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Unmanned Spaceflight.com _ Jupiter _ Galileo IUS ignition
Posted by: kwan3217 Apr 9 2007, 01:33 AM
There are lots of pictures of Galileo being ejected from the cargo bay of the space shuttle, but so far I haven't been able to find any pictures of Galileo when the IUS first stage lit up and Galileo departed for Venus. Is this because there aren't any such pictures?
Basically I want to see what a solid fuel motor looks like when it is fired in space. I suspect it is quite different from the billowing gray smoke we are used to seeing when one is lit in the atmosphere.
Posted by: Decepticon Apr 9 2007, 02:06 AM
I found this one. But thats it. http://members.aol.com/_ht_a/hattonjasonp/hasohp/GALILEO.JPG
Posted by: antipode Apr 9 2007, 02:22 AM
The RocketCam site has some video of some of the little Star solid motors lighting up on Delta II missions and its entirely unremarkable - just a dazzling white light.
P
Posted by: BPCooper Apr 9 2007, 03:43 AM
There are videos taken following deployments from the shuttle in the past, but it is done so far away that all you see is a big white star or splotch in the distance.
Posted by: GregM Apr 9 2007, 05:31 AM
.
Posted by: tasp Apr 9 2007, 01:55 PM
Regarding orientation of the shuttle to the IUS during ignition:
Since the Columbia accident, is policy to orient the shuttle to the IUS to minimize cross sectional area??
Seems like pointing the tail directly at the ignition might be preferable, damage to the TPS on a trailing surface would be better than a divot facing into the re-entry heating.
If I am overlooking something, let me know . . .
Posted by: djellison Apr 9 2007, 02:11 PM
There's been nothing on the Shuttle launch manifest that includes an IUS since before Columbia as far as I know - certainly nothing in the ISS-Complete+Hubble list.
Doug
Posted by: tasp Apr 9 2007, 02:15 PM
Not deploying anything with an upper stage does eliminate the concern . . .
{kind of obvious I haven't had my morning cup of joe . . . }
Posted by: BPCooper Apr 9 2007, 02:40 PM
IUS is history. The last IUS took DSP-22 into orbit aboard a Titan IV on Feb. 14 2004.
Even before Columbia, there were no IUS deploys slated on the shuttle anymore. Chandra on STS-93 was the last.
Posted by: nprev Apr 9 2007, 02:49 PM
Interesting. I didn't know that the IUS had been adapted for use with ELVs. How many were launched this way, BP?
Posted by: ugordan Apr 9 2007, 02:52 PM
Seeing how the Titan IV was a kind of emergency capability mirroring the Shuttle, it's logical IUS would be compatible.
Posted by: nprev Apr 9 2007, 02:55 PM
I see. Still, it's always impressive to me to see dual-application designs like this. I honestly thought that the IUS was Shuttle-only hardware.
Posted by: Jim from NSF.com Apr 9 2007, 03:45 PM
DSP-14 thru 22, except number 17 flew on T-IV IUS. 17 flew on STS-44
DSP was the largest user of IUS. Before,T-IV was the CELV, only 10 launches were to be procured and DSP was a few of them. After Challenger, all moved to T-IV except the one on a previously pay for shuttle mission
The first Titan-IV was a DSP/IUS.
T-IV/IUS was an inefficient combination. It could only launch 5300lb to GSO. The IUS cost was near a T-IV Centaur. Now, an intermediate EELV could launch it. But due to many things including fairing requirements, DSP-23, the last one, is fly on a D-IV heavy
Since most Shuttle/IUS missions were performance critical, the RMS did not fly on them
Posted by: BPCooper Apr 9 2007, 04:03 PM
There is a brief rundown here too:
http://www.spaceflightnow.com/titan/b39/index.html
"Saturday's mission was the 24th and final IUS launch. Dating back to 1982, IUS motors flew aboard 15 space shuttle missions, eight Titan 4 rockets and a single Titan 34D, launching NASA's Magellan space probe to Venus, Galileo to Jupiter, Ulysses to the sun, the Chandra X-ray Observatory, the original fleet of Tracking and Data Relay Satellites, plus many military spacecraft, including a few classified ones."
Posted by: Littlebit Apr 9 2007, 05:16 PM
Good question. The solid propellants used are similar in composition to the ground-launched solids, but the nozzle is relatively longer - the motor is more efficient in a vacuum, and the turbulence much, much less - so the plume, if it could be seen, would still be 'gray' but not 'billowing'.
Posted by: nprev Apr 9 2007, 05:17 PM
Wow. I and certainly others are edified & grateful; thanks very much, Jim & BP! The IUS has a much more varied history than I'd originally realized.
Posted by: Jim from NSF.com Apr 9 2007, 05:32 PM
Forgot to add that DSCS-III flew on Shuttle with two spacecraft on an IUS. After Challenger, it was determined that it would be cheaper to launch the complete constellation of 10 satellites on an uprated Atlas Centaur (the yet to be designed Atlas IIA) with an yet to be designed apogee propulsion system (IABS). A person proposed this through the USAF Suggestion program. The suggestion was declined and then the gov't figured out eventually that is was a good idea and implemented it. The original suggester "protested" the response he got and was awarded 25K (the max amount).
There were backup plans to launch Galileo and Ulysses on T-IV IUS, in case the shuttle was delayed longer
Posted by: nprev Apr 9 2007, 05:43 PM
Now that's a fascinating tidbit, Jim...thanks yet again! I made a couple of $s off of that suggestion program myself back in the day for airplane stuff, but nowhere near the max...good for him or her!
Posted by: edstrick Apr 10 2007, 06:29 AM
The IUS was originally named the "Interim Upper Stage", when it was concieved as a short-on-budget stopgap that would be replaced by a combination of a true inter-orbit Space Tug ... planned as part of the Space Transportation *SYSTEM*.
When it became clear that "Interim" would last to the decay of the last proton in the universe, it was rather quietly renamed the "Inertial Upper Stage", meaning that it had 3 Axis inertial attitude control instead of spin stabilization, unlike most or all other solid fueled upper states.
This bogaceously expensive solid upper stage, with the miserable specific impulse of all solid propellant upper stages, cost as much or more than an equivalent performance Centaur upper stage, particularly when amortized over the enormous development cost of the stage.
In the end, it's only good feature was that as a solid fueled stage, it added minimal extra risk to Shuttle cargo missions that needed a big upper stage to deploy payloads to higher orbit.... an ability that was abandoned as fast as reasonably possible after Challenger.
Posted by: dvandorn Apr 10 2007, 03:36 PM
When you consider that one of the next few flights of the Shuttle after Challenger was scheduled to be the launch of Galileo on a Centaur loaded into the Shuttle's cargo bay, it may not be completely correct that "interim" was a misnomer. There were plans, as of early 1986, to use the Centaur / Shuttle combination for a variety of large payloads, including planetary probes.
Of course, if you talk with Shuttle experts and afficionados, you'll hear the opinion that while Challenger was a tragedy, maybe it was a good thing in one way -- that the systems in place to fly an LO2-LH2 Centaur stage inside the cargo bay were so dangerous that we would have lost an orbiter trying to fly in that configuration. (Just the systems designed to allow fueling of and boil-off from the Centaur stage, IIRC, required major Shuttle safety waivers to be allowed to even be considered for a flight configuration.)
But it's good to remember that while the full "space tug" system was never going to be developed, there were plans to go beyond the PAM / IUS set of capabilities. And, therefore, "interim" wasn't necessarily going to be a completely dead concept. (Up until Challenger, of course, after which even the PAM / IUS configurations were considered too risky and phased out.)
-the other Doug
Posted by: Analyst Apr 10 2007, 05:48 PM
I wonder if Jim has been the "original suggestor".
Analyst
Posted by: Jim from NSF.com Apr 10 2007, 08:21 PM
Analyst
Nope, I was an evaluator, but only on the shuttle parts of the suggestion
Posted by: Jim from NSF.com Apr 10 2007, 08:24 PM
Those plans were as earlier than 1983.
Just IUS and Centaur flew on T-IV, the IUS would have still flown for many more years. Some programs would not have migrated to Centaur
Posted by: Jim from NSF.com Apr 10 2007, 08:26 PM
The PAM/IUS was used for Ulysses
Posted by: BPCooper Apr 10 2007, 11:45 PM
And Magellan.
Posted by: Jim from NSF.com Apr 11 2007, 01:05 PM
There was a smal difference, it was "bare" Star-48 motor, which means it didn't have any of the PAM systems, and it was part of the Magellan spacecraft vs the IUS.
Posted by: mchan Apr 21 2007, 07:43 AM
There were also the 3-stage IUS configuration that were proposed for the split up Galileo orbiter and probe in 1984 after the 1982 launch opportunity with a 2-stage IUS was lost. IIRC, the 1984 proposal would have involved two shuttles launching within a week or two of each other, one with the orbiter, the other with the probe. Would have been an expensive set of launches.
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