Addenda

Just some quick additional notes to my last post. Unfortunately I haven’t had the time to transfer these over from Open Office to google spreadsheets.

  • A direct, unrefueled Atlas V 401 launch could just barely put a 4500-4750lb capsule into LUNO, but that’s even smaller than the 5000lb capsule so many have been complaining about.
  • Most of the criticisms of the 5000lb capsule are based on comparisons to much much older designs, that weren’t exactly apples-to-apples either. However, that doesn’t mean that I’m right. If anyone with actual manned flight hardware experience wants to weigh in (even anonymously), I’d like to hear what you have to say. Anybody can look stuff up on Mark Wade’s site (and then misinterpret it), but it takes some real engineering skill to truly analyze a new proposal–skill that’s unfortunately beyond my experience too. I’m not sure the idea would work, but I think it’s feasible.
  • If you really don’t think a 5000lb capsule is possible, you could do a 10klb capsule by doing a three-launch architecture with two Atlas V 401 flights, and the Delta-IVH flight. The second Atlas V 401 flight would transfer a full load of propellants into the Centaur of the manned Atlas V 401 flight, which would then send the capsule to the moon. The Delta IVH flight would’ve been launched previously, and would deliver the lander to LUNO via a WSB trajectory.
  • If the 95% propellant fraction and 1.5x Centaur size numbers are right for a ICES stage, a single un-refueled Phase I Atlas V 401 could deliver a roughly 9000lb capsule into low lunar orbit. Some of that 9000lb payload would need to be used for the TEI burn, but it’d still give probably about 7klb for the capsule itself.

So, there are still some options, but if you want to go 100% with stock boosters, finding a way to get that 5000lb capsule to work would make it that a lot easier. If you aren’t going with stock boosters, you’d be better off using on-orbit propellant transfer to the maximum extent possible anyway.

The following two tabs change content below.
Jonathan Goff

Jonathan Goff

President/CEO at Altius Space Machines
Jonathan Goff is a space technologist, inventor, and serial space entrepreneur who created the Selenian Boondocks blog. Jon was a co-founder of Masten Space Systems, and is the founder and CEO of Altius Space Machines, a space robotics startup in Broomfield, CO. His family includes his wife, Tiffany, and five boys: Jarom (deceased), Jonathan, James, Peter, and Andrew. Jon has a BS in Manufacturing Engineering (1999) and an MS in Mechanical Engineering (2007) from Brigham Young University, and served an LDS proselytizing mission in Olongapo, Philippines from 2000-2002.
Jonathan Goff

About Jonathan Goff

Jonathan Goff is a space technologist, inventor, and serial space entrepreneur who created the Selenian Boondocks blog. Jon was a co-founder of Masten Space Systems, and is the founder and CEO of Altius Space Machines, a space robotics startup in Broomfield, CO. His family includes his wife, Tiffany, and five boys: Jarom (deceased), Jonathan, James, Peter, and Andrew. Jon has a BS in Manufacturing Engineering (1999) and an MS in Mechanical Engineering (2007) from Brigham Young University, and served an LDS proselytizing mission in Olongapo, Philippines from 2000-2002.
This entry was posted in Uncategorized. Bookmark the permalink.

5 Responses to Addenda

  1. Gaetano Marano says:

    .

    why build a new capsule?

    we already have the Soyuz and Shenzhou for that job

    one year ago I’ve suggested to use them for moon mission, here: http://www.gaetanomarano.it/LSAMshenzhou/lsamshenzhou.html

    their thermal shield already is ready for a direct reentry from the moon

    the internal space and (one week) life support of both capsules are for three astronauts

    with two astronauts their life support will be sufficient for 10 days

    their internal space is sufficient for two astronauts and 200 lbs. of moon samples (same of Orion)

    the Soyuz/Shenzhou SM propellent can be used only for TEI

    we only need a smaller LSAM and a booster for TLI

    the LSAM may be around 20 mT (or less) and must include the propellant for the LOI of the full convoy

    last, the flight must be planned for a “fly around the moon” trajectory, so, if something goes wrong the LSAM+Shenzhou convoy will come back to earth without enter the lunar orbit

    .

  2. Bill White says:

    If you are unwilling to just use Soyuz, maybe use the Soyuz DM & OM architecture.

    Build your own ultra-Spartan descent module for Earth return and landing but attach to a Bigelow made orbital module for living space during passage between Earth & Moon and back.

  3. Mike Puckett says:

    What would help living space issues would be a Bigelow tiny hab that could be inflated and serve the purpose of a Soyuz orbital module. I proposed this about a year or so ago somewhere.

    It could be light, cheap and disposible.

  4. Brad says:

    Jon,

    On mission architecture…

    I know your original 2-man lunar scheme was to squeeze the most out of the fewest launches and using only existing hardware, but I think your launcher economy forces too tight design margins. And in a minor way you recreate the ESAS priority of minimal lunar launches.

    If instead your lunar achitecture is split into three phases — prepositioning on the moon the habitat, prepositioning into LLO the lunar lander, and following up with the manned launch, you gain several advantages. The first advantage is the amazing similarity that lunar architecture would share with the notional ESAS Mars plan. That would give a ring of endorsement (and magnify the arbitrariness of the ESAS lunar plan rationalizations) and if actually carried out give vital experience towards a successful Mars mission. But the most important advantage of splitting the lunar mission into multiple phases is the abiltity to take full advantage of different trajectory and propulsion schemes to increase the payload capability of your launchers.

    That WSB trajectory is amazing. Taking advantage of that 3-month trajectory for as much of the unmanned component of the lunar mission as possible increases payload. Plus the flight time is slow enough so that perhaps an off the shelf supplemental electric propulsion system could also boost the payload delivered. It just makes too much sense to send the minimum payload as possible on the speedy trajectories which the manned component of the mission requires.

    Opening up the design margins might also allow off the shelf propulsion systems for some flight elements. Right now your lunar plan requires LOX/LH2 propellants for almost everything. I’ve seen some of the Lockheed documents and talk about work they are doing on a long-storage passively-cooled Centaur and it’s very exciting, but it’s not currently available. With a three phase architecture I suspect the margins open up enough that even storable propellants would be adequate for the lunar lander and the TEI burn.

    So I’m imagining something like a total of 3 Delta IV heavy + 1 Atlas V 401 launches. One Delta IV sends the habitat to lunar surface, One Delta IV sends a lander into LLO, and One Delta IV sends it’s upper stage into LEO. The Atlas V launches the manned capsule + service module into LEO which then rendezvous with the Delta IV stage.

    I think it’s interesting to note that should the Chinese actually field the Long March 5 booster they have been talking up, they could launch an extremely similar mission to the moon using the 3 x LM 5 + 1 x LM 4 and a modified Shenzou spacecraft.

  5. Brad says:

    oops!

    Correction. When I mentioned the Long March 4 booster I should have said the CZ-2F booster which is the booster for the manned Shenzou spacecraft.

Leave a Reply

Your email address will not be published. Required fields are marked *