Boeing IMIS Replica

[septemberWaves]

I'm putting most of my forum activities on hold until the release of 1.3 (and until the mods I want are updated for 1.3). In the mean time, I am going to focus on one thing: designing a replica of the Boeing Integrated Manned Interplanetary Spacecraft. In this thread I will document the design process, and then release download links once the replica is complete.

Image source

I've done some research into Boeing's proposed Mars and Venus mission architecture that was designed as an extension to the Apollo program (mostly using several technical documents originally published online on NASA's Technical Reports Server and easily found here) and have decided that it would be fun to create a replica in KSP.

The idea of the IMIS is to be a highly-modular and easily configurable spacecraft design based mainly on technology used in the Apollo program. The main deviation from the Apollo hardware was the nuclear thermal rocket engines, that would've been used to propel the spacecraft. It consisted of several modules (listed from front to rear of spacecraft):

• Mars Excursion Module - Mars lander based on the Apollo capsule, designed for 3 crew members
• Mission Module - large habitation and lab module for 6 crew members
• Earth Entry Module - specially-designed return capsule for 6 crew members
• Propulsion Module 3 - single NTR stage used for trans-Earth injection
• Propulsion Module 2 - single NTR stage used for capture in Mars orbit
• Propulsion Module 1 - triple NTR stage used for trans-Mars injection

The NTR stages were designed only for major engine burns; weaker chemical rockets would've been used for minor correction burns. The MEM would also have been launched with several atmospheric probes, to be deployed once at Mars. Venus missions would've used a similar profile, but with additional probes in place of a crew lander since the atmosphere and surface conditions of Venus would've made a crewed surface excursion impossible with 1970s technology.

The vehicle would be assembled in orbit with 6 launches of an upgraded Saturn V (with the addition of 4 SRBs to increase payload capacity).

 

As for the actual purpose of this thread, my replica will be designed with the intention of paying close attention to detail, while still making it a practical spacecraft for use in KSP - though "practical" does not necessarily mean "efficient". I'll be using a few mods and I will add the mod list to this post later.

[Heckspress]

are those buckets on each end???

[Matuchkin]

I don't really know about these ULA mars concepts anymore. Like, I was very excited for Copernicus, but now it just seems like another concept vehicle. This is absolutely no exception. The only company who I believe is actively and openly working on a Mars vehicle is SpaceX, but their idea will be rejected by many, many people.

[septemberWaves]

28 minutes ago, Heckspress said:

are those buckets on each end???

It's a very vague concept drawing. The technical documents I linked to provide a lot more detail. At the front end (the thin end) is the Mars Excursion Module, and the three end caps at the rear end are interstage structures surrounding the nuclear thermal rockets.

[Raptor9]

Nice to see someone else emulating this apparently less-known Mars mission concept.  There were a lot of really ambitious exploration proposals in the 60's.  This and the Apollo Applications proposals are my favorites.

[Rune]

Pretty cool concept to try and recreate. I was myself very close to doing a full "Mars '69" mission at several points in the past. Have you checked that one out? It was a concept by Von Braun, similar to this one, but some orbital mechanics wizardry made all the nuclear stages come back to Earth to be reused. I also think IMLEO was considerably lower.

 

Rune. Very few things are new under the sun.

[septemberWaves]

3 hours ago, Rune said:

Pretty cool concept to try and recreate. I was myself very close to doing a full "Mars '69" mission at several points in the past. Have you checked that one out? It was a concept by Von Braun, similar to this one, but some orbital mechanics wizardry made all the nuclear stages come back to Earth to be reused. I also think IMLEO was considerably lower.

 

Rune. Very few things are new under the sun.

I've encountered the Von Braun mission plan for Mars before, though not in detail. I chose this one mainly because it's the one that I've found the most detailed technical reports about, and because the versatility of the spacecraft design is interesting.

[Rune]

8 minutes ago, eloquentJane said:

I've encountered the Von Braun mission plan for Mars before, though not in detail. I chose this one mainly because it's the one that I've found the most detailed technical reports about, and because the versatility of the spacecraft design is interesting.

You can find it on astronautix, too, and I'm sure some google-fu will take you further: http://www.astronautix.com/v/vonbraunmarpedition-1969.html

Basically it's pretty much the same, minus the conical Earth return capsule, and with only three propulsion modules. I think that would scale much better for KSP. Everything is reused, too, which is a very nice touch. The lateral PPM's detach just short of Earth ejection, and the rest of the ship is light enough to do the Martian roundtrip, taking advantage of a Venus gravity assist, and capturing into a cheaper highly elliptical orbit at Mars.

 

Rune. I think the individual elements are actually the same design, just with a more sensible mission plan.

Edited April 6, 2017 by Rune

[septemberWaves]

Obviously since this is based on the Apollo program I'll need some Apollo spacecraft. I started out by making a Saturn IB and Apollo capsule.

The launch vehicle is technically overpowered for a Kerbin ascent. However, the vehicle (particularly the first stage) experiences excessive amounts of drag, which balances out the excess delta-v. The first stage is powered by 8 engines (the outer ones have the ability to gimbal for control), and the second stage is powered by a single engine. I've tried to mimic the appearance of the Saturn IB as well as I could, though the striped interstage was unfortunately not possible.

The Apollo spacecraft is quite detailed. The command module includes a three-parachute landing system, a docking system, and a shroud to protect the parachutes from re-entry heat. The service module includes a service bay that houses the power storage and three fuel cells, and can contain small satellites that could be released during a lunar mission. The propulsion system is designed to be able to propel the entire spacecraft from the surface of the Mun back to a Kerbin re-entry trajectory, as the Apollo spacecraft was initially designed for a direct ascent mission profile.

There are still a few tweaks that I need to make (such as adding an antenna to the service module) but for the most part it's a fully functional spacecraft.

 

The next thing to design will be the section of the IMIS consisting of the Mars Excursion Module, Mission Module, Earth Entry Module, and Mars probes. That section has to be designed before the rest of the IMIS system because it's the payload that the spacecraft must carry.

[Thor Wotansen]

@Rune There was a challenge based on Von Braun's Marsprojekt mission profile a while back, I designed this for it.

[Raptor9]

@eloquentJane, if you're intending to use mods for this project, Nertea designed the new Mk4-1 command pod in Near Future Construction based on the MEM ascent module.  Just a suggestion if you're looking for something to fit that bill.

Edited April 6, 2017 by Raptor9

[septemberWaves]

@Raptor9 Thanks for the suggestion, though I've already decided on my mod list. Isn't the command pod you're thinking of the 7-kerbal pod? I think that's a bit too big for this project. I've already mostly planned how I'm going to design the vehicles, and the MEM is using the same command pod as the Apollo spacecraft because it was initially intended to be based on the Apollo command module (and also because it only needs 3 kerbals).

Edited April 6, 2017 by eloquentJane