The Sun is Blank

Looks like the sun is very quiet for another cycle, likely leading to continued cooler weather (the warming “pause” will likely continue into it’s 19th and 20th years).

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Antarctic Ice Sheet

Looks like an undersea volcano could be the culprit in melting the Antarctic Ice Sheet, at least partially. 

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Amending the Space Act

According to Space News, Dana Rohrbacher is proposing amending the Space Act, the 1958 legislation that created NASA, to include as part of NASA’s reason for existence to be Space Settlement.

 

Hat tip: Rand Simberg.

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What’s an emDrive?

A means of producing thrust in a vacuum without using a reaction mass. Possibly a reactionless drive.  If it really works, then this is a game changer for spaceflight. The chances that it’s real? Don’t hold your breath. 

Wikipedia has a pretty good article looking at how it works, along with the controversy surrounding the apparently positive independent tests. For now, as long as the method is not disproven, this is a usable means of providing a reactionless drive in Science Fiction. It overcomes one of the major issues in space travel, namely the incredible mass requirements to travel anywhere within a solar system in timeframes reasonable for a interplanetary commerce to make sense. 

Taking the value in the Wikipedia article of 0.1 N/kW, we can compute the mass that could be accelerated at one gravity. Since F=ma, and F=0.1 N and a=9.8 m/sec squared, 0.1=9.8m. Solving for m, we get more=0.1/9.8=.98 kilograms/kW. 

At this point you’ll need to determine the mass necessary to generate that kilowatt of power. I don’t think you can get reasonable results with solar. Possibly 0.1 g in the inner solar system, where the solar flux is higher. I’m not sure nuclear fission will work, either. Haven’t done the math, but the shielding is generally heavy. Nuclear fusion ought to work well. 

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SuborbitalRocketAnalyzer

Rocket Icon1024x1024

The Suborbital Rocket Analyzer is an IOS app written in Swift to perform parametric analysis of single stage suborbital rockets. This version is quite simple. I spent about two days actually creating the app. One of the biggest tasks in this case was capturing all the screenshots required by the App Store.

The app does not provide a means of capturing the output data at this time, nor is it a simulator. It’s primary purpose is as a showpiece and to give me an app in the App Store for discussions with potential employers looking for an IOS developer.

IPhone6 2

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iPhoneSat Communications

Based on the PhoneSat project, which uses Android as the operating system, I decided to pursue an iPhoneSat, which would be a similar project, but based on iOS and using an iPhone rather than Android. Mostly this becomes an excuse to combine my interest in Space settlement with my interest in iOS development

I decided to start with the communications protocol between the space elements and the ground station. This is likely to be a relatively low-bandwidth transport layer, so maximizing the compression in the messaging protocol is important. So I chose ASN.1 unaligned PER. This is a densely packed protocol. There are good open source and commercial tools available to convert compile the message definition into C, C++ or Java source code that can be readily linked into another project. For this effort I am using the open source asn1c compiler.

My next step after compiling into C source from the ASN.1 notation is to wrap the C source in Objective-C objects, making the communications layer into a static library readily added to an iOS application With a different project it could also be made into an OS-X application, possibly for a ground station.

My iPhoneSat project is hosted on GitHub.

The message definition looks as follows:

Module-order DEFINITIONS AUTOMATIC TAGS ::=

BEGIN

 

Message ::= CHOICE {

    request Request,

    response Response,

    …

}

 

Request ::= SEQUENCE {

 

}

 

Response ::= SEQUENCE {

    health System-health,

    location Location,

    …

}

 

System-health ::= ENUMERATED {

    nominal(0),

    …

}

 

Location ::= SEQUENCE {

    latitude INTEGER (-90000000..90000000),

    longitude INTEGER(-180000000..180000000),

    altitude INTEGER(-500..36000000),

    …

}

 

END

A message is either a request or a response.

A request is sent to the satellite from the ground station requesting a response. Currently the Request object contains no data, but that will be changing in the next version. A Request could be a request for location, a request for location and a photo, or a request for location and video. These require further examination and development.

Besides location, a response contains a System-health value, which is currently only nominal. This will be extended as my understanding of the possibilities advance.

A Location object contains latitude, longitude and altitude. All three are INTEGER types. Notice that latitude and longitude are in degrees times one million. each increment is equivalent to one millionth of a degree, less than one centimeter. Altitude is from 500 meters below the WGS-84 datum to 36,000 kilometers above the datum. This is slightly above a geostationary orbit altitude. Future versions of Location will also include velocity and attitude.

Interestingly, the asn1c compiler uses angle brackets (“<“ and “>”) around all #include’s. This creates a problem for the C compiler, which insists that files in the same directory should use quotes instead, so one of the necessary steps before getting a successful compilation of the project is to replace the angle brackets with quotes of all the asn1c generated files included in other generated files. The other interesting action is that in some files the compiler generates a RETURN macro, and in other cases a DEBUG macro. The C compiler objects to both, and I modify the macro, and macro calls by appending a “_”, so RETURN becomes RETURN_ and DEBUG becomes DEBUG_.

My next step, already started with Location.m, is to construct the Objective-C wrappers for Location, Request, Response and Message.

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Macular Degeneration: Good News

This is good news for Age-related Macular Degeneration (AMD) sufferers. 

And a good example of industry-academic collaboration.

Via Transterrestrial Musings.

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Neil Armstrong on being an engineer

Neil Armstrong, the first man to walk on the moon, gives his take on what it means to be an engineer, and what engineers have accomplished. Animation added.

via Universe Today.

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Saturated Fat not bad

At least the respondents criticizing this study are starting to acknowledge that it’s the sugar and refined carbs we need to watch out for, not fat. 

via Transterrestrial Musings.

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The Scale of things

Josh Worth created what has to be the widest web page ever, to display the planets, not only to scale, but the Solar System to scale. Spoiler Alert: There’s a lot of empty space!

Via. Universe Today.

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