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Dec 31, 2016

DSKY Interface (Part 13, Apollo Control Systems)

(DSKY I/O Interface, Apollo Guidance Computer)

[This article describes how the Apollo Guidance Computer (AGC) was connected to the Display and Keyboard Unit (DSKY). This is rather detailed description about the hardware and gives some light about how various devices were connected to the AGC. Since the connection was digital and parallel no special arrangements was required as with the more sensitive analog interfaces. The text is mainly from reference /1/.]

Figure 1. DSKY (Apollo Guidance Computer Display and Keyboard)

Dec 22, 2016

LM Descent to the Moon - Part 6 - Programming (1971)

(Apollo Lunar-Descent Guidance, 1971)

[The following MIT / NASA's 1971 text, partial reprint of the reference /0/, describes the descent algorithms used in the Apollo Lunar Module computer program (Luminary version 099/1A, about 63,000 lines of YUL assembly code) and flown summer 1969. This paper actually describes an advanced version of the algorithm which was not used since the older version which was more tested at that time (1969) was good enough for the job. What so ever, the text gives a good glance to the manned planetary descent programming.]

Figure 1. Components of the Lunar-Descent Guidance System.

Dec 5, 2016

(Mars) Vehicle "2500" - Part 2 - The Plans

Basically if the target planet or object has less gravity than Mars and/or any atmosphere or not at all like Earth's Moon this vehicle should be fine. It differs from the Apollo Lunar Module in those parts which require aerodynamics but is otherwise similar. It can be used with some amount of AB (aero braking) but it can also handle braking with rockets alone. If much gas is available for braking then less fuel is required and that mass can be used for transport purposes if required. So basically our design is a general purpose lander, but fits best to Mars, Moons etc.

Here is the more detailed general plan of the vehicle "2500".

Figure 1. General purpose lander for Mars, Moons, etc.

Nov 25, 2016

Mars Vehicle "2500" - Part 1 - Basics

This Mars Vehicle (MV), model "2500" is part of the LEAMOR (Light Extended Apollo Mars Orbit Rendezvous) total mission plan. See the article for general ideas about that Mars mission plan.

Figure 1. Mars Vehicle (MV) "2500" with ablative lower part and heat shield above ablative fuel balls.

Nov 22, 2016

LM Descent to the Moon - Part 5 - Powered Landing Maneuver (1964)

(LEM Powered Landing Maneuver, 1964)

[This is a partial reprint of a 1964 technical paper from MIT/NASA, which explains the mathematics behind the 1960's lunar landings. See /1/ for details. LM was called LEM (Lunar Excursion Module) those days and the first landing was to be done summer 1969, 5 years after this paper was written. The strength of this algorithm is that it is real time adaptive to the variations of the parameters from different sources (and also errors). This algorithm was called "E Guidance" due to the E matrix used in it. The basic LM descent guidance logic was defined by an acceleration command which was a quadratic function of time and was, therefore, later termed "Quadratic Guidance". ]

Figure 0. Look angle "lambda" is relative to the thrust axis

Oct 31, 2016

Command Module ECS (Part 12, Apollo Control Systems)

Environmental Control System (ECS)

The Apollo environmental control system (ECS) was designed and qualified to support three crewmen for 14 days and to maintain electronic equipment within operating thermal boundaries. The system maintains the pressure atmosphere of 100 percent oxygen and removes trace contaminants and metabolic carbon dioxide by absorption in charcoal and lithium hydroxide beds. (After the Apollo 1 CM accident the launch atmosphere was changed to 60-percent oxygen and 40-percent nitrogen.)

Apollo CM Environmental Control Unit (ECU), a major part of the ECS

[An Apollo Command Module (Block II) Environmental Control Unit (ECU) a major part of the Environmental Control subsystem (ECS), produced by Garrett Corp.'s AiResearch Division, Los Angeles under subcontract to North American Aviation (NAA), prime for the Apollo Command Service Module (CSM) under NASA Contact NAS 9-150. The Environmental Control Unit was the heart of the environmental control subsystem. It is a compact grouping of equipment about 29 inches long, 16 inches deep, and 33 inches at its widest point. It was mounted in the left-hand equipment bay. The unit contains the coolant control panel, water chiller, two water-glycol evaporators, carbon dioxide-odor absorber canisters, and suit heat exchanger, water separator, and compressors.]

Oct 27, 2016

CM Command Module (Part 11, Apollo Control Systems)

This article handles the Apollo Command Module. The current NASA command module is called Orion capsule or crew module.

Command Module CM with the Service Module SM connected together with an umbilical (right).  

Oct 18, 2016

JB-10 Latest Jetpack

Looks like Jetpack people have again created a new version of their "real jetpack", real meaning that it really uses jets and not rockets like some earlier versions of jetpacks did.

Jetpack JB-10 new in 2016 flown single handed.

Oct 12, 2016

New Tiny PC - Intel Compute Stick

The new Intel Compute Stick (2016) is a fully functional Windows PC with "HD" and memory and connects directly to the monitor's HDMI connector. It has USB and other ports in it, fully functional PC with minimal effort.

Intel Compute Stick, small but fully functional PC (Windows) computer

Oct 1, 2016

LM Descent to the Moon - Part 4 - Descent Monitoring


During the real-time situation, monitoring of the spacecraft systems and of the trajectory was performed continually both on board by the crew and on the ground by the flight controllers. The real-time monitoring determined whether the mission was to be continued or aborted, as established by mission techniques prior to flight. The real-time situation for the Apollo 11 descent is described here.

LM (Apollo 11) DOI (Descent Orbit Insertion) is done 180 degrees before PDI (Powered Descent Initiation)

Sep 24, 2016

The US Senate Demands NASA: "Go to Mars"

Fifty-five years after President Kennedy challenged the nation to put a man on the moon, the Senate is challenging NASA to put humans on Mars. The priorities that we’ve laid out for NASA in this bill mark the beginning of a new era of American spaceflight,” said an optimistic Florida Sen. Bill Nelson, senior Democrat on the Commerce panel.

Senator Bill Nelson was also a NASA  Payload Specialist on Space Shuttle Columbia's STS-61-C mission from January 12 to 18, 1986.

The Senate is not giving NASA money just for the sake of exploration. It is also a challenge, a mandate, actually. The bill requires that NASA make it an official goal to send crewed missions to Mars in the next 25 years.

NASA's budget vs. federal budget

The Senate is not giving more money. The NASA' budget will stay about the same as before, about 0.5 % of the United States federal budget. They are just giving more orders at this time. The NASA funding reached its peak during the Apollo era 1966, almost 4.5 % of the federal budget.


/1/ "It’s Official: We’re Going to Mars" -

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Aug 9, 2016

Orbit Calculator (Circular)

Orbit Calculator

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Aug 1, 2016

LM Descent to the Moon - Part 3 - Practice (Apollo 11, 1969)


Feb. 24, 1970, Russell A. Larson (left, Massachusetts Institute of Technology project manager for the lunar module flight program) and David G. Hoag (director of the Apollo Group at MIT’s Draper Lab) in the LM mock-up or simulator.

Jul 27, 2016

Standard Spacecraft Docking Port (IDSS)

If you are going to build the latest and greatest spacecraft you might want to have a standard docking port in it .. so that it could dock with all possible space stations and crafts. Looks like NASA and other national organizations have joined their efforts and created a new standard called "International Docking System Standard" (IDSS). It is available for anybody to be downloaded in this link.

Picture of the IDSS International Docking System Standard docking port

Here is a YouTube video about the principle of the docking port.


The docking connects two identical rings together. So all IDSS ports can dock with each other (there are no male or female versions, etc.). Here is a general view of the docking.

Standard Spacecraft Docking Port (IDSS) Principle

The maximum ball that can be fed through the port is 800 mm diameter .. the outer ring diameter is 1200 mm. It has 3 guide petals which latch with the capture ring. In each petal there is a mechanical latch which will lock with the latch striker in the capture ring automatically. The 3 petals interleave with their counter part petals. All together 6 latches will lock in the soft capture system (SCS). Here is a general view of the port.

IDSS Standard Docking Port

The docking happens in several phases;

  1. Soft Capture
  2. Hard Capture
  3. Electrical Connection

The soft capture system (SCS) makes the initial mechanical connection with soft forces to be later connected harder with the hard capture system.

The Hard Capture System (HCS) performs the final structural mating between the two
vehicles, establishing a connection capable of withstanding atmospheric pressure
combined with the loads from planned mated operations of the two spacecraft. The hard capture is based on pins and hooks.

The final IDSS docking is based on hooks.

There are active and passive hooks in each slot. The active hooks will pull the passive hooks.


Additional to the mechanical docking the standard also defines an electrical connector. The electrical connectors are to be connected after the full mechanical docking is done with some mechanisms. Here is a picture of the electrical connector.

IDSS Electrical Connector pin layout

For additional details consult the IDSS standard.


/1/ International Docking Standard

/2/ NASA Docking System

/3/ International Docking System Standard

/4/ Androgynous Peripheral Attach System

/5/ International Berthing and Docking Mechanism

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Apr 25, 2016

The Fastest ARM Cortex MCU Board (04.2016)

Atmel is making an interesting MCU evolution kit board SAM V71 with  ARM Cortex M7 micro controller core. That is the fastest ARM Cortex micro controller on the market today (04.2016).

General vie of the Atmel SAM V71 Xplained Ultra Evolution Kit PCB

Apr 20, 2016

1341 HP Toroidion Sports Car

A new and very fast sports car from Finland. 1341 HP and all wheels with electric motors will accelerate this car from 0 to 400 km/h in 11 seconds! Most likely you will not be the second one in many places with this car.

Toroidion 1341 HP 0-400 km/h 11 seconds!

Mar 7, 2016

Where is the Solar System "Zero"?

We all know that the origin of the Solar System is usually kept in the center of the Sun. That is the easy part. But where does the X axis point?

After doing some research it seems to be as follows:

"The First Point of Aries" is considered to be the celestial "prime meridian"  (or direction where the x axis points) from which right ascensions are calculated. Due to various reasons this point is NOT constant but drifts.

Vernal and Autumnal Equinoxes

When the Earth is at the Vernal Equinox (Spring Equinox) you can find this point by drawing a line from the center of the Earth through the center of the Sun and forward. The First Point of Aries (also known as the Cusp of Aries) is so called because, when Hipparchus defined this point in 130 BCE, it was located in the western extreme of the constellation of Aries. Now it is not anymore there but the point is still called so.

Since the sideral year is about 365 and 1/4 days .. the vernal equinox will happen almost the same time every 4th year at any given place on the Earth (or there is 6 h drift every year) .. but since the numbers are not exact and there are drifts the timing varies.

"The First Point of Aries"

Notice also that the Vernal Equinox can basically happen any time during a day or night SINCE the rotation of the Earth and its position on the orbit around the Sun are NOT connected to each other.

Standard Solar System coordinates

"J2000" (Current Standard Epoch)

Since the right ascension and declination of stars are constantly changing due to precession, (and, for relatively nearby stars due to proper motion), astronomers always specify these with reference to a particular epoch. The earlier epoch that was in standard use was the B1950.0 epoch.

When the mean equator and equinox of J2000 are used to define a celestial reference frame, that frame may also be denoted J2000 coordinates or simply J2000.

Right ascension and declination

Here is how to convert coordinates from J1950 to J2000:
  1. convert B1950.0 RA and DEC to decimal degrees
  2. work out the following formulas
  3. RA2000 = RA + 0.640265 + 0.278369 * sin(RA) * tan(DEC)
    DEC2000 = DEC + 0.278369 * cos(RA)
  4. convert RA back to (what ever you need)
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Feb 17, 2016

Jetman Canopy and "Bomb Bay" Idea

Since watching the many fascinating flights of "Jetman" team I came to the idea of a canopy that might add some comfort to the flying and also maybe add some extra fuel or bomb bay to the concept. When flying at 200 km/h or so with totally open cockpit the wind pressure to the head is rather large. Also in Jetman's case since the plane is so small the smallest movement of the head will steer the plane to any direction .. so it is rather hard to look around etc. without the wind ripping off your head if flying without any canopy at all.

So here is the idea:

Jetman Canopy (Sled) System idea

If the canopy is made of light materials (honey comp sandwich carbon fiber for example) it should not add much weight. Also the overall air resistance should not be much worse .. or it could even be better since the canopy is more optimal formed than the shoulders and head of the pilot. Notice also the quick release mechanism which allows the pilot to get rid of the canopy if required. The reason to locate the canopy under the belly is the fact that the parachute system needs as much as possible space behind the pilot.

Additionally some extra fuel or even weapons could be carried under the belly .. and also the much required avionics, such as air speed meters and navigators could be included inside the canopy.

Even some wheels might be installed in some future systems..

An future option might be to add small wheels to this sled and maybe even make runway takeoffs and or even landings with it .. but the hanging legs should maybe be included inside the sled in the latter case.

Jetman over Dubai

Here is the picture without the proposed sled.

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