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88 votes
Accepted

What operating system(s) were used in the space shuttle?

I was a NASA contractor working on the same contract, but with 3 different companies, writing GN&C code for the space shuttles from 1989 until 1995. Initially, it was Ford Aerospace, then Loral, ...
JohnP's user avatar
  • 1,527
86 votes
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What makes (or at least made) Ada the language of choice for the ISS's safety-critical systems?

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 ...
Morgloz's user avatar
  • 861
62 votes

What makes (or at least made) Ada the language of choice for the ISS's safety-critical systems?

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) ...
David Hammen's user avatar
61 votes
Accepted

What language is software running on the ISS written in?

Almost all of the safety critical software that runs on the US side of the Space Station is written in Ada. I wrote "almost all" rather than "all" because there are probably some low level device ...
David Hammen's user avatar
48 votes

Why wasn't the Mars Climate Orbiter's fatal error caught prior to launch?

NASA formed a board to investigate the loss of the spacecraft and reached some high level conclusions. The board cited a number of contributing factors, which I have filtered to include the ones most ...
GdD's user avatar
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40 votes
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What was the nature of the known bugs in the Space Shuttle software?

Although the Space Shuttle flight software was of outstanding quality, it's completely incorrect to think that there was only one bug. There were many known bugs in the flight software (FSW). Here are ...
Organic Marble's user avatar
40 votes
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Given small computational resources, how was navigation implemented? (Not samples of old guidance software)

In many of the early probes, up until close to Apollo there were not true computers on space probes. All computing was done on Earth and the onboard electronics was known as a sequencer, for Pioneer ...
GremlinWranger's user avatar
38 votes
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Reasons behind Soviets Using Prolog Programming Language for Buran Space Shuttle?

According to Wikipedia the use of prolog is just a mistake in the CIA report: Researchers at Keldysh developed two languages: PROL2 (used for real-time programming of onboard systems) and DIPOL (used ...
Alan Birtles's user avatar
  • 2,065
34 votes

Does the Voyager team use a wrapper (Fortran(77?) to Python) to transmit current commands?

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 ...
Hobbes's user avatar
  • 128k
31 votes
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Does anybody work on a "spacecraft linux"?

Updates: Added Astro Digital and Planet Labs at bottom. There isn't a specific Linux distribution for spacecraft. At least not yet. I have heard of groups that basically took Buildroot to build only ...
Rick 0xfff's user avatar
27 votes

Given small computational resources, how was navigation implemented? (Not samples of old guidance software)

(originally answered to "Samples of old guidance software") The first that comes to mind is the Github repository of the Apollo 11 Guidance Computer (AGC). The repository has both Command Module and ...
Ludo's user avatar
  • 14.4k
26 votes

Why wasn't the Mars Climate Orbiter's fatal error caught prior to launch?

There were a good number of chances to catch the error after launch, which is what most of the reports on the mission focus on. To look specifically at what testing was done before launch this paper ...
1337joe's user avatar
  • 7,206
24 votes
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How were Wikipedia's orbital simulations made?

Found it (though for a different image from the same user--but it's almost certainly still the answer)! from Phoenix7777's Wikimedia commons page: I wrote the program. There's also the note (because ...
Erin Anne's user avatar
  • 11.8k
22 votes

Does anybody work on a "spacecraft linux"?

Kubos corporation (disclosure: I work at Kubos) have a cubesat-specific Linux distro and a real-time operating system (RTOS), for cubesats with tighter power and processing budgets, since, as noted by ...
Jesse Hamner's user avatar
22 votes

What makes (or at least made) Ada the language of choice for the ISS's safety-critical systems?

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 ...
Machavity's user avatar
  • 7,905
18 votes
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What computer programs does ITAR say I can or can not write, or share, or use in the US?

With the exception of model rockets made of paper, wood, or breakable plastic, that are passively stabilized, that have low thrust and low delta V, and that do not have guidance software, launch ...
David Hammen's user avatar
17 votes

What makes (or at least made) Ada the language of choice for the ISS's safety-critical systems?

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, ...
Cees Timmerman's user avatar
16 votes

What is the most popular programming language in space?

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'...
RickNZ's user avatar
  • 556
15 votes

What language is software running on the ISS written in?

There are a lot of programs involved in running the ISS. The exact details are difficult to discern, a lot of NASA's software is available via this site, with some restrictions, but here is what I can ...
PearsonArtPhoto's user avatar
  • 121k
15 votes

Does the Voyager team use a wrapper (Fortran(77?) to Python) to transmit current commands?

The Voyager spacecraft are still being patched as of 2023. The uplink is only 16 bits/second, just enough to send (simple) commands. How these commands are generated is irrelevant to the spacecraft. ...
Ludo's user avatar
  • 14.4k
15 votes

Given small computational resources, how was navigation implemented? (Not samples of old guidance software)

I am a software developer and with all the resources available today I cannot fathom where one could even start such an endeavour. There are plenty of computer-based systems to this day that have to ...
David Hammen's user avatar
14 votes
Accepted

Besides retarded gravitation, anything else to worry about when calculating MU69's orbit from scratch?

This is not a complete answer. It is instead an extended comment to the following: I understand I will have to retard the gravity from each source by its particular light-time, as well as correct ...
David Hammen's user avatar
12 votes

What operating system(s) were used in the space shuttle?

For the flight control computers, aka General Purpose Computers (GPCs) there is a good writeup on this topic in the ever-useful Shuttle Crew Operations Manual page 2.6-20. DPS in this quote stands for ...
Organic Marble's user avatar
12 votes

Transitioning into space software engineering

Developing software to help with space stuff doesn't just mean building big complex C/C++ engines, or even analytical engines, to use the data. Remember that a significant part of public outreach is ...
PearsonArtPhoto's user avatar
  • 121k
12 votes

Does NASA use any type of office/groupware software and which is that?

NASA's standard desktop office computer configuration is Windows 10 with Microsoft Office. This software is provided agency-wide by the NASA Shared Services Center (NSSC). Here is an excerpt from the ...
Organic Marble's user avatar
11 votes
Accepted

What does the software quality process for NASA's SLS look like?

I have retrieved via FOIA request the "Space Launch System Program (SLSP), Flight Software Application, Software Assurance Plan (SAP)". It is the core document describing the software development ...
Mark Omo's user avatar
  • 5,291
11 votes

Does the Voyager team use a wrapper (Fortran(77?) to Python) to transmit current commands?

I didn't work on Voyager, but can tell you that deep-space missions tend to retain the original ground hardware, software, language, and build environment, both for continuity/safety as well as budget ...
stevegt's user avatar
  • 391
11 votes

How does a command sent to a rocket or rover look like?

Most remotely controlled spacecraft and rovers do not use text-based commands. Instead, each command has a unique identifier, a command-specific data structure that contains data specific to that ...
David Hammen's user avatar
11 votes
Accepted

Can operators put their satellites to sleep temporarily?

Partial answer, perhaps from information on these pages someone can address better Can operators put their satellites to sleep temporarily? Is this the longest that a spacecraft "went to sleep&...
uhoh's user avatar
  • 149k
10 votes
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What caused New Horizon's so-called "40-year glitch"?

I found a bit more detail by googling for "New Horizons Anomaly Review Board Report". The best writeup was from here. By 4 p.m., the mission's Anomaly Review Board had convened to be briefed on ...
Organic Marble's user avatar

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