rjnoe@riccb.UUCP (Roger J. Noe) (09/13/85)
I just heard that range safety officers of the European Space Agency had to destruct an Ariane launcher (with payload) after a guidance failure. Can any- one with access to wire service reports synopsize them and expand on this? -- Roger Noe ihnp4!riccb!rjnoe
karn@petrus.UUCP (Phil R. Karn) (09/14/85)
> I just heard that range safety officers of the European Space Agency had to > destruct an Ariane launcher (with payload) after a guidance failure. I've only seen the wire reports, but they said that there was a loss of chamber pressure in the third stage shortly after ignition. The range safety destruct command was given several minutes later when it appeared that the launcher might fly over inhabited territory. This was the first manually-commanded destruct of an Ariane; the first failure (L-02) blew itself up and the second (L-5) simply dropped into the Atlantic Ocean. It is of course too soon to know what happened, but the last Ariane failure (L-5) also occurred during the third stage burn. That one was caused by a turbopump failure, and this one looks very similar. This is the launch that the French Prime Minister decided to watch in person. Phil
rjnoe@riccb.UUCP (Roger J. Noe) (09/14/85)
I also heard opinions expressed that not only will satellite insurance be difficult to obtain from now on, but that it could actually become impos- sible. I was thinking that maybe this would only be true of launches from expendable launch vehicles (ELVs, or "elves") since the only satellites that have been total losses were on ELVs, not the shuttle. TDRS-A, Westar VI, and Palapa B-2 have all been nudged into their proper orbits, even though their motors failed in one way or another. And Syncom IV-3 has been activated and looks like it may very well overcome manufacturing problems and reach its proper orbit. Not to mention the Solar Max retrieval and on-orbit repair. The shuttle not only gets satellites to low Earth orbit safely every time, it provides a means to repair satellites that have had failures in upper stages after reaching LEO. It seems like insurance rates for satellites deployed from the shuttle should go way down while those for Ariane should go way up. I think this demonstrates what I always felt was a big advantage for deployment by shuttle rather than by ELV. And the latest Ariane failure (bringing their failure rate up to 20%) is not isolated by any means. Just two weeks ago, a Titan III and a USAF recon- nissance satellite were lost after launch at Vandenberg AFB. Cost: an estimated $150 million. Strictly speaking, the Space Transportation System is one launcher which has NEVER failed to get a payload into orbit. Doesn't it seem likely that this will finally cause the insurance and satellite communications industries to realize that the shuttle is actually a more cost effective means of reaching orbit? -- Roger Noe ihnp4!riccb!rjnoe
karn@petrus.UUCP (Phil R. Karn) (09/15/85)
> ...Strictly speaking, the Space Transportation > System is one launcher which has NEVER failed to get a payload into orbit. > Doesn't it seem likely that this will finally cause the insurance and > satellite communications industries to realize that the shuttle is actually > a more cost effective means of reaching orbit? It's not quite that simple. True, the Shuttle has not yet had a launch failure resulting in the complete loss of the payloads (and the launcher!) before reaching orbit. However, Westar-6 and Palapa-B had PAM failures, and PAMs are unnecessary with Ariane because the latter puts you directly in a 35800 x 200 km geostationary transfer orbit. Only one additional burn is needed to reach a circular geostationary orbit. What's important when it comes to insurance rates is the overall probability of the spacecraft reaching its proper orbit and actually doing its job. It doesn't matter whether the satellite goes down in the Atlantic, gets stuck in a useless LEO, or arrives at GEO only to die (like the recently launched Syncom). When it works, Ariane is a much "friendlier" launcher for communications satellites than the Shuttle. Its equatorial launch site gives you a lower inclination transfer orbit. This means you can use a smaller apogee kick motor, allowing increased payload weight. Ariane deploys you immediately after reaching orbit; the Shuttle holds onto you for a day or two during which time you have no solar power, attitude control or control over the thermal environment. Shuttle safety requirements require that you delay 45 minutes after separation before doing the PAM burn. During this time many satellites have to expend considerable amounts of hydrazine to maintain the "excellent" attitude given them by the Shuttle. It has been sheer luck that there have been three opportunities for in-space salvage or repair of satellites launched on the shuttle whose upper stage engines failed. Once the satellite leaves the rather narrow set of orbits that are accessible to the Shuttle, it's on its own. If it had been the apogee kick motors that failed on Westar, Palapa or Syncom, there would have been no chance for in-orbit repair, just as there is no chance of an in-orbit repair on the one that was just launched. Phil
broehl@watdcsu.UUCP (Bernie Roehl) (09/18/85)
In article <539@petrus.UUCP> karn@petrus.UUCP (Phil R. Karn) writes: > >... If it had been the >apogee kick motors that failed on Westar, Palapa or Syncom, there would have >been no chance for in-orbit repair, just as there is no chance of an >in-orbit repair on the one that was just launched. > True. Of course, the same is true for the Ariane. Indeed, with the Ariane there is no chance at all of in-orbit repair, period. A mission can fail at any of several points. It can fail before LEO; this has *never* happened with the Shuttle, but has happened several times with the Ariane. It can fail before injection into the transfer orbit; in this case, the Shuttle can be used to make repairs and/or salvage the satellite for subsequent re-launch. With the Ariane, this kind of failure makes the mission a write-off. It can fail after injection; in this case, it may be a failure in the transfer stage, or with the apogee kick motor. If it's the apogee kick motor, it could happen just as easily with an Ariane launch as with a Shuttle launch (since it's the *satellite* manufacturer who provides that stage). The only failures thus far in Shuttle-launched satellites have been in the trasfer stages, and in at least some of those cases it's been possible to recover from the failure. I'll put my money on the Shuttle, thanks.
ems@amdahl.UUCP (ems) (09/21/85)
> > A mission can fail at any of several points. It can fail before LEO; this > has *never* happened with the Shuttle, but has happened several times with > the Ariane. is I assume you are not counting missions delayed or scrubed as being a failure before LEO ..?. -- E. Michael Smith ...!{hplabs,ihnp4,amd,nsc}!amdahl!ems This is the obligatory disclaimer of everything. (Including but not limited to: typos, spelling, diction, logic, and nuclear war)
broehl@watdcsu.UUCP (Bernie Roehl) (09/23/85)
>> >> A mission can fail at any of several points. It can fail before LEO; this >> has *never* happened with the Shuttle, but has happened several times with >> the Ariane. is > >I assume you are not counting missions delayed or scrubed >as being a failure before LEO ..?. >-- To me, there's a significant difference between delaying a lauch and blowing up the rocket (and payload) in mid-air.
mcb@styx.UUCP (Michael C. Berch) (09/25/85)
In article <536@petrus.UUCP> karn@petrus.UUCP (Phil R. Karn) writes: > . . . > It is of course too soon to know what happened, but the last Ariane failure > (L-5) also occurred during the third stage burn. That one was caused by a > turbopump failure, and this one looks very similar. > > This is the launch that the French Prime Minister decided to watch in person. Which presumably serves him right for the dirty deed done to Greenpeace's "Rainbow Warrior". Karma, anyone? :-( Michael mcb@lll-tis-b.ARPA idi!styx!mcb