74

This Wikibooks link lists its strong points, some of which are: An extremely strong, static and safe type system, which allows the programmer to construct powerful abstractions that reflect the real world, and allows the compiler to detect many logic faults before they become errors. Modularity, whereby the compiler directly manages the construction ...


55

Timing. Ada was developed in the 1970s and 80s with the intent of replacing the plethora of languages used in the US Department of Defense's realtime systems. NASA (and also organizations from Europe) were active participants. The DoD mandated Ada for all major development in 1991. NASA did much the same. The International Space Station had been a paper ...


52

Best Technology Available By late 2002, SSDs had just reached ~80 GB capacities. Of course, JWST is not going to take a product which has never seen enterprise deployment, and plonk it into \$2 billion platform with fingers crossed, hoping the vendor did a really good job. The bleeding edge referred above is for terrestrial, consumer-grade drives. Once we ...


43

Bermuda was one of the tracking stations for the Mercury program. Bermuda was critical as it had a good view of much of the ascent trajectory. In this image, all of the tracking stations are shown along with one of the Mercury flight paths. BDA=Bermuda. Requirements. Early in the design of the Mercury system it was considered mandatory to receive ...


41

(I'm interpreting the question as "what programming language was the first spacecraft software written in?", per discussion in comments above.) This will depend on your definitions of "computer" and "programming language". Almost certainly the first digital computers on spacecraft were programmed in assembly language or ...


39

POSIX time doesn't include leap seconds, and is not implemented the same way in every UNIX, so it routinely gets inconsistent for several seconds every couple of years. It is not a high-precision time scale, and there is little point correcting it for relativistic effects which are smaller than it can represent. GPS has to be corrected --- in particular, ...


36

First of all, it can require a lot of computer power to compute trajectories if they involve multiple gravitational slinghots to reduce fuel usage. This isn't because computing each segment is hard but because the search space is at least potentially exponential in the number of gravitational slingshots. I am pretty sure that this is what the thing in The ...


34

In 2015, the last original Voyager engineer still on the project, retired. NASA specified that his replacement would have to know FORTRAN. The software was updated regularly after launch: The last true software overhaul was in 1990, after the 1989 Neptune encounter and at the beginning of the interstellar mission. "The flight software was basically ...


32

Space hardware almost always is pretty archaic technology. The problem is the long lead time coupled with the need to certify it for flight. It wasn't archaic when it was engineered. The JWT was redesigned in 2005 so look at 2005 tech, not 2020 tech.


31

Well, developing low-thrust trajectories does take more computation than impulsive trajectories (e.g. like Voyager, which was done with rather primitive computers). You have no choice but to run many fully integrated trajectories. However it would not take a supercomputer of the future, or even a supercomputer of the present to search for and find ...


30

No. Computer clocks are inaccurate. They rely on constant corrections to maintain the correct time. Since their inaccuracy is much bigger than the time speed difference between earth and the ISS, it really doesn't matter.


29

I worked at the MIT Instrumentation Lab during the Apollo program. Although I did not work on that program, I knew many of the people who did. The guidance computers for the command module and lunar landing module were each programmed in their own assembly language. The missions were exhaustively simulated on a large IBM 360 Model 75 computer, using a ...


24

Blockchain is a very poor solution to a specific problem: achieving ledger consensus among a large number of agents when there is substantial incentive to corrupt the record, and the entries in the ledger are directly related to one another. This is not a good fit to a satellite ephemeris. A relatively small number of agents add records to the system at a ...


24

It doesn’t yet matter for most practical purposes. The slowdown from faster motion and speedup from a weaker gravitational field partly cancel out, and the net effect is that time on the ISS is only 0.0000000014% slower than time on Earth, so in its whole 22-year history it has lost about one hundredth of a second.


22

What other space applications, projects and agencies are using the Ada programming language? In the US, old stuff such as the Delta rockets, the Atlas rockets, and the TDRSS ground terminal (but this is being switched to C, C++, C#, and Java). There might be new development, but it's mostly stuff you (and I) cannot know about because it's classified. New ...


20

Calculating an energy-optimal orbit for a simple thing like Earth->Mars is no big deal. Even using low-thrust engines doesn't add much to it. It would be tedious but you could do it on a calculator. However, that's not what they needed in the book & movie. The objective wasn't to get there as cheap as possible, the objective was to get there as fast ...


20

1. How did the Apollo guidance computer handle parity bit errors? According to Apollo 15 Hardware by Delco Electronics, Parity Alarm Occurs if any accessed word in fixed or erasable memory whose address is $10_8$ or greater contains an even number of "ones." All locations of $10_8$ or greater are stored in fixed or erasable memory with odd parity. ...


18

I remember taking Computer Science courses in the late 90s. The professor of CS explained to our meager group of CS majors that he was going to teach us C, rather than COBOL or Ada, because it would be more useful in general. At the time, they were the major programming languages colleges were teaching back in the day (every major university in the area ...


18

All that computing power is not dedicated to the Artemis project. As you quote in the body of your question, The new supercomputer will be used by more than 1,500 scientists and engineers from across the country, including on projects like developing a more efficient quadcopter or simulating the inside of our sun. Not all of this computing power is ...


16

From the website: AdaCore tools can be used to meet verification objectives including coding standard compliance, code accuracy (prevention of errors such as buffer overrun, integer overflow, and references to uninitialized variables), and structural coverage analysis up to MC/DC. Specialized high-assurance run-time libraries, including one that ...


15

The laptops on the ISS can only be used for non-time critical uses. Those laptops are used for some mission critical tasks, but only if the task can handle the time needed to replace a toasted laptop with another. Those laptops are commercial off-the-shelf, and they do not fare well against cosmic rays. Most cosmic ray hits result in a "single event upset", ...


14

What a fascinatingly obscure question :-) It took some digging, so perhaps someone who's actually seen an AGC might know better: The parity bit was used to verify that data transferred correctly from memory to the registers. That is, the data in the memory was assumed to be correct, and the error was assumed to take place between the electronics that ...


13

I wrote code that flew on 3 spacecraft that went to Mars, one to the Moon, one to a comet and back, and a few Earth-orbiting satellites, the last of which was about 10 yrs ago. All of them used C. It's not the only language out there, of course, but it's popular because the perception is that code can be made smaller and faster using C, without the overhead ...


13

It's an algorithm to speed up certain matrix operations, not a piece of hardware. It appears that the algorithm was first invented by William M. Lear for the LM guidance computer, as explained in @Uwe's answer. However, the programmers at the Real-Time Computing Center back in Houston then adopted the algorithm to process tracking data of the LM, naming it ...


13

The Voyager spacecraft are not reprogrammed anymore, so the language in which they are programmed is largely irrelevant. The uplink is only 16 bits/second, just enough to send (simple) commands. How these commands are generated is irrelevant to the spacecraft. Any language that can generate a sequence of bits theoretically suffices. This pdf document ...


12

The lower map appears to show the South Atlantic Anomaly (SAA), an area where the inner Van Allen radiation belt comes closest to the surface of the Earth. From the linked article: The effect is caused by the non-concentricity of the Earth and its magnetic dipole. The SAA is the near-Earth region where the Earth's magnetic field is weakest relative ...


12

Let's break your question into separate tasks: Autonomous orbit determination (autonomous because the DSN won't be there to help you when you need it) Autonomous attitude determination Situational awareness for formation flying (relative positions, velocities, attitudes and attitude rates), most efficiently done in a cooperative manner Cooperative collision ...


12

NASA Built-in Hardware The dedicated mission computers are tested extensively for vibration resistance, resistance to cosmic and solar radiation (both particulate and EM), magnetic fields, and are also prioritized for low energy consumption and high reliability. Generally, this results in processors a generation or three older than current desktops, and ...


11

In my youth, I am now retired, I worked on the apollo program at north american space and information systems in downey calif. chief contractor for the Apollo Command/Service Modules. I also worked at Rocketdyne that was a part of north american. All the code I used and developed at that time was in fortran. The fortran programs performed analysis of test ...


10

The first vessel that crossed the Kármán line and reached space - the German V-2 rocket - utilized a program for its analog computer, implemented as a rotating irregular disk of specific shape, with radius(angle) encoding output(input) function; the disk rotated by a motor, with angle and radius read by potentiometers, providing calculations for the control ...


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