of Mars.
InSight is funded by NASA’s Discovery Program of low cost, focused science missions along with the science instrument funding contributions from France and Germany.
Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.
The weather forecast is outstanding! And you can watch all the excitement live!
The primary goal is to deliver Jason-3 to low Earth orbit, where it will gather global measurements of ocean topography, or wave heights, using radar altimitry. These data provide scientists with essential information about global and regional changes in the Earth’s seas such as tracking sea level rise that threatens the resilience of coastal communities and the health of our environment. Continue reading “SpaceX Launching NASA Jason-3 Ocean Surveillance Satellite Jan. 17; with Barge Rocket Landing – Watch Live”
This artist's concept depicts the InSight lander on Mars after the lander's robotic arm has deployed a seismometer and a heat probe directly onto the ground. InSight is the first mission dedicated to investigating the deep interior of Mars. The findings will advance understanding of how all rocky planets, including Earth, formed and evolved. NASA approved a new launch date in May 2018. Credits: NASA/JPL-Caltech
NASA managers have just made the difficult but unavoidable decision to scrub the planned March 2016 launch of the InSight lander, the agency’s next mission to Mars, by at least two years because of a vacuum leak that was just detected in the probes flawed seismometer instrument which cannot be fixed in time.
Author’s note: In the wake of the November 13th terrorist attacks, the French Space Agency CNES canceled the celebration of the 50th anniversary of the launch of Asterix. This post commemorates the launch of France’s first satellite 50 years ago this week, and pays a small tribute to the noblest of human endeavors, namely the exploration of space and the pioneering spirit of humanity exemplified by a heroic nation.
A milestone in space flight occurred 50 years ago tomorrow, when France became the sixth nation—behind the U.S.S.R., the United States, Canada, the United Kingdom and Italy—to field a satellite. The A1 mission, renamed Asterix after a popular cartoon character, launched from a remote desert base in Algeria a few hours after dawn at 9:52 UT on November 26th.
Though France was 6th nation in space, it was 3rd—following the Soviet Union and the United States—to launch a satellite atop its very own rocket: the three stage Diamant-A.
The launch of Asterix into the blue desert skies over Algeria.
The satellite launch was intended mainly to test the ability of the French-built rocket, which flew 11 more times before its retirement in 1975. Asterix did carry a signal transmitter, and was due to carry out ionospheric measurements during its short battery-powered life span. With a high elliptical orbit, Asterix won’t reenter the Earth’s atmosphere for several centuries to come.
The launch occurred from the remote desert air base of Hammaguir, located 31 degrees north of the equator in western Algeria. Then as today, the site is a forlorn and austere location with very few creature comforts, though we can personally attest from our deployment to a similar French Air Base in Djibouti that the French military does serve wine in their mess hall…
The tense control room during the launch of Asterix.
The French space program started in 1961 under president Charles de Gaulle and centered around the construction and use of the Diamant rocket. Three variants were built, including the one used to place Asterix in orbit. One of the stranger tales of the early space age involved the first—and thus far only—sub-orbital launch of a cat into space from the same Algerian site in 1963, though Iran recently made a vague statement that it would do the same in 2013.
An aerial shot of Hammaguir Air Base in Algeria from the early 1960s.
Contact with Asterix was lost due to a damaged satellite antenna shortly after launch. Founded in 1961, the French space agency CNES (The Centre National d’Etudes Spatiales, or National Centre for Space Studies) now partners with NASA and the European Space Agency on missions including micro-gravity studies on the International Space Station, Rosetta’s historic exploration of comet 67P Churyumov-Gerasimenko and more. And although the Hammaguir space facility in Algeria is no longer in use, CNES operates out of the Kourou Space Center in French Guiana and the Toulouse Space Center in southern France today.
A stamp series commemorating the Diamant rocket and Asterix.
Tracking Asterix
Though inoperative, Asterix still orbits the Earth once every 107 minutes in an elliptical low Earth orbit. Asterix ranges from a perigee of 523 kilometers to an apogee of 1,697 kilometers. In an orbit inclined 34 degrees relative to the Earth’s equator, Asterix isn’t expected to reenter for several centuries.
A replica of Asterix hanging in the Paris Air and Space Museum. Image credit: Pine/Wikimedia Commons
A 42 kilogram satellite approximately a meter across, Asterix is visible worldwide from about 40 degrees north to 40 degrees south latitude. Essentially a binocular object, you can nonetheless see Asterix from your backyard if you know exactly where and when to look for it in the sky. Asterix will appear brightest on a perigee pass directly overhead.
Asterix’s NORAD ID satellite catalog number is 01778/COSPAR ID 1965-096A.
The orbital trace of Asterix. Image credit: Orbitron
When it comes to hunting for binocular satellites, you need to now exactly where it’ll be in the sky at what time. We use Heavens-Above to discern exactly when a given satellite will pass a bright star, then simply watch at the appointed time with binoculars. We also run WWV radio in the background for a precise audio time hack. This allows us to keep our eyes continuously on the sky. This simple method is similar to that used by Project Moonwatch volunteers to track and record satellites starting in the late 1950s.
The evolution of the Diamant rocket.
Other satellite challenges from the early Space Age include Alouette-1 (Canada’s first satellite), Prospero (UK’s first and only indigenous satellite) and the oldest of them all, the first three Vanguard satellites launched by the United States.
Don’t miss a chance to see this living relic of the early space age, still in orbit. Happy 50th to the CNES space agency: may your spirit of space exploration continue to soar and inspire us all.
NASA's InSight Mars lander spacecraft in a Lockheed Martin clean room near Denver. As part of a series of deployment tests, the spacecraft was commanded to deploy its solar arrays in the clean room to test and verify the exact process that it will use on the surface of Mars. Credits: NASA/JPL-Caltech/Lockheed Martin
NASA’s ‘Journey to Mars’ is ramping up significantly with ‘InSight’ – as the agency’s next Red Planet lander has now been assembled into its flight configuration and begun a comprehensive series of rigorous and critical environmental stress tests that will pave the path to launch in 2016 on a mission to unlock the riddles of the Martian core.
The countdown clock is ticking relentlessly and in less than nine months time, NASA’s InSight Mars lander is slated to blastoff in March 2016.
InSight, which stands for Interior Exploration Using Seismic Investigations, Geodesy and Heat Transport, is a stationary lander. It will join NASA’s surface science exploration fleet currently comprising of the Curiosity and Opportunity missions which by contrast are mobile rovers.
But before it will even be allowed to get to the launch pad, the Red Planet explorer must first prove its mettle and show that it can operate in and survive the harsh and unforgiving rigors of the space environment via a battery of prelaunch tests. That’s an absolute requirement in order for it to successfully carry out its unprecedented mission to investigate Mars deep interior structure.
InSight’s purpose is to elucidate the nature of the Martian core, measure heat flow and sense for “Marsquakes.” These completely new research findings will radically advance our understanding of the early history of all rocky planets, including Earth and could reveal how they formed and evolved.
“Today, our robotic scientific explorers are paving the way, making great progress on the journey to Mars,” said Jim Green, director of NASA’s Planetary Science Division at the agency’s headquarters in Washington, in a statement.
“Together, humans and robotics will pioneer Mars and the solar system.”
The science deck of NASA’s InSight lander is being turned over in this April 29, 2015, photo from InSight assembly and testing operations inside a clean room at Lockheed Martin Space Systems, Denver. The large circular component on the deck is the protective covering to be placed over InSight’s seismometer after the seismometer is placed directly onto the Martian ground. Credits: NASA/JPL-Caltech/Lockheed Martin
The launch window for InSight opens on March 4 and runs through March 30, 2016.
InSight counts as NASA’s first ever interplanetary mission to launch from California.
The car sized probe will touch down near the Martian equator about six months later in the fall of 2016.
The prime contractor for InSight is Lockheed Martin Space Systems in Denver, Co and the engineering and technical team recently finished assembling the lander into its final configuration.
So now the time has begun to start the shakedown that literally involve “shaking and baking and zapping” the spacecraft to prove its ready and able to meet the March 2016 launch deadline.
During the next seven months of environmental testing at Lockheed’s Denver facility, “the lander will be exposed to extreme temperatures, vacuum conditions of nearly zero air pressure simulating interplanetary space, and a battery of other tests.”
“The assembly of InSight went very well and now it’s time to see how it performs,” said Stu Spath, InSight program manager at Lockheed Martin Space Systems, Denver, in a statement.
“The environmental testing regimen is designed to wring out any issues with the spacecraft so we can resolve them while it’s here on Earth. This phase takes nearly as long as assembly, but we want to make sure we deliver a vehicle to NASA that will perform as expected in extreme environments.”
The first test involves “a thermal vacuum test in the spacecraft’s “cruise” configuration, which will be used during its seven-month journey to Mars. In the cruise configuration, the lander is stowed inside an aeroshell capsule and the spacecraft’s cruise stage – for power, communications, course corrections and other functions on the way to Mars — is fastened to the capsule.”
After the vacuum test, InSight will be subjected to a series of tests simulating the vibrations of launch, separation and deployment shock, as well as checking for electronic interference between different parts of the spacecraft and compatibility testing.
Finally, a second thermal vacuum test will expose the probe “to the temperatures and atmospheric pressures it will experience as it operates on the Martian surface.”
The $425 million InSight mission is expected to operate for about two years on the Martian surface.
Artist rendition of NASA’s Mars InSight (Interior exploration using Seismic Investigations, Geodesy and Heat Transport) Lander. InSight is based on the proven Phoenix Mars spacecraft and lander design with state-of-the-art avionics from the Mars Reconnaissance Orbiter (MRO) and Gravity Recovery and Interior Laboratory (GRAIL) missions. Credit: JPL/NASA
InSight is an international science mission and a near duplicate of NASA’s successful Phoenix Mars landing spacecraft, Bruce Banerdt, InSight Principal Investigator of NASA’s Jet Propulsion Laboratory (JPL), Pasadena, California, told Universe Today.
“InSight is essentially built from scratch, but nearly build-to-print from the Phoenix design,” Banerdt, of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena , Calif, told me. The team can keep costs down by re-using the blueprints pioneered by Phoenix instead of creating an entirely new spacecraft.
3 Footpads of Phoenix Mars Lander atop Martian Ice. NASA’s Mars InSight spacecraft design is based on the successful 2008 Phoenix lander. This mosaic shows Phoenix touchdown atop Martian ice. Phoenix thrusters blasted away Martian soil and exposed water ice. InSight carries instruments to peer deep into the Red Planet and investigate the nature and size of the mysterious Martian core. Credit: Ken Kremer/kenkremer.com/Marco Di Lorenzo/NASA/JPL/UA/Max Planck Institute
It is funded by NASA’s Discovery Program as well as several European national space agency’s and countries. Germany and France are providing InSight’s two main science instruments; HP3 and SEIS through the Deutsches Zentrum für Luft- und Raumfahrt. or German Aerospace Center (DLR) and the Centre National d’Etudes Spatiales (CNES).
“The seismometer (SEIS, stands for Seismic Experiment for Interior Structure) is from France (built by CNES and IPGP) and the heat flow probe (HP3, stands for Heat Flow and Physical Properties Probe) is from Germany (built by DLR),” Banerdt explained.
SEIS and HP3 are stationed on the lander deck. They will each be picked up and deployed by a robotic arm similar to that flown on Phoenix with some modifications.
Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.
Five candidate sites were identified on Comet 67P/Churyumov-Gerasimenko for Rosetta’s Philae lander. The approximate locations of the five regions are marked on these OSIRIS narrow-angle camera images taken on 16 August 2014 from a distance of about 100 km. Enlarged insets below highlight 5 landing zones. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA Processing: Marco Di Lorenzo/Ken Kremer
Five candidate sites were identified on Comet 67P/Churyumov-Gerasimenko for Rosetta’s Philae lander. The approximate locations of the five regions are marked on these OSIRIS narrow-angle camera images taken on 16 August 2014 from a distance of about 100 km. Enlarged insets below highlight 5 landing zones. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA Processing: Marco Di Lorenzo/Ken Kremer
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The ‘Top 5’ landing site candidates have been chosen for the Rosetta orbiters piggybacked Philae lander for humankind’s first attempt to land on a comet. See graphics above and below.
The potential touchdown sites were announce today, Aug. 25, based on high resolution measurements collected by ESA’s Rosetta spacecraft over the past two weeks since arriving at the bizarre and pockmarked Comet 67P/Churyumov-Gerasimenko on Aug. 6, 2014.
Rosetta is a mission of many firsts, including history’s first ever attempt to orbit a comet for long term study.
Philae’s history making landing on comet 67P is currently scheduled for around Nov. 11, 2014, and will be entirely automatic. The 100 kg lander is equipped with 10 science instruments.
“This is the first time landing sites on a comet have been considered,” said Stephan Ulamec, Lander Manager at DLR (German Aerospace Center), in an ESA statement.
Artist impression of Philae on the surface of comet 67P/Churyumov-Gerasimenko. Credit: ESA/ATG medialab
Since rendezvousing with the comet after a decade long chase of over 6.4 billion kilometers (4 Billion miles), a top priority task for the science and engineering team leading Rosetta has been “Finding a landing strip” for the Philae comet lander.
“The challenge ahead is to map the surface and find a landing strip,” said Andrea Accomazzo, ESA Rosetta Spacecraft Operations Manager, at the Aug. 6 ESA arrival live webcast.
So ‘the clock is ticking’ to select a suitable landing zone soon as the comet warms up and the surface becomes ever more active as it swings in closer to the sun and makes the landing ever more hazardous.
This past weekend, the site selection team met at CNES, Toulouse, France, and intensively discussed and scrutinized a preliminary list of 10 potential sites, and whittled that down to the ‘Top 5.’
Their goal was to find a ‘technically feasible’ touchdown site that was both safe and scientifically interesting.
“The site must balance the technical needs of the orbiter and lander during all phases of the separation, descent, and landing, and during operations on the surface with the scientific requirements of the 10 instruments on board Philae,” said ESA.
They also had to be within an ellipse of at least 1 square kilometer (six-tenths of a square mile) in diameter due to uncertainties in navigation as well as many other factors.
“For each possible zone, important questions must be asked: Will the lander be able to maintain regular communications with Rosetta? How common are surface hazards such as large boulders, deep crevasses or steep slopes? Is there sufficient illumination for scientific operations and enough sunlight to recharge the lander’s batteries beyond its initial 64-hour lifetime, while not so much as to cause overheating?” according to ESA.
Stephan Ulamec, Philae Lander Manager at DLR (German Aerospace Center) discusses landing during ESA webcast of Rosetta’s arrival at comet Comet 67P/Churyumov-Gerasimenko. Credit: ESA
The Landing Site Selection Group (LSSG) team was comprised of engineers and scientists from Philae’s Science, Operations and Navigation Centre (SONC) at CNES, the Lander Control Centre (LCC) at DLR, scientists representing the Philae Lander instruments as well as the ESA Rosetta team, which includes representatives from science, operations and flight dynamics.
“Based on the particular shape and the global topography of Comet 67P/ Churyumov-Gerasimenko, it is probably no surprise that many locations had to be ruled out,” said Ulamec.
“The candidate sites that we want to follow up for further analysis are thought to be technically feasible on the basis of a preliminary analysis of flight dynamics and other key issues – for example they all provide at least six hours of daylight per comet rotation and offer some flat terrain. Of course, every site has the potential for unique scientific discoveries.”
When Rosetta arrived on Aug. 6, it was initially orbiting at a distance of about 100 km (62 miles) in front of the comet. Carefully timed thruster firings then brought it to within about 80 km distance. And it is moving far closer – to within 50 kilometers (31 miles) and even closer!
Upon arrival the comet was 522 million km from the Sun. As Rosetta escorts the comet looping around the sun, they move much closer. By landing time in mid-November they are only about 450 million km (280 million mi) from the sun.
At closest approach on 13 August 2015 the comet and Rosetta will be 185 million km from the Sun. That corresponds to an eightfold increase in the light received from the Sun.
Five candidate sites were identified on Comet 67P/Churyumov-Gerasimenko for Rosetta’s Philae lander. The approximate locations of the five regions are marked on these OSIRIS narrow-angle camera images taken on 16 August 2014 from a distance of about 100 km. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
Therefore Rosetta and Philae will simultaneously study the warming effects of the sun as the comet outgases dust, water and much more.
The short period Comet 67P/Churyumov-Gerasimenko has an orbital period of 6.5 years.
“The comet is very different to anything we’ve seen before, and exhibits spectacular features still to be understood,” says Jean-Pierre Bibring, a lead lander scientist and principal investigator of the CIVA instrument.
“The five chosen sites offer us the best chance to land and study the composition, internal structure and activity of the comet with the ten lander experiments.”
A close-up view of Comet 67P/Churyumov–Gerasimenko taken by the Rosetta spacecraft on Aug. 7, 2014. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
The ‘Top 5’ zones will be ranked by 14 September. Three are on the ‘head’ and two are on the ‘body’ of the bizarre two lobed alien world.
And a backup landing site will also be chosen for planning purposes and to develop landing sequences.
The ultimate selection of the primary landing site is slated for 14 October after consultation between ESA and the lander team on a “Go/No Go” decision.
The three-legged lander will fire two harpoons and use ice screws to anchor itself to the 4 kilometer (2.5 mile) wide comet’s surface. Philae will collect stereo and panoramic images and also drill 23 centimeters into and sample its incredibly varied surface.
Why study comets?
Comets are leftover remnants from the formation of the solar system. Scientists believe they delivered a vast quantity of water to Earth. They may have also seeded Earth with organic molecules – the building blocks of life as we know it.
Any finding of organic molecules will be a major discovery for Rosetta and ESA and inform us about the origin of life on Earth.
Read an Italian language version of this story by my imaging partner Marco Di Lorenzo – here
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
Holger Sierks, OSIRIS principal investigator, discusses spectacular hi res comet images returned so far by Rosetta during the Aug. 6 ESA webcast from mission control at ESOC, Darmstadt, Germany. Credit: Roland Keller
ESA’s Rosetta Spacecraft nears final approach to Comet 67P/Churyumov-Gerasimenko in late July 2014. This collage of imagery from Rosetta combines Navcam camera images at right taken nearing final approach from July 25 (3000 km distant) to July 31, 2014 (1327 km distant), with OSIRIS wide angle camera image at left of comet’s expanding coma cloud on July 25. Images to scale and contrast enhanced to show further detail. Credit: ESA/Rosetta/NAVCAM/OSIRIS/MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA Collage/Processing: Marco Di Lorenzo/Ken Kremer
Holger Sierks, OSIRIS principal investigator, discusses spectacular hi res comet images returned so far by Rosetta during the Aug. 6 ESA webcast from mission control at ESOC, Darmstadt, Germany. Credit: Roland Keller
Animation Caption: Possible landing sites on Comet 67P/Churyumov-Gerasimenko. The model shows the illumination of the comets surface and regions under landing site consideration for the Philae lander on board ESA’s Rosetta spececraft . Credit: CNES
“The race is on” to find a safe and scientifically interesting landing site for the Philae lander piggybacked on ESA’s Rosetta spacecraft as it swoops in ever closer to the heavily cratered Comet 67P/Churyumov-Gerasimenko since arriving two weeks ago after a decade long chase of 6.4 billion kilometers (4 Billion miles).
Rosetta made history by becoming the first ever probe from Earth to orbit a comet upon arrival on Aug. 6, 2014.
The probe discovered an utterly alien and bizarre icy wanderer that science team member Mark McCaughrean, of ESA’s Science Directorate, delightedly calls a ‘Scientific Disneyland.’
“It’s just astonishing,” he said during a live ESA webcast of the Aug. 6 arrival event.
Now, another audacious and history making event is on tap – Landing on the comet!
To enable a safe landing, Rosetta is moving in closer to the comet to gather higher resolution imaging and spectroscopic data. When Rosetta arrived on Aug. 6, it was initially orbiting at a distance of about 100 km (62 miles). As of today, carefully timed thruster firings have brought it to within about 80 km distance. And it will get far closer.
Right now a top priority task for the science and engineering team leading Rosetta is “Finding a landing strip” for the Philae comet lander.
Philae’s landing on comet 67P is currently scheduled for Nov. 11, 2014. The 100 kg lander is equipped with 10 science instruments
“The challenge ahead is to map the surface and find a landing strip,” said Andrea Accomazzo, ESA Rosetta Spacecraft Operations Manager, at the Aug. 6 ESA webcast.
The team responsibility for choosing the candidate sites comprises “the Landing Site Selection Group (LSSG), which comprises engineers and scientists from Philae’s Science, Operations and Navigation Centre (SONC) at CNES, the Lander Control Centre (LCC) at DLR, scientists representing the Philae Lander instruments, and supported by the ESA Rosetta team, which includes representatives from science, operations and flight dynamics,” according to an ESA statement.
This week the team is intensively combing through a preliminary list of 10 potential landing sites.
Over the weekend they will whittle the list down to five candidate landing sites for continued detailed analysis.
ESA will announce the Top 5 landing site candidates on Monday, Aug. 25.
Where will Philae land?
This image of comet 67P/Churyumov-Gerasimenko shows the diversity of surface structures on the comet’s nucleus. It was taken by the Rosetta spacecraft’s OSIRIS narrow-angle camera on August 7, 2014. At the time, the spacecraft was 65 miles (104 kilometers) away from the 2.5 mile (4 kilometer) wide nucleus. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA/Enhanced processing Marco Di Lorenzo/Ken Kremer
The decision rests on the results of Rosetta’s ongoing global mapping campaign, including high resolution imaging from the OSIRIS and NAVCAM cameras and further observations from the other science instruments, especially MIRO, VIRTIS, ALICE, GIADA and ROSINA.
The surface criteria for a suitable landing site include day time landing illumination, a balance between day and night to allow the solar panels to recharge the batteries, avoiding steep slopes, large boulders and deep crevasses so it doesn’t topple over.
Of course the team also must consider the comet’s rotation period (12.4 hours) and axis of rotation (see animation at top). Sites near the equator offering roughly equal periods of day and night may be preferred.
The selection of the primary landing site is slated for mid-October after consultation between ESA and the lander team on a “Go/No Go” decision.
The three-legged lander will fire two harpoons and use ice screws to anchor itself to the 4 kilometer (2.5 mile) wide comet’s surface. Philae will collect stereo and panoramic images and also drill 23 centimeters into and sample its incredibly varied surface.
Artist impression of Philae on the surface of comet 67P/Churyumov-Gerasimenko. Credit: ESA/ATG medialab
Read an Italian language version of this story by my imaging partner Marco Di Lorenzo – here
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
