On 2/21/2012 1:20 PM, krw@att.bizzzzzzzzzzzz wrote:> On Tue, 21 Feb 2012 12:23:37 -0500, Jerry Avins<jya@ieee.org> wrote: > >> On 2/21/2012 6:22 AM, Uwe Hercksen wrote: >>> >>> >>> brent schrieb: >>> >>>>> I told him that the glow was probably a plasma from the ablation heat >>>>> shield, and that given the antenna locations, the plasma had probably >>>>> shorted them all out. He spoke to others in the room and then got back >>>>> to tell me that I was probably right, and thanks. He asked me to wait on >>>>> the line, then after a short time said that communication had been >>>>> reestablished. We were both choked up with relief. >>> >>> Hello, >>> >>> there were two missions with the Mercury capsule in an earth orbit >>> before the manned mission with John Glenn, the communication problem >>> during reentry should have been noticed before. Telemetry was used with >>> these unmanned missions also. >> >> There was no plasma problem with any of the the sub-orbital reentries. I >> can make a reasonable guess about why, but I don't know. > > Not enough energy.Possibly also revised antenna placement. Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
OT Manned reentry
Started by ●February 20, 2012
Reply by ●February 21, 20122012-02-21
Reply by ●February 21, 20122012-02-21
On Tue, 21 Feb 2012 15:28:49 -0500, Jerry Avins <jya@ieee.org> wrote:>On 2/21/2012 1:20 PM, krw@att.bizzzzzzzzzzzz wrote: >> On Tue, 21 Feb 2012 12:23:37 -0500, Jerry Avins<jya@ieee.org> wrote: >> >>> On 2/21/2012 6:22 AM, Uwe Hercksen wrote: >>>> >>>> >>>> brent schrieb: >>>> >>>>>> I told him that the glow was probably a plasma from the ablation heat >>>>>> shield, and that given the antenna locations, the plasma had probably >>>>>> shorted them all out. He spoke to others in the room and then got back >>>>>> to tell me that I was probably right, and thanks. He asked me to wait on >>>>>> the line, then after a short time said that communication had been >>>>>> reestablished. We were both choked up with relief. >>>> >>>> Hello, >>>> >>>> there were two missions with the Mercury capsule in an earth orbit >>>> before the manned mission with John Glenn, the communication problem >>>> during reentry should have been noticed before. Telemetry was used with >>>> these unmanned missions also. >>> >>> There was no plasma problem with any of the the sub-orbital reentries. I >>> can make a reasonable guess about why, but I don't know. >> >> Not enough energy. > >Possibly also revised antenna placement.No, that would suggest an easy solution when none was ever found.
Reply by ●February 21, 20122012-02-21
In comp.dsp Uwe Hercksen <hercksen@mew.uni-erlangen.de> wrote: (snip)>>>I told him that the glow was probably a plasma from the ablation heat >>>shield, and that given the antenna locations, the plasma had probably >>>shorted them all out. He spoke to others in the room and then got back >>>to tell me that I was probably right, and thanks. He asked me to wait on >>>the line, then after a short time said that communication had been >>>reestablished. We were both choked up with relief.As well as I remember it, that was still there in Apollo. For some time before splashdown there was no communication with the astronauts, as well as I remember due to the plasma glow.> there were two missions with the Mercury capsule in an earth orbit > before the manned mission with John Glenn, the communication problem > during reentry should have been noticed before. Telemetry was used with > these unmanned missions also.But they wouldn't be talking to anyone. -- glen
Reply by ●February 22, 20122012-02-22
On 2/21/2012 6:40 PM, krw@att.bizzzzzzzzzzzz wrote:> On Tue, 21 Feb 2012 15:28:49 -0500, Jerry Avins<jya@ieee.org> wrote: > >> On 2/21/2012 1:20 PM, krw@att.bizzzzzzzzzzzz wrote: >>> On Tue, 21 Feb 2012 12:23:37 -0500, Jerry Avins<jya@ieee.org> wrote: >>> >>>> On 2/21/2012 6:22 AM, Uwe Hercksen wrote: >>>>> >>>>> >>>>> brent schrieb: >>>>> >>>>>>> I told him that the glow was probably a plasma from the ablation heat >>>>>>> shield, and that given the antenna locations, the plasma had probably >>>>>>> shorted them all out. He spoke to others in the room and then got back >>>>>>> to tell me that I was probably right, and thanks. He asked me to wait on >>>>>>> the line, then after a short time said that communication had been >>>>>>> reestablished. We were both choked up with relief. >>>>> >>>>> Hello, >>>>> >>>>> there were two missions with the Mercury capsule in an earth orbit >>>>> before the manned mission with John Glenn, the communication problem >>>>> during reentry should have been noticed before. Telemetry was used with >>>>> these unmanned missions also. >>>> >>>> There was no plasma problem with any of the the sub-orbital reentries. I >>>> can make a reasonable guess about why, but I don't know. >>> >>> Not enough energy. >> >> Possibly also revised antenna placement. > > No, that would suggest an easy solution when none was ever found.There's some logic to that, but the possibility remains that the revised placement's advantage outweighed the annoyance of what was -- by then -- known to be a temporary annoyance. There must be someone who actually knows, so let's not speculate. Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Reply by ●February 22, 20122012-02-22
On Wed, 22 Feb 2012 00:02:24 -0500, Jerry Avins <jya@ieee.org> wrote:>On 2/21/2012 6:40 PM, krw@att.bizzzzzzzzzzzz wrote: >> On Tue, 21 Feb 2012 15:28:49 -0500, Jerry Avins<jya@ieee.org> wrote: >> >>> On 2/21/2012 1:20 PM, krw@att.bizzzzzzzzzzzz wrote: >>>> On Tue, 21 Feb 2012 12:23:37 -0500, Jerry Avins<jya@ieee.org> wrote: >>>> >>>>> On 2/21/2012 6:22 AM, Uwe Hercksen wrote: >>>>>> >>>>>> >>>>>> brent schrieb: >>>>>> >>>>>>>> I told him that the glow was probably a plasma from the ablation heat >>>>>>>> shield, and that given the antenna locations, the plasma had probably >>>>>>>> shorted them all out. He spoke to others in the room and then got back >>>>>>>> to tell me that I was probably right, and thanks. He asked me to wait on >>>>>>>> the line, then after a short time said that communication had been >>>>>>>> reestablished. We were both choked up with relief. >>>>>> >>>>>> Hello, >>>>>> >>>>>> there were two missions with the Mercury capsule in an earth orbit >>>>>> before the manned mission with John Glenn, the communication problem >>>>>> during reentry should have been noticed before. Telemetry was used with >>>>>> these unmanned missions also. >>>>> >>>>> There was no plasma problem with any of the the sub-orbital reentries. I >>>>> can make a reasonable guess about why, but I don't know. >>>> >>>> Not enough energy. >>> >>> Possibly also revised antenna placement. >> >> No, that would suggest an easy solution when none was ever found. > >There's some logic to that, but the possibility remains that the revised >placement's advantage outweighed the annoyance of what was -- by then -- >known to be a temporary annoyance. There must be someone who actually >knows, so let's not speculate.No, it absolutely does not. The blackout period is a big safety problem and all sorts of crazy solutions were tried (like trying to cool a hole in the plasma by injecting water). All failed. If it had been a simple matter of moving an antenna, or such, it would have been done by the time the Shuttle flew. I'm not speculating.
Reply by ●February 22, 20122012-02-22
On Tue, 21 Feb 2012 10:51:21 -0500, "Michael A. Terrell" <mike.terrell@earthlink.net> wrote:> >Uwe Hercksen wrote: >> >> Hello, >> >> there were two missions with the Mercury capsule in an earth orbit >> before the manned mission with John Glenn, the communication problem >> during reentry should have been noticed before. Telemetry was used with >> these unmanned missions also. > > > Sure, but that was before NASA started buying all of their Telemetry >receiving equipment from Microdyne. They bought it from the company that >Microdyne put out of business. :)Collins (now Rockewll-Collins) never quite went out of business. Their product line is rather different now. Or did you mean somebody else. ?-)
Reply by ●February 23, 20122012-02-23
josephkk wrote:> > On Tue, 21 Feb 2012 10:51:21 -0500, "Michael A. Terrell" > <mike.terrell@earthlink.net> wrote: > > > > >Uwe Hercksen wrote: > >> > >> Hello, > >> > >> there were two missions with the Mercury capsule in an earth orbit > >> before the manned mission with John Glenn, the communication problem > >> during reentry should have been noticed before. Telemetry was used with > >> these unmanned missions also. > > > > > > Sure, but that was before NASA started buying all of their Telemetry > >receiving equipment from Microdyne. They bought it from the company that > >Microdyne put out of business. :) > > Collins (now Rockewll-Collins) never quite went out of business. Their > product line is rather different now. Or did you mean somebody else.Yes. Defense Electronics. Several engineers left that company to found Microdyne, after their bosses refuse to modernize their designs. They built a prototype in one of the engineer's garage, then talked one of the salesmen into joining them. One of the engineers was still there as a consultant when I worked there. He was Asian and spoke in broken English. He still thought like he was working at a startup, which was a pain because he was responsible for approving new test equipment purchase. he didn't think engineers needed computers, and threw a fit when manufacturing test wanted a network analyzer. He stormed out onto the floor and jury rigged a setup that he said was all they needed to do the job. It tied up too much equipment, and wasted a lot of the test tech's time. He finally gave in ad approvedthe purchase of a used model. That analyzer cut the test time by over 90%. :) By the time I left we had almost a dozen in test, and several in engineering. I shocked the entire test department when a new batch of test equipment arrived, and i was offered a new HP analyzer for my bench, and told the boss to assign it to another tech's bench where I could borrow it, if needed. I did take the Tektronix 2465B scope for my bench, though. ;-) -- You can't have a sense of humor, if you have no sense.
