Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from beak.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl) (->ota+space.digests) ID ; Tue, 3 Jul 1990 01:43:18 -0400 (EDT) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Tue, 3 Jul 1990 01:42:44 -0400 (EDT) Subject: SPACE Digest V12 #4 SPACE Digest Volume 12 : Issue 4 Today's Topics: Re: RE Hubble Space Telescope Update - 06/28/90 Re: NASA announces next steps in Space Exploration Outreach Program (F AUSTRAILIA TO SEE GIOTTO! Re: The HST was risky from square one Hubble Space Telescope Update - 06/29/90 Re: Space Telescopes Re: MOL (yes, yet more...) SPACE Digest V11 #575 Re: Is there a backup HST mirror ??? (see sci.astro) Management of space projects (specifics of GPB) Administrivia: Submissions to the SPACE Digest/sci.space should be mailed to space+@andrew.cmu.edu. Other mail, esp. [un]subscription notices, should be sent to space-request+@andrew.cmu.edu, or, if urgent, to tm2b+@andrew.cmu.edu ---------------------------------------------------------------------- Date: 3 Jul 90 02:36:38 GMT From: fluke!mce@beaver.cs.washington.edu (Brian McElhinney) Subject: Re: RE Hubble Space Telescope Update - 06/28/90 In article <1990Jun30.034700.16258@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes: > The amount and form of testing was, based on current accounts, comparable to > what is normally done for large Earth-based telescopes. It is not usual to > test the entire optical system together before telescope installation. The > normal assumption is that if the components check out, the telescope will > work. It always has in the past. The key difference is that the sub-system containing these components can be replaced. It is understandable why that might fool some management teams. But NASA is supposed to be technical enough to understand the key problem: sub-systems that are *designed* not to be replaceable *must* be tested, even if the best you can do is "primitive". As you said, hindsight is always 20-20. And you can always re-define "sub-system" to show lapses in testing to be "ludicrous". Still, I am always amazed at the number of managers that are afraid of testing. The reasoning seems to be that by running a test, you may find something. That may cost $$$ to fix, so much that it blows your budget. The project dies. So why do you need to test it? Don't you know what you're doing? (Yes, that seems unbelievable, but it's happened to me on a mere multi-million dollar project. By the way, the latter question should be just-cause for homicide! :-) I only wish that Richard Feynman could be a part of the NASA "investigation". Brian McElhinney "Knowledge is soon changed, then lost in the mce@tc.fluke.com mist, an echo half-heard" --Gene Wolfe ------------------------------ Date: 2 Jul 90 13:41:37 GMT From: mcsun!ukc!edcastle!eoph12@uunet.uu.net (I F Gow) Subject: Re: NASA announces next steps in Space Exploration Outreach Program (F What's all this about English Colonial Power? Remember Union of the Crowns and Parliaments! IFG ------------------------------ Date: 28 Jun 90 17:35:58 GMT From: mcsun!ukc!icdoc!mvax.cc.ic.ac.uk!sund!zmapj36@uunet.uu.net (M.S.Bennett Supvs= Prof Pendry) Subject: AUSTRAILIA TO SEE GIOTTO! Giotto will have its closest approach at 9:59.50 GMT 2 July 1990. Closest aproach to Earth surface will be in the Indian Ocean close to the Southern tip of Austrailia at a distance of 22680 km. Giotto will just be visible to the Amature (if they are in OZ else forget it) Magnitude : Most Probable 10-12 th : Optimistic 8 th Professional Observers should have details of orbital elements & ground track. The main difficulty will be in working out the star coords. to look at- You would need to perform a Topocentric analasys. If still intrested (and BT willing) I will have the Hyperbolic Orbital Elements by Friday. Mail me >>>> Cc: Bcc: /------ ------- -----\ /------ | ====================== | | | | \ | | M. Sean Bennett | \-----\ |---- | | \-----\ | UKSEDS TECH.OFF. | | | | / | | Janet:SEDS@CC.IC.AC.UK | ------/ ------- -----/ ------/ | Bitnet- | | SEDS%CC.IC.AC.UK@ukacrl | | ====================== | ------------------------------ Date: 1 Jul 90 17:33:59 GMT From: mtndew!friedl@uunet.uu.net (Stephen J. Friedl) Subject: Re: The HST was risky from square one In article <451@newave.UUCP>, john@newave.UUCP (John A. Weeks III) writes: > > Discover Magazine, July 1989, Page 68 "The Big Glass". Excellent article > on the construction of the primary mirror. Drama, suspense, and technical > details. ... and reprinted (in condensed form) in _Reader's Digest_, April 1990. Steve -- Stephen J. Friedl, KA8CMY / Software Consultant / Tustin, CA / 3B2-kind-of-guy +1 714 544 6561 / friedl@mtndew.Tustin.CA.US / {uunet,attmail}!mtndew!friedl Still not sure what to think about this Heisenberg fellow... ------------------------------ Date: 2 Jul 90 15:18:00 GMT From: zaphod.mps.ohio-state.edu!sdd.hp.com!usc!elroy.jpl.nasa.gov!forsight!jato!mars.jpl.nasa.gov!baalke@tut.cis.ohio-state.edu (Ron Baalke) Subject: Hubble Space Telescope Update - 06/29/90 Hubble Space Telescope Update June 29, 1990 Since June 26 there has only a little activity in orbit but, as I am sure most of you aware of by now, a lot of action on the ground. The Faint Object Spectrograph (FOS) successfully turned on their Red Side High Voltage (HV) over the past three days. All went very well with no anomalies. The High Speed Photometer (HSP) turned on their Photomultiplier Tube (PMT) detector to check out the "rising counts" problem. A quick look at the data indicated that the problem had disappeared. Unfortunately, analysis of the data showed that this perception was due to differences in the way the two tests were run and that the problem was still there, unchanged from before. A move to the star eps Sco was accomplished and a new series of Bootstrap proposals were started. Things have not gone as well as people were hoping -- guide star acquisitions were failing (cause is under investigation). Some coarse alignment data has been obtained today but it was too early to tell if enough data will be gathered to accomplish the alignment. This Bootstrap runs until 12:30 AM EDT on July 1. The news regarding the Pointing Control Subsystem (PCS) day/night terminator instabilities looks very promising. All indications are that the efforts of engineers may be able to remove most of the disturbances; reducing the ~200 milli-arc-second peak-to-peak oscillation by between a factor of 10 to 100. If this proves true then it would bring the HST stability very close to or within pre-orbital specifications. The delivery schedule of the PCS fix is late July or early August. As for the rest of the PCS system, things are generally going well with the exception of the most recent failed acquisitions. Two of the failures have been traced to "bit flips" in the Fine Guidance Sensors (FGS) caused by the South Atlantic Anomaly (SAA), the remaining failures are under study. All indications are that the FGS S-Curve calibration went well for FGS 2 and 3 (no data on FGS 1) and that significant updates of the S-curve calibration will be implemented for these two FGS's. Analysis of the run of focus images and Wavefront Sensor (WFS) measurements made over the past week appear to show about 0.5 waves RMS field independent spherical aberration at the Optical Telescope Assembly (OTA) focal plane. The cause is, at present, unknown. From all indications the spherical aberration is the only mirror problem -- in all other respects the mirrors are perfect. The current best guess explanation for the aberration is that one of the mirrors has the wrong figure, a wrong conic constant. At the present time it is unknown if the problem lies in the primary or the secondary mirror. Other items of interest: the paraxial to marginal focus is 4 cm, the circle of least confusion is ~1.5 arc second, if you were to assume that the error is in the primary mirror and that the center of the mirror is correct, then there will be ~2 micron error at the edge. In terms of real image quality we are talking about ~70% of the encircled energy in ~0.8 arc second radius and ~12% in 0.1 arcsec (spec was 70% in 0.1 arcsec radius). Also, the current focus produces significant differences in image quality in the 3 FGS's (FGS 1 and 3 have ~0.7 arc-second images, whereas FGS 2 has ~1.4 arc-second images). The primary mirror has 24 force actuators on it but they were designed to remove aberrations other than spherical and are not likely to significantly improve the image. Lots of testing to fully characterize the image on and off axis are being planned for the next weeks. With these data we should have a much better description of the focus of the OTA. Unfortunately, the bottom line appears to be that based on current knowledge it is unlikely that there will be a significant improvement in image quality in the OTA, even after the aberration is better characterized. However, the aberration is fully and easily corrected in the next generation of Scientific Instruments (SI). So, with the installation of Wide Field Planetary Camera II (WFPC II) in 1993 (obviously an accelerated schedule is under study) HST should regain its full imaging characteristics. HST is currently observing eps Sco for Bootstrap activities. To do this the telescope must be off nominal roll. This is producing a cooling of the SPA (Solar Power Array) Blanket. As of this morning it was at -102 C (~-80 C is normal and -100 C is the "red" limit). The European Space Agency (ESA) is studying the impact of the low temperature, if they find that it is potentially harmful, then the spacecraft will be sent back to nominal roll and the focus testing will come to a temporary halt. The Faint Object Camera (FOC) is in hold. FOC diagnostic images in support of focus efforts will start early on July 2. FOS is back in hold. Blue side HV on went very well. Dark count was as expected (~1 x 10^-2), one possible new noisy diode was found but otherwise all was as expected. WFPC is in full operate mode. Next images are scheduled to start at 2 AM EDT on July 1. ___ _____ ___ /_ /| /____/ \ /_ /| | | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov ___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov /___| | | | ___/ | |/__ /| M/S 301-355 | |_____|/ |_|/ |_____|/ Pasadena, CA 91109 | ------------------------------ Date: Mon, 02 Jul 90 15:07:42 CDT From: John Nordlie Subject: Re: Space Telescopes In the March 1984 issue of Astronomy, Astronews column, I found an article about the "Amateur Space Telescope", then being built by about 30 students from Rensselaer Polytechnic Institute and the University of Rockester in New York. The project was being supervised by the Independent Space Research Group, which hoped to get the AST launched via shuttle GAS can by 1985. AST has an 18" primary mirror, television cameras, photometers, and a small spectrograph. Attitude control was to be done via three variable speed gyros. The satellite weighed 175 pounds, and cost aprox $100,000. (article continues with more specs and info) What has become of this device? Did it ever get completed/launched? Is the project still functioning? ======================================================================= John Nordlie | I tried to think of something intelligent to say. | " Urgh..", I managed. | - Harry Harrison 'A Stainless Steel Rat | is Born' ======================================================================= ------------------------------ Date: 30 Jun 90 05:53:36 GMT From: sdd.hp.com!elroy.jpl.nasa.gov!peregrine!ccicpg!felix!dhw68k!ofa123!Wales.Larrison@ucsd.edu (Wales Larrison) Subject: Re: MOL (yes, yet more...) In article <440@newave.UUCP> john@newave.mn.org (John A. Weeks III) writes: >Can anyone tell me more about MOL... After reading many of the responses, I'm surprized that no one else picked up this explanation: Klauss, author of "Secret Sentries in Space" (now out of print, but probably the best reference on the early days of military observations satellites), claims the MOL program was primarily directed to resolve a fundamental problem with early missile warning systems. He claims that early missile launch warning satellites could not discriminate well enough to reliably detect submarine launched missiles from sun-lit cloud cover. They could detect the launches, but the rate of false warnings was so high, that the U.S. government could not rely upon it for sufficent warning time. One ofthe primary objectives of the MOL program (according to Klauss) was to provide direct observation and verification of missile launch detection to the national command authority. Man-in-the-loop was required due to the vulnerability of the U.S. to Soviet missile submarines and the short warning times, and to avoid the potential hazards of accepting a false warning. However, this sensor inability to discriminate missile launches was overcome by a significant effort in new IR sensor design, and significant scientific investigation into the phenomenology of missile launch signatures. This included the use of a Gemini crew to photograph and track an ICBM launch from Vandenberg during a Gemini flight, gathering space-based data that unmanned satellites could not gather at that time. (Klauss includes a public domain picture taken from space by the Gemini mission of the ICBM launch from Vandenberg). As the ability to confidently detect missile launches was put into place by unmanned satellites, the reason for a manned MOL died. An unmanned version could do the job, very well, and a new generation of unmanned satellites could do the job even better, and cheaper. - Wales - -- uucp: Wales Larrison Internet: Wales.Larrison@ofa123.fidonet.org BBS: 714 544-0934 2400/1200/300 ------------------------------ Date: Mon, 02 Jul 90 14:53 EDT From: ALVLOUA%YALEVM.BITNET@vma.cc.cmu.edu Subject: SPACE Digest V11 #575 ------------------------------ Date: 2 Jul 90 19:31:50 GMT From: sdd.hp.com!zaphod.mps.ohio-state.edu!wuarchive!rex!rouge!dlbres10@ucsd.edu (Fraering Philip) Subject: Re: Is there a backup HST mirror ??? (see sci.astro) OOPS! I meant aren't the launch vibration loads much worse than landing? [missed it by that much] Phil ------------------------------ Date: 2 Jul 90 11:59:06 GMT From: unmvax!nmt.edu!nraoaoc@ucbvax.Berkeley.EDU (Daniel Briggs) Subject: Management of space projects (specifics of GPB) In article <7620@aggie.ucdavis.edu> hulse@iris.ucdavis.edu (C. Andy Hulse) writes: >[comments on the poor handing of the HST project -- at least as it looks > now] Well, this post may be a bit premature, but I'd like to hear what the net has to say about the subject. Simply put, what CAN we learn from the HST fiasco? How can management of space projects be made better? Does anyone have experience with space projects that they think have gone particularly well, and how can we learn from them? What made them work well? Just kick off the ball, I will toss out the observation that the Apollo program and the Voyager program seem to be NASA's leading examples of how to do a project right. My knowledge of these two is fairly limited, so I'll leave discussion of these programs to the sci.space.gurus. However, I would like to bring another program to your collective attention. It is one that hasn't flown yet, but seems to show very promising signs of maximising the science while (relatively speaking), minimising the bureaucratic overhead. The project is the Stanford Relativty Gyroscope Project, also known as Gravity Probe B or the Schiff Experiment. It is a project that has almost as long a history as HST. I believe that the project is about 25 years old. (The paper that proposed the basic idea was written in 1960, and NASA funded the first exploratory study a few years later.) The idea is very simple. One orbits a number of gyroscopes, and watches them precess. If you do it carefully enough, then you will be able to detect two different general relativistic effects that have never before been measured. The only problem is, that these effects are *extremely* small. The smaller of the two effects amounts to a prediction of 42 milliarc-seconds of precession in one year. They are shooting for a one percent measurement of this. This in turn requires some unholy levels of experimental precision. The "NASA glossie" that I have quotes the following tolerances: Environment: Temperature approx 1.8 K Gravity less than 10e-10 g Magnetic Field less than 10e-7 Gauss Pressure less than 10e-11 Torr Gyro Rotor: Homogeneity less than 3 parts in 10e7 Mechanical Sphericity less than 3e-7 inch Electrical Sphericity less than 5e-7 (From: Testing Einstein with Orbiting Gyroscopes - Gravity Probe B) This is arguably one of the toughest measurements that has ever been attempted, period. Several fundamentally new experimental techniques have been developed for this project. Most of these techniques have already seen application elsewhere by now. For instance, the idea of the drag free satellite was invented for this project. (This is the technique of flying a satellite around a test mass, to produce a really low micro g environment. Most navigation satellites use this today.) The problem of superfluid helium boil in the dewar off was solved by a special porus plug that has already been used in IRAS and COBE, among others. I don't really mean to be a simple cheering section for this project, although it *is* damned impressive. It just seems to me that here we have a project that is at least as complex as Hubble is, and they seem to be doing it right. (The few quibbles that I have heard via scuttlebutt seem to be pretty minor. Nothing at all like the trepidations that people have been having with HST.) In this case, we have a project that is simultaineously breaking substantial ground on a number of different measurement frontiers. They *know* that there are going to be unanticipated problems. Quoting again from the same PR glossie, Cost control versus on-orbit success is one issue. One into spacecraft development, a program inevitably has a large "marching army" of engineers. Any technical delays will cause large cost overruns. Gravity Probe B manages this risk through incremental verification-building progressively more and more complete subsets of the experiment hardware while the army is still only a platoon, with firm engineering solutions verified at each stage. In all, four major steps of incremental verification drive out risk and attendant cost uncertainties. * Gimballed Gyro Test (GCT) precise ground testing of individual flight gyroscope. * First Integrated System Test (FIST) ground evaluation of a prototype science payload. * Shuttle Test Of Relativity Experiment (STORE) a rigorous seven-day engineering test of the Science Mission dewar-instrument package on the shuttle * Science Mission up to two years of relativity measurements in a drag free spacecraft. OK, even stripped of the PR hype, it looks to me like they have their heads firmly on their shoulders. BTW, note that this gadget is designed to run strictly in a zero g environment, yet they still manage to build a prototype system that *runs* on the ground. This means things like they have to suspend the rotors on 10000 volts electrostatic suspension instead of 1/10 volt. There are some differences between a ground based system, and an orbiting one, but there are even more similarities. Hence, they test the ground system first. Note the third step above. They fly the entire payload in the space shuttle for a week. No science data here, only engineering data. They get the engineering data back, think about it for a year or two, tweak what didn't work quite right, and send up the real payload on a dedicated launcher. I believe that we just passed the FIST a few months ago, and that the STORE is scheduled for 1993 or 1994. GPB should fly in 1996 ?? Another interesting point about this project is the management situation. It is a sufficiently front line research effort that there is just no way they can send it out to a subcontractor. No way to write a flexible enough contract, given that nobody knows (knew?) exactly what the job would require. Alternatively, you simply can't ask a university to build a spacecraft like this. They just aren't set up for that kind of project. The solution was to link two groups at Lockheed and Stanford into essentially one development group. They share a common framework, so these is little duplication of bureaucratic framework between the two groups. NASA claims that the paperwork has been simplified. (Believe it if you will.) I can't remember a source, but I think that I read elsewhere that the ratio of managers to engineers on this project was something like 40 - 50 percent less than in other typical NASA projects. It seems to me that this is an example of a NASA style project that (seems to be) going right. By the standards of a small start up company, it is still bulky and bloated, but it is demonstrably less bulky and bloated than some other NASA projects. Then again, it's a very hard problem. The question I put to the group is this: Why did this one work, and other projects not? How can we encourage more of this style thinking in the NASA bureaucracy? -- This is a shared guest account, please send replies to dbriggs@nrao.edu (Internet) Dan Briggs / NRAO / P.O. Box O / Socorro, NM / 87801 (U.S. Snail) ------------------------------ End of SPACE Digest V12 #4 *******************