ExoMars probe narrowly avoids death, still in peril after rocket snafu The European Space Agency's ExoMars probe is on its way to the Red Planet – although the spacecraft may not complete its mission intact. The craft, carrying the Trace Gas Orbiter atmosphere sniffer and the Schiaparelli lander, took off on March 14 aboard a Russian Proton rocket and began circling Earth. The fourth stage of the …
The Briz-M going pompers because it didn't vent the tanks?
here:: Michel Denis, ExoMars flight director at the European Space Operations, Center in Darmstadt, Germany, said that the two craft were many kilometers apart at the time of the breakup, so the explosion wouldn’t have posed a risk. Still, the mission team won’t be 100% certain until all the science instruments are completely checked over in the coming weeks.
Face it: Russian technology for deep space launches is very primitive and little tested. Russia never sent anything beyond Mars and Venus - if not by mistake - and even then, with a very high failure rate. Russia has been always very interested in the Earth orbit for military reasons. Anything sent beyond has no military value, just a scientific one. Thereby, choosing a Russian launcher for Earth orbit may be a cheaper alternative. For deep space launches, just a very riskier one.
I don't see that there is any difference between "deep space launches" and anything else. You just launch the crap when near Earth, from then on it's intertia and minor course corrections based on hydrazine injections.
It's not as if there were any Captain Future-style spaceship operations going on out there.
There definitely is a difference in Earth Orbit and planetary transfer orbits. For planetary transfer you need fuels and systems that can be restarted on orbit after a usually longer rest period (you need storable fuel that still flows in the frigid temperatures of space and you need to get that fuel into the engine at 0g) And you need just that little bit more oomph.
I foresee rising insurance premiums in the future for Russian Proton launches.
systems that can be restarted on orbit after a usually longer rest period (you need storable fuel that still flows in the frigid temperatures of space and you need to get that fuel into the engine at 0g)
This seems to not be the case here as Russian manoeuvering is over: ESA is responsible for future manoeuvers. Plus, these are not new technologies at all and they are not different from any orbital manoeuvering which seems to be well within Russian skillset.
I foresee rising insurance premiums in the future for Russian Proton launches.
Launchers are not "deep space", you are contradicting yourself.
No, I'm not. Read the article and my comment again. The insertion into the earth-mars transfer orbit is performed by the Briz-m 4th stage which is part of the launch vehicle stack. After tranfer-orbit insertion the 4th stage and the craft separate and the craft is then responsible for its own manoeuvring while the 4th stage puts itself into a parking orbit. This is all right there in the article. In this case it seems that after separation the Briz-M went kablewy as it started the manoeuvre to put itself into parking.
As the Briz-M is also used for GEO launches and the track record is so far not exactly stellar I do suspect this will have its repercussions on insurance premiums.
noyourenotyourewonderful "...need to get that fuel into the engine at 0g..."
It's common to activate some wee thrusters to push the rocket forward, causing the fuel(s) to settle to the 'bottom' of the tanks.
In other words, the 0g ('Floaty McFuelFace') problem is easily sorted.
Sorry to be a bit thick about this. But are we expecting the probe's velocity and direction were so spot on and all gravitational, solar, magnetic and other influences were forecast absolutely and correctly were taken into account and cannot change?
Or is the probe carrying a little fuel for flight corrections along the way. So it gets to Mars but all the following crap continues on the original path and will miss Mars by a width of a cigarette paper amplified a few million times. You know - a thousand or million miles.
The initial trajectory is a little off on purpose so all the debris (or the probe if course corrections fail) will miss Mars. The problem is there is now a load of debris following the probe, so some extra manouvering might be needed before the course correction burns are made to prevent the probe slamming into anything.
Parts of the exploding 4th stage might also have hit the probe as it was only a few km away when the thing blew (In space terms thats a gnats hair)
(you need storable fuel that still flows in the frigid temperatures of space and you need to get that fuel into the engine at 0g)
That's usually achieved by keeping the fuel tanks at a desired temperature, especially for hydrazine, which freezes at about 2C. The Voyagers, New Horizons, and Cassini are maintaining their hydrazine and electronics at approx. 20C. New Horizons, for example, put its hydrazine tank in the center of its structure and keeps it at 10 - 30C with waste heat from its electronics.
Of course, there are still risks of fuel freezing in an outlying pipe, which has happened. In 2014, a Russian Fregat upper stage failed because hydrazine froze in a pipe. That case was due to the line being too close to a super chilled helium line rather than the "frigid temperatures of space," but the means of addressing fuel freezing needn't be very low freezing point substances. (Fregat relocated the fuel and helium lines.)
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" Russia never sent anything beyond Mars and Venus"
Actually, Russia has never sent anything beyond an Earth orbit.
Note to potential down-voters: check your facts first. Although SOVIET UNION did have a successful deep space program, all attempts by sovereign RUSSIA to move beyond Earth ended in failures.
FAIL of course, to remind of Russian failures in space
I believe they usually do some sort of test and calibration of instruments after launch and the major engine burn. Then they get put into hibernation until just before arrival. Of course, if some of the rocket debris is on the same course - then when the probe slows down for insertion into Mars orbit, it's going to have a cloud of higher velocity debris right up its arse. In which case it could get near to Mars and only then go kaboom.
Of course, that depends on which way the rocket was pointing when it went boom whether they do a course correction en route and such. They've got a while to work it all out.
I have it in the back of my mind (I used to be a real space buff, a long time ago) that Mars probes were deliberately aimed slightly off target, until a later course correction corrected it, to avoid just this problem.
Any debris would follow the wrong path and miss Mars, the probe would be steered onto target.
But I may be imagining this (middle age problems, dontcha know)
Well, there you go:
https://en.m.wikipedia.org/wiki/Planetary_protection#Impact_prevention
"For both landers and orbiters, the technique of trajectory biasing is used during approach to the target. The spacecraft trajectory is designed so that if communications are lost, it will miss the target."
"We" are still frantically trying to prove whether or not there are microorganisms on mars. Introducing earthly microbes to the surface COULD pollute the environment to the point where we'd never be able to prove one way or the other whether or not there were ever martian microbes. So the boffins try to avoid introducing "foreign" microbes to the surface or atmosphere at all cost.
"Introducing earthly microbes to the surface COULD pollute the environment"
Its pretty much certain that earth origin microbes have been landing on Mars, intermittently, for the past 4 billion years. This would be due to large scale Earth impactors spreading debris into space, some of which will almost certainly have found its way there, just as its happened in the other direction.
Sure there's a lot more obstacles in the way of an organism surviving than from a borked rocket, but over this timescale, it must be almost commonplace.
Fast forward a few (thousand) generations and:
"across the gulf of space, minds that are to our minds as ours are to those of the beasts that perish, intellects vast and cool and unsympathetic, regarded this earth with envious eyes, and slowly and surely drew their plans against us.”
The chance of any live microbes from earth arriving on Mars from this launch are so small they're effectively negligible.
Even if one of the pieces manages to hit Mars ( a very big If, given that there'll be no course corrections for the debris, and a different momentum for each piece..) , there is the cold, the radiation, and the heat of re-entry without a heat shield or parachute.
But the odds are easy to demonstrate.. Take a bit of steel, and drop it on the floor of your average pub loo at closing time ( or a healthy compost heap if you're squeamish ) . This guarantees Contamination. Then drop it in liquid nitrogen, and place it near a convenient gamma source for 7 months. After that , take the piece and put it in an induction ring at full power until orange-yellow. Let it cool until safe enough to swab, and inoculate some agar plates, see what grows.
It's pretty safe to say that piece of steel will be more sterile than anything classified as such here on Earth.
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Deinococcus radiodurans is resistant to radiation, cold, desiccation and vacuum. An experiment was performed where a microbe, probably D.R, was placed on the outside of the ISS. It was still viable after 1.5 years.
http://www.popsci.com/technology/article/2010-08/bacteria-survive-553-day-exposure-exterior-iss
Yep, if you think about re-entry failures like (sad to bring this up) the space shuttle Columbia, it didn't burn up in the dense part of Earth's atmosphere, but something like 20-30 miles up. At that altitude the Earth's atmosphere is probably less dense than Mars' atmosphere as you get towards 10000-20000 feet above ground level.
When you hit even that little atmosphere at 30,000 mph, things still heat up pretty quickly.
Also, the trajectory that the debris are at might be too shallow, so if they hit Mars (not a given at this time) then the microbe-transporting pieces might skip off of Mars' atmosphere and head out into space.
And that skip-derived heat and the Martian radiations cause those microbes to mutate. The debris gets a new solar orbit from the Mars encounter. A piece could return and cross Earth orbit, eventually to re-enter.
Those now-buff quasi-martian microbes shrug off the re-entry heat easily. And thus the Earth is conquered by minute, harmless bacteria...
I thought Mars has a very thin atmosphere, is it really enough to produce significant entry heating?
Yep. The Curiosity rover saw 3800F on its heat shield during its 21,200kph entry**, and the Mars Climate Orbiter peppered the face of Mars as well-roasted confetti because of a too-deep aerobraking maneuver.
As Marketing Hack noted, Earth atmospheric entries tend to see peak heating at altitudes where pressures are similar to that of Mars. Most meteors burn up at ~50km altitude, so a fast-moving probe at Mars can see plenty of heating.
Or not. Several probes have used much, much higher altitude aerobraking maneuvers to save fuel. MCO, which lacked a real heat shield, planned to skim Mars' atmosphere at around 110km and could survive to 80km.
**I had to mix Imperial/metric because my next example was Mars Climate orbiter.
Wonder if they could slow the probe a teensie bit. Just enough to let the debris overtake the probe at very slow speed, like a couple of mm an hour. Like two lorries overtaking on a dual carriageway.
Then when it brakes properly the debris is already ahead.
Nothing they can do about the stuff hitting Mars now anyway, might as well just worry about the probe.
You can't easily brake to avoid debris, unless you know the debris definitely has the same velocity of you... that's something of an unknown. In principle, assuming that no catastrophic collision has occured, most (if not all) of the debris should be gradually moving apart laterally due to the separation event, but there is the risk that when performing the course correction to actually point at Mars, you end up pointing your spacecraft at a piece of space junk.
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