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Tag Archives: rocket

Congratulations to SpaceX for sticking the landing

As someone who has been listening with some interest to the trials of SpaceX in perfecting its re-usable rocket system, I was very happy to see news that they had successfully stuck their landing on this, their fifth overall attempt.

Easy peasy, right? Try it youself:

https://scratch.mit.edu/projects/76866912/

I’m not sure it’s even possible in the game. Frankly, I would never have thought that it was possible in real life long enough to even put engineers on the project- even if I was using $100 bills as toilet paper because I just had to get rid of the stuff somehow.

The two-stage Falcon 9 rocket blasted off from Cape Canaveral on April 8 carrying the robotic Dragon cargo spacecraft into orbit for resupplying the International Space Station (ISS). Following the deployment of the cargo craft, the Falcon 9’s stage 1 rocket returned to earth to stick a perfect vertical landing atop on a floating sea platform.

The long-term purpose of this feat is to re-use the first rocket stage in subsequent launches, thereby lowering the cost of these space taxi flights, and increasing the frequency of their missions. Hans Koenigsmann, VP of flight reliability at SpaceX said, “… we hope …  to be able to launch basically every other week by the end of the year.”

The strategy employed in managing these rockets is outlined below, where the first stage executes a flip orienting its exhaust forward to allow for firings to slow the craft down and orient it towards the landing platform:

https://i1.wp.com/www.spacex.com/sites/spacex/files/16892430560_f87dff78c0_o_1.jpg

It is important to keep in mind that the landing is a great challenge, but it is not the only hurdle SpaceX has had to overcome. Delivering something into space may not seem terribly difficult. ‘How high does this need to go?’ is a reasonable first question. The ISS orbits at an altitude of 249 miles. Farther than you would want to commute on a day to day basis, but nothing like the distance to the moon or Mars (230,000 miles and 35.8 million miles away at their closest, respectively).

But another consideration is just how fast the rocket needs to travel in order to put something into orbit. Orbit isn’t just height, but requires a horizontal speed tangent to the planet such that as the craft falls to Earth, it’s horizontal movement has pushed it far enough that the Earth is dropping away below it just as quickly as it falls. The ISS travels at a speed of 4.76 miles / second, which translates to a 17,136 miles per hour. So, if it shot straight up and reached the height of the ISS orbital, there would still be this 17,000 mph speed difference to deal with, a problem that may sound familiar to viewers of the recent films, Gravity and The Martian.

To bring  cargo destined for the ISS into orbit, Falcon needs to list off, gain an altitude of almost 450 miles, and accelerate to a speed that would carry a traveler from Washington D.C. to New York City in 43 seconds.

The first stage, or main rocket engine, is designed with an array of nine ‘Merlin’ engines producing 6,806 kiloNewtons (at sea level) of force for 162 seconds of thrust. The first stage actually only fires for 180 seconds during liftoff, leaving 82 seconds of thrust for three separate return trip burns.

Following separation of the first stage, a second stage is equipped to navigate into one or more orbits for payload delivery with 8 minutes of burn. This is an unusual capability because  reigniting these large engines several times, just isn’t done in most rockets.

Ok, I’m gushing like a fanboy, but with NASA doing less and less in the way of manned spaceflight (believe me, I’m plenty impressed with their unmanned flights), SpaceX gives big kids like me something to watch and dream of a second – wait, third- career as an astronaut.

 
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Posted by on April 13, 2016 in Uncategorized

 

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Is the Space Age over for the US?

I grew up in an age when the USA dominated space. The Apollo missions had put the first men on the moon and American kids everywhere were tasting victory with each sip of Tang.

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Good Dog. 

Read the story of Laika in the eponymous graphic Novel.

It didn’t matter that the Soviets had launched the first artificial satellite (Sputnik), the first animal to orbit the Earth (Laika), or the first man in space (Yuri Gagarin). I mean, really – out of the gate, the Russians (we never troubled ourselves to distinguish Russia from the Soviet Union in any way) were kicking our butts. Then the US turned the tide, and following a solid series of incremental achievements, sent not one, but six successful missions to the moon.

And, just to make sure the world knew it, we declared that landing on the moon was the endgame and we made it. We win. Game over. No other country has accomplished the same — yet.

For years NASA maintained a presence in space with the shuttle program, although it was less than evident what larger purpose these missions served before the international space station (ISS) came online. It’s easy to have objections to the way the shuttle program was run. The objectives never matched the clear progression that the Mercury, Gemini, Apollo missions illustrated.

Mercury:

  • To successfully orbit a manned spacecraft around Earth.
  • To investigate humankinds’ ability to function in space.
  • To recover both occupant and spacecraft.

Gemini:

  • Subject astronauts to long duration flights.
  • Perfect methods of reentry and landing the spacecraft.
  • Gain information concerning the effects of weightlessness on astronauts during long flights.

Apollo:

  • Demonstrate crew, space vehicle, and the mission support facilities during a manned lunar mission.
  • Evaluation of the LM performance in lunar orbit and the lunar environment.
  • Land a man on the moon and return him safely to the Earth
  • Gather lunar rocks and soil samples

Space Shuttle:

  • A reusable spacecraft
  • ???
  • Establish, man and supply a long-term space station

Then, in 2011, the last shuttle flight landed and The US is reduced to hitching rides to the ISS. As someone whose patriotic spirit is ignited by our collective will and ability to conquer big problems, I feel a real degree of shame that the US has relinquished its ability to make great strides into space. 

“What nationality was Christopher Columbus?”

“Spanish…right?”

“Might as well be. They were the one’s who made it happen.”

Like the Italians (or the Portuguese or the English), the US appears to be abdicating it’s power and allowing other nations to go forth as leaders.

ImageFortunately, this isn’t the end. If funding continues, the US is on track to construct its next space deliver vehicle, the Space Launch System, for its first launch in 2017. Perhaps you could call my position one of cautious optimism. 

The stated mission of the SLC with its Orion modules would be to:

  • capture an asteroid and bring it into high lunar orbit
  • Perform a manned flyby of Venus and Mars before returning to Earth in the early 2020s.
  • Establish a permanent or semi-permanent presence  on the moon.

I, for one, am keeping my fingers crossed that once clear, incremental objectives are established, we will re-commit to the exploration of spec in my lifetime.

 
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Posted by on March 10, 2014 in Uncategorized

 

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V GER

ImageLast week’s Science magazine had a pair of articles about Voyager 1’s arrival at the heliopause and the fluctuations of particles it has encountered. For about a year astronomers have been talking about the limits of the solar system.  An idea that I admit I had never entertained in any absolute way. Instead, my image of the extent of the solar system is mostly shaped by the most distant planets’ orbital paths. Sometime in the past decade or two, I became aware of plutoid objects, among which Pluto is one and that there is an Oort Cloud beyond that. I’ve always been a bit hazy about the details of what comprises the Oort cloud and how this differs from the plutoid objects.

Sometime during the conversation ignited by Pluto’s demotion to a dwarf planet, I head a good description of the solar system that described it as: four small, rocky planets close to the sun, then a belt of asteroids, followed by four large, gas planets, then another ring of small objects.

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The edge of the solar system

I really am looking for someone to explain this in terms that a reasonably intelligent person without much astronomy background can comprehend. That is, I don’t want too much left out, but I’m not necessarily ready for an overly technical explanation.

With respect to local suns, what is the position of our solar system? What forces interact between the suns? What do we know of the space between solar systems (or between galaxies?)

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A simplistic view of nine balls circling a star

That’s a pretty tidy description, but I think it leaves out a lot.

The interest now is in defining the edges, the limitation of the sun’s influence on space in favor of extra-solar forces. From what I gather, this is referring to both ‘solar wind’ and magnetic field.

I can understand this from the inside (although I need correcting here too) ,  but what I don’t fully grasp are what the forces are outside of the solar system. What dominates those forces? One thing I notice in the illustrations I’ve seen is a teardrop shape to the system resulting from a unidirectional current. What is this current? Is it emanating from other solar systems? Some local influence of nearby stars? Or a galactic force?

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Heliosphere warping under external pressure

I hope someone out there can help me understand this better.

 
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Posted by on July 20, 2013 in Uncategorized

 

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