E.T. fall home

By Phil Plait | May 12, 2009 2:00 pm

External Tank, that is. As Spacewriter said, this speaks for itself:

CATEGORIZED UNDER: Cool stuff, NASA
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Comments (68)

  1. no burny burny?

    poo.

  2. Looks like a giant cigar made of awesome.

  3. And no, no burny.

  4. Ramel

    They might get more veiwers if the comentator went burny burny… Most incredibly dull vioce I’ve ever heard (Possible exeption of my old school chaplin, but I never stayed awake long enough to be sure)

  5. Vernon Balbert

    Dang, I wanted to see it all the way until the parachute deployed.

  6. Mike

    It’s not immediately clear to me why it falls back to Earth. At what point is the E.T. released from the orbiter? How close does it get to obtaining orbit itself?

  7. Zyggy

    Actually, to me it looked like first it visibly “blackened” on the underside and the closer end, then the whole thing started to glow from the heat. That was my perception, but it could have been the lighting as well.

    But burny burny could have been fun as well =)

  8. Brian

    Hey, Phil. The Youtube video in the text link, while interesting in itself, does not match the embedded video.

  9. Mchl

    Is the second link supposed to lead to ‘FSM Evangelism’ video?

  10. Christopher Ferro

    ***curses corporate firewall***

    :-((

    CJSF

  11. Sir Eccles

    Possible “minor” damage to the shuttle?????

    http://news.bbc.co.uk/1/hi/sci/tech/8046219.stm

  12. Jay

    @Mike – the ET is released shortly after main engine cut off.

    It falls back to Earth since at the time of its release, it and the orbiter are on a sub-orbital trajectory. The shuttle then uses its OMS engines to attain orbit.

    See http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts_mes.html#mes_2nd_stage and http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts_mes.html#mes_insertion

  13. Steve

    That is quite spectacular. It must be falling a one hell of a rate. Where was camera? Surely not on the shuttle itself. (I don’t have audio, so if it was mentioned I would have missed it).

    A few years back I recall seeing this from a camera on the fuel tank itself. Watching the shuttle “fall away” was fantastic. Most of the journey down to earth was a bit tedious, but it was great to see the ‘chute open and then SPLASH!!

  14. dbalsdon

    Vernon, there’s no parachute attached to it… the whole tank burns/breaks up on reentry.

    Looked like the video cut off just before the fun part. :(

  15. Very cool, especially in High Def! At about the 2:10 mark, a piece of debris can be seen… either foam or ice!

  16. dbalsdon:
    I may be wronng on this, But I believe the tank re-enters over the Indian Ocean

  17. F Jordan

    I thought at one time the shuttle would detach the E.T before it reached orbital speed so that the E.T. would not go into orbit and then obtain orbital velocity with the OMS engines. Is this right and if so when did they change this?

  18. TheWalruss

    Definitely foam – they’re doomed.

  19. dbalsdon

    Disclaimer: Wikipedia is my source on this, so may not be accurate.

    The tank breaks up, and the debris lands in the Indian ocean.

  20. Davidlpf

    This blog use to be about antivaxxers, creationists and politics
    not space. I’m very disapointted and I am thinking about not readin this blog again.(sorry had to get at least on snark a day or I would explode.)

  21. Davidlpf

    Suppose to be “one snark”, also need to make on corredtion a day.

  22. QUASAR

    That’s a big one!

  23. dbalsdon

    Oh, and an update from the bbc(and kinda O.T.).. apparently they’ve found some minor damage to Atlantis. http://news.bbc.co.uk/1/hi/sci/tech/8046219.stm

  24. I can’t decide:

    Epic Fall!

    or

    Intelligent Falling!

    J/P=?

  25. John Baxter

    That camera likely has more processing power than the shuttle’s computer(s). Which if true is a bit chilling.

  26. Chip

    Falling back to Earth from very high altitude looks much the same as a low, decaying orbit. It really illustrates the Newtonian idea that an orbit is the same as falling but constantly missing the Earth.

  27. @dbalsdon:
    The Lockheed Martin website confirms the re-entry area for the ET… Looks like wiki got this one right! :)

    lockheedmartin dot com/data/assets/12742 dot pdf

    Type in as you would a regular net addy!

  28. Great more space junk / more sea pollution.

    When are we going to be able to get to space with a fully reusable spacecraft (+fuel) again?

  29. It looks as if it’s accelerating ahead of the shuttle as it falls. I think it makes sense that a lower orbit is a faster one, which is interesting. I remembered this from Larry Niven’s “Integral Trees”:

    In takes you East.
    East takes you Out.
    Out takes you West.
    West takes you In.

    …which I found quite beautiful for some reason.

  30. Bigfoot

    I would not expect the shuttle to be able to see a close-up of the actual friction burn, or I would fear for the shuttle! Thinking about it, the “burn” happens when the atmosphere has become thick enough to cause massive air resistance/friction (which of course causes deceleration) at the speed of the object. Here, the tank does not even appear to be decelerating, and still looks awfully close to shuttle orbiter speed and altitude, only slowly drifting away in a slightly lesser orbit. I would think that by the time the glow builds, the tank would have already experienced quite a bit more altitude drop and some significant deceleration as the friction built up in the early pre-glow phase. By then, I would think the tank would be well away from the shuttle, rapidly being left behind, probably out of line-of-sight from the curvature of the Earth (I could be wrong on this) from the orbiter.

  31. AFAIK ET is one burn away from reaching orbit – at the time of ET separation, the orbiter is in preliminary orbit with low point still in the upper reaches of the atmosphere, so the perigee is raised with an OMS burn at apogee. With no such burn for the ET, on its next perigee, it loses speed and reenters.
    Disclaimer: I don’t even remember where I have read this, so it could be completely wrong :-)
    But I’m almost sure, that ETs don’t fall in the Indian ocean – being completely in the southern hemisphere, it would severely restrict available launch windows – they should be timed so the shuttle always flies over the ocean. Pacific and Atlantic oceans are better – they run from pole to pole :-)
    And the only time, when I have seen both shuttle and ET, they flew in SW – NE direction over me (I’m in Bulgaria), i.e. flying generally towards Russia – several thousand kms away from Indian ocean.
    Btw. is was a FANTASTIC sight – bright white shuttle flying with no so bright orange ET nearby. Here is a picture of this flyby: http://forum.starrydreams.com/viewtopic.php?t=1727 (click on the image for a video – little shaky, but still it was an incredible sight for me)

  32. NASA released pictures of the damage and completed the heat shield survey: http://www.nasa.gov/mission_pages/shuttle/main.

    @Michael L — Good eye on the debris!

  33. Rob

    Another successful fallure from NASA?

  34. MadScientist

    I’m glad it speaks for itself because the commentator is more asinine than a sports commentator.

  35. T.E.L.

    From the rate at which the background clouds are sweeping past, it’s evident that the scene was shot with a long focal length lens. Assuming that the orbiter is only at an altitude of about 160 km, that places its orbital speed at 7.8 km/s, and the clouds are (at nadir) whipping by at 2.8 degrees/s. It’s a little hard to get a very accurate rate, but the clouds appear to be crossing the field from lower-right to upper-left at roughly 3 degrees/s (early in the video, before the zoom is changed), and the tank then is about 2.8 degrees from tip to tail. The tank is 48 m tall, so that places it at not less than 1 km from the orbiter.

    Of course, if the orbiter was much higher than 160 km, and/or the tank wasn’t immediately beneath it (which I think is the case), that places the tank at more than 1 km.

  36. aarrgghh

    Am I the only one that watched this and immediately thought, hey that looks just like BSG camera work?

  37. Rift

    @Davidlpf

    >This blog use to be about antivaxxers, creationists and politics
    >not space. I’m very disapointted and I am thinking about not readin this blog again.

    Oh gawd that was funny, not sure why but I laughed hard at that David. Thanks 😛

  38. OtherRob

    Am I the only one that watched this and immediately thought, hey that looks just like BSG camera work?

    That was my first thought as well. :) Very reminiscent of it.

  39. 26. Chip Says:
    Falling back to Earth from very high altitude looks much the same as a low, decaying orbit. It really illustrates the Newtonian idea that an orbit is the same as falling but constantly missing the Earth

    I thought that was Arthur Dent (Douglas Adams)!

    J/P=?

  40. Mount

    That is a great video, it even got my heart rate up a bit. I must see that with my own eyes someday!

  41. Steve Says: “Where was camera? Surely not on the shuttle itself.”

    Actually, yes, the audio mentioned that it was shot through the flightdeck windows.

    “A few years back I recall seeing this from a camera on the fuel tank itself. Watching the shuttle “fall away” was fantastic. Most of the journey down to earth was a bit tedious, but it was great to see the ‘chute open and then SPLASH!!”

    You’re thinking of the SRB (strap-on booter) video. They instrumented one of them with a camera and you could watch the whole sequence.

  42. Michael L Says: “I may be wrong on this, But I believe the tank re-enters over the Indian Ocean”

    Depending on the orbit it’s injecting into, the tank re-enters over anywhere from south-central Europe to northern Africa and the remaining debris that doesn’t burn up lands in the Indian Ocean.

    – Jack

  43. alexandre van de sande Says: “Great more space junk / more sea pollution.”

    No space junk. The SRB’s are recovered and reused. The ET mostly burns up with only some of the hardpoints and denser structure hitting the water. It’s far, far less than even one ship sinking.

    “When are we going to be able to get to space with a fully reusable spacecraft (+fuel) again?”

    As soon as someone wants to fund developement.

    – Jack

  44. There’s a subtle aspect to this video that might escape most people. Note as you’re watching it, the portion of the ET visible keeps changing. That’s because the the attitude of the tank stays fixed in space while it’s orbiting the Earth. The orbiter is given a pitch rate such that it completes one complete 360° pitch per orbit (so that the radiators in the cargo bay doors remain pointed at the Earth). The tank has no such pitch rate, so our viewpoint changes at about 4 degrees/min, or almost 20° over the period of this video.

    The motion of the tank away from the orbiter is not due to atmospheric friction, but is just the separation velocity given when the two part company.

    – Jack

  45. @Jack Hagerty,

    Thanks Jack, I was wonderin’.

  46. Timothy from Boulder

    (Mostly cut and pasted from an earlier BABlog post)

    On April 24, 1990, I had the good fortune to witness the re-entry of the Space Shuttle external tank from a vantage point on Maui. STS-31 was the flight that put the Hubble Space Telecope in orbit. The external tank usually burns up over the Indian Ocean, but the higher inclination orbit of this flight gave NASA an opportunity to dump the tank over Hawaii. The advantage of that was to observe the breakup with the array of telescopes at the Air Force Maui Optical Station on top of Haleakala.

    Detailed observation was desired because NASA wanted to see if the tank would sufficiently break up without the use of the external tank tumble valve, which is used to jettison residual oxygen and hydrogen to start the tank rotating so that when it enters the atmosphere it breaks up more readily. (If you want something to break up in the atmosphere, the last thing you want is a nice stable aerodynamic shape easily slicing through the air.)

    Working on a project associated with the Haleakala station, I was notified of the impending re-entry at about 3 a.m. local time. Two bright flashes early in the re-entry were presumably the ruptures of the oxygen and hydrogen tanks. The spectacle was like watching fireworks in slow motion — colorful, bright, silent — as the streaking pieces glowed across the night leaving trails and breaking apart into an increasingly wider spray of debris. Sadly, that’s what the videos of the Columbia orbiter breaking up over Texas looked like years later.

    Timothy Reed

  47. madge

    Cool video. I loved the launch. Watched the whole thing. I am following the mission on NASA TV and Astro_Mike on Twitter. Didja see his home movie of the crew looking all relaxed and so cool aboard Atlantis?

  48. Shaun

    I’m kinda disappointed with this video. I know shaky-cam is popular in the movies these days, but I thought NASA fakes were held to a higher standard. 😀

  49. Fish

    See if we got a ufo video, just one, of that quality then maybe we’d have something to talk about.

  50. Michael Gray

    “Marvelous” is the only adjective that is literally appropriate for clip!

  51. Uhhhmmm, ET TANK? ET TANK? EXTERNAL TANK TANK?

    ATM MACHINE!!! VIN NUMBER!!!

    Sweet crimony almighty, what is it with people and redundancy?

    Please fix this absurd title for crying out loud.

  52. Mike

    “AFAIK ET is one burn away from reaching orbit – at the time of ET separation, the orbiter is in preliminary orbit with low point still in the upper reaches of the atmosphere, so the perigee is raised with an OMS burn at apogee. With no such burn for the ET, on its next perigee, it loses speed and reenters.”

    Does this mean that the ET makes one full orbit before reentering at the Indian Ocean?

  53. Mchl

    Nitpicker: why don’t you go and nitpick at people who uploaded the video to YouTube? Nitpicking about it here doesn’t make much sense, does it?

  54. Calli Arcale

    Zyggy says:

    Actually, to me it looked like first it visibly “blackened” on the underside and the closer end, then the whole thing started to glow from the heat. That was my perception, but it could have been the lighting as well.

    There is some visible blackening, but this has nothing to do with reentry, which won’t happen for some time (by which time it will have moved so far away from Atlantis that it is no longer visible). The blackening is soot from the SRB’s separation motors, little solid-fueled rockets that push the spent SRBs so they fall neatly away and don’t impact the vehicle, Which Would Be Bad. It’s actually quite a dramatic amount of soot; the first ET-cam sent up became utterly useless at the point of SRB sep because the soot totally smudged its lens. Lots of folks suggested clever and innovative ideas to resolve the issue, but NASA, opting for the KISS principle (Keep It Simple Stupid) just moved the camera a few yards down and out of range of the motors for the next ET cam.

    Jack Hagerty says:

    Steve Says: “Where was camera? Surely not on the shuttle itself.”

    Actually, yes, the audio mentioned that it was shot through the flightdeck windows.

    “A few years back I recall seeing this from a camera on the fuel tank itself. Watching the shuttle “fall away” was fantastic. Most of the journey down to earth was a bit tedious, but it was great to see the ‘chute open and then SPLASH!!”

    You’re thinking of the SRB (strap-on booter) video. They instrumented one of them with a camera and you could watch the whole sequence.

    The SRBs are actually always instrumented with cameras, but not with any kind of live downlink; the cameras record to tape, which is recovered and then reviewed a couple of days later. It’s always cool, and the tumbling at the beginning is reminiscent of the sounding rocket films that were the earliest sort of spacecraft film.

    The ET film is also done on every mission, even before most of the crew are allowed to leave their seats. Right away, the orbiter pitches around so that the receding ET is visible from the flight deck, allowing the crew to take footage of it. This supplements footage of the receding ET taken by cameras built into the Orbiter’s underside, right next to one of the ET’s attach points under a protective door not far from the main gear. This mission is having some trouble with the latter footage; they’re running into problems getting the system to play back the ET separation footage so they can downlink it. But at least they have the handheld images, and the tile inspection doesn’t give much reason for worry. It’d be nice to identify where the foam came from on the ET, though.

    Mike says:

    “AFAIK ET is one burn away from reaching orbit – at the time of ET separation, the orbiter is in preliminary orbit with low point still in the upper reaches of the atmosphere, so the perigee is raised with an OMS burn at apogee. With no such burn for the ET, on its next perigee, it loses speed and reenters.”

    Does this mean that the ET makes one full orbit before reentering at the Indian Ocean?

    Not quite; it reenters before it completes an orbit, but it does get halfway around the Earth. Technically, you have to get all the way around for it to be an orbit. There is some controversy surrounding Yuri Gagarin’s flight aboard Vostok 1 for this reason — he took off from Kazakhstan but landed in Russia after one revolution, but that would mean the landing zone was somewhat short of the liftoff site. So was he the first to orbit, or not? Certainly, Vostok 1 was capable of completing additional orbits; it was in a stable orbit. It just deorbited before it got all the way around. So the question is a semantic one for the record keepers. His trajectory was clearly orbital (unlike the clearly suborbital Mercury-Redstone shots), so for all practical purposes he was indeed the first to orbit the Earth.

  55. Mike

    I’m still not fully getting this. Obviously, the ET and the orbiter part company before they reach a sufficient velocity to obtain orbit. The ET falls to Earth pretty quickly if it falls into the Indian Ocean, so it seems that the orbiter still needs to add quite a bit of velocity, but I’m surprised it has sufficient fuel to do this (where are the fuel tanks containing this fuel?).

    I’ve googled around a bit for a description of when events (such as ET separation) ocurr during a launch, velocity at that point, etc. but I haven’t found it yet. Can anybody point me in the right direction?

  56. Tom

    Thank you for the great Video. Sure wouldn’t want to be in an airplane and get hit with anything that survives re-entry.

  57. Sorry, this post is not about the EFT. Just wanted to alert folks to this awesome Flash anim of the ISS assembly. One of the nicest info-graphics/animations I’ve seen:

    http://i.usatoday.net/tech/graphics/iss_timeline/flash.htm

  58. Thespis

    Those tanks go right back to Michoud in New Orleans and are recycled. Here’s the site for more info. http://www.lockheedmartin.com/ssc/michoud/ExternalTank/index.html
    When Challenger happened, half the kids in my school had parents working on the E.T.

  59. T.E.L.

    Mike,

    After the orbiter’s fuel tanks are in those two large bumps to port & starboard of the vertical stabilizer. There are smallish-sized rocket motors just behind those tanks which take care of finalizing the velocity changes.

  60. Tom

    The tanks from the SRBs are reused, but the large tank in the video burns up on re-entry.

    http://en.wikipedia.org/wiki/Space_Shuttle_external_tank

  61. So that’s where my lipstick ended up.

    Claire

  62. a lurker

    Phil, your blog has gotten yet another Fark green light from this post.

  63. StevoR-Correcting

    @ Davidlpf : (May 12th, 2009 at 3:28 pm)

    Suppose to be “one snark”, also need to make on corredtion a day.

    What only *one* correction per day?!

    You’re doing very well then.

    I usually need to make several per post. :-(

  64. Grammar Nazi

    @ Jack Hagerty: (May 12th, 2009 at 7:59 pm)

    You’re thinking of the SRB (strap-on booter) video. They instrumented one of them with a camera and you could watch the whole sequence.

    I could be wrong but I thought SRB stood for:

    Solid
    Rocket
    Boosters

    not “strap-on”. Although I suppose they do “strap on” in a way, there are certainly no visible straps that I can see! 😉

  65. Grammar Nazi

    Also I think the ‘Solid’ in the SRB comes from the fact that the SRB’s use a solid chemical fuel whilst the External Tank and Orbiter components use liquid hydrogen and oxygen(?) fuel.

    Incidentally, that video made me nostalgic for the time when NASA went to the trouble of painting the ET white on the earliest shuttle flights.

    To see a white falling tank there would be much prettier. In My Humble Opinion anyway.

    Not sure if there was any video made of the descending ETs back then.

  66. Bein'Silly

    Although I suppose they do “strap on” in a way, there are certainly no visible straps that I can see!

    Now I’m just picturing the SRBs being attached with a giant pair of occy straps! 😉

    Might make separation a bit awkward! 😉

    ‘Spose it could be worse … It could be duct or sticky tape holding ’em on! 😉

  67. SteveA

    Sorry if I missed it in the comments, but do we have any indication on how fast it was falling?

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