Alternative Capabilities to send Cargo to ISS while Baikonur Site 31/6 is down

[catdlr]

Absence of Progress and its fuel seems to be a more pressing issue than crew rotation. F9 could easily fit a fully loaded Progress in its fairing. The problems to adapt it for US launch would seem to be more political than technical. More likely though if the service platform cannot be fixed easily, Progress flies from the Soyuz carrier rocket pads at Plesetsk or Vostochny with GSE modifications. Crew Soyuz waits until the 31/6 pad is repaired.

Plesetsk is too far north in latitude to match the ISS's orbit, Vostochny is just 30 km too high to do the same, and Progress doesn't have cross-range capability. 

Plesetsk was designed to launch military spy satellites in polar orbits; Vostok was intended primarily for communication satellites.

[Lee Jay]

Absence of Progress and its fuel seems to be a more pressing issue than crew rotation. F9 could easily fit a fully loaded Progress in its fairing. The problems to adapt it for US launch would seem to be more political than technical. More likely though if the service platform cannot be fixed easily, Progress flies from the Soyuz carrier rocket pads at Plesetsk or Vostochny with GSE modifications. Crew Soyuz waits until the 31/6 pad is repaired.

Yes...I was going to ask if we really, for sure know that Progress cannot be launched by Russia.  They have seemed pretty adaptable in the past in such situations.  I would expect a delay of the December Progress, but I'm not convinced yet that they cannot launch it at all until the pad that was damaged is repaired.  Can someone convince me?

[russianhalo117]

Absence of Progress and its fuel seems to be a more pressing issue than crew rotation. F9 could easily fit a fully loaded Progress in its fairing. The problems to adapt it for US launch would seem to be more political than technical. More likely though if the service platform cannot be fixed easily, Progress flies from the Soyuz carrier rocket pads at Plesetsk or Vostochny with GSE modifications. Crew Soyuz waits until the 31/6 pad is repaired.

Plesetsk is too far north in latitude to match the ISS's orbit, Vostochny is just 30 km too high to do the same, and Progress doesn't have cross-range capability. 

Plesetsk was designed to launch military spy satellites in polar orbits; Vostok was intended primarily for communication satellites.

Soyuz-2.1b can because it can carry more

[Twark_Main]

Yes, I expect they'll try to fly the ISS in TEA to minimize CMG desaturation burns.




Zero-Propellant Maneuvers are a closely related technique, using the same natural external forces to reorient the station without using propellant.

https://en.wikipedia.org/wiki/Zero-propellant_maneuver

[Twark_Main]

Vostochny is just 30 km too high to [match the ISS's orbit], and Progress doesn't have cross-range capability. 

It's only a 37 m/s plane change, by my math, but the problem is more a lack of suitable ground infrastructure.

[StraumliBlight]

I still believe reboosting is the biggest challenge without Progress.
And neither Dragon with the demonstrated Boost Kit or Starliner with its Service Module LES has enough impulse.

Progress's Refuelling Module likely fits inside Dragon's trunk. If a docking probe with fuel lines and a grapple fixture were installed, then Canadarm could retrieve it and refuel Zarya.

EDIT: Progress is currently critical to the ISS deorbit plans.

The Joint Commission wants a secondary deorbit capability in case something goes awry with the USDV. The contingency plan is using two Russian Progress cargo vehicles and the Russian segment itself to dispose of the ISS. That requires ensuring the propellant tanks on the Russian segment are full. Cabana said they reviewed a plan to have the tanks on the Zvezda Service Module and Zarya Functional Cargo Block (FGB) “sufficiently filled by 2028,”

If there was long delay between launches or Roscosmos don't have the resources to repair the pad, this idea would be to cannibalise existing Progress spacecraft in production into a smaller form factor (transportable by SpaceX) that could be manipulated by either the arm or a spacewalk to simulate a normal docking and fuel transfer.

[Jim]

I still believe reboosting is the biggest challenge without Progress.
And neither Dragon with the demonstrated Boost Kit or Starliner with its Service Module LES has enough impulse.

Progress's Refuelling Module likely fits inside Dragon's trunk. If a docking probe with fuel lines and a grapple fixture were installed, then Canadarm could retrieve it and refuel Zarya.

no,  it requires docking on the Russian segment. 

[Comga]

I still believe reboosting is the biggest challenge without Progress.
And neither Dragon with the demonstrated Boost Kit or Starliner with its Service Module LES has enough impulse.

Progress's Refuelling Module likely fits inside Dragon's trunk. If a docking probe with fuel lines and a grapple fixture were installed, then Canadarm could retrieve it and refuel Zarya.

no,  it requires docking on the Russian segment. 

Jim, you make me chuckle
That the Canadarm can't reach the Russian end of the ISS assembly is not the first fatal flaw in this idea.
How is NASA going to get a stand-alone "Progress Refueling Module", never mind one ready to launch, ready to hang in the Dragon trunk or one commandable through a Dragon?
This is "rocket Legos(tm)" at its finest.
It would be sufficiently difficult, maybe impossible, to add enough impulse to either the Dragon Boost Kit or Starliner's Service Module, but at least these are NASA suppliers.

[Space Pete]

How about Progress on Falcon 9?

I'll get my coat. 

[laszlo]

A kluge for use on the ground is a lot safer and easier to develop, test and certify than one for orbit.

By the time the suggested orbiting kluges could be worked up, the damaged launch pad will have been made usable somehow.

[TrevorMonty]

A kluge for use on the ground is a lot safer and easier to develop, test and certify than one for orbit.

By the time the suggested orbiting kluges could be worked up, the damaged launch pad will have been made usable somehow.

I can see some Russian driving new diamond coated car by time repair is complete.
Good thing they aren't using SLS launch pad contractors as repair will cost 1000 diamond coated cars.

[catdlr]

After key Russian launch site is damaged, NASA accelerates Dragon supply missions
It is by no means specific that Russia will be able to fix Site 31 soon.

Eric Berger – Dec 10, 2025 10:13 AM

[Comga]

It’s not a question of “surging” cargo missions
It is a question of ISS orbit maintenance.
If the Russians can’t reestablish Soyuz launch before their fuel on orbit runs out (How long will that be?) then Dragon (or Cygnus) would have to step in.

At what pace can SpaceX launch Dragons, crew and cargo?
If it’s, say, 4 per year, can the Boost Kit cover, or be expanded to cover, 3 months of reboosting?

At the current density altitude that’s very close to 10 km per quarter or ~3.3 m/sec delta-V.
For a 4,200 ton ISS, that’s ~3400 seconds of 400 N Draco firing time.
With an Isp of 234 sec, where it burns ~0.78 kg/sec/Draco, that’s ~2,650 kg.
Can the Boost Kit carry, or be expanded to carry, that much propellent?
Will that kill the cargo capacity?
Would that be allowed with astronauts?

Pardon the self-quote but I found an answer to the question above in Arstechnia.

The proven Dragon Boost Kit can provide 9 m/s to the ISS.
That’s equivalent to ~3 months of reboosting.
It’s almost the “calendar quarter” discussed above
It’s also equivalent to ~1.5 Progress loads, so each Progress covers ~2 months.

While the six tank Boost Kit is seen in another Arstechnia article to occupy only a fraction of the trunk of CRS-33 Dragon, the mass is a large fraction of the 3,300 kg cargo capacity.

So a Cargo Dragon every 3 months and the ISS reboost needs will be fully met until the Russians resume Progress launches.

(Somebody please check my arithmetic)

Edit: If the above is correct, and if reports are also correct that the Russian launch site can be repaired in 4 months, the on-orbit boost kit may have the deficit covered.  If it’s 6 months, one more Boost Kit.

[AmigaClone]

SpaceX has shown that the forward hatch of their Crew Dragon 2 can be replaced with a dome (Inspiration 4, Fran2) or a 'porch' (Polaris Dawn). Would it be possible to replace the docking interface of one of the Crew and one of the Cargo Dragons to dock to the Russian side?

[Comga]

SpaceX has shown that the forward hatch of their Crew Dragon 2 can be replaced with a dome (Inspiration 4, Fran2) or a 'porch' (Polaris Dawn). Would it be possible to replace the docking interface of one of the Crew and one of the Cargo Dragons to dock to the Russian side?

Probably not, but why would that be needed?
Dock to Node 2 Forward and turn the ISS around.
That's how the Boost Kit is being used, IIUIC.

Edit: Even if they did manage to dock to the Russian docking interface, they couldn't transfer propellant to the Russian side.

[DanClemmensen]

SpaceX has shown that the forward hatch of their Crew Dragon 2 can be replaced with a dome (Inspiration 4, Fran2) or a 'porch' (Polaris Dawn). Would it be possible to replace the docking interface of one of the Crew and one of the Cargo Dragons to dock to the Russian side?

Technically possible, but by the time you got the paperwork done, followed by the design, test, and implementation, it would take at least a year until the first uncrewed test flight. This still does not allow transfer of propellant for the Russian RCS on ISS. It does increase flexibility, by freeing up an IDSS port, especially after the USDV is connected.

[Brigantine]

How about Progress on Falcon 9?

How about Progress on ZhuQue-3? JiuQuan is not much further from Russia than Baikonur

[russianhalo117]

How about Progress on Falcon 9?

How about Progress on ZhuQue-3? JiuQuan is not much further from Russia than Baikonur

Requires custom processing hardware that is only at RKK Energia and Baikonur.

[AmigaClone]

SpaceX has shown that the forward hatch of their Crew Dragon 2 can be replaced with a dome (Inspiration 4, Fran2) or a 'porch' (Polaris Dawn). Would it be possible to replace the docking interface of one of the Crew and one of the Cargo Dragons to dock to the Russian side?

Probably not, but why would that be needed?
Dock to Node 2 Forward and turn the ISS around.
That's how the Boost Kit is being used, IIUIC.

Edit: Even if they did manage to dock to the Russian docking interface, they couldn't transfer propellant to the Russian side.

The reason would be flexibility in docking locations. Those modified Dragons would be capable of docking in four locations as opposed to only two on the US side.

[Comga]

@Brigantine, @AmigaClone :Why?
There is no need, and probably no money, to develop anything new, especially Franken-systems.

Some here object when others suggest SpaceX solving every problem, but for the ISS it’s close to correct.

Dragon brought back cargo runs to the ISS, with both pressurized and external cargo.
(Yes Cygnus is needed for larger cargo and bulk transport.)
Dragon brought back significant downmass.
Dragon does crew transport and lifeboat support.
Dragon’s Boost Kit can handle as much reboosting and Collision Avoidance Maneuvers as is needed.

It’s all paid for, developed, and proven.
Lego(tm) Launches not needed

A Dragon variant will deorbit the ISS when the time comes.
For speculation, Dragon capsules firing their lateral Dracos could provide angular momentum to desaturate the CMGs.
If the Boost Kit was to incorporate a 0.2 N thruster and run it continuously, it could even improve (but not perfect) the microgravity environment, countering the exoatmospheric drag and maintaining nearly constant altitude.