Category Archives: Spaceflight

Why Wink When You Should Salute?

August 25th, 2016 marks the fourth anniversary of the death of Neil Armstrong, the first human being to set foot on the lunar surface.  Shortly after his death, the Armstrong family announced that, to honor Neil, every August 25th, people should wink at the Moon if they see it.  I feel that does not go far enough.  One should salute it instead.

One of the main reasons for this was that the man was a true American hero.  While taking over the lunar module’s controls to steer the craft away from a field of boulders that would have brought the mission to a fatal end would be considered a very heroic feat, it wasn’t his only one or even his first.

In the Korean War, Armstrong flew fighter jets from a carrier to attack targets in North Korea.  On one of his missions, his plane ran into a cable stretched across a valley by the North Koreans to wreck low-flying American planes.  For most pilots, the level of damage would have been enough to cause the pilot to eject, which would have likely resulted in a stay at a North Korean POW camp.  But Armstrong was no ordinary pilot.  He managed to maintain some control over the plane.  While returning to the carrier was impossible, there was a Marine base that was within flying range.  Armstrong proceeded to fly to the base.  Just before he reached the base, the plane became uncontrollable and he was forced to eject.  Armstrong made it safely to the ground and was promptly rescued by Marines from the nearby base.

Another heroic feat was during the Gemini 8 mission.  This was to test the concept of docking spacecraft in orbit.  The test target was the upper stage of an Agena rocket.  Shortly after docking, the crew noticed the capsule was moving in an odd manner.  Thinking the problem was with the upper stage, they quickly undocked.  The problem only got worse and the capsule started to spin.  What had happened was one of the Gemini capsule’s thrusters got stuck in the on position and was causing the spacecraft to spin, almost to the point of uncontrollability.  Sizing up the situation, Armstrong decided to use the thrusters designed for reentry as a means of stopping the motion, something that nobody had considered.  Fortunately, the maneuver worked but it meant that they had to return to Earth immediately.  But that quick action saved the life of Armstrong and that of his fellow astronaut.

However, heroism wasn’t his only claim to greatness.  There was his character.  He never bragged about his heroic deeds.  When Apollo 11 returned from the Moon, Armstrong was always quick to credit the success of the mission to the vast number of engineers, scientists, and workers who designed and built the spacecraft.  He never lorded his accomplishment over others and, after he retired from NASA, he became a professor of aeronautics.  If our elected officials had only one-percent of his character, this country would be a better place.

Armstrong’s post-Apollo conduct was reminiscent of that of another great American hero – one of our first.  After the Revolutionary War, George Washington could have asked for, and got, anything he wanted.  Yet, he decided to return to his home at Mount Vernon and operate his plantation.  At the end of his two terms (he felt two terms were enough) as president, he again went back home and kept to himself.

So, if you see the Moon on August 25th, don’t wink, salute.  Let’s honor a great American hero, one who never disgraced himself and one we don’t have to apologize for.

Orion Oversold?

December 4th is the date set for the first test flight of NASA’s new Orion capsule.  It will be launched into Earth orbit using a Delta IV rocket at about 7:05 AM.  Then, Orion will circle the Earth twice, conduct some test maneuvers, then enter the atmosphere at about 80% of the velocity the capsule would have if it was returning from the Moon.  If the reentry systems work properly, Orion should splash down in the Pacific off the coast of San Diego, California before noon.  Unless it lands like the capsule in “Gravity”, Orion will be bobbing at the surface and picked up by a waiting ship.

NASA has been loudly promoting Orion, claiming that it is the vehicle that will take American astronauts beyond low Earth orbit and to destinations such as the Moon and Mars.  Much ink and many pixels have been used to promote Orion as a truly advanced spacecraft.  But let’s see it for what it is.

I dimly recall back in the early 1970’s there was a proposal to build a larger version of the Apollo-era command module.  The plans were all drawn up for it, then it was decided that there was no need for it.  Orion looks like the resurrection of this project.  Of course, Orion does have some updated technology, such as new heat shield material, far superior computers, nicely decorated interior, and touchscreen panels (like the controls you would find on “Star Trek: The Next Generation” or on an Asgard ship from the “Stargate” franchise, if you prefer).  But don’t be fooled, it is still based on your father’s (or grandfather’s depending on your age) Apollo command module.

Actually, there is something about Orion that is actually inferior to the original Apollo-era vehicle.  The Orion will use a service module that is based on the ESA’s (European Space Agency) Automated Transfer Vehicle (ATV) that has been used to send supplies up to the ISS.  This ATV-derived service module will use solar panels instead of fuel cells to generate electrical power and will certainly have far less powerful engines than the original Apollo-era service module did.

Then, there was a statement made about the Orion by a Russian commentator who pointed out that, for a vessel that is supposed to house a crew for up to three weeks or so, it lacked certain amenities.  While on a short trip to the Moon, that might not be a big deal since the original Apollo astronauts didn’t complain about the lack of a convenience, it could pose a problem for longer trips.

What bothers me is how NASA keeps pushing the idea that Orion will take astronauts to Mars.  It is simply way too small for the job (unless someone manages to develop the technology used to create the sub-light propulsion systems of mainstream science fiction programs).  Even Robert Zubrin (creator of the Mars Direct concept of a reasonably priced program of Mars exploration) and his colleagues and the folks at Mars Direct have put more thought into designing a spacecraft to take people to Mars.

Why has NASA gone so far overboard in promoting Orion?  Probably because that it is about the only idea they have left for manned spaceflight (besides the Space Launch System – SLS – heavy rocket).

Hopefully the test flight of Orion will go well and not wind up exploding, running out of power,  sinking on splashdown, or anything like that.  But do you think that Orion’s “Back to the Future” approach is the way to go or do you think it’s another one of NASA’s ideas that will fall well short of the mark?

What is the Real Cost of Saving Kepler?

Kepler K2 Mission Diagram

Diagram of Kepler’s K2 Mission

In March of 2009, the Kepler mission was launched.  It was placed in an Earth-trailing orbit around the Sun and observed a patch of sky located in the Milky Way near the constellation of Cygnus to look at thousands of stars to detect any dimming that was caused by a planet passing in front of a star.  This mission was by any criterion a great success and racked up an impressive number of discoveries, including the first rocky planets in the habitable zone of a star.

However, in April of 2013, one of the spacecraft’s reaction wheels (powered gyroscopes used to control the pointing of the vehicle) failed.  One had failed earlier, but there were still enough wheels for the mission to continue.  This time was different.  Kepler was placed into a safe mode which allowed it to communicate to Earth.  For the next three months, various strategies were tried to see if the reaction wheel that failed earlier could be restarted.  It was restarted but did not function well.

Then, some on the team had a stroke of brilliance.  After doing the complicated math and computer simulations, they came up with a way to save the mission by using the pressure of solar radiation (a major cause of instability to Kepler) as a means to help keep the spacecraft stable.  NASA liked the idea, known as “K2” (no connection to the extremely dangerous Himalayan mountain of the same designation) and depicted in the above diagram.  So, Kepler was saved, but at what cost?

In terms of dollars and cents, it was a great bargain.  However, when it came to Kepler’s capabilities, it turns out to be an almost Faustian deal.

The great strength of the original Kepler mission was that it kept one well-known section of sky under continuous surveillance.  That way, Kepler would not miss anything that took place.  As a result, Kepler discovered planets of longer periods and was able to observe the three transits required to confirm the discoveries.  The success of this strategy can be seen in the large number of planet discoveries from the mission.

Due to the use of solar radiation pressure as stabilization, Kepler has to be pointed at the ecliptic plane (the plane where the planets of the solar system tend orbit).  That doesn’t sound so bad, but since the Sun appears in the ecliptic plane, Kepler has to move to observe another field about every 83 days so the Sun doesn’t shine into the instrument and burn out the detectors.  Factoring in the time it would take to adjust Kepler each time it moved to one of the eight fields, that yields less than 83 days per field.  So, the concept of continuous surveillance goes right out the window.

Since a “year” for Kepler in its solar orbit is 379 days and only about four and a half fields can be observed in one Kepler “year”, that means quite a bit of time will pass before it returns to a field for further observation.  A lot can happen in that time and a many potential planets will be missed.  Mission scientists naturally downplay this and claim that the increased number of viewing locations will make up for it.  True, there will be some discoveries made from the K2 mission, but they won’t be anywhere near as numerous due to the spotty nature of the observations.  If you are a fan of extrasolar planets, you better get used to most of the new discoveries being hot Jupiters, hot Neptunes, and lava worlds, rather than the more interesting habitable zone planets, because the short duration of observations in each field will favor the planets with really short orbital periods, even with the new policy of requiring only two repeat transits to confirm a planet instead of three.

And this approach of observing lots of area for shorter intervals appears to be the wave of the future in searching for extrasolar planets from space.  If you like the K2 mission, you’ll love the followup mission to Kepler called TESS (Transiting Exoplanet Survey Satellite) which will survey most of the sky while in an eccentric Earth orbit with little time devoted to each field.

You can read the full gory details about K2 here.  Is the new strategy of observing more area in less time worth it for extrasolar planets or should there be a return to more time in less area in the future?

It was 45 Years Ago

Back on the summer evening of July 20th, 1969, forty five years ago tonight (I’m writing this on July 20th, 2014), the late Neil Armstrong and Edwin “Buzz” Aldrin literally stepped into history when they were the first human beings to land on the Moon.

This historic milestone has received some discussion in the media recently.  So far, while the coverage has been less than it was at the 40th anniversary (back in 2009, the anniversary of Woodstock actually got more press – I suppose that is a statement on American society), it doesn’t seem to be upstaged by any other anniversaries this time around.

While the landing of Apollo 11 and the subsequent lunar missions were impressive achievements, they wound up representing high water marks in space achievement and, outside of the amazing success of our robotic exploration of the solar system, are fading into history.

Sadly, the Apollo astronauts are also passing from the scene.  I have a feeling that, by the time a human being ever returns to the Moon – most likely a Chinese person – none of the original Moon travelers will be around.

On the brighter side, by the time people get back to the Moon, we might be better able to deal with the various issues concerning lunar travel (the ubiquitous lunar dust and radiation exposure) than the Apollo crews.

In the meantime, let’s honor the original lunar travelers while they can still appreciate it.