Poll

By anyone. Year first test is attempted using a reusable framework intended to lay groundwork for routine refueling operations on future missions. Whether test is part of a mission or just a technical demonstration.

2018
2019
2020
2021
2022+

Voting closes: 12/02/2018 02:27 PM


Author Topic: POLL: When will on-orbit cryogenic refueling for BEO missions testing begin?  (Read 1247 times)

Offline Eer

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Identify who you think will conduct the test in comments.

The intent of the poll is to estimate when full main propulsion refueling tests of the sort envisioned by Apollo orbital rendezvous refueling would take place for new beyond earth orbit missions. Crewed or uncrewed missions, but excluding station-keeping mono-propellant refueling, which has been done for a while.  Fuel-depot tests would be in-scope.

I specially acknowledge that on orbit refueling tests have been conducted by DARPA and others with the aim of extending satellite station keeping. But here we’re talking about transferring tons of propellant, and specifically bi propellants including cryogenic propellants, with the aim of enabling BEO missions with larger payloads.

Edited to refine the scope of the question being posed.
« Last Edit: 09/03/2018 07:14 PM by Eer »

Offline Tomness

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Re: POLL: When will on-orbit refueling testing begin?
« Reply #1 on: 09/03/2018 03:30 PM »
SpaceX 2020 BFS & BFS Tanker

Offline jak Kennedy

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Re: POLL: When will on-orbit refueling testing begin?
« Reply #2 on: 09/03/2018 03:59 PM »
Perhaps your question is not clear. Here is a link that explains in the answers many previous on-orbit refueling’s.
https://space.stackexchange.com/questions/10145/has-in-space-refueling-been-done

Offline Eer

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Re: POLL: When will on-orbit refueling testing begin?
« Reply #3 on: 09/03/2018 04:07 PM »
Thank you for those historical references. I’m amend the title post to refer to new testing along the lines of the Apollo orbital rendezvous main propulsion sort of mission they chose not to use, but which differs it would seem from the sort of station keeping missions used with satellites. Would that make the poll better focused?

Offline speedevil

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Re: POLL: When will on-orbit refueling testing begin?
« Reply #4 on: 09/03/2018 04:31 PM »
RRM3 is a worthwhile note.
 'NASA, 2018/19' - RRM3
Quote
What Makes RRM Unique?
First demo to test the robotic refueling of satellite interfaces not designed to be accessed or serviced. The Orbital Refueling System tested by astronaut Kathryn D. Sullivan during the 1984 STS-41-G shuttle flight and DARPA's robotic Orbital Express Mission were very successful, but had different objectives.

2020 is a plausible timeframe for BFS at least though ambitious for BFR.
In principle, you can demonstrate suborbital fuel transfer very easily with two BFS - orbital is rather harder.

As another note, on-orbit refueling is one option.
If you imagine, for example, two 55 ton FH launches, and a 20 ton payload on top of one, with 35 extra tons of propellant remaining in LEO, and the ability to attach a second stage with no payload, but 55 ton propellant to the top of your craft, you get most of the benefit of refueling.

(300m/s less of around 4.6km/[email protected] tons)

Significant benefits can also come from swapping the payload on orbit to another stage that came up empty.


Offline jbenton

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Re: POLL: When will on-orbit refueling testing begin?
« Reply #5 on: 09/03/2018 05:37 PM »
Thank you for those historical references. I’ll amend the title post to refer to new testing along the lines of the Apollo orbital rendezvous main propulsion sort of mission they chose not to use, but which differs it would seem from the sort of station keeping missions used with satellites. Would that make the poll better focused?

I was going to mention Salyut, Mir, and ISS (through Soyuz, Progress, and ATV), but it looks like jak Kennedy beat me to it.

I'd recommend amending the title to "...on-orbit cryogenic refueling.
storables' refueling has been around for decades.

Now that I think about it, you may also want to consider rocket refueling, since the examples I just mentioned were just for "station keeping" as you said (but not with uncrewed satellites ;) ).

Offline meberbs

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I picked 2021, which is when SpaceX may get to it. (2019 BFS testing, 2020 full BFR, 2021 testing, 2022 send stuff to Mars) even then, 2021 is somewhat optimistic for this, since I have always expected their first launch to Mars will slip a synod. I don't think 2020 will happen for the refueling tests, because they need 2 BFS, and given the infrastructure needs I expect at best it won't be until later in 2020 that a full BFR launches.

The poll could use some more options before going to "or later", since it obviously won't happen in the next 4 months, and SpaceX is the only contender in the timeframe provided that I know of, Vulcan ACES isn't planned until 2024, and SpaceX isn't guaranteed to do it before 2022.

Offline TripleSeven

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Offline speedevil

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Re: POLL: When will on-orbit refueling testing begin?
« Reply #8 on: 09/03/2018 08:19 PM »
I'd recommend amending the title to "...on-orbit cryogenic refueling.
storables' refueling has been around for decades.
I question if this is particularly meaningful.
Nothing interesting happens from ISP=300 to ISP=370 that make refueling particularly magical. (Draco vs Raptor).

Even going to 450s if you bother with hydrogen often does not change much.

For no particular reason, picking a F9S2 mass stage, with 100 tons of propellant and 5 tons dry mass throws 20 tons at 4700m/s at ISP=300.

Going to 370 seconds only increases that by 8 tons.
450 does double it - but you're going to need a _lot_ more tank volume, as well as raising boiloff issues.

F9S2 mass stage at ISP=300 can put 15 tons on the surface of the moon.

This is misleading, as staging is rather easier, and can make propellant choice a lot less critical.

Doubling the mass of uplift for a mission, when that uplift can be storable fuel vs hydrogen/oxygen is not really a major issue in many cases, and will not cause the costs to alter.

A strict reading would also exclude refuelling F9S2 as one propellant is kerosene.
« Last Edit: 09/04/2018 10:34 AM by speedevil »

Offline oldAtlas_Eguy

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I voted 2021 becasuse both SpaceX and ULA are headed toward testing (not operational) in that year. ULA needs to demonstrate the technology as an option for Vulcan ACES to be able to entice customers and SpaceX would need to demonstrate it on BFR to show that it really is a BEO vehicle.

Offline darkenfast

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I believe it will be SpaceX for large-scale re-fueling.  I picked 2022+ because, as Elon himself said, SpaceX's timeline is "aspirational" and 2022 is more realistic for having actual ships up there and testing.

Online guckyfan

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I picked 2020 for BFR but would not be disappointed if it slips to 2021.

ULA with the possible timeline for ACES won't be before 2024/5.

Offline jongoff

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I picked 2022+ in spite of the fact that my company is actively working cryogenic transfer quick disconnects for in-space refueling. I think BFR is likely going to take a lot longer to get orbital than many here expect. And I'm not very optimistic about ULA doing it anytime soon either. Realistically for us, even if we raised money to develop a microdepot tomorrow, it would likely be 2022+ before we could have anything flying, and we're nowhere close to raising money to do a microdepot.

If I had to guess, I'd say 2024ish, and either SpaceX or someone like us doing an operational demo.

~Jon

Online Wudizzle

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2021. Some form of BFS/BFT PoC. I think that's wildly optimistic, but when humans are pursuing the prospect of launching themselves at another planet I find the world an optimistic place.

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