15 May 2012

Private Space Companies: Don't Try to Convince People -- Just Do It

At 4:55 a.m. on Saturday, a rocket is scheduled to lift off from Cape Canaveral, Fla., and carry cargo — but no people — to the International Space Station.

But if all goes as planned, that morning will mark something transformative for the space industry: a victory for capitalism in what has been for decades a government-run enterprise. The capsule, built by Space Exploration Technologies Corporation — SpaceX, for short — would be the first commercial spacecraft to make it to the space station, and many observers view its launching as the starting gun in an entrepreneurial race to turn space travel into a profit-making business in which NASA is not necessarily the biggest customer. _NYT

SpaceX Falcoln 9 Hotfire Test of First Stage
The long-awaited mission will, if all goes well, combine the milestones of two separate missions, designated C2 and C3, originally planned as part of NASA’s award to SpaceX under the Commercial Orbital Transportation Services (COTS) program. This “C2+” mission will perform a series of maneuvers in the vicinity of the station—milestones from the original C2 mission—and, if all goes well, then approach the station, whose robot arm will grapple the spacecraft and berth it—milestones from the C3 mission.

That mission will begin with the launch of the Dragon on a Falcon 9 rocket from Cape Canaveral at 4:55 am EDT on Saturday, May 19. The launch window is instantaneous, leaving no margin for error in the event of a technical or meteorological issue during the countdown. Moreover, launch opportunities are only once every three days, something SpaceX CEO Elon Musk said at a press conference last month was designed to minimize the propellant Dragon will have to use to reach the ISS, maximizing the amount available for maneuvering in the station’s vicinity.

After the Falcon 9’s second stage places Dragon into an approximately 310 by 340 kilometer orbit, the spacecraft will spend two days gradually maneuvering towards the ISS. On Day 3 of the mission, Dragon will move to a position 2.5 kilometers below the ISS, then fly around the station before returning to that initial location, demonstrating its ability to precisely and safely fly in proximity to the ISS. As soon as the following day, pending approval from NASA, Dragon will approach the station, holding at positions 250 and then 30 meters from it, before moving to its “capture point” 10 meters below the station. At that point, the station’s Canadarm2 will grapple Dragon and berth it to the Earth-facing node on the station’s Harmony module.

Should all that go according to plan, the station’s crew will open the hatches between the station and Dragon the following day and start to unload the 520 kilograms of cargo it contains. While not an official cargo delivery flight under SpaceX’s separate Commercial Resupply Services (CRS) contract with NASA, the Dragon is carrying some relatively nonessential cargo, including food and other supplies, as well as a laboratory module for NanoRacks, a company that provides access to the station for commercial and educational research.

After about two weeks on the station, the Dragon will be loaded with 660 kilograms of cargo for return to Earth, including experiments and unneeded equipment. Dragon will undock, maneuver away from the station, and reenter, splashing down in the Pacific Ocean off the coast of California... _Space Review
That is the plan, anyway. In a few days, we will see if things go according to plan.
...Only recently have smaller, nimbler companies like SpaceX, some of them run by billionaires who proved themselves in other fields, started trying to compete as equals with NASA and its major contractors. (Mr. Musk, for example, is an Internet entrepreneur who founded PayPal.)

...Already, there are some hints of how the era of commercial space travel might unfold. Companies like Virgin Galactic, XCOR and Space Adventures are booking passengers on suborbital joy rides to space, promised for dates within the next few years, and hundreds of people are signing up. And already there are celebrity tie-ins: Among the people who have signed up for Virgin’s first flights are Ashton Kutcher, Angelina Jolie, Brad Pitt, Tom Hanks and Katy Perry.

On a more mundane note, the launching of commercial satellites has been a steady business for decades, and SpaceX is among the companies already competing for contracts. Indeed, SpaceX already seems to have built a viable business here, having announced more than $1 billion of contracts in the last few years.

Then there are the longer-term dreams, which may sound less far-fetched as each landmark in space travel grows nearer.

“I think humanity needs to get to Mars, one way or another,” said Elon Musk, the founder and chief executive of SpaceX, who vows that his company will send people to Mars in as little as 10 years — more likely 15 years, and certainly within 20. He said he would do this with or without NASA: “I would prefer it would be with NASA. If not, we have to find another path.” _NYT
For humans to be able to move around the solar system quickly enough to make a difference, we will need better methods of propulsion. Perhaps something like an antimatter rocket:
First, some basic rocket science. The maximum speed of a rocket depends on its exhaust velocity, the fraction of mass devoted to fuel and the configuration of the rocket stages. "The latter two factors depend strongly on fine details of engineering and construction, and when considering space propulsion for the distant future, it seems appropriate to defer the study of such specifics," say Keane and Zhang.

So these guys focus on the exhaust velocity--the speed of the particles produced in matter-antimatter annihilations as they leave the rocket engine.

The thrust from these annihilations comes largely from using a magnetic field to deflect charged particles created in the annihilation. These guys focus on the annihilation of protons and antiprotons to produce charged pions.

So an important factor is how efficiently the magnetic field can channel these particles out of the nozzle.

In fact, the exhaust velocity of these pions depends on two factors--their average initial velocity when they are created and the efficiency of the magnetic nozzle design.

In the past, various physicists have calculated that the pions should travel at over 90 per cent the speed of light but that the nozzle would be only 36 per cent efficient. That translates into an average exhaust velocity of only a third of lightspeed, barely relativistic and somewhat of a disappointment for antimatter propulsion fans.

All that is set to change now, however. Keane and Zhang have come up with a different set of figures with the help of software developed by CERN that simulates the interaction between particles, matter and fields of various kinds. _TechnologyReview
More from Brian Wang:

How Space Can Open Up a World of Unprecedented Abundance

Anticipated Propulsion Breakthroughs

Ultimately, it is a waste of time to try to convince people that you are going to do something spectacular. The best approach is to just do it.

At this time, the governments and inter-governments of the world exist to limit what individuals and groups of independent individuals can do. Such limitations will not always be in force, for all humans everywhere.

Remember: It is never too late to have a dangerous childhood. The world of the future will need as many dangerous children as it can get.


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“During times of universal deceit, telling the truth becomes a revolutionary act” _George Orwell

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