Saturn V

Today we celebrate the 50th anniversary of the inaugural flight of Wernher von Braun’s magnum opus, the giant Saturn V moon rocket.  This first flight was an unmanned mission, Apollo 4, and took place less than 10 months after the tragic launch pad fire that killed astronauts Gus Grissom, 40, Ed White, 36, and Roger Chaffee, 31.

Apollo 4 launch, November 9, 1967
Apollo 4 image of Earth at an altitude of 7,300 miles

The unmanned Apollo 4 mission was a complete success, paving the way for astronauts to go to the Moon.  After another successful unmanned test flight (Apollo 6), the Saturn V rocket carried the first astronauts into space on the Apollo 8 mission in December 1968.  On that mission, astronauts Frank Borman, Jim Lovell, and Bill Anders orbited the Moon for 20 hours and then returned safely to Earth.

Bill Anders took this iconic photo of Earth from Apollo 8 while in orbit around the Moon

“As of 2017, the Saturn V remains the tallest, heaviest, and most powerful (highest total impulse) rocket ever brought to operational status, and holds records for the heaviest payload launched and largest payload capacity to low Earth orbit (LEO) of 140,000 kg (310,000 lb), which included the third stage and unburned propellant needed to send the Apollo Command/Service Module and Lunar Module to the Moon.  To date, the Saturn V remains the only launch vehicle to launch missions to carry humans beyond low Earth orbit.”

Reference (for quoted material above)
Wikipedia contributors, “Saturn V,” Wikipedia, The Free Encyclopedia, (accessed November 9, 2017).

ISS & SS Memories

The last Space Shuttle flight took place in July 2011 (Atlantis, STS-135), and in going through the archives from ten years ago, I found this write-up about the International Space Station and the Space Shuttle seen together in the sky.

International Space Station & Space Shuttle – Docked

This past Sunday evening brought my family to Governor Dodge State Park north of Dodgeville for a stroll in the dark—and what we thought would be a “routine” flyover of the International Space Station.  Boy, were we surprised!  Even though conditions were quite hazy, the ISS made its appearance as predicted, but as it reached its culmination of 62° at 10:27 p.m. (6/17/07 CDT) we witnessed something none of us had ever seen before: a gradual brightening of the ISS to between -6 and -9 magnitude, followed by a gradual dimming back to the normal slightly negative magnitude of a favorable flyover.  We had observed a “sun glint” off of the large station’s many reflective surfaces.  What a treat!

Footnote #1: The ISS had a definite orangish tint to us, which may have been real in spite of the hazy conditions.

Footnote #2: No-line bifocals (progressive lenses) work well during the day, but try looking at a bright moving object at night (or stars in general) to see just how bad the optics are!  For night viewing, I recommend a pair of glasses (if you need them) for distance viewing only, with glass lenses (not plastic!) and 0.5 diopter greater correction than you normally use.  I have such a pair, but forgot to bring them with me that night.

International Space Station & Space Shuttle – Undocked

This past Tuesday, the Space Shuttle Atlantis (STS-117) undocked from the International Space Station, and, as luck would have it, there were two opportunities that evening to view the pair—separated by only 46 miles—cross the sky in a beautiful pas de deux.  The first and best event, which culminated at 9:33 p.m. (6/19/07 CDT), was still impressive in spite of bright twilight because the spacecraft were so bright.  The brighter and oranger ISS was leading Space Shuttle Atlantis by about 3° when first sighted low in the NW, which expanded to about 6° at culmination since both spacecraft were closer to Wisconsin and the axis between the two least foreshortened, shrinking again to 3° when both spacecraft disappeared into the shadow of the Earth low in the ESE.  The changing orientation of the axis connecting the two spacecraft as they crossed the sky was interesting to observe.

A curious phenomenon that my wife, daughter, and I all noticed was that the positions of the two spacecraft with respect to each other seemed to “wiggle” a bit at times as they crossed the sky.  What a strange optical illusion, because obviously both spacecraft were moving smoothly relative to Earth and relative to each other!

I also observed the second pass that evening, which reached a maximum altitude of only 14° in the WSW sky before the pair entered the shadow of the Earth at 11:07 p.m. CDT.  Both spacecraft were about two magnitudes fainter than before, and this time Atlantis seemed brighter and oranger than the ISS!

As any double star observer knows, though, the perceived color of an object is strongly dependent upon its brightness!

Science News

Some people are molded by their admirations, others by their hostilities. – Elizabeth Bowen (1899-1973)

I have many admirations, and one of them is for a bi-weekly magazine called Science News.  My first introduction to this amazing publication was in 1973, when a friend of my recently-divorced mother, Frank Gillotti, started giving me his copies after he was finished reading them.  I was a sophomore at Hoover High School in Des Moines then, and by my senior year I was a subscriber for life.

Science News has been around a long time.  It started way back in 1922 as Science News-Letter, and remained that until 1966, when it became Science News.  Today, Science News has an international circulation of about 94,000—alarmingly, down quite a bit (like most magazines) from its peak circulation of nearly 250,000 in the late 1980s.  Unlike most magazines these days, Science News is not saturated with advertising, but is instead chock-full of well-written, accurate, and timely news and feature articles about all areas of science, technology, and mathematics.  Yes, astronomy and space science are covered thoroughly!  And, with each bi-weekly1 issue numbering 32 pages (though, occasionally 40+), it is easy to find the time to read or at least skim it cover-to-cover every two weeks.

In my early years reading Science News, one writer I particularly admired was senior editor / physics editor Dietrick E. Thomsen, whom I was so fortunate to meet at the AAS Meeting in Ames, Iowa in June 1986.  Sadly, he passed away in 1988.  One thing I remember about him besides his always-excellent articles was his passion for passenger trains, and his growing distaste for air travel at the time (and it has only gotten worse).  At that time, I had never ridden on a passenger train, but nowadays I ride Amtrak regularly, and love it!

Another fantastic writer in those days at Science News was space science editor Jonathan Eberhart (1942-2003) whose brilliant and unconventional career was sidelined by multiple sclerosis by 1991.  The AAS Division for Planetary Sciences (DPS) has awarded the Jonathan Eberhart Planetary Sciences Journalism Award annually since 2009.  J. Kelly Beatty (Sky & Telescope) was the first recipient (in 2009), and Emily Lakdawalla (The Planetary Society) won the 2011 award.

Science News maintains an excellent web site.  One feature I really like is they provide a complete list of sources and references for their magazine articles.

And, Society for Science & the Public (SSP), the nonprofit corporation that produces Science News, also produces an excellent website for readers ages 9-14, Science News for Students.

Check out these wonderful resources regularly, and while you’re at it, don’t forget to subscribe!

1Science News published weekly through April 12, 2008.  Science News began publishing bi-weekly on May 10, 2008.

Saturn at Eastern Quadrature

Wednesday evening, September 13, 2017, at 9:59 p.m. CDT, Saturn reaches eastern quadrature as Saturn, Earth, and Sun form a right triangle.  Eastern quadrature is so named as Saturn is 90° east of the Sun.  This is the time when Saturn presents to us its most gibbous phase.  Even so, Saturn will be 99.7% illuminated due to its great distance from us.

A more noticeable effect will be the shadow of Saturn on its rings, a phenomenon best seen at eastern or western quadrature.

Saturn will only be 12° above our horizon in SW Wisconsin at the exact moment of eastern quadrature Wednesday evening.  Earlier that evening, Saturn crosses the celestial meridian at 6:51 p.m.—22 minutes before sunset.  If it weren’t for daylight, that would be the best time to observe Saturn: when it is highest in the sky and we are seeing it through the least amount of atmosphere.  If you have a telescope equipped with a polarizing filter, you can significantly darken the blue sky background around Saturn since the planet will be exactly 90° away from the Sun, where the scattered sunlight is most highly polarized.  Rotate the polarizer until the sky is darkest around Saturn.

Speaking of Saturn, the Cassini mission will come to a bittersweet end on Friday, September 15 around 5:31 a.m. CDT when the storied spacecraft, which has been orbiting Saturn since June 30, 2004, will have plunged deep enough into Saturn’s atmosphere that it is no longer able to point its high gain antenna towards Earth.  Soon after that, Cassini will burn up in Saturn’s massive atmosphere.  We on Earth will not receive Cassini’s last radio transmission until 1h23m later—at around 6:54 a.m. CDT.

Emily Lakdawalla, who is arguably the best planetary science journalist in the world these days, includes the visual timeline of Cassini’s demise shown below and in her recent blog entry, “What to expect during Cassini’s final hours”.

Also, on Wednesday evening, don’t miss NOVA: Death Dive to Saturn, which will air on Wisconsin Public Television’s flagship channel at 8:00 p.m.

It may be a while before we visit ringed Saturn and its retinue of moons again.  But further exploration of Titan and Enceladus is certain to feature prominently in humankind’s next mission to Saturn.  Hopefully, that will be soon.

Satellite Crossings 2016-2017

Edmund Weiss (1837-1917) and many astronomers since have called asteroids “vermin of the sky”, but since October 4, 1957 another “species” of sky vermin made their debut: artificial satellites.  In the process of video recording stars for possible asteroid occultations, I frequently see satellites passing through my ~¼° field of view.

I’ve put together a video montage of satellites I’ve recorded between December 14, 2016 and August 5, 2017.  The component events are presented chronologically as follows:

UT Date
7-25-2017 (2 satellites)

Target Star
UCAC4 538-7253
Tycho 586-1051-1
Tycho 1422-911-1
Tycho 4997-136-1
Tycho 6799-309-1
Tycho 666-190-1
UCAC4 548-7392

2485 Scheffler
19807 (2000 SE16)
71612 (2000 EH12)
11133 Kumotori
68112 (2000 YC143)
491 Carina
151 Abundantia

In all cases, the asteroids were too faint to be recorded.  And, in all cases, the target star was not occulted by the asteroid (a miss).  In the final event, the satellite passed right over the target star (9:40:11.679 UT) during the period of time the event would be most likely to occur (9:40:10 ± 3 s)!  Fortunately, the seeing disc of the target star was never completely obliterated by the passing satellite, so I was able to determine unequivocally that the asteroid missed passing in front of the star from my location on Spaceship Earth.

Here’s a graph of the brightness of UCAC4 548-7392 during the last video clip.  You can definitely see the close appulse of the satellite with the star!

In general, the slower the satellite is moving across the field, the higher is its orbit around the Earth.  One must also consider how much of the satellite’s orbital motion is along your line of sight to the satellite.  In the following montage of two video clips, the first satellite is very slow moving and thus most likely in a very high orbit.  The second video clip shows a satellite that is quite faint.  Again, the asteroids are too faint to be recorded and no asteroid occultation event occurred.

UT Date

Target Star
Tycho 5011-133-1
Tycho 5719-308-1

190471 (2000 DG27)
321656 (2010 BM90)

Hughes, D. W. & Marsden, B. G. 2007, J. Astron. Hist. Heritage, 10, 21

In the Shadow of the Moon

Every once in a while a really great documentary comes along.  In the Shadow of the Moon is one of them. This 2007 British film, which like most documentaries (unfortunately), had a very limited theater engagement, is now widely available for rental or purchase.

It is the remarkable story of the Apollo missions to the Moon, told eloquently by many of the astronauts who journeyed there: Buzz Aldrin, Michael Collins (Apollo 11), Alan Bean (Apollo 12), Jim Lovell (Apollo 8 & 13), Edgar Mitchell (Apollo 14), David Scott (Apollo 9 & 15), John Young (Apollo 10 & 16), Charles Duke (Apollo 16), Eugene Cernan (Apollo 10 & 17), and Harrison Schmitt (Apollo 17).  You certainly get the impression that not only are these guys personable and intelligent, but that they have aged well and still have much insight and wisdom to offer us about the past, present, and future.

The historical importance of this documentary cannot be overstated.  There is nothing, and I mean nothing, like hearing about the first (and still only) human missions to the Moon firsthand from the astronauts who journeyed there.  And, sadly, these pioneering astronauts are not going to be with us much longer. Some have already left us.  In the ten years since this documentary was released, Edgar Mitchell, the last surviving member of the Apollo 14 crew, passed away in 2016, and Gene Cernan, the last man to walk on the Moon, passed away earlier this year.  The eight surviving Apollo astronauts who shared their stories with us in this film are all octogenarians: Buzz Aldrin is 87, Michael Collins is 86, Alan Bean is 85, Jim Lovell is 89, David Scott is 85, John Young is 86, Charles Duke is 81, and Harrison Schmitt is 81.

This is a story that needed to be told by those who can tell it best.  There is no narrator, nor is there any need for one.  Kudos to directors David Sington & Christopher Riley, producers Duncan Copp, Christopher Riley, Sarah Kinsella, John Battsek, & Julie Goldman, and  composer Philip Sheppard for making this a film of lasting cultural significance, a film that will be admired and appreciated a hundred-plus years from now.

Space Pioneers

In April 1959, NASA announced the first seven astronauts.  The Mercury Seven are, in order of birth date:

John Glenn (1921)

Wally Schirra (1923)

Alan Shepard (1923)

Deke Slayton (1924)

Scott Carpenter (1925)

Gus Grissom (1926)

Gordon Cooper (1927)

John Glenn, the oldest of the Project Mercury astronauts and the first American to orbit the Earth, was the last to die, in 2016, at the age of 95.

Gus Grissom (1967) – Apollo 1 launch pad fire
Deke Slayton (1993) – brain tumor
Alan Shepard (1998) – leukemia
Gordon Cooper (2004) – Parkinson’s disease; heart failure
Wally Schirra (2007) – abdominal cancer; heart attack
Scott Carpenter (2013) – complications following a stroke
John Glenn (2016) – complications after heart valve replacement, stroke

Walter Cronkite (1916-2009) and Wally Schirra (1923-2007) covered the Apollo moon missions on CBS—far better than anyone else—and I can still remember the events as if they happened only recently.

Want to know who holds the title for longest duration human spaceflight (so far)?  Valeri Polyakov (1942-) entered space aboard Soyuz TM-18 on January 8, 1994 and stayed aboard the Mir space station until returning to Earth aboard Soyuz TM-20 on March 22, 1995.  That’s nearly 438 days (1.2 years) in space!  Moreover, Polyakov, who is a medical doctor, spent over 240 days in space during his first visit to Mir in 1988-1989, giving a total spaceflight time of nearly 1.9 years.

While Polyakov still holds the record for the single longest duration spaceflight, Gennady Padalka (1958-) has spent more time in space than anyone else: 878.5 days (2.4 years)!