Live from the Hubble Space Telescope
UPDATE # 6
PART 1: Information through Email
PART 2: International television
PART 3: Arizona and North Carolina educators wanted
PART 4: ABC Kidzine
PART 5: "Who's Who at the Hubble?" activity
PART 6: Heidi stays busy
PART 7: Programming the HST
Besides these email updates, there is a wealth of information available online at our Web site. But we understand that many teachers do not have access to the Web. A new service is now available which will let you receive certain information via Email. To receive a summary of the files available, please send a mail message firstname.lastname@example.org. You do not need to include any other information in the message.
Our speedy mail robot will automatically send back a message which will list the files available. To start, we will provide biographies of the HST team through this service.
This just in from Executive Producer Geoff Haines-Stiles I know some of you were very excited by the participation in the Great Planet Debate of students from Germany, Ukraine, Russia and Japan. Since then "greetings for Clyde Tombaugh" have come in from around the world, including Croatia. Now, I'm glad to say, our international participants may have a chance to see the programs -- if not live, then soon after.
This should be possible courtesy of the U.S. Information Agency's WORLDNET satellite. They have already committed to carrying both programs, 3/14 and 4/23, LIVE to Latin America. Time zones and transponder availability mean that they cannot, at this point, confirm LIVE carriage to the rest of the world, but a recent conversation indicated they are planning on re-feeding the signal in the evening of our live broadcasts, or on the following day.
How to access the signal? Apparently this varies, nation by nation, with some educational networks and cable systems downloading WORLDNET, and with other nations primarily receiving programming via U.S. government installations. In Brazil, for example, the signal will be accessible at certain consular and other Embassy facilities, as well as via a domestic educational satellite. Neither PASSPORT TO KNOWLEDGE nor the USIA can give our international participants a full and complete listing of your LOCAL access points, but we hope you will be interested enough to make some calls, and find out. By the way, we've been testing the videoconference link we will be using to link STScI and ESA's Hubble Coordinating Facility in Europe, and things are looking good for that major component of the March 14 program.
We expect to have more definite carriage information (days and times) in the week before each live broadcast.
This flashed across the net recently; perhaps you are interested:
ABC Kidzine is a new online area for ABC News being created. It draws heavily on ABC's mandate to get children involved in the news - and to make them, therefore, more media savvy. ABC is looking for kids who would be willing to write opinion pieces about issues - national, local, school - that concern them.
ABC is also seeking interesting *classrooms* to tell us about projects they're doing - preferably, but not necessarily, involving technology and the web.
If you have any interest or questions, please email myself the producer at DKearns@aol.com.
Did you know that there are almost 30 intriguing and informative biographies ready for integration into your classroom or learning environment?
This special feature of the Live From the Hubble Space Telescope project allows the day-to-day lives of the Hubble astronomers, researchers, and support staff to be shared. You will meet the men and women who ultimately make the Hubble an unparalleled scientific resource.
You will find an archive of the biographies at our web site under "The HST Team" heading. Also these biographies are available via Gopher and Email (as described above in PART 1).
The following activity is designed to help you and your students get to know the Hubble scientists and researchers.
Assign teams of students to read the biographies online or download and distribute copies to students.
Use these clues to have your students find out WHICH of the Space Science Telescope Institute (STScI) and Goddard team members each of these statements describes. They should also explore WHAT type of WORK each person does in regards to the Hubble Space Telescope.
-- studied to be an actor and is even writing screen plays -- worked in the Baltimore Police Department Crime Lab -- knew after the first week of 8th grade he/she would pursue a career in astronomy; rock climbs -- plans to videotape the 1998 solar eclipse from somewhere within the Caribbean; read every science book he/she could find as a child -- tap dances and enjoys koosh ball games with his/her children; learned about computers by using his/her brother's TRS-80 Radio Shack computer -- loves to ride bicycle around the Washington monuments at lightning speeds -- has three ferrets as pets; built his/her own telescope while in high school -- is named after the brightest star in the constellation of Scorpio; enjoys white water rafting -- creates the "phone book of the stars," tutors inner city students and likes singing -- took apart clocks as a young child just to see how things work -- is interested in Taek Won Do; knew he/she wanted to become an astronomer after reading National Geographic's book, Our Universe -- climbs mountains and says the movie 2001 influenced his/her decision to study the space sciences -- new at seven years old would become an astronomer -- shot a roll of film a day for six months straight for the college yearbook and now rarely takes pictures -- gave up hopes of being an astronaut after riding a roller coaster; coaches little league baseball and says teamwork is one of the most important skills to learn -- made picture scrapbooks as a child; had three teachers whose last name begin with M who influenced him/her
Of course, your students will find out much more about the actual work of these people by reading each of the stories they share online and distributed via the updates-hst mail list.
Some educators use the Field Journals as a basis of reading and language arts activities. You might have the students role-play, interview, write their own "day-in-the-life of a Hubble scientist" journal or even begin to prepare questions to be sent online in early March. I know that I found that by reading these journals that I felt much more a part of the Hubble experience and have a much clearer view of the large number and diverse backgrounds of the key players involved in this endeavor.
If you are an interested in the having a set of answers to the above Who's Who activity, please email me directly, but I encourage you to personally try out "Who's Who..." and get acquainted with our special Hubble hosts.
If you have ideas on how to integrate the use of the Field Journals into the classroom, please share online with the rest of our forum.
Jan Wee, discuss-hst moderator and Education Outreach Coordinator
Heidi B. Hammel
February 23, 1996
* Science Planning for the LHST Images of Neptune There really hasn't been much more action on my part for the LHST Neptune imaging. Once I got all the initial planning done (see 6 Jan 96 Journal), most of the work is done by the folks (namely Tony) at the Space Telescope Science Institute.
I did get one phone call from Tony, who was converting what I had written into the proper format to be used by HST. He asked why I had put in an "Orbital Longitude" (OLG) constraint, which would restrict the observations to a certain time of year that didn't include the LHST window! Ooops!
The answer to that was that I had used my previous Neptune plan as a blueprint, and in that plan I had put the OLG constraint in so that HST would look when Neptune was visible to ground-based observatories. That way, I could take pictures in the infrared as the same time that HST was doing its imaging (which is what I did last Fall, 1995, using the NASA Infrared Telescope on Mauna Kea in Hawaii). But (obviously!) we didn't need that constraint for the LHST observations. I told Tony he could just go ahead and delete it.
I heard through the grapevine that our observations were set for next weekend. So I guess everything is going okay!
* Non-science LHST Plans
I got my hair cut this week, since it is awful to get a brand-new haircut just before doing a TV program (you feel extra nervous because you are not used to the way your hair feels). This way it'll have a few weeks to grow in and I'll get comfortable with it.
* Other Projects I've Been Working On
February 20, 1996
When I first heard of the observations that were intended, I asked Alex Storrs for the proposal number and the anticipated execution times. Every proposal gets a five digit number AND a three character Program ID. In general we use the proposal number during preparation and planning while the program number gets associated with the data as they are received after observation. I wanted to know if the observations would occur during a week I would be building. We all work in teams here and (thankfully) take turns with building calendars, so each one of us gets to work with a particular week in detail, while having only slight or no input on other weeks. It turns out that these observations will likely be completed before I start my next calendar. So I can just watch as other capable hands make them happen, yet I can supply some background on just how these things occur.
My other excitement is that the week I _am_ scheduled to build covers the week that the newly discovered comet Hyakutake passes closest to Earth. While it is still being determined if HST will be able to observe it during this time - while it will be moving very fast! - it will be an interesting experience one way or the other.
We have (as you can imagine) quite a number of software tools for scheduling observations and analyzing the calendar. In this and later journals, I hope to show you some of them.
One that can be seen directly is the Calendar display. This shows activities that must occur for an observation to succeed and the times they start and finish. Here is an example from today (20-FEB-1996, day 051 of the year. (Thirty-one days in January plus the 20 in Feb. equals 51.) This one shows what was executing on the spacecraft as I looked this afternoon.
Following this display I will translate some of the odd "words" so everyone should be able to follow the progress.
CALENDAR TIMELINE C&C List ID: 960507B3;1 Generated On: 20-FEB-1996 18:32 Orbit File: OR96022WA;1 Baseline Name: GLOBAL TDRS East: TDRSTDE TDRS West: TDRSTDW Displayed From: 1996.051:19:00:00 Calendar Start: 1996.050:00:00:00 To: 1996.052:00:00:00 End: 1996.057:00:00:00 ------------------------------------------------------------------------------- START END DESCRIPTION PROP-PROG:OB:AL VER ------------------------------------------------------------------------------- 050:00:00:00 ******** Calendar Start ******************************* 051:20:46:56 051:21:26:36 FGS_AVD (ENT,L= 15.8) 06095:11:01 01 051:21:03:55 051:21:19:13 M Slew (AN=112,RA=279,DE=-33,PA= 79,OR= 0,SN=55) 051:21:19:13 051:21:24:43 M FHST Updte (FULL ,MAN,E= 185,1,2,3) 051:21:24:43 ******** Main SU 0609511 ******************************* 051:21:24:43 051:21:33:43 M PCS AQ(FGS ,E= 54,BASE1 ) 06095-2VO:11:01 051:21:26:36 051:22:23:27 FGS_AVD (EXT,L= 7.8) 06095:11:01 01 051:21:33:42 051:21:33:43 SI UP WFII OPER 06095-2VO:11:01 01 051:21:33:43 051:22:23:43 M Sci WFII UPC1FIX 1 06095-2VO:11:01 01 051:22:23:27 051:23:03:04 FGS_AVD (ENT,L= 15.8) 06095:11:01 01 051:22:23:43 051:22:24:43 SI DOWN WFII READY 06095-2VO:11:01 01 051:22:23:43 ******** End Main SU 0609511 ********************************** 051:22:24:43 051:22:25:43 SI DOWN WFII STANDBY 06095-2VO:11:01 01 051:22:48:58 051:23:00:15 SAA 02 (ENTRY) 051:23:00:15 052:00:27:07 SAA 02 (EXIT) 051:23:03:14 051:23:19:48 M Slew (AN=128,RA=167,DE= 73,PA= 12,OR= 2,SN=118) 051:23:19:48 051:23:25:18 M FHST Updte (FULL ,MAN,E= 213,1,3, ) 057:00:00:00 ******** Calendar End *******************************
Here is the translation:
C&C List ID: 960507B3;1
Each week of observations gets a name. The "96" means the year is 1996; the "50" is the first day of the week (19-FEB-1996 equals day 050), the "7" means the calendar does indeed cover seven days (it is possible to use a shorter or longer calendar but we generally stick to a standard week); and the "B3" shows the version we finally ended up with. For example, the first attempt at building a calendar might be "A1".
START END DESCRIPTION PROP-PROG:OB:AL VER 051:20:46:56 051:21:26:36 FGS_AVD (ENT,L= 15.8) 06095:11:01 01
^^^ FGS is the Fine Guidance Sensor which looks for the guide stars needed for holding the telescope steady for the observations. The "AVD" means the AVoiDance region where the Earth blocks our view. The "ENT" means that the spacecraft is ENTering that AVoiDance region. Notice that this lasts for 39 minutes and 40 seconds. Subtracting hours and minutes and seconds We can also make the computer do this, but sometimes it is faster to do it yourself. And it also is useful to check occasionally to see that the computer has really done what you want it to do. Blind faith in computer generated numbers will leave you in the dark sometimes.
The "L" means that we are actually avoiding the bright Limb of the earth by 15.8 degrees, which is our practical limit for scattered light from the Earth. The target that is blocked is indicated by the 06095:11:01. This translates to Proposal 06095, Observation Set 11 and Alignment 01.
051:21:03:55 051:21:19:13 M Slew (AN=112,RA=279,DE=-33,PA= 79,OR= 0,SN= 55)^^^^ This uses 15 minutes and 18 seconds to "Slew" (turn the telescope) to the desired pointing. The target is at Right Ascension 279 degrees and DEclination -33 degrees. This points to the middle of the Milky Way in the constellation Sagittarius. The telescope turned 112 degrees (AN) from the previous target. The pointing is 55 degrees (SN) from the position of the Sun for that day. The PA and OR show the roll of the spacecraft. We cannot point the telescope any closer to the Sun than 50 degrees, but 55 degrees is fine.
051:21:19:13 051:21:24:43 M FHST Updte (FULL ,MAN,E= 185,1,2,3) ^^^^As soon as the Slew completed, we schedule a Fixed Head Star Tracker Update. The FHSTs are small telescopes pointed out the bottom end of the spacecraft to help us be sure the movement of the telescope took us to the right place. (Those round holes you might see on a picture or model of HST.) The stars that it sees are compared to a catalog and if all match up, we have a confirmation. (If the check shows we are a little off, the controllers can nudge the pointing to put us back where we should be.)
051:21:24:43 ******** Main SU 0609511 ******************************* This 0609511 is the name of the "SU" (Scheduling Unit) which starts running at this time. 051:21:24:43 051:21:33:43 M PCS AQ(FGS ,E= 54,BASE1 ) 06095-2VO:11:01 051:21:26:36 051:22:23:27 FGS_AVD (EXT,L= 7.8) 06095:11:01 01Again, the FGS_AVD shows the AVoiDance region, but this time we EXiT the region at 051:21:26:36 - but on the dark limb of the earth, which is why we can start looking at only 7.8 degrees from the edge. The dark edge gives less scattered light for us to avoid than the bright limb does. Most times if we enter from the bright limb, we will exit from the dark limb and if we enter from the dark limb, we will exit from the bright limb. Can you visualize why this is so? Why would we rarely see the dark limb both on entry and exit? When would we see both limbs as bright?
Since we can now see the sky, the PCS - Pointing Control System will start to AQ (AcQuire) the guide stars for the observation 06095:11. Notice the Program number is 2VO. A sharp reader might notice that this sequence actually starts 1 minute 53 second BEFORE the EXiT from AVoiDance. We are able to do this because we know that it takes that long for the FGS mechanisms and detector to turn on and get in position to see any light. Rather than let this time go to waste (at estimates of spacecraft time of $8.00 per second) we use this time to start the sequence running.
During the nine minutes of PCS AQ, ( 21:33:43 minus 21:24:43 ) the FGS looks for the guide stars, locks onto their light, confirms that they have the correct brightness and positions, nudges the pointing of the telescope to put the target star into the light-gathering aperture of the Scientific Instrument, in this case the Wide Field Planetary Camera II. Only then can the observations proceed.
051:21:33:42 051:21:33:43 SI UP WFII OPER 06095-2VO:11:01 01
This simply gives the time it takes for the WFII instrument to turn on to an OPERating condition to make it ready to observe the target. This SI (Scientific Instrument) only takes a second to get ready, but we must account for every second of activity. Other SIs take longer times to get ready. Since we can get them ready to turn on during the slew to the target or during the PCS AQ (as we did here) no time gets wasted.
051:21:33:43 051:22:23:43 M Sci WFII UPC1FIX 1 06095-2VO:11:01 01Finally, after all the preparation, we can expose the WFII to light from the target for 50 minutes. The "Sci" means Science data is being collected here. The UPC1FIX shows which of the (many) apertures the target is centered on. In this case the PC1 shows it is in the Planetary Camera CCD chip - the smallest one and the one with the sharpest view.
051:22:23:27 051:23:03:04 FGS_AVD (ENT,L= 15.8) 06095:11:01 01After 56 minutes and 51 seconds the spacecraft has flown half-way around the world and at 051:22:23:27 the Bright edge of the earth comes around and blocks our view of that piece of the sky. So we ENTer the FGS AVoiDance region again. Again you might notice that the WFII observation does not end until 051:22:23:43, 16 seconds later. But we do know that the exposure has already ended and this is part of the time the WFII needs to read out the data so we are safe - and again squeezing out a few more seconds of valuable time that can be used for the next observation.
051:22:23:43 ******** End Main SU 0609511 **********************************
The end of observations for this SU.
051:22:23:43 051:22:24:43 SI DOWN WFII READY 06095-2VO:11:01 01
Just a few minutes later the spacecraft crosses a region over the South Atlantic that has a large amount of high energy radiation. During these eleven minutes and 17 seconds, we want to have all cameras turned off and all high voltage turned down. Luckily this happened when the target had already been blocked by the Earth anyway. Actually it is not just luck - we try to schedule things to match up this way.
051:23:03:14 051:23:19:48 M Slew (AN=128,RA=167,DE= 73,PA= 12,OR= 2,SN=118)
This shows the maneuver of the telescope to the next target on the list, located 128 degrees away in the sky at Right Ascension 167, Declination 73. This is in the northern area of Ursa Major, just beyond the "Pointer Stars" in the bowl of the Big Dipper. Why did we not slew immediately to the next target after the end of the previous exposure? Hint: There is no simple way to answer this with just the information contained in this calendar display. Maybe you will have some good guesses.
051:23:19:48 051:23:25:18 M FHST Updte (FULL ,MAN,E= 213,1,3, )
Another Fixed Head Star Tracker Update to check the position before the next observation.
Well, you have just seen a fairly standard sequence of events of a scheduled observation. Different programs could use one or more of the other Scientific Instruments on the spacecraft; some might take a shorter exposure; some might need a longer one. We might point at a target for another orbit - waiting for the earth to clear out of the way, then the PCS would find the same guide stars again, and the camera could take another exposure. Sometimes we may stay at the same pointing for many hours. The target might be so faint that many exposures are needed, or perhaps the astronomer might request the same exposure through several different filters.
A target that is moving (like a planet or comet) is a little more complicated. We not only have to know where it is, but at just what time it will be located there. Once we are pointed there though, we have to make the telescope follow its motion exactly throughout the exposure. And if the planet is rotating, we would want to look at it at the time the side we want is facing us. All these make scheduling a little more fun.
In future journals I hope to show some other computer tools we use to show the motion of the HST and its view of the sky. I'll use this same example so readers can compare the position and motion of the telescope as it moves and the positions of the stars in the sky.