The MRO team has now released high-res images acquired during a planned pass by MRO over the Schiaparelli landing site. It does shed a little more light, although engineers will glean far more useful information from the 600MB of data it managed to uplink to Mars Express before perishing. (The early indications from that, by the way, are that it was probably a software problem, not hardware, although ESA has not given more detail than that yet. The most they’ve said is that some events were clearly commanded too soon.)
The new image clearly shows not only the impact site, but also the heatshield and and the parachute, still attached to the backshell. Perhaps the most interesting feature is a lighter arc extending out from the Schiaparelli impact site. This could be a debris trail left behind by a ruptured propellant tank exiting the spacecraft on impact. It will certainly be subject to careful analysis in the coming weeks.
The MRO team plans another pass later, which will allow stereo imaging of the site. This should help determine whether the black smudge is just a smudge or if its more of a crater. If nothing else, in addition to the wealth of engineering data obtained during descent, this is a unique opportunity to advance impact science.
One of the most remarkable advantages of having an orbiter at Saturn is that we are able to record and study changes in it over time. Back during the Pioneer and Voyager programs, it was all too tempting to think that these fleeting glimpses we got of the gas giants were representative of them always. But of course it wasn’t. Even a barren world like Mars changes over human timescales; a gas giant is essentially *made* of weather and so should change constantly. Perhaps it’s because Saturn looks like such a smooth set of bands from Earth, or perhaps we have misled ourselves by thinking extremely long-term storms like the Great Red Spot are common. But just as Galileo and the Hubble Space Telescope and increasingly acute ground-based observatories have shown dramatic change in the GRS and the rest of Jupiter’s storms, Cassini is now doing the same for Saturn. Saturn has an axial tilt more like Earth, so it experiences significant seasonal variation, and this has created intriguing variety over time. One of the things only Cassini can tell us about is the Hexagon, a vast structure across Saturn’s north pole. From Earth, we cannot see structures at high latitudes; we just don’t have the right viewing angle. But Voyager 1 saw the hexagon, and now Cassini has been watching it. And although it’s clearly stable over long timescales, it isn’t static. In fact, it’s color has changed rather dramatically:
No one yet knows why, although going theories involve a shift in the distribution of methane due to changing levels of sunlight. (Sunlight accelerates the breakdown of methane.) We will not have Cassini around to watch the Hexagon for much longer, unfortunately, so scientists are working to gather whatever they can during the remainder of Cassini’s mission.
The next interesting thing to look for will be Juno: it’s the first mission ever to have a good viewing angle on Jupiter’s polar regions. What will it find? So far, we know Jupiter does not have a hexagon, and that the polar regions look very different from the mid-latitudes. Less stripey, for one thing. But that’s all we know so far.
The ISS is a busy place! They’ve had two arrivals in the past few days. First off, Soyuz MS-02 arrived following a two-day chase. It docked to the Poisk module located at the zenith port of Zvezda’s forward compartment. This lovely time-lapse has the perfect musical score to go along:
And now, the Cygnus OA-5 mission, with the spacecraft “SS Alan Poindexter”, has arrived at the ISS. Crews on board captured the spacecraft with the SSRMS; ground controllers later took over and completed the berthing remotely while the crew slept, mating the spacecraft to the nadir port of the Unity node of the ISS.
Orbital ATK names each of their cargo vehicles, and the tradition they’ve chosen is to name each for a deceased astronaut. Alan Poindexter, this spacecraft’s namesake, joined the astronaut corps in 1998, later flying on two missions, STS-122 and STS-131. The latter was the longest mission for the Space Shuttle Discovery, at 15 days 2 hours, 47 min, 11 seconds. Poindexter retired from NASA in 2010, one of many realizing they would never get another chance to fly into space. He tragically passed away at the age of 50 in 2012 in a personal watercraft accident. But thanks to Orbital ATK, his name at least can fly in space one more time.
Unfortunately, it confirms what we all pretty much already knew: it has crashed. Any faint hope that the apparent three-second burn was due to communications problems has been dashed. MRO photographed the lander (and its parachute) in this image. The animation basically compares an image of the same location taken before the landing with now:
This image is from a preplanned sequence of images designed specifically to find the lander after touchdown; MRO has photographed several landers in this manner, including Mars Phoenix Lander and Mars Science Laboratory Curiosity, and it can provide invaluable engineering data. On this occasion, that paid off in spades by providing the first post-landing data on what happened to the probe.
The white dot that appears in the bottom of the right-hand inset is probably the supersonic parachute. The dark smudge at the top is probably the impact site of Schiaparelli. This spot is 5.4 km uprange from the target site for the landing, although well within Schiaparelli’s landing ellipse and thus a reasonable place to have found the probe even if all had gone well – and if nothing else, this indicates it was right on track before the mishap occurred. The bright and dark patches are about a kilometer apart; the dark patch is about 15 x 40 meters, which is far too large to represent an intact lander. If, as seems likely, the engines shut off after just a few seconds, it would have had full tanks of hydrazine monopropellant; it could have exploded on impact. Analyzing the descent data and the imagery, ESA engineers believe it may have fallen 2-4 km, resulting in an impact velocity of upwards of 300 km per hour, which would have been pretty destructive even if the tanks didn’t rupture.
It’s unfortunate, but ESA is keeping a positive attitude. The primary objective for this mission was the Trace Gas Orbiter, and that is doing excellently. TGO is a necessary element for phase two of the ExoMars mission, a rover due to launch in 2020 (originally 2018, but about six months ago, ESA moved it to the next Mars window due to technical delays), so it is good to have it there. And while Schiaparelli will not have been able to test all of the landing technology, it did successfully validate most of it. Going to Mars is extremely difficult, and Schiaparelli is far from the first probe to be eaten by the Red Planet. ESA will learn from this, and incorporate lessons from it into the ExoMars rover’s landing system.
Meanwhile, a higher-resolution imaging sequence of the site by MRO is being planned, to hopefully collect more specific information on the ill-fated spacecraft.
And now, the stirring conclusion!
In case you missed last the previous episodes, here are the links to Episode One, Two, and Three.
First off, the happy news! Soyuz MS-02 launched successfully from Baikonur Cosmodrome yesterday. Aboard were Sergey Ryzhikov, Andrei Borisenko, and Shane Kimbrough. The mission was delayed a month due to technical issues with the spacecraft, but the repaired vehicle is performing well. They will arrive at the ISS tomorrow; the longer two-day approach was selected to allow more opportunity to test the new Soyuz MS series.
And now the less happy news: ESA has analyzed the data from the Schiaparelli lander, and although they still do not know what happened exactly, they have a better picture and it isn’t good. The only data they have comes from monitoring of its telemetry during descent. The entry sequence was nominal through atmospheric entry and parachute deploy, but then events started to deviate. The signal indicating parachute and backshell jettison came early, and then the engines ignited and the descent radar was switched on. However, they only appear to have burned for 3-4 seconds, and it isn’t clear whether all nine engines fired, nor what altitude the probe was actually at. They were expecting the engines to fire for about 30 seconds. At this point, they do not know whether backshell jettison was too high, or whether something caused a false indication of landing leading to premature engine cutoff (which is what killed Mars Polar Lander), or whether it actually came in much lower than expected, leading to it hitting the ground just a few second after ignition. They actually got about 600 MB of data during the descent, so they have a lot more data to look at. But although ESA hasn’t completely given up, it really looks like the lander is dead. Hopefully the second lander, in two years, will have better fortune; Mars is difficult, extremely difficult, but it rewards persistence.
First off, a bit of good news: ESA’s Trace Gas Orbiter (the first major element of the ExoMars program) has successfully entered orbit around the planet Mars! It joins the existing fleet of Martian orbiters, including ESA’s Mars Express, NASA’s Mars Odyssey 2001, Mars Reconnaissance Orbiter, and MAVEN, and India’s Mangalyaan-1 (or Mars Orbiter Mission). This puts a record-breaking six active spacecraft around Mars.
Unfortunately, the news is less cheerful for the Schiaparelli lander that was hitching a piggyback ride to Mars atop TGO. A direct beam to Earth was observed on an experimental basis by an Indian radio telescope; the signal indicated successful backshell release, parachute deploy, and heat shield separation, but cut off abruptly moments before touchdown was expected. Mars Express had been listening to the lander as well, and after completing an orbit it was able to relay what it had received — unfortunately, it received exactly the same thing. Schiaparelli was scheduled to contact Mars Reconnaissance Orbiter half an hour after landing, but MRO received no signal, on that or its next pass over the landing site. At this point, the fate of Schiaparelli is unknown.
Mars has eaten a lot of landers through the years. It is significantly more difficult to land on Mars than on other worlds, and the extreme speed of entry from solar orbit means there is a hell of a lot of energy to cope with if anything is even slightly misjudged. At this point, I have to say it doesn’t look good for Schiaparelli. But the good news is that TGO, the larger and more significant portion of the project, is in good health! ESA will learn from this, and be ready for the much more ambitious rover mission planned for the second half of the ExoMars program, scheduled for launched in 2018.
TGO and Schiaparelli prepare for vibration testing in their launch configuration. TGO’s solar arrays are tightly folded, and the cone at the top is Schiaparelli’s descent module.